WO2016129415A1 - Power conversion device - Google Patents

Power conversion device Download PDF

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Publication number
WO2016129415A1
WO2016129415A1 PCT/JP2016/052692 JP2016052692W WO2016129415A1 WO 2016129415 A1 WO2016129415 A1 WO 2016129415A1 JP 2016052692 W JP2016052692 W JP 2016052692W WO 2016129415 A1 WO2016129415 A1 WO 2016129415A1
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WO
WIPO (PCT)
Prior art keywords
switching element
state
semiconductor switching
time
reactor
Prior art date
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PCT/JP2016/052692
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French (fr)
Japanese (ja)
Inventor
健志 網本
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三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2016574727A priority Critical patent/JP6531767B2/en
Publication of WO2016129415A1 publication Critical patent/WO2016129415A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only

Definitions

  • the present invention relates to a power conversion device.
  • One stone type booster circuit is one of the circuits of a power conversion device that converts a DC voltage output from a power source into a DC voltage having a different value and supplies it to a load.
  • a general one-stone booster circuit includes a first capacitor for smoothing the voltage on the input side of the circuit, a reactor for storing energy, and an on-state when charging the reactor with energy.
  • the first semiconductor switching element includes a first semiconductor switching element for protecting the first semiconductor switching element from a high voltage applied to the first semiconductor switching element when the first semiconductor switching element is turned off. Rectifier elements are connected in antiparallel.
  • the second rectifying element that releases the energy charged in the reactor to the output side and prevents backflow from the output side of the circuit, and the voltage on the output side of the circuit And a second capacitor for smoothing.
  • the second semiconductor switching element is connected in antiparallel to the second rectifying element of such a general one-stone booster circuit, and the second semiconductor switching element is connected during a period in which current flows through the second rectifying element.
  • There is a one-stone type booster circuit that enables a synchronous rectification operation in which a current flows through a second semiconductor switching element in an on state.
  • the second semiconductor switching element is maintained in the OFF state, and One semiconductor switching element performs a first switching to switch between a first on state and a first off state, and does not perform synchronous rectification (this operation is referred to as asynchronous rectification).
  • the second semiconductor switching element When the voltage supplied from the power source is lower than a preset voltage threshold, the second semiconductor switching element changes between the second on state and the second off state in synchronization with the first switching. Synchronous rectification for performing the second switching is performed (for example, Patent Document 1).
  • the threshold voltage is set so that no backflow from the output side occurs.
  • the first semiconductor switching element is maintained in the off state, and the first semiconductor switching element repeats the first switching for switching between the first on state and the first off state, and the first on state time is increased.
  • the first on-time shown is shorter than the first off-time showing the time of the first off state, and less energy is stored in the reactor.
  • the current flowing through the reactor may become discontinuous.
  • the amount of current that flows in the reverse direction that is, the direction from the load to the power source increases when the state of asynchronous rectification is shifted to the state of synchronous rectification.
  • the state where the power to be supplied to the load cannot be supplied to the load occurs. That is, the power converter cannot supply the power to be supplied to the load, and the power supplied to the load by the power converter varies.
  • the present invention has been made to solve the above-described problems, and provides a power conversion device that suppresses fluctuations in power supplied to a load when the state of asynchronous rectification is shifted to the state of synchronous rectification. With the goal.
  • the power converter according to the present invention includes a reactor having a first terminal and a second terminal, the first terminal being connected to the positive electrode of the power source, and the second terminal of the reactor and the negative electrode of the power source.
  • a first semiconductor switching element connected between the rectifier and a rectifier connected between the second terminal of the reactor and the positive side of the load to rectify the current sent from the second terminal to the load
  • a control device for sending a control signal for controlling the driving of the second semiconductor switching element to the driving device, wherein the second semiconductor switching device is maintained in the OFF state, and the first semiconductor
  • the second semiconductor switching element is switched to the second ON state in synchronization with the first switching from the asynchronous rectification state in which the switching element performs the first switching to switch between the first ON state and the first OFF state.
  • the control device is configured to change the second switching state between the first semiconductor switching element and the second OFF state.
  • the second semiconductor switching element is controlled to be in the second on state with a second on time shorter than the first off time indicating the time of one off state.
  • the power conversion device can suppress fluctuations in the power supplied to the load when the asynchronous rectification state is shifted to the synchronous rectification state. This is because the control device controls the on-time of the second semiconductor switching element to be shorter than the off-time of the first semiconductor switching element, so that the time during which the current flows in the reverse direction is shortened.
  • FIG. 1 is a schematic diagram illustrating a power conversion system 31 configured using the power conversion device 30 according to the first embodiment of the present invention.
  • the power conversion device 30 according to the first exemplary embodiment of the present invention configures a power conversion system 31 that boosts a DC voltage output from a power supply 301 and supplies the boosted DC voltage to a load 309.
  • the power conversion device 30 according to the first embodiment of the present invention has a one-stone booster circuit capable of synchronous rectification.
  • the power conversion device 30 according to the first exemplary embodiment of the present invention includes a first capacitor 302, a first terminal, and a second terminal, and the first terminal is a positive side of the first capacitor 302. And a connected reactor 303.
  • the 1st terminal of the reactor 303 is connected with the 1st capacitor
  • the left end of the reactor 303 is shown in FIG.
  • the second terminal is the right end of the reactor 303.
  • the power conversion device 30 further includes a first semiconductor switching element 304 connected between the second terminal of the reactor 303 and the negative side of the first capacitor 302,
  • the first rectifying element 305 is connected in reverse parallel to the first semiconductor switching element 304 and protects the first semiconductor switching element 304 when the first semiconductor switching element 304 is turned off. That is, the first semiconductor switching element 304 has a positive terminal connected to the second terminal of the reactor 303 and a negative terminal connected to the negative side of the first capacitor 302.
  • the first rectifying element 305 has an anode connected to the negative side of the first capacitor 302 and a cathode connected to the second terminal of the reactor 303.
  • a second rectifier element 306 that is connected to the second terminal of the reactor 303 and rectifies the current sent from the second terminal, and a second semiconductor connected in antiparallel to the second rectifier element 306.
  • the switching element 307 includes a second rectifying element 306 and a second capacitor 308 connected to the negative side of the first capacitor 302 at a position where the current rectified by the second rectifying element 306 flows. . That is, the second rectifying element 306 has an anode side connected to the second terminal of the reactor 303 and a cathode side connected to the positive side of the load 309.
  • the second semiconductor switching element 307 has a negative terminal connected to the second terminal of the reactor 303 and a positive terminal connected to the positive side of the second capacitor 308 and the positive side of the load 309.
  • the positive side of the first capacitor 302 indicates the upper end of the first capacitor 302 in FIG. Therefore, the negative side of the first capacitor 302 is the lower end of the first capacitor 302 in FIG.
  • the direction of rectification from left to right is the forward direction
  • the direction from right to left is the reverse direction.
  • the power supply 301 has two poles, the positive electrode is connected to the first terminal of the reactor 303, and the negative electrode is connected to the first semiconductor switching element 304. Furthermore, a first capacitor 302 is connected to the power supply 301 in parallel. The load 309 is connected so that the current rectified by the second rectifying element 306 is input to the positive side.
  • the power conversion device 30 includes a one-stone booster circuit configured as described above and capable of synchronous rectification, a first semiconductor switching element 304, and a second semiconductor switching element.
  • a driving device 320 for sending a driving signal for driving 307; and a control device 321 for sending a control signal for controlling the driving of the first semiconductor switching element 304 and the second semiconductor switching element 307 to the driving device 320. Yes.
  • the driving device 320 sends a driving signal 315 for driving the first semiconductor switching element 304 to the control terminal of the first semiconductor switching element 304, and sends it to the control terminal of the second semiconductor switching element 307.
  • the control device 321 sends a control signal 312 for controlling the first semiconductor switching element 304, a control signal 314 for controlling the second semiconductor switching element 307, and a synchronous rectification operation switching signal 313 to the driving device 320.
  • the drive device 320 that receives the control signal 312 of the first semiconductor switching element 304 generated by the control device 321 turns on the first semiconductor switching element 304. By switching between the state and the off state, a voltage higher than the voltage output from the power supply 301 is output to the load 309.
  • the power conversion apparatus 30 further includes an input side voltage detector 310 and an output side voltage detector 311.
  • the input side voltage detector 310 measures the value of the voltage applied to both ends of the first capacitor 302.
  • the output side voltage detector 311 measures the value of the voltage applied to both ends of the second capacitor 308.
  • the power supply 301 will be described assuming that a DC stabilized power supply is used in the first embodiment of the present invention, but may be a storage battery, a solar battery, or the like.
  • the load 309 is described assuming an AC load via an inverter in the first embodiment of the present invention, but the load 309 to which the power conversion device 30 according to the first embodiment of the present invention is connected is an inverter.
  • a pure resistance load, a constant power load, or the like may be used instead of the AC load via the.
  • the second semiconductor switching element 307 is a metal oxide semiconductor field effect transistor (MOSFET) capable of flowing a current in both directions (MOSFET: Metal Oxide Semiconductor Field Effect Transistor).
  • MOSFET Metal Oxide Semiconductor Field Effect Transistor
  • IGBT Insulated Gate Bipolar Transistor
  • the first semiconductor switching element 304 is a MOSFET in the first embodiment of the present invention, but may be an IGBT.
  • an IGBT is used for the first semiconductor switching element 304, the current flows through the IGBT only in one direction, so the collector electrode side is connected to the second terminal of the reactor 303.
  • the second semiconductor switching element 307 is maintained in the off state, and the first semiconductor switching element 304 is in the first on state and the first off state.
  • the second switching in which the second semiconductor switching element 307 switches between the second on state and the second off state in synchronization with the first switching from the asynchronous rectification state in which the first switching is performed.
  • the control device 321 indicates the first off-state time when the first semiconductor switching element 304 is set to the first off state in the state of synchronous rectification.
  • the second semiconductor switching element 307 is controlled to be in the second on state with a second on time shorter than the off time. That is, the power conversion device 30 according to the first embodiment of the present invention is characterized by the control signal that the control device 321 sends out to the main circuit of the power conversion device 30 according to the first embodiment of the present invention. Yes.
  • the power conversion device 30 according to the first exemplary embodiment of the present invention solves a problem that occurs when a single-step boost circuit capable of synchronous rectification shifts from an asynchronous rectification state to a synchronous rectification state.
  • FIG. 2 is a diagram for explaining a problem to be solved by the power conversion device 30 according to the first exemplary embodiment of the present invention.
  • the control signal waveform and the reactor 303 transmitted by the control device of the power conversion device of the comparative example are illustrated in FIG. It is the schematic which showed the waveform of the electric current which flows.
  • FIG. 2 shows a waveform of a control signal sent out by the control device of the power conversion device of the comparative example and a waveform of a current flowing through the reactor.
  • the waveform of the control signal for controlling the driving of the first semiconductor switching element 304 is shown as the switching signal waveform 5201 of the first semiconductor switching element 304.
  • a waveform of a control signal that controls driving of the second semiconductor switching element 307 is shown as a switching signal waveform 5202 of the second semiconductor switching element 307.
  • FIG. 2 shows a synchronous rectification operation switching signal waveform 5204 and a current waveform 5203 of the reactor 303.
  • the current waveform 5203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the first ON time indicating the time of the first ON state is indicated as T1 in FIG. 2, and the first OFF time indicating the time of the first OFF state is indicated as T2.
  • the switching period in FIG. 2 is shown as T and is one period of the first switching.
  • the second semiconductor switching element 307 is maintained in the off state, and the first semiconductor switching element 304 is in the first on state and the first off state.
  • the asynchronous rectification state in which the first switching for switching between states is repeated for example, consider a case where the first on-time T1 is shorter than the first off-time T2 and less energy is stored in the reactor 303. .
  • region A1 shows the range of the state where asynchronous rectification is performed.
  • the region A1 is sent to the first semiconductor switching element 304 of the one-stone booster circuit capable of synchronous rectification.
  • the control signal waveform has a short energy stored in the reactor 303 because the first on-time T1 is short.
  • the state of asynchronous rectification in which the second semiconductor switching element 307 is maintained in the off state and the first semiconductor switching element 304 performs the first switching for switching between the first on state and the first off state is: Before the synchronous rectification operation switching signal waveform 5204 is turned on.
  • the current flowing through the reactor 303 temporarily becomes zero.
  • the current may be discontinuous.
  • an operation in which a current flows discontinuously due to the first on-time T1 being shorter than the first off-time T2 is referred to as a discontinuous mode.
  • the power conversion device of the comparative example that performs the operation of FIG. 2 accumulates energy in the reactor 303 while the first semiconductor switching element 304 is turned on, and the first semiconductor switching element 304 Is in the off state, the energy stored in the reactor 303 is supplied to the load 309 through the second rectifying element 306. At this time, a voltage drop occurs in the second rectifier element 306 due to the current that has passed through the second rectifier element 306. The product of the current flowing through the second rectifier element 306 and the voltage that has dropped is the power loss generated in the second rectifier element 306.
  • the second semiconductor switching element 307 when no current flows through the reactor 303, the voltage applied to both ends of the second capacitor 308 is higher than the voltage applied to both ends of the first capacitor 302. Therefore, if the second semiconductor switching element 307 is in an on state, a current flows from the second capacitor 308 side to the first capacitor 302 side. However, in the state of the region A1, the second semiconductor switching element 307 is in the off state, and the second rectifier element 306 prevents the current in the reverse direction. No current flows to the capacitor 302 side. Therefore, no current flows from the second capacitor 308 to the first capacitor 302, that is, from the second terminal of the reactor 303 to the first terminal.
  • the direction in which current flows from the first terminal to the second terminal of the reactor 303 is referred to as a positive direction (forward direction), and the direction in which current flows from the second terminal to the first terminal is negative ( We will call it the reverse direction.
  • Synchronous rectification starts when the synchronous rectification operation switching signal is turned on.
  • the timing at which the synchronous rectification operation switching signal is turned on is the same as the timing at which the control device 321 turns the first semiconductor switching element 304 on, so that the control device 321 performs the first semiconductor switching.
  • the element 304 is turned off, the second semiconductor switching element 307 is turned on. While the first semiconductor switching element 304 is in the on state, energy is stored in the reactor 303, and the control device 321 turns off the first semiconductor switching element 304 and turns on the second semiconductor switching element 307.
  • the energy stored in the reactor 303 is supplied to the load 309 through the second semiconductor switching element 307.
  • the current flowing in the positive direction becomes zero
  • the voltage applied to both ends of the second capacitor 308 is higher than the voltage applied to both ends of the first capacitor 302. Therefore, next, a current flows in the negative direction through the second semiconductor switching element 307.
  • the current flowing through the first capacitor 302 flows through the reactor 303. Therefore, a rapid current increase to the first capacitor 302 is suppressed.
  • the amount of increase in the current flowing in the negative direction is determined by the voltage value at both ends of the first capacitor 302, the voltage value at both ends of the second capacitor 308, and the inductance value of the reactor 303.
  • the control device 321 turns off the second semiconductor switching element 307 and turns on the first semiconductor switching element 305 in the next switching cycle T, the second capacitor 308 side to the first capacitor 302 side There is no longer a path for current to flow. Therefore, there is no increase in current in the negative direction, and the current flowing in the negative direction becomes zero. Furthermore, the current is in the positive direction. Since the current waveform 5203 of the reactor 303 in FIG. 2 is a schematic diagram, the slope of the current waveform when the current flowing in the negative direction approaches 0 and the current when the current flows from 0 to the positive direction are shown. The waveform is shown with the same slope.
  • the current waveform 5203 of the reactor 303 is not originally represented only by such a straight line, and thus the current that has flowed in the negative direction as described above is not necessarily zero.
  • the current waveform and the current waveform when current flows from 0 to the positive direction are not the same shape.
  • the control device 321 turns off the first semiconductor switching element 304 and turns on the second semiconductor switching element 307, the current flowing in the positive direction of the reactor 303 becomes 0, and the current flows in the negative direction. Begins to flow. Then, in the next switching cycle T, the control device 321 turns off the second semiconductor switching element 307 and turns on the first semiconductor switching element 305 again.
  • the control signal of the second semiconductor switching element 307 is an inverted signal of the control signal of the first semiconductor switching element 304 from the time when the state is shifted to the synchronous rectification state.
  • the value is a negative value because the amount of current flowing in the negative direction is large. It becomes.
  • the first on-time T1 in FIG. 2 is obtained so that the current flowing through the reactor 303 is in a positive direction and is shorter than the first off-time T2 and can cover the power consumed by the load. Is. Accordingly, when the amount of current flowing in the reverse direction through the reactor 303 increases and the average value of the current flowing through the reactor 303 within one switching cycle T becomes a negative value, the reactor 303 is charged in the first on-time T1. Alone will not be able to cover the power consumed by the load.
  • the load is a power system or an AC load.
  • a photovoltaic power conditioner having a booster circuit and an inverter between the solar cell and the load, and the power converter corresponds to a booster circuit of the photovoltaic power conditioner.
  • the power conversion device is in the discontinuous mode, for example, when the output power of the solar cell is low and the current flowing through the power conversion device is small, or when the power conditioner for solar power generation is connected.
  • the solar cell has a characteristic that the voltage of the solar cell increases when the output current is small.
  • the power conversion device is in the discontinuous mode, the voltage of the first capacitor is similarly increased because the first capacitor is connected in parallel with the solar cell.
  • the power conversion device is a bidirectional DC-DC converter.
  • the power source is a storage battery
  • the protection function operates so as not to overcharge and the power converter is stopped.
  • the control device uses the first on-time T1 as the on-time of the first semiconductor switching element 304 necessary for sufficiently charging the reactor 303. It may be adjusted. After the region P in FIG. 2, the control device changes the on-time of the first semiconductor switching element 304 while obtaining the necessary first on-time T1, and flows to the reactor 303 within one switching cycle T. It shows a state where the average value of the current is adjusted so as to be a positive value.
  • An object of this invention is to obtain the power converter device which suppressed the electric current amount which flows into a reverse direction.
  • the control device 321 maintains the second semiconductor switching element 307 in the off state, and sets the first semiconductor switching element 304 in the first on state and the first on state.
  • the second semiconductor switching element 307 is switched from the second on-state to the second off-state in synchronization with the first switching from the asynchronous rectification state in which the first switching to the off-state is performed. The problem which arises when shifting to the state of the synchronous rectification which switches 2 is solved.
  • FIG. 3 is a schematic diagram illustrating a waveform of a control signal transmitted by the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • FIG. 3 shows a synchronous rectification operation switching signal waveform 6204 and a current waveform 6203 of the reactor 303.
  • the current waveform 6203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the signal waveform and the current waveform shown in the region A1 are the same as the signal waveform and the current waveform in the region A1 in FIG. Therefore, in the region A1 of FIG. 3, the control device 321 maintains the second semiconductor switching element 307 in the off state and switches the first semiconductor switching element 304 between the first on state and the first off state.
  • the state of asynchronous rectification for performing the first switching is shown.
  • the state of this area A1 shifts to the state of synchronous rectification.
  • the switching period T is also one period of the second switching. That is, since one cycle of the first switching and one cycle of the second switching are the same, the switching frequency of the first semiconductor switching element 304 and the switching frequency of the second semiconductor switching element 307 are equal.
  • the control device 321 of the power conversion device 30 shifts from the state of the region A1 to the synchronous rectification state, the control device 321 performs the first semiconductor switching element 304 in the synchronous rectification state. Is maintained in the first off state, the second semiconductor switching element 307 is turned on in the second on time T3 that is shorter than the first off time T2 indicating the time of the first off state. It is characterized by controlling to be in a state.
  • the second on-time T3 is shorter than the time obtained by subtracting the dead time period (about 1 ⁇ s to 5 ⁇ s) from the first off-time T2.
  • the control device 321 outputs a signal for switching the first semiconductor switching element 304 to the off state and a signal for switching the second semiconductor switching 307 to the on state at the same time.
  • the control device 321 outputs a signal for switching the first semiconductor switching element 304 to the off state and a signal for switching the second semiconductor switching 307 to the on state at the same time.
  • the first semiconductor switching element 304 and the second semiconductor switching element 307 are turned on simultaneously.
  • the second capacitor 308 may be short-circuited between the positive electrode and the negative electrode by the second semiconductor switching element 307 and the first semiconductor switching element 304.
  • a short-circuit current flows through the first semiconductor switching element 304 and the second semiconductor switching element 307, and there is a possibility that the first semiconductor switching element 304 and the second semiconductor switching element 307 are destroyed. Therefore, a dead time period is usually provided when the first semiconductor switching element 304 and the second semiconductor switching element 307 are switched between the on state and the off state.
  • Synchronous rectification starts when the synchronous rectification operation switching signal 313 is turned on. Since the synchronous rectification is enabled by the synchronous rectification switching signal 313, the second semiconductor switching element 307 can be turned on.
  • the power conversion device 30 according to the first embodiment of the present invention can suppress the amount of current flowing through the reactor 303 in the reverse direction. That is, the power conversion device according to the first embodiment of the present invention can suppress fluctuations in the power supplied to the load 309.
  • the second switching to turn on the second semiconductor switching element 307 at the second on-time T3 shorter than the first off-time T2 is performed a plurality of times, so that the current further reverses the reactor 303.
  • the amount flowing in the direction can be suppressed.
  • the control signal 314 of the second semiconductor switching element 307 sent out by the control device 321 has a waveform as shown in the switching signal waveform 6202 of the second semiconductor switching element 307 in FIG. Further, there is a feature that the ON time of the second semiconductor switching element 307, which is shorter than the first OFF time T2, is gradually increased. Finally, the ON time of the second semiconductor switching element 307 is set to be the same length as the first OFF time T2 of the first semiconductor switching element 304. That is, the second on-time in the second and subsequent second switching after the transition to the synchronous rectification state is made longer than the second on-time in the first second switching after the transition.
  • the on-time of the second semiconductor switching element 307 in the second switching for the first time after shifting to the synchronous rectification state is set as a second on-time T3.
  • the second on-time T3 is shorter than the off-time T2 of the first semiconductor switching element 304.
  • the on-time of the second semiconductor switching element 307 in the second switching period T that is, the second switching after the transition to the synchronous rectification state, is an on-time T5 longer than the second on-time T3.
  • the on-time of the second semiconductor switching element 307 in the next switching period T is an on-time T7 longer than the on-time T5.
  • the on-time of the second semiconductor switching element 307 in the next switching period T is an on-time T9 longer than the on-time T7.
  • the ON time of the second semiconductor switching element 307 is gradually increased, and finally the same length as the first OFF time T2 of the first semiconductor switching element 304 is set. That is, finally, the control signal 312 for controlling the driving of the second semiconductor switching element 307 becomes an inverted signal of the control signal 314 for controlling the driving of the first semiconductor switching element 304.
  • the ON time of the second semiconductor switching element 307 which is shorter than the OFF time T2 of the first semiconductor switching element 304, is gradually increased, and finally the first OFF If the length is the same as the time T2, the amount of current flowing in the reverse direction can be suppressed, and power loss, which is the original purpose of performing synchronous rectification, can be suppressed. This is because the first semiconductor switching element 304 and the second semiconductor switching element 307 are in the off state, and the current does not flow in the positive direction in the end.
  • the amount of increase in increasing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the circuit configuration and control response speed.
  • a method of increasing in a quadratic function in 0.5 seconds is also conceivable.
  • the method is not limited thereto, and the second semiconductor switching element is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to reduce the ON time of the second semiconductor switching element 307 again while increasing the ON time of 307.
  • the timing for turning on the second semiconductor switching element 307 is set while the current flowing through the reactor 303 is flowing in the positive direction.
  • the second semiconductor switching element 307 is symmetrical about the center between the ON signal of the first semiconductor switching element 304 and the ON signal of the first semiconductor switching element 304 in the next switching period T. ON signal is provided.
  • a current in the positive direction is included in the current passing through the second semiconductor switching element 307 while the second semiconductor switching element 307 is on. Therefore, the amount of current flowing in the reverse direction can be further suppressed.
  • the first semiconductor switching element 304 When the second semiconductor switching element 307 that has been turned on by making the on time shorter than the first off time T2 is turned off, the first semiconductor switching element 304 is also in the second state until the next switching period T.
  • the semiconductor switching element 307 is also in the off state. As shown in FIG. 3, if the current flowing through the reactor 303 is positive when the second semiconductor switching element 307 is turned off, the reactor is turned off even if the second semiconductor switching element 307 is turned off.
  • the energy stored in 303 passes through the second rectifying element 306, and the current flows to the load 309. If the current flowing through the reactor 303 is negative when the second semiconductor switching element 307 is turned off, the current becomes 0 after the second semiconductor switching element 307 is turned off.
  • the power converter 30 according to the first embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, it turns out that the fluctuation
  • FIG. 4 is a schematic diagram illustrating a waveform of a control signal transmitted by a modification of the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor.
  • the waveform of the control signal 312 of the first semiconductor switching element 304 is the switching signal waveform 7101 of the first semiconductor switching element 304.
  • the waveform of the second semiconductor switching element 307 control signal 314 is the switching signal waveform 7102 of the second semiconductor switching element 307.
  • FIG. 4 shows a synchronous rectification operation switching signal waveform 7104 and a current waveform 7103 of the reactor 303.
  • the current waveform 7103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the switching signal waveform 7101 in FIG. 4 is the same as the switching signal waveform 6201 in FIG. Only the difference between the switching signal waveform 7102 of FIG. 4 and the switching signal waveform 6202 of FIG. 3 will be described.
  • the timing at which the second semiconductor switching element 307 is turned on is the same as the timing at which the first semiconductor switching element 304 is turned off.
  • the second semiconductor switching element 307 is turned on in the meaning that the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off.
  • a dead time period (about 1 ⁇ s to 5 ⁇ s) is provided between the timing of switching and the timing of turning off the first semiconductor switching element 304, that is, they are not exactly the same, but are about several ⁇ s apart. This is also included.
  • the time for turning on the second semiconductor switching element 307 is gradually increased, the time for the current to flow through the reactor 303 in the negative direction is also gradually increased. Therefore, the average value of the current flowing through the reactor 303 within one switching cycle T gradually decreases.
  • the switching signal waveform 7102 as shown in FIG. 4 when the current flows through the reactor 303 in the negative direction, the energy stored in the reactor 303 is performed following the flow of the current supplied to the load 309.
  • the rate at which the average value of the current flowing through the reactor 303 within one switching cycle T decreases can be smaller than in the case of FIG. Therefore, it is also suitable when the switching speed of the second semiconductor switching element 307 is not high.
  • the current waveform 7103 of the reactor 303 in FIG. 4 is a schematic waveform, but it can be seen that the power converter 30 according to the first embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, it turns out that the fluctuation
  • FIG. 5 is a schematic diagram illustrating a waveform of a control signal sent out by another modification of the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor.
  • the waveform of the control signal 312 of the first semiconductor switching element 304 becomes the switching signal waveform 7201 of the first semiconductor switching element 304.
  • the waveform of the control signal 314 of the second semiconductor switching element 307 becomes the switching signal waveform 7202 of the second semiconductor switching element 307.
  • FIG. 5 shows a synchronous rectification operation switching signal waveform 7204 and a current waveform 7203 of the reactor 303.
  • the current waveform 7203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the switching signal waveform 7201 in FIG. 5 is the same as the switching signal waveform 6201 in FIG. Only a difference between the switching signal waveform 7202 of FIG. 5 and the switching signal waveform 6202 of FIG. 3 will be described.
  • the timing for turning the second semiconductor switching element 307 off and the timing for turning the first semiconductor switching element 304 on are the same.
  • the power conversion device 30 can suppress the amount of current flowing in the reverse direction.
  • the second semiconductor switching element 307 has a switching signal waveform 7202 as shown in FIG. 5, a semiconductor switching element that operates at high speed is used for the first semiconductor switching element 304 and the second semiconductor switching element 307. desirable.
  • the timing at which synchronous rectification is started is described as being the same as the timing at which the switching period T is switched.
  • the timing for starting the synchronous rectification may be in the middle of the switching cycle T, but the timing for starting the synchronous rectification is preferably the same as the timing for switching the switching cycle T.
  • FIG. 2 In the second embodiment of the present invention, portions that are different from the first embodiment of the present invention will be described, and descriptions of the same or corresponding portions will be omitted.
  • a power source 301 is disposed on the input side of a one-stone booster circuit capable of synchronous rectification, and a load 309 that consumes power is disposed on the output side. Yes, power was transmitted in one direction.
  • a power conversion device and a power conversion system in a case where power is transmitted bidirectionally instead of unidirectionally will be described.
  • the load 309 of the power conversion device 30 according to the first embodiment of the present invention is the power source 809.
  • FIG. 6 is a schematic diagram showing a power conversion system 81 configured using the power conversion device 80 according to the second embodiment of the present invention.
  • the circuit included in the power conversion device 80 according to the second embodiment of the present invention is a one-stone booster circuit capable of synchronous rectification, and is the same as the circuit included in the power conversion device 30 according to the first embodiment of the present invention. is there.
  • the circuit included in the power conversion device 80 according to the second embodiment of the present invention is connected to the power source 801 and the power source 809.
  • One pole of the power source 801 is connected to the first terminal of the reactor 303, and the other pole is connected to the first semiconductor switching element 304.
  • a first capacitor 302 is connected to the power source 801 in parallel.
  • the cathode side of the second rectifier element 306 is connected to the pole side having the same polarity as the pole connected to the first terminal of the reactor 303 of the power source 801.
  • the power conversion device 80 includes a detection device 810 that detects the average value of the current of the reactor 303 within one switching cycle, the first semiconductor switching element 304, and the second And a driving device 820 for sending a driving signal for driving the semiconductor switching element 307. Further, a control device 821 for sending a control signal for controlling driving of the first semiconductor switching element 304 and the second semiconductor switching element 307 to the driving device 820 is provided.
  • the drive device 820 sends a drive signal 816 of the first semiconductor switching element 304 to the control terminal of the first semiconductor switching element 304, and to the control terminal of the second semiconductor switching element 307. A drive signal 817 for the second semiconductor switching element 307 is transmitted.
  • Control device 821 determines whether one of first semiconductor switching element 304 and second semiconductor switching element 307 is in an OFF state based on the average value of current in reactor 303 within one switching cycle detected by detection device 810. And the third switching that switches between the third on-state and the third off-state, either the first semiconductor switching element 304 or the second semiconductor switching element 307
  • the synchronous switching element determination signal 812 is sent to the driving device 820.
  • the operation is a booster circuit supplying power from the power source 801 to the power source 809.
  • the synchronous switching element maintained in the OFF state is the second semiconductor switching element 307, and the asynchronous switching element that performs the third switching for switching between the third ON state and the third OFF state is the first semiconductor.
  • This is a switching element 304.
  • the synchronous switching element maintained in the OFF state is the first semiconductor switching element 304, and the asynchronous switching element that performs the third switching for switching between the third ON state and the third OFF state is the second semiconductor.
  • control device 821 includes a control signal 813 for controlling driving of the first semiconductor switching element 304, a control signal 815 for controlling driving of the second semiconductor switching element 307, and a synchronous rectification switching signal 814. Send to 820.
  • the control signal of the first semiconductor switching element 304 generated by the control device 821 when the asynchronous switching element is the first semiconductor switching element 304, the control signal of the first semiconductor switching element 304 generated by the control device 821.
  • the driving device 820 that has received 813 can transmit a voltage higher than the voltage output from the power source 801 to the power source 809 by switching between the on state and the off state of the first semiconductor switching element 304.
  • the driving device 820 that has received the control signal 815 of the second semiconductor switching element 307 generated by the control device 821 is connected to the second semiconductor switching element 307. By switching between the on state and the off state, a voltage lower than the voltage output from the power source 809 can be transmitted to the power source 801.
  • the power conversion device 80 according to the second embodiment of the present invention further includes an input side voltage detector 310 and an output side voltage detector 311. I have.
  • the input side voltage detector 310 measures the value of the voltage applied to both ends of the first capacitor 302.
  • the output side voltage detector 311 measures the value of the voltage applied to both ends of the second capacitor 308.
  • the power is transmitted from the power source 801 to the power source 809 and bidirectional when the power is transmitted from the power source 809 to the power source 801.
  • the power source 801 is a storage battery and the power source 809 is a DC system
  • power is supplied from the power source 809 to the power source 801 when the storage battery is charged.
  • the power of the storage battery is sent to the DC system
  • the power is transmitted from the power source 801 to the power source 809.
  • the case where the power sources 801 and 809 include an electric motor / generator may be considered.
  • the power sources 801 and 809 are not specified in particular and the power converter 80 has a bidirectional power flow.
  • the direction in which current flows from the first terminal of the reactor 303 to the second terminal is referred to as a positive direction (forward direction), and the first terminal from the second terminal
  • the direction in which the current flows to the terminal is called the negative direction (reverse direction). Therefore, when power is transmitted from power supply 809 to power supply 801, the direction of current flow is opposite to that of Embodiment 1 of the present invention, and therefore the object is to suppress the amount of current flowing in the positive direction. . It is an object to obtain a power conversion device that suppresses fluctuations in the power supplied (transmitted) by both the first embodiment and the second embodiment of the present invention even when the direction of current flow is reversed.
  • FIG. 7 is a schematic diagram showing the waveform of the control signal sent out by the control device 821 of the power conversion device 80 according to the second embodiment of the present invention and the waveform of the current flowing through the reactor 303.
  • the signal waveform and the current waveform shown in the region A ⁇ b> 2 indicate that the control device 821 keeps the second semiconductor switching element 307 in the off state and the first semiconductor switching element 304 in the third on state and the third on state.
  • the state of the asynchronous rectification which performs the 3rd switching switched to an OFF state is shown.
  • the third on-state time is defined as a third on-time T11
  • the third off-state time is defined as a third off-time T12.
  • the current flowing through the reactor 303 is discontinuous, and the third off time T12 is longer than the third on time T11. Moreover, the switching period in FIG. 7 is indicated as T10 and is one period of the third switching. The state of this area A2 shifts to the state of synchronous rectification.
  • the average value of the current flowing through the reactor 303 within one switching period T10 detected by the detection device 810 is a positive value, and power is transmitted from the power source 801 to the power source 809.
  • the waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 are shown.
  • the control device 821 determines the power supply direction from the average value of the current flowing through the reactor 303 within one switching cycle T10 detected by the detection device 810, and this is driven by the synchronous switching element determination signal 812. To the device 820.
  • the synchronous switching element maintained in the OFF state before the transition to the synchronous rectification state is the second semiconductor switching element 307, and the third ON state
  • the first switching element 304 is the asynchronous switching element that performs the third switching to switch between the first semiconductor switching element 304 and the third OFF state.
  • the driving device 820 determines which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is a synchronous switching element maintained in an off state, and the first semiconductor It can be seen which of the switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element that performs a third switching to switch between a third on state and a third off state.
  • the power supply direction is determined by detecting the average value of the current flowing through the reactor 303 in one switching cycle T10 by the detector 810, and the value is positive or negative.
  • the instantaneous current value flowing through the reactor 303 is detected by the detector 810, and the control device 821 that has acquired the current value information calculates the average value of the current flowing through the reactor 303 in one switching cycle T10.
  • the direction of power supply may be determined based on whether the power is negative or negative.
  • the control device 821 of the power conversion device 80 has one switching cycle T10 detected by the detection device 810 before shifting to the synchronous rectification state, that is, in the state of the region A2.
  • Which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is a synchronous switching element maintained in the OFF state, and the first semiconductor switching It is determined which of the element 304 and the second semiconductor switching element 307 is an asynchronous switching element that performs the third switching for switching between the third on state and the third off state.
  • the control device 821 has the asynchronous switching element in the synchronous rectification state. Controlling the synchronous switching element to be in the fourth on state at a fourth on time T13 that is shorter than the third off time T12 indicating the time of the third off state in the third off state. It is a feature.
  • one cycle of the fourth switching is also T10. That is, since one cycle of the third switching is the same as one cycle of the fourth switching, the switching frequency of the synchronous switching element and the switching frequency of the asynchronous switching element are equal.
  • FIG. 7 shows a synchronous rectification operation switching signal waveform 9104, a current waveform 9103 of the reactor 303, and a synchronous switching element determination signal waveform 9105.
  • the current waveform 7103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the synchronous switching element determination signal waveform 9105 is shown in FIG. It is a straight line like this.
  • the control device 821 of the power conversion device 80 shifts from the state of the region A2 to the synchronous rectification state
  • the first semiconductor switching element 304 is in the third OFF state
  • the second semiconductor switching element 307 is controlled to be in the fourth on state at the fourth on time T13 that is shorter than the third off time T12 indicating the time of the third off state.
  • the fourth on-time T13 is shorter than the time obtained by subtracting the dead time period (about 1 ⁇ s to about 5 ⁇ s) from the third off-time T12.
  • Synchronous rectification starts when the synchronous rectification operation switching signal 814 is turned on. Since the synchronous rectification is enabled by the synchronous rectification switching signal 814, the second semiconductor switching element 307 can be turned on.
  • the power converter device 80 concerning Embodiment 2 of this invention can suppress the quantity which an electric current flows through the reactor 303 to a reverse direction. That is, when power is supplied from the power source 801 to the power source 809, the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 809.
  • the fourth switching for turning on the second semiconductor switching element 307 at the fourth on-time T13 shorter than the third off-time T12 is performed a plurality of times, so that the current further reverses the reactor 303. The amount flowing in the direction can be suppressed.
  • the control signal 815 of the second semiconductor switching element 307 sent out by the control device 821 has a waveform as shown in the switching signal waveform 9102 of the second semiconductor switching element 307 in FIG. Further, there is a feature that the ON time of the second semiconductor switching element 307, which is shorter than the OFF time T12 of the first semiconductor switching element 304, is gradually increased. Finally, the ON time of the second semiconductor switching element 307 is set to be the same as the OFF time T12 of the first semiconductor switching element 304. That is, the fourth on time in the fourth switching after the second time after the transition to the synchronous rectification state is made longer than the fourth on time in the first fourth switching after the transition.
  • the switching signal waveform 9102 of the second semiconductor switching element 307 in FIG. 7 will be described in more detail.
  • the on-time of the second semiconductor switching element 307 in the second switching for the first time after shifting to the synchronous rectification state is set as a fourth on-time T13.
  • the fourth on-time T13 is shorter than the third off-time T12 of the first semiconductor switching element 304.
  • the on-time of the second semiconductor switching element 307 in the second switching period T10 that is, the second switching after the transition to the synchronous rectification state, is an on-time T15 longer than the fourth on-time T13.
  • the on-time of the second semiconductor switching element 307 in the next switching period T10 is an on-time T17 longer than the on-time T15. Furthermore, the on-time of the second semiconductor switching element 307 in the next switching period T10 is an on-time T19 longer than the on-time T17. In this way, the ON time of the second semiconductor switching element 307 is gradually increased, and finally the same length as the first OFF time T12 of the first semiconductor switching element 304 is set. That is, finally, the control signal 815 of the second semiconductor switching element 307 becomes an inverted signal of the control signal 812 of the first semiconductor switching element 304.
  • the amount of increase in increasing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the response speed of the circuit configuration control.
  • the first semiconductor switching element 304 can be increased in one second.
  • a method of increasing in a quadratic function in 0.5 seconds is also conceivable.
  • the method is not limited thereto, and the second semiconductor switching element is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to reduce the ON time of the second semiconductor switching element 307 again while increasing the ON time of 307.
  • the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off. Since the timing at which the first semiconductor switching element 304 is turned off and the timing at which the second semiconductor switching element 307 is turned on are the same, when current flows in the reactor 303 in the negative direction, This is performed following the flow of current for supplying the stored energy to the power source 809.
  • the time for turning on the second semiconductor switching element 307 is gradually increased, the time for the current to flow through the reactor 303 in the negative direction is also gradually increased. Therefore, the average value of the current flowing through reactor 303 within one switching cycle T10 gradually decreases.
  • the second semiconductor switching element 307 switching signal waveform 9102 as shown in FIG. 7 when the current flows through the reactor 303 in the negative direction, the current flow for supplying the energy stored in the reactor 303 to the power source 809. Therefore, the rate at which the average value of the current flowing through the reactor 303 in one switching cycle T10 decreases can be reduced. Therefore, it is also suitable when the switching speed of the second semiconductor switching element 307 is not high.
  • the power converter 80 according to the second embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, when power is supplied from the power source 801 to the power source 809, it can be seen that the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 809.
  • FIG. 7 is the same as FIG. 4 in the first embodiment of the present invention in the waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 shown in FIG. This is because when the power is transmitted from the power source 801 to the power source 809, the synchronous switching element maintained in the off state in the asynchronous rectification state is the second semiconductor switching element 307, and the third on state This is because the asynchronous switching element that performs the third switching for switching to the third OFF state is the first semiconductor switching element 304. Accordingly, FIG. 7 is the same as FIG. 4 with the addition of the synchronous switching element determination signal waveform 9105.
  • the switching signal waveform 9102 of the second semiconductor switching element 307 shown in FIG. 7 can be modified as shown in FIGS.
  • FIG. 8 is a schematic diagram showing a waveform of a control signal sent out by a modification of the control device 821 of the power conversion device 80 according to the second embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • the signal waveform and the current waveform shown in the region A3 indicate that the first semiconductor switching element 304 is maintained in the off state, and the second semiconductor switching element 307 is in the third on state and the third off state.
  • the state of the asynchronous rectification which performs the 3rd switching which switches is shown.
  • the third on-state time is defined as a third on-time T11
  • the third off-state time is defined as a third off-time T12.
  • FIG. 8 shows that in the region A3, the average value of the current flowing through the reactor 303 in one switching cycle T10 is a negative value, and the control device 821 sends power from the power source 809 to the power source 801. The waveform of the control signal to be performed and the waveform of the current flowing through the reactor are shown.
  • the waveform of the control signal 813 of the first semiconductor switching element 304 is shown as the switching signal waveform 9201 of the first semiconductor switching element 304.
  • the waveform of the control signal 815 of the second semiconductor switching element 307 is shown as the switching signal waveform 9202 of the second semiconductor switching element 307.
  • FIG. 8 shows a synchronous rectification operation switching signal waveform 9204, a current waveform 9203 of the reactor 303, and a synchronous switching element determination signal waveform 9205.
  • the current waveform 9103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the synchronous switching element determination signal waveform 9105 is shown in FIG. It is a straight line like this.
  • the synchronous switching element maintained in the OFF state before the transition to the synchronous rectification state is the first semiconductor switching element 304, and the third ON state
  • the second semiconductor switching element 307 is the asynchronous switching element that performs the third switching to switch between the third semiconductor switching element 307 and the third OFF state. Therefore, in FIG. 8, the signal sent to the first semiconductor switching element 304 in FIG. 7 and the signal sent to the second semiconductor switching element 307 are interchanged.
  • the ON signal of the first semiconductor switching element 304 is between the ON signal of the second semiconductor switching element 307 and the ON signal of the second semiconductor switching element 307 in the next switching period T10. At the center of the off signal of the second semiconductor switching element 307.
  • FIG. 8 is a schematic diagram
  • the power conversion device 80 according to the second exemplary embodiment of the present invention can suppress the amount of current flowing in the positive direction when transmitting power from the power source 809 to the power source 801. I understand. That is, when power is supplied from the power source 809 to the power source 801, it can be seen that the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 801.
  • the waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 shown in FIG. 8 are those when power is transmitted from the power supply 301 to the power supply 309, the first semiconductor switching is performed.
  • the signal transmitted to the element 304 and the signal transmitted to the second semiconductor switching element 307 are interchanged, and the characteristic portion is not different from FIG. 3 in the first embodiment of the present invention.
  • the synchronous switching element determination signal waveform 9105 is added to FIG. 3, and only the signal sent to the first semiconductor switching element 304 and the signal sent to the second semiconductor switching element 307 are replaced. It is.
  • the switching signal waveform 9201 of the first semiconductor switching element 304 shown in FIG. 8 can be modified like the switching signal waveform of the second semiconductor switching element 307 of FIGS.
  • the synchronous switching element is the first semiconductor switching element 304 or the second semiconductor switching element 307, and is asynchronous.
  • shifting from the rectification state to the synchronous rectification state when the asynchronous switching element is in the third OFF state, it is synchronized with a fourth ON time shorter than the third OFF time indicating the time of the third OFF state.
  • the switching element By controlling the switching element to be in the fourth ON state, the amount of current flowing in the reverse direction can be suppressed. That is, in Embodiment 2 of the present invention, it is possible to obtain a power conversion device 80 that suppresses fluctuations in supplied power.
  • the timing for starting the synchronous rectification is described as being the same as the timing for switching the switching cycle T10.
  • the timing for starting the synchronous rectification may be in the middle of the switching cycle T10, but the timing for starting the synchronous rectification is preferably the same as the timing for switching the switching cycle T10.
  • Embodiment 3 In the third embodiment of the present invention, portions that are different from the first embodiment of the present invention and the second embodiment of the present invention will be described, and description of the same or corresponding portions will be omitted.
  • the first embodiment and the second embodiment of the present invention the case of shifting from the asynchronous rectification state to the synchronous rectification state has been described, but in the third embodiment of the present invention, the asynchronous rectification state is changed to the asynchronous rectification state. A case of shifting to the state will be described.
  • the power transmission direction is one direction in the third embodiment of the present invention, as in the first embodiment of the present invention.
  • FIG. 1 is also a power conversion system 31 configured using the power conversion device 30 according to the third embodiment of the present invention. Therefore, in the third embodiment of the present invention, from the state of synchronous rectification to the state of asynchronous rectification, using the same names and symbols as those constituting the power conversion system 31 according to the first embodiment of the present invention. A case of migration will be described.
  • the power conversion device 30 solves a problem that occurs when a single rectifier booster circuit capable of synchronous rectification shifts from a synchronous rectification state to an asynchronous rectification state. First, the problem which the power converter device 30 concerning Embodiment 3 of this invention solves is demonstrated.
  • FIG. 9 is a diagram for explaining a problem to be solved by the power conversion device 30 according to the third embodiment of the present invention.
  • the control signal waveform and the reactor 303 sent out by the control device of the power conversion device of the comparative example are shown in FIG. It is the schematic which showed the waveform of the electric current which flows.
  • FIG. 9 shows a switching signal waveform 8101 of the first semiconductor switching element 304, a switching signal waveform 8102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 8104, and a current waveform 8103 of the reactor 303. Indicated.
  • the current waveform 8103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • Region A4 in FIG. 9 repeats the first switching in which the first semiconductor switching element 304 switches between the first on-state and the first off-state, and the second semiconductor switching element 307 is in the second on-state. And a synchronous rectification state in which the second switching for switching between the second off state and the second off state is repeated.
  • the first semiconductor switching element 307 Prior to the region A4 in FIG. 9, the first semiconductor switching element 307 is maintained in the OFF state, and the first switching is performed so that the first semiconductor switching element 304 switches between the first ON state and the first OFF state. Shows the state of asynchronous rectification.
  • the power conversion device of the comparative example that performs the operation of FIG.
  • the first on-time is indicated as T21
  • the first off-time is indicated as T22
  • the switching period in FIG. 9 is indicated as T20 and is one period of the first switching of the first semiconductor switching element 304 and the second switching of the second semiconductor switching element 307. That is, the switching frequency of the first semiconductor switching element 304 and the switching frequency of the second semiconductor switching element 307 are equal.
  • the switching signal waveform 8102 of the second semiconductor switching element 307 is an inverted signal of the first semiconductor switching element 304.
  • the first on-time T21 of the first semiconductor switching element 304 is shorter than the first off-time T22, and the energy stored in the reactor 303 is Consider the case of few.
  • the current flowing through the reactor 303 increases in the positive direction while the first semiconductor switching element 304 is on, and flows into the reactor 303 when the first semiconductor switching element 304 is turned off. The current decreases and becomes zero.
  • the second semiconductor switching element 307 is in the on state, so the current flowing through the reactor 303 flows in the negative direction as it is.
  • the synchronous rectification operation switching signal 313 is turned off at the timing when the second semiconductor switching element 307 is turned off. That is, the state is shifted from the synchronous rectification state to the asynchronous rectification state. Even after the transition to the asynchronous rectification state, the current flowing through the reactor 303 remains in the synchronous rectification state until the current flowing through the reactor 303 decreases to zero after the first semiconductor switching element 304 is turned off. It is the same. However, in the asynchronous rectification state, since the second semiconductor switching element 307 is always in the off state, there is no path for current to flow through the reactor 303 in the negative direction. For this reason, after the first semiconductor switching element 304 is turned off, the current flowing through the reactor 303 that has decreased to 0 remains temporarily 0, and the current flowing through the reactor 303 may become discontinuous. is there.
  • the control device requires the first on-state of the first semiconductor switching element 304 on the assumption that there is a period in which the current flows through the reactor 303 in the negative direction within one switching cycle T20.
  • Time T21 was determined. However, since the current does not flow negatively through the reactor 303 immediately after canceling the synchronous rectification state, the first on-time of the first semiconductor switching element 304 is the same as that immediately before canceling the synchronous rectification state. If T21 is provided, the average value of the current in one switching cycle T20 flowing through the reactor 303 will increase more than expected. As a result, a current greater than expected may be supplied to the load 309 or the voltage of the load 309 increases, the protection function operates, and the power conversion device of the comparative example in FIG. 9 stops. there is a possibility.
  • the control device may adjust the first on-time T21 to the originally required on-time of the first semiconductor switching element 304 from there.
  • FIG. 10 is a schematic diagram illustrating a waveform of a control signal sent out by the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • FIG. 10 shows a switching signal waveform 10101 of the first semiconductor switching element 304, a switching signal waveform 10102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 10104, and a current waveform 6203 of the reactor 303. Indicated.
  • the current waveform 10103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the signal waveform and current waveform shown in region A4 are the same as the signal waveform and current waveform in region A4 in FIG.
  • the first semiconductor switching element 304 is in the first OFF state during the transition from the state of the region A4 in FIG. 10 to the asynchronous rectification state.
  • the state of asynchronous rectification is changed from the state of synchronous rectification to the state of asynchronous rectification immediately after the state of synchronous rectification is canceled, instead of the state of asynchronous rectification immediately after the state of synchronous rectification is eliminated.
  • a period for shifting to (hereinafter referred to as a transition period) is provided.
  • the second on-time T23 is shorter than the time obtained by subtracting the dead time period (about 1 ⁇ s to 5 ⁇ s) from the first off-time T22.
  • the second ON time of the second semiconductor switching element that is shorter than the first OFF time T22 of the first semiconductor switching element 304 It is preferable that the second switching for turning on the second semiconductor switching element at T23 is performed a plurality of times. Thereby, when it transfers to the state of asynchronous rectification from the state of synchronous rectification, the raise of the average value of the electric current which flows into the reactor 30 in one switching period T20 can further be suppressed.
  • the control signal 314 of the second semiconductor switching element 307 sent out by the control device 321 is the second on-state of the second semiconductor switching element 307 in the transition period as shown in FIG.
  • the time T23 is gradually shortened.
  • the second on-time T23 of the second semiconductor switching element 307 becomes 0, the second semiconductor switching element 307 is always turned off, the transition period ends, and the state of asynchronous rectification is entered.
  • the amount of change when reducing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the circuit configuration and control response speed.
  • the second semiconductor switching element 307 is always set in 1 s.
  • the on-time of the second semiconductor switching element 307 is linearly reduced to the state of asynchronous rectification to be turned off.
  • a method of reducing it by a quadratic function at 0.5 s is also conceivable.
  • the method is not limited to these, and the second semiconductor switching element 307 is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to increase the on-time of the second semiconductor switching element 307 again while the on-time is being reduced.
  • the timing for turning on the second semiconductor switching element 307 is delayed and the timing at which the second semiconductor switching element 307 is turned off. There is a way to speed up as much.
  • the first semiconductor switching element 304 is turned on symmetrically around the center between the ON signal of the first semiconductor switching element 304 and the ON signal of the first semiconductor switching element 304 in the next switching period T20. An ON signal of the second semiconductor switching element 307 is provided.
  • the power conversion device 30 according to the third embodiment of the present invention can further suppress fluctuations in the power supplied to the load 309.
  • the control device 321 can quickly adjust the amount of power supplied to the load 309.
  • the transition from the synchronous rectification state to the asynchronous rectification state is performed when the power supplied from the power supply 301 to the load 309 is small. For example, when considering the power loss that occurs when the current flows through the second rectifying element 306 and the magnitude of the electromotive force of the second semiconductor switching element 307 when the current flows in the positive direction through the reactor 303 When it is determined that the current should pass through the second rectifier element 306, the state shifts from the synchronous rectification state to the asynchronous rectification state.
  • FIG. 11 is a schematic diagram illustrating a waveform of a control signal sent by a modification of the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • FIG. 11 shows a switching signal waveform 11101 of the first semiconductor switching element 304, a switching signal waveform 11102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 11104, and a current waveform 11103 of the reactor 303. Indicated.
  • the current waveform 11103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the timing for turning on the second semiconductor switching element 307 is different between FIG. 10 and FIG. 11 in the transition period immediately after the cancellation of the synchronous rectification state.
  • FIG. 10 Only differences from FIG. 10 will be described with reference to FIG.
  • the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off.
  • the timing for turning on the second semiconductor switching element 307 is the same as the timing for turning on the first semiconductor switching element 304 in the meaning that the timing at which the second semiconductor switching element 307 is turned on.
  • a dead time period (about 1 ⁇ s to 5 ⁇ s) is provided between the first semiconductor switching element 304 and the timing at which the first semiconductor switching element 304 is turned off, that is, not exactly the same, but there is a gap of about several ⁇ s. It is included.
  • the timing for turning the second semiconductor switching element 307 OFF is gradually advanced. Also in the modified example as shown in FIG. 11, the fluctuation of the power supplied to the load 309 is suppressed by providing a period in which the current can flow negatively through the reactor 303 after the synchronous rectification state is canceled. Can do.
  • FIG. 11 and FIG. 10 are compared, it is known that the current flowing through the reactor 303 shown in FIG. 11 is faster in reducing the current flowing in the negative direction. Therefore, when the switching signal waveform 11102 of the second semiconductor switching element 307 as shown in FIG. 11 is used, it is preferable to use the second semiconductor switching element 307 having a high switching speed.
  • FIG. 12 is a schematic diagram illustrating a waveform of a control signal sent out by another modification of the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • FIG. 12 shows a switching signal waveform 12101 of the first semiconductor switching element 304, a switching signal waveform 12102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 12104, and a current waveform 12103 of the reactor 303. Indicated.
  • the current waveform 12103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the switching signal waveform 12102 of the second semiconductor switching element 307 has the same timing when the second semiconductor switching element 307 is turned off as the timing when the first semiconductor switching element 304 is turned on.
  • the timing at which the second semiconductor switching element 307 is turned off means that the timing at which the second semiconductor switching element 307 is turned off is the same as the timing at which the first semiconductor switching element 304 is turned on.
  • a dead time period (about 1 ⁇ s to 5 ⁇ s) is provided between the first semiconductor switching element 304 and the timing at which the first semiconductor switching element 304 is turned on, that is, not exactly the same, but there is a gap of about several ⁇ s. It is included.
  • the timing for turning on the second semiconductor switching element 307 is gradually delayed.
  • the current always flows in the negative direction through the reactor 303 while the second semiconductor switching element 307 is in the ON state. Therefore, even in the modified example as shown in FIG. 12, the fluctuation of the power supplied to the load 309 is suppressed by providing a period in which the current can flow in the negative direction through the reactor 303 after the synchronous rectification state is canceled. can do.
  • the timing for canceling the synchronous rectification state is described as being the same as the timing for switching the switching cycle T20.
  • the timing for canceling the synchronous rectification state may be in the middle of the switching cycle T20, but the timing for canceling the synchronous rectification state is preferably the same as the timing for switching the switching cycle T20.
  • Embodiment 4 FIG.
  • parts different from the first to third embodiments of the present invention will be described, and description of the same or corresponding parts will be omitted.
  • the case of shifting from the asynchronous rectification state to the synchronous rectification state has been described.
  • the third embodiment of the present invention is described.
  • a case where the state is shifted from the synchronous rectification state to the asynchronous rectification state will be described.
  • the power transmission direction is bidirectional in the fourth embodiment of the present invention, as in the second embodiment of the present invention.
  • FIG. 6 is also a power conversion system 81 configured using the power conversion device 80 according to the fourth embodiment of the present invention. Therefore, in the fourth embodiment of the present invention, from the state of synchronous rectification to the state of asynchronous rectification, using the same names and symbols as those constituting the power conversion system 81 according to the second embodiment of the present invention. A case of migration will be described.
  • bidirectional operation is performed when power is transmitted from the power source 801 to the power source 809 and when power is transmitted from the power source 809 to the power source 801.
  • the direction in which current flows from the first terminal of the reactor 303 to the second terminal is referred to as the positive direction (forward direction) as in the first to third embodiments of the present invention.
  • the direction in which current flows from the second terminal to the first terminal is referred to as the negative direction (reverse direction).
  • the average value of the current flowing through reactor 303 decreases (the average value of the current flowing through reactor 303 in the negative direction).
  • the purpose is to suppress the rise).
  • the object is to obtain a power conversion device that suppresses fluctuations in the power that is supplied (transmitted) in the fourth embodiment of the present invention even when the direction in which the power is transmitted is reversed. This is the same as Embodiment 1 to Embodiment 3 of the present invention.
  • FIG. 13 is a schematic diagram illustrating a waveform of a control signal sent out by the control device 821 of the power conversion device 80 according to the fourth embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • FIG. 13 includes a switching signal waveform 13101 of the first semiconductor switching element 304, a switching signal waveform 13102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 13104, a current waveform 13103 of the reactor 303, A synchronous switching element determination signal waveform 13105 is shown.
  • the current waveform 13103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • the signal waveform and the current waveform shown in the region A5 cause the control device 821 to repeat the third switching for switching the first semiconductor switching element 304 between the third on state and the third off state, and
  • the state of synchronous rectification in which the fourth switching for switching the second semiconductor switching element 307 between the fourth on state and the fourth off state is repeated in synchronization with the third switching is shown.
  • the third on-time is shown as T31
  • the third off-time is shown as T32.
  • the switching period in FIG. 13 is shown as T30, and is one period of the third switching and the fourth switching. That is, the frequency of the first semiconductor switching element 304 and the frequency of the second semiconductor switching element 307 are equal.
  • a switching signal waveform 13102 of the second semiconductor switching element 307 is an inverted signal of the first semiconductor switching element 304.
  • FIG. 13 shows that in region A5, the average value of the current flowing through the reactor 303 within one switching cycle T30 detected by the detection device 810 is a positive value, so that power is transmitted from the power source 801 to the power source 809. 6 shows a waveform of a control signal sent out by the control device 821 and a waveform of a current flowing through the reactor 303. That is, the synchronous switching element determination signal waveform 13105 in FIG. 13 outputs 1 as the synchronous switching element determination signal 812.
  • the control device 821 when the power is supplied from the power source 801 to the power source 809, the control device 821 outputs 1 as the synchronous switching element determination signal 812, and the power source 809 This is because 0 is output as the synchronous switching element determination signal 812 when power is supplied from the power source 801 to the power source 801.
  • the state of the region A5 which is the state of synchronous rectification is shifted to the state of asynchronous rectification.
  • the first semiconductor switching element 304 and the second semiconductor are set in order to cancel the synchronous rectification state and enter the asynchronous rectification state. It is determined which switching signal waveform of the switching element 307 is to be changed.
  • the switching signal waveform of the first semiconductor switching element 304 and the second semiconductor switching element 307 is changed.
  • the synchronous switching element is the second semiconductor switching element 307
  • the asynchronous switching element is the first semiconductor switching element 304.
  • the detection device 810 of the power conversion device 80 detects the average value of the current flowing through the reactor 303 within one switching cycle T30.
  • Control device 821 transmits the average value of the current flowing through reactor 303 within one switching cycle T30 to drive device 820.
  • the driving device 820 determines which one of the first semiconductor switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element, and the first semiconductor switching element 304 and the second semiconductor switching element. It is determined which of 307 is a synchronous switching element.
  • drive device 820 also determines the direction of power supply from the average value of the current flowing through reactor 303 within one switching cycle T30.
  • the power supply direction can be determined by, for example, detecting the average value of the current flowing through the reactor 303 in one switching cycle T10 by the detector 810 and determining whether the value is positive or negative. A discrimination method may be used.
  • the instantaneous current value flowing through the reactor 303 is detected by the detector 810, and the average of the current flowing through the reactor 303 in one switching cycle T10 is detected by the control device 821 that has acquired the current value information. A value is calculated, and the power supply direction is determined depending on whether the value is positive or negative.
  • the means for determining which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element and which is a synchronous switching element is performed in the same manner as the determination of the power supply direction. .
  • the contents are not limited to those described above.
  • the second semiconductor switching element 307 that is a synchronous switching element is maintained in an off state, and the first semiconductor switching element 304 that is an asynchronous switching element is in a third on state and a third off state.
  • the third switching for switching is repeated.
  • the control device 821 of the power conversion device 80 operates when the asynchronous switching element is in the third OFF state during the transition from the state of the region A5 in FIG. 13 to the asynchronous rectification state.
  • a period (transition period) is provided in which the synchronous switching element is controlled to be in the fourth on state at a fourth on time T33 that is shorter than the third off time T32 indicating the time of three off states. That is, it indicates that the transition period is provided immediately after the state of the synchronous rectification is canceled, not the state of the asynchronous rectification immediately after the state of the synchronous rectification is canceled.
  • the fourth on-time T33 is shorter than the time obtained by subtracting the dead time period (about 1 ⁇ s to about 5 ⁇ s) from the third off-time T32.
  • the transition period is provided so that the time during which the current flows in the negative direction of the reactor 303 is created immediately after the state of the synchronous rectification is eliminated. That is, part of the time during which the current flows in the negative direction of the reactor 303 is continued following the synchronous rectification state.
  • the power conversion device 80 when the transition from the synchronous rectification state to the asynchronous rectification state is made, if a transition period as shown in FIG. 13 is provided, the current flowing through the reactor 303 within one switching cycle T30 Therefore, the power conversion device 80 according to the fourth embodiment of the present invention can suppress fluctuations in supplied (transmitted) power.
  • the fourth ON state of the second semiconductor switching element 307 that is shorter than the third OFF time T32 of the first semiconductor switching element 304 is set. It is preferable that the fourth switching for turning on the second semiconductor switching element at time T33 is performed a plurality of times. Thereby, when it transfers to the state of asynchronous rectification from the state of synchronous rectification, the raise of the average value of the electric current which flows into the reactor 30 in one switching period T30 can further be suppressed.
  • the control signal 815 of the second semiconductor switching element 307 sent out by the control device 821 has a waveform as shown in the switching signal waveform 13102 of the second semiconductor switching element 307 in FIG.
  • the fourth on-time T33 of the second semiconductor switching element 307 which is shorter than the third off-time T32 of the first semiconductor switching element 304, is gradually shortened.
  • the fourth on-time T33 of the second semiconductor switching element 307 becomes 0, the second semiconductor switching element 307 is always turned off, the transition period ends, and the state of asynchronous rectification is entered.
  • the ON signal of the first semiconductor switching element 304 and the next The ON signal of the second semiconductor switching element 307 is provided symmetrically about the center between the ON signal of the first semiconductor switching element 304 and the switching period T30.
  • the switching signal waveform 13102 of the second semiconductor switching element 307 shown in FIG. 13 can be modified as shown in FIGS.
  • FIG. 14 is a schematic diagram illustrating a waveform of a control signal sent by a modification of the control device 821 of the power conversion device 80 according to the fourth embodiment of the present invention and a waveform of a current flowing through the reactor 303.
  • a modification of the fourth embodiment of the present invention is a case where the average value of the current flowing through reactor 303 in one switching cycle T30 is a negative value, and power is transmitted from power supply 809 to power supply 801.
  • a synchronous switching element determination signal waveform 14105 is shown.
  • the current waveform 14103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
  • FIG. 13 Only differences from FIG. 13 will be described with reference to FIG
  • the signal waveform and current waveform shown in region A5 indicate the state of synchronous rectification, as in FIG. 13.
  • FIG. 14 shows that in region A5, the average value of the current flowing through the reactor 303 within one switching cycle T30 detected by the detection device 810 is a negative value, so that power is transmitted from the power source 809 to the power source 801.
  • the waveform of the control signal sent out by the control device 821 and the current waveform flowing through the reactor 303 are shown. That is, the synchronous switching element determination signal waveform 14105 in FIG. 14 outputs 0 as the synchronous switching element determination signal 812.
  • the asynchronous switching element that repeats the third switching for switching between the third on state and the third off state is the second semiconductor switching element 307.
  • the synchronous switching element that repeats the fourth switching that switches between the fourth on state and the fourth off state in synchronization with the third switching is the first semiconductor switching element 304. That is, in FIG. 14, the signal sent to the first semiconductor switching element 304 in FIG. 13 and the signal sent to the second semiconductor switching element 307 are switched.
  • the control device 821 of the power conversion device 80 also changes the state of the region A5 in FIG. 14 to the asynchronous rectification state in the modified example of the fourth exemplary embodiment of the present invention.
  • the synchronous switching element is set to the fourth ON state at a fourth ON time T33 that is shorter than the third OFF time T32 indicating the time of the third OFF state.
  • a control period (transition period) is provided. That is, it indicates that the transition period is provided immediately after the state of the synchronous rectification is canceled, not the state of the asynchronous rectification immediately after the state of the synchronous rectification is canceled.
  • the fourth on-time T33 is shorter than the time obtained by subtracting the dead time period (about 1 ⁇ s to about 5 ⁇ s) from the third off-time T32.
  • a transition period is provided immediately after the cancellation of the synchronous rectification state. Continue part of the time flowing in the direction.
  • the power conversion device 80 can suppress fluctuations in the supplied (transmitted) power.
  • various timings for turning on the first semiconductor switching element 304 can be considered.
  • the timing at which the semiconductor switching element 307 is turned off is the same.
  • the switching signal waveform 14101 of the first semiconductor switching element 304 shown in FIG. 14 can be modified like the switching signal waveform of the second semiconductor switching element 307 of FIGS.
  • the power conversion device 80 that can supply power bidirectionally, first, it is determined whether the synchronous switching element is the first semiconductor switching element 304 or the second semiconductor switching element 307. . Then, in the transition from the synchronous rectification state to the asynchronous rectification state, after the synchronous rectification state is canceled, the asynchronous switching element is switched to the third off state during the transition from the synchronous rectification state to the asynchronous rectification state. At this time, a period for controlling the synchronous switching element to be in the fourth on-state with a fourth on-time shorter than the third off-time indicating the time of the third off-state is provided. Thereby, in Embodiment 4 of this invention, the power converter device 80 which suppressed the fluctuation
  • the timing for canceling the synchronous rectification state is described as being the same as the timing for switching the switching cycle T20.
  • the timing for canceling the synchronous rectification state may be in the middle of the switching cycle T20, but the timing for canceling the synchronous rectification state is preferably the same as the timing for switching the switching cycle T20.
  • FIG. 7 to 5, FIG. 7, FIG. 8, and FIG. 10 to FIG. 14 are schematic diagrams. In FIG. 3 to FIG. 5, FIG. 7, FIG. It is omitted.
  • the first semiconductor switching element 304, the second semiconductor switching element 307, the first rectifying element 305, and the second rectifying element 306 are elements formed of a wide band gap semiconductor. When is applied, switching loss and conduction loss are further reduced. Thus, it goes without saying that the power supply of the power converter can be made more efficient.
  • wide band gap semiconductors include silicon carbide, gallium nitride-based materials, and diamond.
  • An element formed of such a wide band gap semiconductor has high voltage resistance and high allowable current density, and thus can be miniaturized.
  • a semiconductor module incorporating these elements can be miniaturized.
  • the heat resistance is also high, it is possible to reduce the size of the radiating fin and further reduce the size of the semiconductor module.
  • the power loss is low, it is possible to increase the efficiency of the characteristics of the element itself, and further increase the efficiency of the semiconductor module.
  • the embodiments can be freely combined within the scope of the invention, and the embodiments can be appropriately modified or omitted.

Abstract

A power conversion device (30) is equipped with a monolithic booster circuit that can perform a synchronous rectification. When the power conversion device (30) starts to shift from an asynchronous rectification state during which first switching is performed in which a second semiconductor switching element (307) is maintained in an off-state and a first semiconductor switching element (304) is switched between a first on-state and a first off-state to a synchronous rectification state during which second switching is performed in which the second semiconductor switching element (307) is switched between a second on-state and a second off-state in synchronization with the first switching, a control device (321) is characterized by performing control so that when the first semiconductor switching element (304) is in the first off-state in the synchronous rectification state, the second semiconductor switching element (307) is brought into the second on-state during a second on-time shorter than a first off-time indicating the time frame of the first off-state.

Description

電力変換装置Power converter
　本発明は、電力変換装置に関するものである。 The present invention relates to a power conversion device.
　電源から出力された直流電圧を値の異なる直流電圧に変換して負荷に供給する電力変換装置が有する回路の一つに、１石型昇圧回路がある。一般的な１石型昇圧回路は、回路の入力側の電圧を平滑化するための第１のコンデンサーと、エネルギーを蓄積させるためのリアクトルと、リアクトルにエネルギーを充電する際にオン状態となる第１の半導体スイッチング素子とを備えている。そして、第１の半導体スイッチング素子には、第１の半導体スイッチング素子がオフ状態となる時に第１の半導体スイッチング素子に印加される高電圧から第１の半導体スイッチング素子を保護するための第１の整流素子が逆並列に接続されている。さらに、第１の半導体スイッチング素子がオフ状態のときにリアクトルに充電されたエネルギーを出力側に放出すると共に回路の出力側からの逆流を防止する第２の整流素子と、回路の出力側の電圧を平滑化するための第２のコンデンサーとを備えている。 One stone type booster circuit is one of the circuits of a power conversion device that converts a DC voltage output from a power source into a DC voltage having a different value and supplies it to a load. A general one-stone booster circuit includes a first capacitor for smoothing the voltage on the input side of the circuit, a reactor for storing energy, and an on-state when charging the reactor with energy. 1 semiconductor switching elements. The first semiconductor switching element includes a first semiconductor switching element for protecting the first semiconductor switching element from a high voltage applied to the first semiconductor switching element when the first semiconductor switching element is turned off. Rectifier elements are connected in antiparallel. Furthermore, when the first semiconductor switching element is in the OFF state, the second rectifying element that releases the energy charged in the reactor to the output side and prevents backflow from the output side of the circuit, and the voltage on the output side of the circuit And a second capacitor for smoothing.
　このような一般的な１石型昇圧回路の第２の整流素子に、第２の半導体スイッチング素子を逆並列に接続し、第２の整流素子に電流が流れる期間に第２の半導体スイッチング素子をオン状態として第２の半導体スイッチング素子に電流を流す同期整流の動作を可能にした１石型昇圧回路がある。このような同期整流可能な１石型昇圧回路において、電源から供給される電圧が予め設定された電圧の閾値よりも高い電圧のときには、第２の半導体スイッチング素子をオフ状態に維持し、かつ第１の半導体スイッチング素子が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを行い、同期整流を行わない（この動作を非同期整流と呼ぶ。）。そして、電源から供給される電圧が予め設定された電圧の閾値よりも低いときには、第１の切り替えに同期して、第２の半導体スイッチング素子が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを行う同期整流を行う（例えば、特許文献１）。ここで、閾値電圧は、出力側からの逆流が生じないように設定されている。 The second semiconductor switching element is connected in antiparallel to the second rectifying element of such a general one-stone booster circuit, and the second semiconductor switching element is connected during a period in which current flows through the second rectifying element. There is a one-stone type booster circuit that enables a synchronous rectification operation in which a current flows through a second semiconductor switching element in an on state. In such a one-step booster circuit capable of synchronous rectification, when the voltage supplied from the power supply is higher than a preset voltage threshold, the second semiconductor switching element is maintained in the OFF state, and One semiconductor switching element performs a first switching to switch between a first on state and a first off state, and does not perform synchronous rectification (this operation is referred to as asynchronous rectification). When the voltage supplied from the power source is lower than a preset voltage threshold, the second semiconductor switching element changes between the second on state and the second off state in synchronization with the first switching. Synchronous rectification for performing the second switching is performed (for example, Patent Document 1). Here, the threshold voltage is set so that no backflow from the output side occurs.
特開２００６－１４９１２８号公報JP 2006-149128 A
　しかしながら、このような非同期整流と同期整流との切り替えを行うことがある同期整流が可能な１石型昇圧回路においては、実際には非同期整流から同期整流へ切り替える際に問題が起きることがあった。 However, in such a one-step booster circuit capable of synchronous rectification that may be switched between asynchronous rectification and synchronous rectification, there may actually be a problem when switching from asynchronous rectification to synchronous rectification. .
　第２の半導体スイッチング素子をオフ状態に維持し、かつ第１の半導体スイッチング素子が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返し、第１のオン状態の時間を示す第１のオン時間の方が第１のオフ状態の時間を示す第１のオフ時間よりも短く、リアクトルに蓄えられるエネルギーが少ない場合を考える。このとき、リアクトルに流れる電流が不連続となることがある。このリアクトルに流れる電流が不連続の場合に、非同期整流の状態から同期整流の状態へ移行すると、逆方向、すなわち負荷から電源へ向かう方向に流れてしまう電流量が多くなり、電力変換装置が負荷に供給したい電力を負荷に供給出来ていない状態が発生してしまう。つまり、電力変換装置は負荷に供給するべき電力を負荷に供給することが出来ず、電力変換装置が負荷に供給する電力に変動が発生してしまう。 The first semiconductor switching element is maintained in the off state, and the first semiconductor switching element repeats the first switching for switching between the first on state and the first off state, and the first on state time is increased. Consider a case in which the first on-time shown is shorter than the first off-time showing the time of the first off state, and less energy is stored in the reactor. At this time, the current flowing through the reactor may become discontinuous. When the current flowing through the reactor is discontinuous, the amount of current that flows in the reverse direction, that is, the direction from the load to the power source increases when the state of asynchronous rectification is shifted to the state of synchronous rectification. The state where the power to be supplied to the load cannot be supplied to the load occurs. That is, the power converter cannot supply the power to be supplied to the load, and the power supplied to the load by the power converter varies.
　本発明は、上述のような問題を解決するためになされたもので、非同期整流の状態から同期整流の状態へ移行したときに、負荷に供給する電力の変動を抑制した電力変換装置を得ることを目的とする。 The present invention has been made to solve the above-described problems, and provides a power conversion device that suppresses fluctuations in power supplied to a load when the state of asynchronous rectification is shifted to the state of synchronous rectification. With the goal.
　本発明にかかる電力変換装置は、第１の端子と第２の端子とを有し、第１の端子が電源の正極と接続されたリアクトルと、リアクトルの第２の端子と電源の負極との間に接続された第１の半導体スイッチング素子と、リアクトルの第２の端子と負荷の正側との間に接続され、第２の端子から送出された電流を負荷に送出するように整流する整流素子と、整流素子に並列に接続された第２の半導体スイッチング素子と、第１の半導体スイッチング素子及び第２の半導体スイッチング素子を駆動させる駆動信号を送出する駆動装置と、第１の半導体スイッチング素子及び第２の半導体スイッチング素子の駆動を制御する制御信号を駆動装置へ送出する制御装置とを備え、第２の半導体スイッチング素子がオフ状態に維持され、かつ第１の半導体スイッチング素子が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを行う非同期整流の状態から、第１の切り替えに同期して、第２の半導体スイッチング素子が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを行う同期整流の状態へ移行する場合に、制御装置は、同期整流の状態において第１の半導体スイッチング素子が第１のオフ状態の時に、第１のオフ状態の時間を示す第１のオフ時間よりも短い第２のオン時間で第２の半導体スイッチング素子を第２のオン状態とするように制御することを特徴とする。 The power converter according to the present invention includes a reactor having a first terminal and a second terminal, the first terminal being connected to the positive electrode of the power source, and the second terminal of the reactor and the negative electrode of the power source. A first semiconductor switching element connected between the rectifier and a rectifier connected between the second terminal of the reactor and the positive side of the load to rectify the current sent from the second terminal to the load An element, a second semiconductor switching element connected in parallel to the rectifying element, a drive device for sending a drive signal for driving the first semiconductor switching element and the second semiconductor switching element, and the first semiconductor switching element And a control device for sending a control signal for controlling the driving of the second semiconductor switching element to the driving device, wherein the second semiconductor switching device is maintained in the OFF state, and the first semiconductor The second semiconductor switching element is switched to the second ON state in synchronization with the first switching from the asynchronous rectification state in which the switching element performs the first switching to switch between the first ON state and the first OFF state. And when the first semiconductor switching element is in the first OFF state in the synchronous rectification state, the control device is configured to change the second switching state between the first semiconductor switching element and the second OFF state. The second semiconductor switching element is controlled to be in the second on state with a second on time shorter than the first off time indicating the time of one off state.
　本発明にかかる電力変換装置は、非同期整流の状態から同期整流の状態へ移行したときに、負荷に供給する電力の変動を抑制することができる。制御装置は、第２の半導体スイッチング素子のオン時間を、第１の半導体スイッチング素子のオフ時間よりも短くなるように制御しているので、電流が逆方向に流れる時間が短くなるからである。 The power conversion device according to the present invention can suppress fluctuations in the power supplied to the load when the asynchronous rectification state is shifted to the synchronous rectification state. This is because the control device controls the on-time of the second semiconductor switching element to be shorter than the off-time of the first semiconductor switching element, so that the time during which the current flows in the reverse direction is shortened.
本発明の実施の形態１にかかる電力変換装置を用いて構成された電力変換システムを示す概略図である。It is the schematic which shows the power conversion system comprised using the power converter device concerning Embodiment 1 of this invention. 本発明の実施の形態１にかかる電力変換装置が解決する課題を説明するための図である。It is a figure for demonstrating the subject which the power converter device concerning Embodiment 1 of this invention solves. 本発明の実施の形態１にかかる電力変換装置の制御装置が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the control apparatus of the power converter device concerning Embodiment 1 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態１にかかる電力変換装置の制御装置の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the modification of the control apparatus of the power converter device concerning Embodiment 1 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態１にかかる電力変換装置の制御装置の別の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which another modification of the control apparatus of the power converter device concerning Embodiment 1 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態２にかかる電力変換装置を用いて構成された電力変換システムを示す概略図である。It is the schematic which shows the power conversion system comprised using the power converter device concerning Embodiment 2 of this invention. 本発明の実施の形態２にかかる電力変換装置の制御装置が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the control apparatus of the power converter device concerning Embodiment 2 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態２にかかる電力変換装置の制御装置の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the modification of the control apparatus of the power converter device concerning Embodiment 2 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態３にかかる電力変換装置が解決する課題を説明するための図である。It is a figure for demonstrating the subject which the power converter device concerning Embodiment 3 of this invention solves. 本発明の実施の形態３にかかる電力変換装置の制御装置が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the control apparatus of the power converter device concerning Embodiment 3 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態３にかかる電力変換装置の制御装置の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the modification of the control apparatus of the power converter device concerning Embodiment 3 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態３にかかる電力変換装置の制御装置の別の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the another modification of the control apparatus of the power converter device concerning Embodiment 3 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態４にかかる電力変換装置の制御装置が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the control apparatus of the power converter device concerning Embodiment 4 of this invention sends out, and the waveform of the electric current which flows into a reactor. 本発明の実施の形態４にかかる電力変換装置の制御装置の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。It is the schematic which showed the waveform of the control signal which the modification of the control apparatus of the power converter device concerning Embodiment 4 of this invention sends out, and the waveform of the electric current which flows into a reactor.
実施の形態１．
　本発明の実施の形態１にかかる電力変換装置の構成を説明する。図１は、本発明の実施の形態１にかかる電力変換装置３０を用いて構成された電力変換システム３１を示す概略図である。図１において、本発明の実施の形態１にかかる電力変換装置３０は、電源３０１から出力された直流電圧を、昇圧して、負荷３０９に供給する電力変換システム３１を構成する。 Embodiment 1 FIG.
The structure of the power converter device concerning Embodiment 1 of this invention is demonstrated. FIG. 1 is a schematic diagram illustrating a power conversion system 31 configured using the power conversion device 30 according to the first embodiment of the present invention. In FIG. 1, the power conversion device 30 according to the first exemplary embodiment of the present invention configures a power conversion system 31 that boosts a DC voltage output from a power supply 301 and supplies the boosted DC voltage to a load 309.
　本発明の実施の形態１にかかる電力変換装置３０は、同期整流が可能な１石型昇圧回路を有する。本発明の実施の形態１にかかる電力変換装置３０は、第１のコンデンサー３０２と、第１の端子と第２の端子とを有し第１の端子が第１のコンデンサーの３０２の正側と接続されたリアクトル３０３とを有する。ここで、リアクトル３０３の第１の端子は、第１のコンデンサー３０２と接続されるので、図１において、リアクトル３０３の左端を示している。第２の端子は、リアクトル３０３の右端である。 The power conversion device 30 according to the first embodiment of the present invention has a one-stone booster circuit capable of synchronous rectification. The power conversion device 30 according to the first exemplary embodiment of the present invention includes a first capacitor 302, a first terminal, and a second terminal, and the first terminal is a positive side of the first capacitor 302. And a connected reactor 303. Here, since the 1st terminal of the reactor 303 is connected with the 1st capacitor | condenser 302, the left end of the reactor 303 is shown in FIG. The second terminal is the right end of the reactor 303.
　本発明の実施の形態１にかかる電力変換装置３０は、さらに、リアクトル３０３の第２の端子と第１のコンデンサー３０２の負側との間に接続された第１の半導体スイッチング素子３０４と、第１の半導体スイッチング素子３０４と逆並列に接続され、第１の半導体スイッチング素子３０４がオフ状態となったときに第１の半導体スイッチング素子３０４を保護する第１の整流素子３０５とを有する。すなわち、第１の半導体スイッチング素子３０４は、正端子がリアクトル３０３の第２の端子に接続し、負端子が第１のコンデンサー３０２の負側に接続している。第１の整流素子３０５は、アノード側が第１のコンデンサー３０２の負側に接続し、カソード側がリアクトル３０３の第２の端子に接続している。 The power conversion device 30 according to the first exemplary embodiment of the present invention further includes a first semiconductor switching element 304 connected between the second terminal of the reactor 303 and the negative side of the first capacitor 302, The first rectifying element 305 is connected in reverse parallel to the first semiconductor switching element 304 and protects the first semiconductor switching element 304 when the first semiconductor switching element 304 is turned off. That is, the first semiconductor switching element 304 has a positive terminal connected to the second terminal of the reactor 303 and a negative terminal connected to the negative side of the first capacitor 302. The first rectifying element 305 has an anode connected to the negative side of the first capacitor 302 and a cathode connected to the second terminal of the reactor 303.
　さらに、リアクトル３０３の第２の端子に接続され、第２の端子から送出された電流を整流する第２の整流素子３０６と、第２の整流素子３０６に逆並列に接続された第２の半導体スイッチング素子３０７と、第２の整流素子３０６によって整流された電流が流れる位置であって、第２の整流素子３０６と第１のコンデンサー３０２の負側に接続された第２のコンデンサー３０８とを有する。すなわち、第２の整流素子３０６は、アノード側がリアクトル３０３の第２の端子に接続し、カソード側が負荷３０９の正側に接続している。第２の半導体スイッチング素子３０７は、負端子がリアクトル３０３の第２の端子に接続し、正端子が第２のコンデンサー３０８の正側及び負荷３０９の正側に接続している。 Further, a second rectifier element 306 that is connected to the second terminal of the reactor 303 and rectifies the current sent from the second terminal, and a second semiconductor connected in antiparallel to the second rectifier element 306. The switching element 307 includes a second rectifying element 306 and a second capacitor 308 connected to the negative side of the first capacitor 302 at a position where the current rectified by the second rectifying element 306 flows. . That is, the second rectifying element 306 has an anode side connected to the second terminal of the reactor 303 and a cathode side connected to the positive side of the load 309. The second semiconductor switching element 307 has a negative terminal connected to the second terminal of the reactor 303 and a positive terminal connected to the positive side of the second capacitor 308 and the positive side of the load 309.
　ここで、第１のコンデンサー３０２の正側とは、図１において第１のコンデンサー３０２の上端を示している。したがって、第１のコンデンサー３０２の負側とは、図１において第１のコンデンサー３０２の下端である。なお、第２の整流素子３０６は、図１に示されているように整流方向が左から右へ向かう方向が順方向で、右から左へ向かう方向が逆方向となっている。 Here, the positive side of the first capacitor 302 indicates the upper end of the first capacitor 302 in FIG. Therefore, the negative side of the first capacitor 302 is the lower end of the first capacitor 302 in FIG. In the second rectifying element 306, as shown in FIG. 1, the direction of rectification from left to right is the forward direction, and the direction from right to left is the reverse direction.
　電源３０１は二極を有し、正極はリアクトル３０３の第１の端子と接続し、負極は第１の半導体スイッチング素子３０４と接続されている。さらに、電源３０１には、第１のコンデンサー３０２が並列に接続されている。負荷３０９は、正側に第２の整流素子３０６によって整流された電流が入力されるように接続されている。 The power supply 301 has two poles, the positive electrode is connected to the first terminal of the reactor 303, and the negative electrode is connected to the first semiconductor switching element 304. Furthermore, a first capacitor 302 is connected to the power supply 301 in parallel. The load 309 is connected so that the current rectified by the second rectifying element 306 is input to the positive side.
　本発明の実施の形態１にかかる電力変換装置３０は、上述したような構成となっている同期整流が可能な１石型昇圧回路と、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７を駆動させる駆動信号を送出する駆動装置３２０と、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７の駆動を制御する制御信号を駆動装置３２０へ送出する制御装置３２１とを備えている。 The power conversion device 30 according to the first exemplary embodiment of the present invention includes a one-stone booster circuit configured as described above and capable of synchronous rectification, a first semiconductor switching element 304, and a second semiconductor switching element. A driving device 320 for sending a driving signal for driving 307; and a control device 321 for sending a control signal for controlling the driving of the first semiconductor switching element 304 and the second semiconductor switching element 307 to the driving device 320. Yes.
　駆動装置３２０は、第１の半導体スイッチング素子３０４の制御端子に対しては、第１の半導体スイッチング素子３０４を駆動する駆動信号３１５を送出し、第２の半導体スイッチング素子３０７の制御端子に対しては、第２の半導体スイッチング素子３０７を駆動する駆動信号３１６を送出する。制御装置３２１は、第１の半導体スイッチング素子３０４を制御する制御信号３１２と、第２の半導体スイッチング素子３０７を制御する制御信号３１４と、同期整流動作切り替え信号３１３とを駆動装置３２０へ送出する。 The driving device 320 sends a driving signal 315 for driving the first semiconductor switching element 304 to the control terminal of the first semiconductor switching element 304, and sends it to the control terminal of the second semiconductor switching element 307. Sends a drive signal 316 for driving the second semiconductor switching element 307. The control device 321 sends a control signal 312 for controlling the first semiconductor switching element 304, a control signal 314 for controlling the second semiconductor switching element 307, and a synchronous rectification operation switching signal 313 to the driving device 320.
　本発明の実施の形態１にかかる電力変換装置３０は、制御装置３２１によって生成された第１の半導体スイッチング素子３０４の制御信号３１２を受けた駆動装置３２０が、第１の半導体スイッチング素子３０４のオン状態とオフ状態を切り替えることによって、電源３０１から出力された電圧よりも高い電圧を負荷３０９に出力する。 In the power conversion device 30 according to the first exemplary embodiment of the present invention, the drive device 320 that receives the control signal 312 of the first semiconductor switching element 304 generated by the control device 321 turns on the first semiconductor switching element 304. By switching between the state and the off state, a voltage higher than the voltage output from the power supply 301 is output to the load 309.
　本発明の実施の形態１にかかる電力変換装置３０は、さらに、入力側電圧検出器３１０と、出力側電圧検出器３１１とを備えている。入力側電圧検出器３１０は、第１のコンデンサー３０２の両端にかかる電圧の値を測定している。出力側電圧検出器３１１は、第２のコンデンサー３０８の両端にかかる電圧の値を測定している。 The power conversion apparatus 30 according to the first embodiment of the present invention further includes an input side voltage detector 310 and an output side voltage detector 311. The input side voltage detector 310 measures the value of the voltage applied to both ends of the first capacitor 302. The output side voltage detector 311 measures the value of the voltage applied to both ends of the second capacitor 308.
　ここで電源３０１は、本発明の実施の形態１では、直流安定化電源を使用した場合を想定して説明するが、蓄電池、太陽光電池などであってもよい。また、負荷３０９は、本発明の実施の形態１ではインバータを介した交流負荷を想定して説明するが、本発明の実施の形態１にかかる電力変換装置３０が接続される負荷３０９は、インバータを介した交流負荷に替えて、純抵抗負荷、定電力負荷などであってもよい。 Here, the power supply 301 will be described assuming that a DC stabilized power supply is used in the first embodiment of the present invention, but may be a storage battery, a solar battery, or the like. The load 309 is described assuming an AC load via an inverter in the first embodiment of the present invention, but the load 309 to which the power conversion device 30 according to the first embodiment of the present invention is connected is an inverter. A pure resistance load, a constant power load, or the like may be used instead of the AC load via the.
　第１の整流素子３０５は、第１の半導体スイッチング素子３０４がオフ状態となったときに第１の半導体スイッチング素子３０４を保護するものであるので、還流ダイオード、フリーホイールダイオード（ＦＷＤ：Ｆｒｅｅ　Ｗｈｅｅｌ　Ｄｉｏｄｅ）などと呼ばれるものである。 Since the first rectifying element 305 protects the first semiconductor switching element 304 when the first semiconductor switching element 304 is turned off, a free wheel diode (FWD: Free Wheel Diode) is used. ) Etc.
　第２の半導体スイッチング素子３０７は、本発明の実施の形態１では、双方向に電流を流すことができる金属酸化物半導体電界効果トランジスタ（ＭＯＳＦＥＴ：Ｍｅｔａｌ　Ｏｘｉｄｅ　Ｓｅｍｉｃｏｎｄｕｃｔｏｒ　Ｆｉｅｌｄ　Ｅｆｆｅｃｔ　Ｔｒａｎｓｉｓｔｏｒ）としている。これに限ることはなく、絶縁ゲート型バイポーラトランジスタ（ＩＧＢＴ：Ｉｎｓｕｌａｔｅｄ　Ｇａｔｅ　Ｂｉｐｏｌａｒ　Ｔｒａｎｓｉｓｔｏｒ）であってもよい。第２の半導体スイッチング素子３０７にＩＧＢＴを使用する場合は、ＩＧＢＴは片方向にのみ電流が流れるので、コレクタ電極側を第２のコンデンサー３０８の正側と接続する。 In the first embodiment of the present invention, the second semiconductor switching element 307 is a metal oxide semiconductor field effect transistor (MOSFET) capable of flowing a current in both directions (MOSFET: Metal Oxide Semiconductor Field Effect Transistor). However, the present invention is not limited to this, and an insulated gate bipolar transistor (IGBT: Insulated Gate Bipolar Transistor) may be used. When an IGBT is used for the second semiconductor switching element 307, the current flows in only one direction of the IGBT, so the collector electrode side is connected to the positive side of the second capacitor 308.
　第１の半導体スイッチング素子３０４は、本発明の実施の形態１では、ＭＯＳＦＥＴとしているが、ＩＧＢＴであってもよい。第１の半導体スイッチング素子３０４にＩＧＢＴを使用する場合は、ＩＧＢＴは片方向にのみ電流が流れるので、コレクタ電極側をリアクトル３０３の第２の端子と接続する。 The first semiconductor switching element 304 is a MOSFET in the first embodiment of the present invention, but may be an IGBT. When an IGBT is used for the first semiconductor switching element 304, the current flows through the IGBT only in one direction, so the collector electrode side is connected to the second terminal of the reactor 303.
　本発明の実施の形態１にかかる電力変換装置３０は、第２の半導体スイッチング素子３０７がオフ状態に維持され、かつ第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを行う非同期整流の状態から、第１の切り替えに同期して、第２の半導体スイッチング素子３０７が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを行う同期整流の状態へ移行する場合に、制御装置３２１は、同期整流の状態において第１の半導体スイッチング素子３０４を第１のオフ状態とする時に、第１のオフ状態の時間を示す第１のオフ時間よりも短い第２のオン時間で第２の半導体スイッチング素子３０７を第２のオン状態とするように制御することを特徴としている。すなわち、本発明の実施の形態１にかかる電力変換装置３０は、制御装置３２１が本発明の実施の形態１にかかる電力変換装置３０の主回路に対して送出する制御信号に特徴を有している。 In the power conversion device 30 according to the first exemplary embodiment of the present invention, the second semiconductor switching element 307 is maintained in the off state, and the first semiconductor switching element 304 is in the first on state and the first off state. The second switching in which the second semiconductor switching element 307 switches between the second on state and the second off state in synchronization with the first switching from the asynchronous rectification state in which the first switching is performed. In the case of shifting to the state of synchronous rectification to be performed, the control device 321 indicates the first off-state time when the first semiconductor switching element 304 is set to the first off state in the state of synchronous rectification. The second semiconductor switching element 307 is controlled to be in the second on state with a second on time shorter than the off time. That is, the power conversion device 30 according to the first embodiment of the present invention is characterized by the control signal that the control device 321 sends out to the main circuit of the power conversion device 30 according to the first embodiment of the present invention. Yes.
　本発明の実施の形態１にかかる電力変換装置３０は、同期整流が可能な１石型昇圧回路において、非同期整流の状態から同期整流の状態へ移行する際に起きる課題を解決する。本発明の実施の形態１にかかる電力変換装置３０についてさらに詳細な説明をする前に、まず、本発明の実施の形態１にかかる電力変換装置３０が解決するその課題について説明する。 The power conversion device 30 according to the first exemplary embodiment of the present invention solves a problem that occurs when a single-step boost circuit capable of synchronous rectification shifts from an asynchronous rectification state to a synchronous rectification state. Before describing the power conversion device 30 according to the first embodiment of the present invention in more detail, first, the problem to be solved by the power conversion device 30 according to the first embodiment of the present invention will be described.
　図２は、本発明の実施の形態１にかかる電力変換装置３０が解決する課題を説明するための図であり、比較例の電力変換装置の制御装置が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。 FIG. 2 is a diagram for explaining a problem to be solved by the power conversion device 30 according to the first exemplary embodiment of the present invention. The control signal waveform and the reactor 303 transmitted by the control device of the power conversion device of the comparative example are illustrated in FIG. It is the schematic which showed the waveform of the electric current which flows.
　本発明の実施の形態１にかかる電力変換装置３０が有する主回路と、比較例の電力変換装置が有する主回路は同じ構成であるため、構成の図示は省略する。そのため、比較例の電力変換装置が有する主回路を構成しているものも、本発明の実施の形態１にかかる電力変換装置３０が有する主回路を構成しているものと同じ名称及び符号を使用して図２を説明するが、図２は比較例の電力変換装置の制御装置が送出する制御信号の波形とリアクトルに流れる電流の波形である。 Since the main circuit included in the power conversion device 30 according to the first embodiment of the present invention and the main circuit included in the power conversion device of the comparative example have the same configuration, illustration of the configuration is omitted. Therefore, what constitutes the main circuit of the power conversion device of the comparative example uses the same name and code as those of the main circuit of the power conversion device 30 according to the first embodiment of the present invention. 2 will be described. FIG. 2 shows a waveform of a control signal sent out by the control device of the power conversion device of the comparative example and a waveform of a current flowing through the reactor.
　図２では、第１の半導体スイッチング素子３０４の駆動を制御する制御信号の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形５２０１として示されている。第２の半導体スイッチング素子３０７の駆動を制御する制御信号の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形５２０２として示されている。他に図２には、同期整流動作切り替え信号波形５２０４と、リアクトル３０３の電流波形５２０３とが示されている。リアクトル３０３の電流波形５２０３は、リアクトル３０３に流れる電流の波形を示しているが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 In FIG. 2, the waveform of the control signal for controlling the driving of the first semiconductor switching element 304 is shown as the switching signal waveform 5201 of the first semiconductor switching element 304. A waveform of a control signal that controls driving of the second semiconductor switching element 307 is shown as a switching signal waveform 5202 of the second semiconductor switching element 307. In addition, FIG. 2 shows a synchronous rectification operation switching signal waveform 5204 and a current waveform 5203 of the reactor 303. Although the current waveform 5203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　第１のオン状態の時間を示す第１のオン時間は、図２ではＴ１として示し、第１のオフ状態の時間を示す第１のオフ時間はＴ２として示す。また、図２におけるスイッチング周期は、Ｔとして示され、第１の切り替えの１周期である。図２の動作を行う比較例の電力変換装置が備える回路において、第２の半導体スイッチング素子３０７をオフ状態に維持し、かつ第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返している非同期整流の状態において、例えば、第１のオン時間Ｔ１の方が第１のオフ時間Ｔ２よりも短く、リアクトル３０３に蓄えられるエネルギーが少ない場合を考える。図２において、領域Ａ１は非同期整流を行っている状態の範囲を示しているが、領域Ａ１では、同期整流が可能な１石型昇圧回路の第１の半導体スイッチング素子３０４に対して送出されている制御信号の波形は、図２のスイッチング信号波形５２０１に示されるように、第１のオン時間Ｔ１が短いためにリアクトル３０３に蓄えられるエネルギーが少ない。第２の半導体スイッチング素子３０７をオフ状態に維持し、かつ第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを行う非同期整流の状態とは、同期整流動作切り替え信号波形５２０４がオンになる前である。 The first ON time indicating the time of the first ON state is indicated as T1 in FIG. 2, and the first OFF time indicating the time of the first OFF state is indicated as T2. Moreover, the switching period in FIG. 2 is shown as T and is one period of the first switching. In the circuit included in the power conversion device of the comparative example that performs the operation of FIG. 2, the second semiconductor switching element 307 is maintained in the off state, and the first semiconductor switching element 304 is in the first on state and the first off state. In the asynchronous rectification state in which the first switching for switching between states is repeated, for example, consider a case where the first on-time T1 is shorter than the first off-time T2 and less energy is stored in the reactor 303. . In FIG. 2, region A1 shows the range of the state where asynchronous rectification is performed. In region A1, the region A1 is sent to the first semiconductor switching element 304 of the one-stone booster circuit capable of synchronous rectification. As shown in the switching signal waveform 5201 of FIG. 2, the control signal waveform has a short energy stored in the reactor 303 because the first on-time T1 is short. The state of asynchronous rectification in which the second semiconductor switching element 307 is maintained in the off state and the first semiconductor switching element 304 performs the first switching for switching between the first on state and the first off state is: Before the synchronous rectification operation switching signal waveform 5204 is turned on.
　図２に示すように、第１のオン時間Ｔ１の方が第１のオフ時間Ｔ２よりも短く、リアクトル３０３に蓄えられるエネルギーが少ないとき、リアクトル３０３に流れる電流が、一時的に０となって電流が不連続となることがある。このように、第１のオン時間Ｔ１が第１のオフ時間Ｔ２よりも短くするなどしたことで、電流が不連続に流れる状態する動作を、不連続モードと呼ぶことにする。 As shown in FIG. 2, when the first on-time T1 is shorter than the first off-time T2 and less energy is stored in the reactor 303, the current flowing through the reactor 303 temporarily becomes zero. The current may be discontinuous. As described above, an operation in which a current flows discontinuously due to the first on-time T1 being shorter than the first off-time T2 is referred to as a discontinuous mode.
　領域Ａ１の状態では、図２の動作を行う比較例の電力変換装置は、第１の半導体スイッチング素子３０４をオン状態にしている間はリアクトル３０３にエネルギーを蓄積し、第１の半導体スイッチング素子３０４をオフ状態としている間ではリアクトル３０３に蓄えられたエネルギーを第２の整流素子３０６を通過させて負荷３０９へと供給している。このとき、第２の整流素子３０６を通過した電流によって第２の整流素子３０６で電圧降下が発生する。第２の整流素子３０６に流れる電流と電圧降下した電圧の積が第２の整流素子３０６で発生する電力損失となる。 In the state of the region A1, the power conversion device of the comparative example that performs the operation of FIG. 2 accumulates energy in the reactor 303 while the first semiconductor switching element 304 is turned on, and the first semiconductor switching element 304 Is in the off state, the energy stored in the reactor 303 is supplied to the load 309 through the second rectifying element 306. At this time, a voltage drop occurs in the second rectifier element 306 due to the current that has passed through the second rectifier element 306. The product of the current flowing through the second rectifier element 306 and the voltage that has dropped is the power loss generated in the second rectifier element 306.
　ここで、リアクトル３０３に電流が流れなくなると、第２のコンデンサー３０８の両端にかかる電圧の方が、第１のコンデンサー３０２の両端にかかる電圧よりも高くなっている。そのため、第２の半導体スイッチング素子３０７がオン状態であれば、第２のコンデンサー３０８側から第１のコンデンサー３０２側へと電流が流れる。しかしながら、領域Ａ１の状態では第２の半導体スイッチング素子３０７はオフ状態であり、かつ第２の整流素子３０６が逆方向への電流を防止しているので、第２のコンデンサー３０８側から第１のコンデンサー３０２側へと電流は流れない。したがって、第２のコンデンサー３０８から第１のコンデンサー３０２へ、すなわちリアクトル３０３の第２の端子から第１の端子へと電流が流れることはない。なお、以下では、リアクトル３０３の第１の端子から第２の端子へ電流が流れる方向を正方向（順方向）と呼び、第２の端子から第１の端子へ電流が流れる方向を負方向（逆方向）と呼ぶことにする。 Here, when no current flows through the reactor 303, the voltage applied to both ends of the second capacitor 308 is higher than the voltage applied to both ends of the first capacitor 302. Therefore, if the second semiconductor switching element 307 is in an on state, a current flows from the second capacitor 308 side to the first capacitor 302 side. However, in the state of the region A1, the second semiconductor switching element 307 is in the off state, and the second rectifier element 306 prevents the current in the reverse direction. No current flows to the capacitor 302 side. Therefore, no current flows from the second capacitor 308 to the first capacitor 302, that is, from the second terminal of the reactor 303 to the first terminal. Hereinafter, the direction in which current flows from the first terminal to the second terminal of the reactor 303 is referred to as a positive direction (forward direction), and the direction in which current flows from the second terminal to the first terminal is negative ( We will call it the reverse direction.
　領域Ａ１の非同期整流を行っている状態から、同期整流の状態へ移行する。同期整流は、同期整流動作切り替え信号がオン状態になることによって始まる。図２では、同期整流動作切り替え信号がオン状態となるタイミングと、制御装置３２１が第１の半導体スイッチング素子３０４をオン状態とするタイミングとが同じであるので、制御装置３２１が第１の半導体スイッチング素子３０４をオフ状態にする時に第２の半導体スイッチング素子３０７をオン状態とする。第１の半導体スイッチング素子３０４をオン状態にしている間はリアクトル３０３にエネルギーを蓄積し、制御装置３２１が第１の半導体スイッチング素子３０４をオフ状態とし、第２の半導体スイッチング素子３０７をオン状態とする間ではリアクトル３０３に蓄えられたエネルギーを第２の半導体スイッチング素子３０７を通過させて負荷３０９へと供給する。正方向に流れていた電流が０となると、第２のコンデンサー３０８の両端にかかる電圧の方が、第１のコンデンサー３０２の両端にかかる電圧よりも高くなっている。そのため、次は第２の半導体スイッチング素子３０７を通って負方向に電流が流れる。 Transition from the state of performing asynchronous rectification in the area A1 to the state of synchronous rectification. Synchronous rectification starts when the synchronous rectification operation switching signal is turned on. In FIG. 2, the timing at which the synchronous rectification operation switching signal is turned on is the same as the timing at which the control device 321 turns the first semiconductor switching element 304 on, so that the control device 321 performs the first semiconductor switching. When the element 304 is turned off, the second semiconductor switching element 307 is turned on. While the first semiconductor switching element 304 is in the on state, energy is stored in the reactor 303, and the control device 321 turns off the first semiconductor switching element 304 and turns on the second semiconductor switching element 307. In the meantime, the energy stored in the reactor 303 is supplied to the load 309 through the second semiconductor switching element 307. When the current flowing in the positive direction becomes zero, the voltage applied to both ends of the second capacitor 308 is higher than the voltage applied to both ends of the first capacitor 302. Therefore, next, a current flows in the negative direction through the second semiconductor switching element 307.
　第１のコンデンサー３０２に流れる電流は、リアクトル３０３を通過して流れる。したがって、第１のコンデンサー３０２への急激な電流増加は抑制される。負方向に流れる電流の増加量は、第１のコンデンサー３０２の両端の電圧の値と第２のコンデンサー３０８の両端の電圧の値とリアクトル３０３のインダクタンスの値によって決まるものである。 The current flowing through the first capacitor 302 flows through the reactor 303. Therefore, a rapid current increase to the first capacitor 302 is suppressed. The amount of increase in the current flowing in the negative direction is determined by the voltage value at both ends of the first capacitor 302, the voltage value at both ends of the second capacitor 308, and the inductance value of the reactor 303.
　その後、制御装置３２１が次のスイッチング周期Ｔで第２の半導体スイッチング素子３０７をオフ状態とし、第１の半導体スイッチング素子３０５をオン状態とすると、第２のコンデンサー３０８側から第１のコンデンサー３０２側へ電流が流れる経路は無くなる。そのため、負方向への電流増加はなくなり、負方向に流れていた電流は０となる。さらには正方向への電流となる。図２におけるリアクトル３０３の電流波形５２０３は概略図であるので、負方向に流れていた電流が０に近づいていくときの電流波形の傾きと、０から正方向へ電流が流れていくときの電流波形の傾きとを同じにして示している。しかしながら、上述したように、リアクトル３０３の電流波形５２０３は、本来はこのような直線のみで表されるものではないので、必ずしもこのように負方向に流れていた電流が０に近づいていくときの電流波形と、０から正方向へ電流が流れていくときの電流波形が同じ形状ではない。 After that, when the control device 321 turns off the second semiconductor switching element 307 and turns on the first semiconductor switching element 305 in the next switching cycle T, the second capacitor 308 side to the first capacitor 302 side There is no longer a path for current to flow. Therefore, there is no increase in current in the negative direction, and the current flowing in the negative direction becomes zero. Furthermore, the current is in the positive direction. Since the current waveform 5203 of the reactor 303 in FIG. 2 is a schematic diagram, the slope of the current waveform when the current flowing in the negative direction approaches 0 and the current when the current flows from 0 to the positive direction are shown. The waveform is shown with the same slope. However, as described above, the current waveform 5203 of the reactor 303 is not originally represented only by such a straight line, and thus the current that has flowed in the negative direction as described above is not necessarily zero. The current waveform and the current waveform when current flows from 0 to the positive direction are not the same shape.
　さらにその後、制御装置３２１が第１の半導体スイッチング素子３０４をオフ状態とし、第２の半導体スイッチング素子３０７をオン状態とすると、リアクトル３０３の正方向へ流れていた電流は０となり、負方向へ電流が流れ始める。そして、制御装置３２１が次のスイッチング周期Ｔで、再び第２の半導体スイッチング素子３０７をオフ状態とし、第１の半導体スイッチング素子３０５をオン状態とする。比較例の電力変換装置では、第２の半導体スイッチング素子３０７の制御信号は、同期整流の状態へ移行した時点から、第１の半導体スイッチング素子３０４の制御信号の反転信号である。 After that, when the control device 321 turns off the first semiconductor switching element 304 and turns on the second semiconductor switching element 307, the current flowing in the positive direction of the reactor 303 becomes 0, and the current flows in the negative direction. Begins to flow. Then, in the next switching cycle T, the control device 321 turns off the second semiconductor switching element 307 and turns on the first semiconductor switching element 305 again. In the power conversion device of the comparative example, the control signal of the second semiconductor switching element 307 is an inverted signal of the control signal of the first semiconductor switching element 304 from the time when the state is shifted to the synchronous rectification state.
　ここで、同期整流を開始した直後の２回目のスイッチング周期Ｔである領域Ｐにおけるリアクトル３０３に流れる電流の平均値を求めると、その値は、負方向に流れる電流量が多いため、負の値となる。 Here, when the average value of the current flowing through the reactor 303 in the region P that is the second switching cycle T immediately after the start of the synchronous rectification is obtained, the value is a negative value because the amount of current flowing in the negative direction is large. It becomes.
　図２における第１のオン時間Ｔ１は、リアクトル３０３に流れる電流が正方向の状態で、第１のオフ時間Ｔ２よりも短く、負荷で消費される電力分を賄うことができるように求められたものである。したがって、リアクトル３０３に流れる逆方向の電流量が多くなり、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が負の値となると、第１のオン時間Ｔ１でリアクトル３０３を充電しただけでは、負荷で消費する電力を賄うことができなくなる。 The first on-time T1 in FIG. 2 is obtained so that the current flowing through the reactor 303 is in a positive direction and is shorter than the first off-time T2 and can cover the power consumed by the load. Is. Accordingly, when the amount of current flowing in the reverse direction through the reactor 303 increases and the average value of the current flowing through the reactor 303 within one switching cycle T becomes a negative value, the reactor 303 is charged in the first on-time T1. Alone will not be able to cover the power consumed by the load.
　リアクトル３０３に流れる電流が負方向のとき、第２のコンデンサー３０８から第１のコンデンサー３０２へと電力が供給されている。１回のスイッチング周期Ｔ内にリアクトル３０３に流れる電流が負方向となるような状況が含まれていても、負荷に供給したい電力は、リアクトル３０３に流れる電流の平均値が正の値である限り、負荷に供給されている。しかしながら、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が負の値であるということは、第２のコンデンサー３０８から第１のコンデンサー３０２へと供給される電力が多く、負荷に供給したい電力が供給されていないということを表す。すなわち、図２の動作を行う比較例の電力変換装置が出力した電力の値は、領域Ｐにおいて図２の動作を行う比較例の電力変換装置が負荷に供給したい電力の値より低くなっていることになる。つまり、図２の動作を行う比較例の電力変換装置は、負荷が必要とする電力を供給出来ていないことになる。 When the current flowing through the reactor 303 is negative, power is supplied from the second capacitor 308 to the first capacitor 302. Even if a situation in which the current flowing through the reactor 303 is in the negative direction within one switching cycle T is included, as long as the average value of the current flowing through the reactor 303 is a positive value, Is being supplied to the load. However, the average value of the current flowing through the reactor 303 within one switching period T is a negative value, which means that a large amount of power is supplied from the second capacitor 308 to the first capacitor 302, and is applied to the load. This indicates that the power to be supplied is not supplied. That is, the value of the power output by the power converter of the comparative example that performs the operation of FIG. 2 is lower than the value of power that the power converter of the comparative example that performs the operation of FIG. It will be. That is, the power conversion device of the comparative example that performs the operation of FIG. 2 cannot supply the power required by the load.
　さらに、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７のスイッチング速度が低速である場合、かつ第２の半導体スイッチング素子３０７のオン時間が長い場合においては、リアクトル３０３に流れる負方向の電流が多くなってしまう。そのため、想定以上の電流が電源へ回生するということが発生したり、第１のコンデンサー３０２の両端の電圧が想定以上に大きくなったり、第２のコンデンサー３０８の両端の電圧が想定以下に小さくなったりする。その結果、図２の動作を行う比較例の電力変換装置の保護機能による動作停止など、望ましくない動作が生じてしまう可能性がある。 Furthermore, when the switching speed of the first semiconductor switching element 304 and the second semiconductor switching element 307 is low and when the ON time of the second semiconductor switching element 307 is long, the negative direction of the current flowing through the reactor 303 is reduced. The current will increase. For this reason, it may occur that a current larger than expected is regenerated to the power supply, the voltage across the first capacitor 302 becomes larger than expected, or the voltage across the second capacitor 308 becomes smaller than expected. Or As a result, there is a possibility that an undesirable operation such as an operation stop by the protection function of the power conversion device of the comparative example that performs the operation of FIG. 2 may occur.
　例えば、電源が太陽電池である場合は、負荷は電力系統や交流負荷である。太陽電池と負荷との間には、昇圧回路とインバータとを有する太陽光発電用パワーコンディショナーがあり、電力変換装置は、太陽光発電用パワーコンディショナーの昇圧回路に相当する。電源が太陽電池である場合に、電力変換装置が不連続モードになるのは、例えば、太陽電池の出力電力が低く電力変換装置に流れる電流が少ない場合や、太陽光発電用パワーコンディショナーが接続する電力系統の状態によって太陽電池の出力電力が抑制されて電力変換装置に流れる電流が少ない場合などが考えられる。太陽電池は、出力する電流が小さい場合、太陽電池の電圧が高くなる特性を持っている。電力変換装置が不連続モードになる場合は、第１のコンデンサーが太陽電池と並列に接続されているために同じように第１のコンデンサーの電圧が高くなる。 For example, when the power source is a solar battery, the load is a power system or an AC load. There is a photovoltaic power conditioner having a booster circuit and an inverter between the solar cell and the load, and the power converter corresponds to a booster circuit of the photovoltaic power conditioner. When the power source is a solar cell, the power conversion device is in the discontinuous mode, for example, when the output power of the solar cell is low and the current flowing through the power conversion device is small, or when the power conditioner for solar power generation is connected The case where the output electric power of a solar cell is suppressed by the state of an electric power system, and the electric current which flows into a power converter device is few etc. can be considered. The solar cell has a characteristic that the voltage of the solar cell increases when the output current is small. When the power conversion device is in the discontinuous mode, the voltage of the first capacitor is similarly increased because the first capacitor is connected in parallel with the solar cell.
　このとき、非同期整流の状態であれば、第２のコンデンサーから第１のコンデンサーへ流れる電流はない。しかしながら、非同期整流の状態から同期整流の状態へ移行した場合には、第１のコンデンサーへの電流の流入があり、第１のコンデンサーの電圧が上昇する。太陽電池は、電池の特性上、ある一定以上の電圧の値以上に電圧の値は上がらないため、第１のコンデンサーの電圧が、太陽電池の電圧よりも高くなった場合は、太陽電池へ電流が流入する可能性がある。 At this time, there is no current flowing from the second capacitor to the first capacitor in the asynchronous rectification state. However, when the asynchronous rectification state is changed to the synchronous rectification state, there is an inflow of current to the first capacitor, and the voltage of the first capacitor rises. Since the voltage of the solar cell does not increase beyond a certain voltage value due to the characteristics of the battery, if the voltage of the first capacitor becomes higher than the voltage of the solar cell, the current flows to the solar cell. May flow in.
　太陽電池にとって電流の逆流は非常に望ましくないため、太陽電池と直列にダイオードが挿入される場合が多いが、第１のコンデンサーの電圧の値が太陽電池の電圧よりも高い場合には、太陽光発電用パワーコンディショナーの動作を停止させるなどの保護機能が動作してしまい、電力変換装置を停止することが考えられる。 Since the reverse current of the current is very undesirable for the solar cell, a diode is often inserted in series with the solar cell. However, if the voltage value of the first capacitor is higher than the voltage of the solar cell, It is conceivable that a protective function such as stopping the operation of the power conditioner for power generation is activated and the power converter is stopped.
　また、例えば、電源が蓄電池である場合は、電力変換装置は双方向の直流－直流変換器である。電源が蓄電池である場合に、例えば蓄電池が十分に充電されている状態で、上記のような非同期整流の状態から同期整流の状態へ移行して、電流が逆流してくると、充電過多となることが考えられる。さらに、充電過多とならないように保護機能が動作して、電力変換装置を停止することも考えられる。 For example, when the power source is a storage battery, the power conversion device is a bidirectional DC-DC converter. When the power source is a storage battery, for example, when the storage battery is sufficiently charged and the current shifts from the asynchronous rectification state to the synchronous rectification state as described above and the current flows backward, overcharging occurs. It is possible. Furthermore, it is conceivable that the protection function operates so as not to overcharge and the power converter is stopped.
　図２の動作を行う比較例の電力変換装置では、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が負の値となったとき、すなわち負荷に供給したい電力の値よりも出力した電力の値の方が低くなってしまったとき、そこから制御装置が、第１のオン時間Ｔ１を、リアクトル３０３を十分に充電するために必要な第１の半導体スイッチング素子３０４のオン時間に調整していくこともある。図２の領域Ｐ以降は、制御装置が、必要な第１のオン時間Ｔ１を求めながら、第１の半導体スイッチング素子３０４のオン時間を変化させ、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が正の値となるように調整している様子を示している。 In the power conversion device of the comparative example that performs the operation of FIG. 2, when the average value of the current flowing through the reactor 303 in one switching cycle T becomes a negative value, that is, the output is larger than the value of the power that is desired to be supplied to the load. When the value of the generated power becomes lower, the control device uses the first on-time T1 as the on-time of the first semiconductor switching element 304 necessary for sufficiently charging the reactor 303. It may be adjusted. After the region P in FIG. 2, the control device changes the on-time of the first semiconductor switching element 304 while obtaining the necessary first on-time T1, and flows to the reactor 303 within one switching cycle T. It shows a state where the average value of the current is adjusted so as to be a positive value.
　しかしながら、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が負の値となっている状況をすぐに改善することは困難である。以上のように、図２の動作を行う比較例の電力変換装置では、非同期整流の状態から同期整流の状態に移行する際に、逆方向に流れる電流量が多くなり、負荷３０９に供給したい電力を負荷３０９に供給出来ていない状態が発生してしまうという課題があった。すなわち、図２の動作を行う比較例の電力変換装置は負荷３０９に供給するべき電力を負荷３０９に供給することが出来ず、図２の比較例の電力変換装置が負荷３０９に供給する電力に変動が発生してしまうという課題があった。 However, it is difficult to immediately improve the situation where the average value of the current flowing through the reactor 303 in one switching cycle T is a negative value. As described above, in the power conversion device of the comparative example that performs the operation of FIG. 2, the amount of current flowing in the reverse direction increases when shifting from the asynchronous rectification state to the synchronous rectification state, and the power to be supplied to the load 309 There is a problem that a state where the power cannot be supplied to the load 309 occurs. That is, the power converter of the comparative example that performs the operation of FIG. 2 cannot supply the power to be supplied to the load 309 to the load 309, and the power that is supplied to the load 309 by the power converter of the comparative example of FIG. There was a problem that fluctuations would occur.
　次に、以下では、本発明の実施の形態１にかかる電力変換装置３０について詳細な説明をする。本発明は、逆方向に流れる電流量を抑制した電力変換装置を得ることを目的としている。本発明の実施の形態１にかかる電力変換装置３０は、制御装置３２１が第２の半導体スイッチング素子３０７をオフ状態に維持し、かつ第１の半導体スイッチング素子３０４を第１のオン状態と第１のオフ状態とに切り替える第１の切り替えを行う非同期整流の状態から、第１の切り替えに同期して、第２の半導体スイッチング素子３０７を第２のオン状態と第２のオフ状態とに切り替える第２の切り替えを行う同期整流の状態へ移行する場合に起きる課題を解決する。 Next, the power converter 30 according to the first embodiment of the present invention will be described in detail below. An object of this invention is to obtain the power converter device which suppressed the electric current amount which flows into a reverse direction. In the power conversion device 30 according to the first exemplary embodiment of the present invention, the control device 321 maintains the second semiconductor switching element 307 in the off state, and sets the first semiconductor switching element 304 in the first on state and the first on state. The second semiconductor switching element 307 is switched from the second on-state to the second off-state in synchronization with the first switching from the asynchronous rectification state in which the first switching to the off-state is performed. The problem which arises when shifting to the state of the synchronous rectification which switches 2 is solved.
　図３は、本発明の実施の形態１にかかる電力変換装置３０の制御装置３２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図３では、第１の半導体スイッチング素子３０４の制御信号３１２の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形６２０１として示されている第２の半導体スイッチング素子３０７の制御信号３１４の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形６２０２として示されている。他に図３には、同期整流動作切り替え信号波形６２０４と、リアクトル３０３の電流波形６２０３とが示されている。リアクトル３０３の電流波形６２０３は、リアクトル３０３に流れる電流の波形を示しているが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 3 is a schematic diagram illustrating a waveform of a control signal transmitted by the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor 303. In FIG. 3, the waveform of the control signal 314 of the second semiconductor switching element 307 in which the waveform of the control signal 312 of the first semiconductor switching element 304 is shown as the switching signal waveform 6201 of the first semiconductor switching element 304 is , Shown as a switching signal waveform 6202 of the second semiconductor switching element 307. In addition, FIG. 3 shows a synchronous rectification operation switching signal waveform 6204 and a current waveform 6203 of the reactor 303. Although the current waveform 6203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　図３において、領域Ａ１に示す信号波形及び電流波形は、図２の領域Ａ１の信号波形及び電流波形と同じである。したがって、図３の領域Ａ１は、制御装置３２１が第２の半導体スイッチング素子３０７をオフ状態に維持し、かつ第１の半導体スイッチング素子３０４を第１のオン状態と第１のオフ状態とに切り替える第１の切り替えを行う非同期整流の状態を示している。この領域Ａ１の状態から、同期整流の状態へ移行する。ここで、スイッチング周期Ｔは、第２の切り替えの１周期でもある。すなわち、第１の切り替えの１周期と第２の切り替えの１周期は同じであるので、第１の半導体スイッチング素子３０４のスイッチング周波数と第２の半導体スイッチング素子３０７のスイッチング周波数は等しい。 In FIG. 3, the signal waveform and the current waveform shown in the region A1 are the same as the signal waveform and the current waveform in the region A1 in FIG. Therefore, in the region A1 of FIG. 3, the control device 321 maintains the second semiconductor switching element 307 in the off state and switches the first semiconductor switching element 304 between the first on state and the first off state. The state of asynchronous rectification for performing the first switching is shown. The state of this area A1 shifts to the state of synchronous rectification. Here, the switching period T is also one period of the second switching. That is, since one cycle of the first switching and one cycle of the second switching are the same, the switching frequency of the first semiconductor switching element 304 and the switching frequency of the second semiconductor switching element 307 are equal.
　本発明の実施の形態１にかかる電力変換装置３０の制御装置３２１は、領域Ａ１の状態から同期整流の状態へ移行する場合に、同期整流の状態において制御装置３２１が第１の半導体スイッチング素子３０４を第１のオフ状態を維持している時に、第１のオフ状態の時間を示す第１のオフ時間Ｔ２よりも短い第２のオン時間Ｔ３で第２の半導体スイッチング素子３０７を第２のオン状態とするように制御することを特徴としている。第２のオン時間Ｔ３は、第１のオフ時間Ｔ２からデッドタイム期間（１μｓから５μｓ程度）を引いた時間よりも短いものである。 When the control device 321 of the power conversion device 30 according to the first exemplary embodiment of the present invention shifts from the state of the region A1 to the synchronous rectification state, the control device 321 performs the first semiconductor switching element 304 in the synchronous rectification state. Is maintained in the first off state, the second semiconductor switching element 307 is turned on in the second on time T3 that is shorter than the first off time T2 indicating the time of the first off state. It is characterized by controlling to be in a state. The second on-time T3 is shorter than the time obtained by subtracting the dead time period (about 1 μs to 5 μs) from the first off-time T2.
　通常、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７がオン状態からオフ状態に切り替わるためには数百ｎｓ程度の時間を要する。また、オフ状態からオン状態に切り替わる場合も同様であり、制御装置３２１が第１の半導体スイッチング素子３０４をオフ状態に切り換える信号と第２の半導体スイッチング３０７をオン状態に切り替える信号を同時に出力した場合、駆動装置３２０内部の信号伝達遅延によっては第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７が同時にオン状態となる期間が発生することがある。そして、第２のコンデンサー３０８は第２の半導体スイッチング素子３０７と第１の半導体スイッチング素子３０４によって正極と負極を短絡させられることがある。この場合、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７には短絡電流が流れ、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７を破壊する恐れがある。そのため、通常、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７のオン状態とオフ状態を切り替える場合にはデッドタイム期間を設ける。 Usually, it takes about several hundreds of ns for the first semiconductor switching element 304 and the second semiconductor switching element 307 to switch from the on state to the off state. The same applies to the case of switching from the off state to the on state, where the control device 321 outputs a signal for switching the first semiconductor switching element 304 to the off state and a signal for switching the second semiconductor switching 307 to the on state at the same time. Depending on the signal transmission delay in the driving device 320, there may occur a period in which the first semiconductor switching element 304 and the second semiconductor switching element 307 are turned on simultaneously. The second capacitor 308 may be short-circuited between the positive electrode and the negative electrode by the second semiconductor switching element 307 and the first semiconductor switching element 304. In this case, a short-circuit current flows through the first semiconductor switching element 304 and the second semiconductor switching element 307, and there is a possibility that the first semiconductor switching element 304 and the second semiconductor switching element 307 are destroyed. Therefore, a dead time period is usually provided when the first semiconductor switching element 304 and the second semiconductor switching element 307 are switched between the on state and the off state.
　同期整流は、同期整流動作切り替え信号３１３がオン状態になることによって始まる。同期整流切り替え信号３１３によって同期整流が可能となったところから、第２の半導体スイッチング素子３０７をオン状態にできるようになる。 Synchronous rectification starts when the synchronous rectification operation switching signal 313 is turned on. Since the synchronous rectification is enabled by the synchronous rectification switching signal 313, the second semiconductor switching element 307 can be turned on.
　制御装置３２１が第２の半導体スイッチング素子３０７をオン状態にしている期間のみ、電流がリアクトル３０３を負方向に流れる。この期間は、本発明の実施の形態１では、第２の半導体スイッチング素子３０７のオン時間は、第１の半導体スイッチング素子３０４のオフ時間よりも短くなっている。この動作によって、本発明の実施の形態１にかかる電力変換装置３０は、電流がリアクトル３０３を逆方向に流れる量を抑制することができる。すなわち、本発明の実施の形態１にかかる電力変換装置は、負荷３０９に供給する電力の変動を抑制することができる。第１のオフ時間Ｔ２よりも短くした第２のオン時間Ｔ３で第２の半導体スイッチング素子３０７をオン状態とする第２の切り替えは複数回あることが好ましく、それによってさらに電流がリアクトル３０３を逆方向に流れる量を抑制することができる。 Only during the period when the control device 321 turns on the second semiconductor switching element 307, the current flows through the reactor 303 in the negative direction. During this period, in the first embodiment of the present invention, the on-time of the second semiconductor switching element 307 is shorter than the off-time of the first semiconductor switching element 304. By this operation, the power conversion device 30 according to the first embodiment of the present invention can suppress the amount of current flowing through the reactor 303 in the reverse direction. That is, the power conversion device according to the first embodiment of the present invention can suppress fluctuations in the power supplied to the load 309. It is preferable that the second switching to turn on the second semiconductor switching element 307 at the second on-time T3 shorter than the first off-time T2 is performed a plurality of times, so that the current further reverses the reactor 303. The amount flowing in the direction can be suppressed.
　本発明の実施の形態１では、制御装置３２１が送出する第２の半導体スイッチング素子３０７の制御信号３１４は、図３の第２の半導体スイッチング素子３０７のスイッチング信号波形６２０２に示すような波形であって、さらに、第１のオフ時間Ｔ２よりも短くした第２の半導体スイッチング素子３０７のオン時間を徐々に長くするという特徴がある。最終的には第２の半導体スイッチング素子３０７のオン時間は、第１の半導体スイッチング素子３０４の第１のオフ時間Ｔ２と同じ長さにする。すなわち、同期整流の状態に移行後の２回目以降の第２の切り替えにおける第２のオン時間を、移行後の１回目の第２の切り替えにおける第２のオン時間よりも長くする。 In the first embodiment of the present invention, the control signal 314 of the second semiconductor switching element 307 sent out by the control device 321 has a waveform as shown in the switching signal waveform 6202 of the second semiconductor switching element 307 in FIG. Further, there is a feature that the ON time of the second semiconductor switching element 307, which is shorter than the first OFF time T2, is gradually increased. Finally, the ON time of the second semiconductor switching element 307 is set to be the same length as the first OFF time T2 of the first semiconductor switching element 304. That is, the second on-time in the second and subsequent second switching after the transition to the synchronous rectification state is made longer than the second on-time in the first second switching after the transition.
　図３の第２の半導体スイッチング素子３０７のスイッチング信号波形６２０２について、さらに詳しく説明する。まず、図３に示すように、同期整流の状態に移行後の１回目の第２の切り替えにおける第２の半導体スイッチング素子３０７のオン時間を第２のオン時間Ｔ３とする。もちろん、第２のオン時間Ｔ３は、第１の半導体スイッチング素子３０４のオフ時間Ｔ２より短くなる。次のスイッチング周期Ｔ、すなわち同期整流の状態に移行後の２回目の第２の切り替えにおける第２の半導体スイッチング素子３０７のオン時間は、第２のオン時間Ｔ３よりも長いオン時間Ｔ５とする。そして、次のスイッチング周期Ｔにおける第２の半導体スイッチング素子３０７のオン時間は、オン時間Ｔ５よりも長いオン時間Ｔ７とする。さらに、次のスイッチング周期Ｔにおける第２の半導体スイッチング素子３０７のオン時間は、オン時間Ｔ７よりも長いオン時間Ｔ９とする。このようにして、第２の半導体スイッチング素子３０７のオン時間を徐々に長くし、最終的には、第１の半導体スイッチング素子３０４の第１のオフ時間Ｔ２と同じ長さにする。すなわち、最終的には、第２の半導体スイッチング素子３０７の駆動を制御する制御信号３１２は、第１の半導体スイッチング素子３０４の駆動を制御する制御信号３１４の反転信号となる。 The switching signal waveform 6202 of the second semiconductor switching element 307 in FIG. 3 will be described in more detail. First, as shown in FIG. 3, the on-time of the second semiconductor switching element 307 in the second switching for the first time after shifting to the synchronous rectification state is set as a second on-time T3. Of course, the second on-time T3 is shorter than the off-time T2 of the first semiconductor switching element 304. The on-time of the second semiconductor switching element 307 in the second switching period T, that is, the second switching after the transition to the synchronous rectification state, is an on-time T5 longer than the second on-time T3. The on-time of the second semiconductor switching element 307 in the next switching period T is an on-time T7 longer than the on-time T5. Further, the on-time of the second semiconductor switching element 307 in the next switching period T is an on-time T9 longer than the on-time T7. In this way, the ON time of the second semiconductor switching element 307 is gradually increased, and finally the same length as the first OFF time T2 of the first semiconductor switching element 304 is set. That is, finally, the control signal 312 for controlling the driving of the second semiconductor switching element 307 becomes an inverted signal of the control signal 314 for controlling the driving of the first semiconductor switching element 304.
　第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７とがオフ状態で、電流が正方向に流れるときは、電流は第２の整流素子３０６を通るため、電圧降下が大きく、電力損失が大きくなってしまう。しかしながら、図３に示したように、第１の半導体スイッチング素子３０４のオフ時間Ｔ２よりも短くした第２の半導体スイッチング素子３０７のオン時間を徐々に長くし、最終的には、第１のオフ時間Ｔ２と同じ長さにすれば、逆方向に流れる電流量を抑制することができ、かつ同期整流を行う本来の目的である電力損失を抑えることができる。第１の半導体スイッチング素子３０４も第２の半導体スイッチング素子３０７もオフ状態で、電流が正方向に流れるということが、最終的にはなくなるからである。 When the first semiconductor switching element 304 and the second semiconductor switching element 307 are in the OFF state and the current flows in the positive direction, the current flows through the second rectifier element 306, so that the voltage drop is large and the power loss is large. It gets bigger. However, as shown in FIG. 3, the ON time of the second semiconductor switching element 307, which is shorter than the OFF time T2 of the first semiconductor switching element 304, is gradually increased, and finally the first OFF If the length is the same as the time T2, the amount of current flowing in the reverse direction can be suppressed, and power loss, which is the original purpose of performing synchronous rectification, can be suppressed. This is because the first semiconductor switching element 304 and the second semiconductor switching element 307 are in the off state, and the current does not flow in the positive direction in the end.
　第２の半導体スイッチング素子３０７のオン時間を増加させる際の増加量は、回路構成や制御の応答速度によって適切な量があると考えられるが、例えば、１秒で第１の半導体スイッチング素子３０４のオフ時間Ｔ２と同じ長さまで線形的に、第２の半導体スイッチング素子３０７のオン時間を増加させる方法がある。他にも、０．５秒で２次関数的に増加させる方法なども考えられるが、これらだけに限定されるものではなく、回路に流れる電流や電圧を検出して、第２の半導体スイッチング素子３０７のオン時間を増加させている途中で、第２の半導体スイッチング素子３０７のオン時間を再度減少させることも考えられる。 The amount of increase in increasing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the circuit configuration and control response speed. There is a method of increasing the ON time of the second semiconductor switching element 307 linearly up to the same length as the OFF time T2. In addition, a method of increasing in a quadratic function in 0.5 seconds is also conceivable. However, the method is not limited thereto, and the second semiconductor switching element is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to reduce the ON time of the second semiconductor switching element 307 again while increasing the ON time of 307.
　さらに、図３に示すように、第２の半導体スイッチング素子３０７のオン状態にするタイミングは、リアクトル３０３に流れる電流が正方向に流れている間とする。特にここでは、第１の半導体スイッチング素子３０４のオン信号と、次のスイッチング周期Ｔの第１の半導体スイッチング素子３０４のオン信号との間の中央を中心に対称に、第２の半導体スイッチング素子３０７のオン信号を設けている。 Furthermore, as shown in FIG. 3, the timing for turning on the second semiconductor switching element 307 is set while the current flowing through the reactor 303 is flowing in the positive direction. In particular, here, the second semiconductor switching element 307 is symmetrical about the center between the ON signal of the first semiconductor switching element 304 and the ON signal of the first semiconductor switching element 304 in the next switching period T. ON signal is provided.
　これによって、本発明の実施の形態１にかかる電力変換装置３０は、第２の半導体スイッチング素子３０７がオンしている期間に第２の半導体スイッチング素子３０７を通る電流に、正方向の電流が含まれるので、逆方向に流れる電流量をさらに抑制することができている。 As a result, in the power conversion device 30 according to the first exemplary embodiment of the present invention, a current in the positive direction is included in the current passing through the second semiconductor switching element 307 while the second semiconductor switching element 307 is on. Therefore, the amount of current flowing in the reverse direction can be further suppressed.
　第１のオフ時間Ｔ２よりもオン時間を短くしてオン状態にしていた第２の半導体スイッチング素子３０７がオフ状態になると、次のスイッチング周期Ｔまでは、第１の半導体スイッチング素子３０４も第２の半導体スイッチング素子３０７もオフ状態である。図３に示すように、第２の半導体スイッチング素子３０７がオフ状態となるときに、リアクトル３０３に流れる電流が正方向であれば、第２の半導体スイッチング素子３０７がオフ状態となっても、リアクトル３０３に蓄えられたエネルギーは、第２の整流素子３０６を通って、電流は負荷３０９へ流れる。第２の半導体スイッチング素子３０７がオフ状態となるときに、リアクトル３０３に流れる電流が負方向であれば、その電流は、第２の半導体スイッチング素子３０７がオフ状態となったあと０となる。 When the second semiconductor switching element 307 that has been turned on by making the on time shorter than the first off time T2 is turned off, the first semiconductor switching element 304 is also in the second state until the next switching period T. The semiconductor switching element 307 is also in the off state. As shown in FIG. 3, if the current flowing through the reactor 303 is positive when the second semiconductor switching element 307 is turned off, the reactor is turned off even if the second semiconductor switching element 307 is turned off. The energy stored in 303 passes through the second rectifying element 306, and the current flows to the load 309. If the current flowing through the reactor 303 is negative when the second semiconductor switching element 307 is turned off, the current becomes 0 after the second semiconductor switching element 307 is turned off.
　図３におけるアクトル３０３の電流波形６２０３は概略波形であるが、本発明の実施の形態１にかかる電力変換装置３０が逆方向に流れる電流量を抑制できていることは分かる。すなわち、本発明の実施の形態１にかかる電力変換装置３０が負荷３０９に供給する電力の変動を抑制できていることは分かる。 3 is a schematic waveform, it can be seen that the power converter 30 according to the first embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, it turns out that the fluctuation | variation of the electric power which the power converter device 30 concerning Embodiment 1 of this invention supplies to the load 309 can be suppressed.
　図４は、本発明の実施の形態１にかかる電力変換装置３０の制御装置３２１の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。ここでは、第１の半導体スイッチング素子３０４の制御信号３１２の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形７１０１となる。第２の半導体スイッチング素子３０７制御信号３１４の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形７１０２となる。他に図４には、同期整流動作切り替え信号波形７１０４と、リアクトル３０３の電流波形７１０３とが示されている。リアクトル３０３の電流波形７１０３は、リアクトル３０３に流れる電流の波形を示しているが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 4 is a schematic diagram illustrating a waveform of a control signal transmitted by a modification of the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor. Here, the waveform of the control signal 312 of the first semiconductor switching element 304 is the switching signal waveform 7101 of the first semiconductor switching element 304. The waveform of the second semiconductor switching element 307 control signal 314 is the switching signal waveform 7102 of the second semiconductor switching element 307. In addition, FIG. 4 shows a synchronous rectification operation switching signal waveform 7104 and a current waveform 7103 of the reactor 303. Although the current waveform 7103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　図４のスイッチング信号波形７１０１は、図３のスイッチング信号波形６２０１と同じである。図４のスイッチング信号波形７１０２に関して、図３のスイッチング信号波形６２０２と異なるところのみを説明する。第２の半導体スイッチング素子３０７のスイッチング信号波形７２０２は、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、第１の半導体スイッチング素子３０４をオフ状態にするタイミングと同じである。本明細書において、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、第１の半導体スイッチング素子３０４をオフ状態にしたタイミングと同じという意味には、第２の半導体スイッチング素子３０７をオン状態にするタイミングと第１の半導体スイッチング素子３０４をオフ状態にするタイミングとの間に、デットタイム期間（１μｓから５μｓ程度）を設けた場合、すなわち、厳密に同じではなく、間が数μｓ程度空いた場合も含まれるものである。 The switching signal waveform 7101 in FIG. 4 is the same as the switching signal waveform 6201 in FIG. Only the difference between the switching signal waveform 7102 of FIG. 4 and the switching signal waveform 6202 of FIG. 3 will be described. In the switching signal waveform 7202 of the second semiconductor switching element 307, the timing at which the second semiconductor switching element 307 is turned on is the same as the timing at which the first semiconductor switching element 304 is turned off. In this specification, the second semiconductor switching element 307 is turned on in the meaning that the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off. When a dead time period (about 1 μs to 5 μs) is provided between the timing of switching and the timing of turning off the first semiconductor switching element 304, that is, they are not exactly the same, but are about several μs apart. This is also included.
　第１の半導体スイッチング素子３０４をオフ状態にしたタイミングと第２の半導体スイッチング素子３０７のオン状態にするタイミングが同じであるので、電流がリアクトル３０３を負方向に流れる場合、それは必ず、リアクトル３０３に蓄えられたエネルギーを負荷３０９へ供給する電流の流れに引き続いて行われる。 Since the timing at which the first semiconductor switching element 304 is turned off and the timing at which the second semiconductor switching element 307 is turned on are the same, when current flows through the reactor 303 in the negative direction, This is performed following the flow of current that supplies the stored energy to the load 309.
　第２の半導体スイッチング素子３０７をオン状態にする時間が徐々に長くなっていくと、電流がリアクトル３０３を負方向に流れる時間も徐々に長くなってくる。そのため、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値は、徐々に低下する。このとき、図４のようなスイッチング信号波形７１０２とすると、電流がリアクトル３０３を負方向に流れる場合は、リアクトル３０３に蓄えられたエネルギーを負荷３０９へ供給する電流の流れに引き続いて行われるので、１回のスイッチング周期Ｔ内におけるリアクトル３０３に流れる電流の平均値が低下していく割合が図３の場合に比べて小さくて済む。そのため、第２の半導体スイッチング素子３０７のスイッチング速度が高速でない場合にも適している。 As the time for turning on the second semiconductor switching element 307 is gradually increased, the time for the current to flow through the reactor 303 in the negative direction is also gradually increased. Therefore, the average value of the current flowing through the reactor 303 within one switching cycle T gradually decreases. At this time, when the switching signal waveform 7102 as shown in FIG. 4 is used, when the current flows through the reactor 303 in the negative direction, the energy stored in the reactor 303 is performed following the flow of the current supplied to the load 309. The rate at which the average value of the current flowing through the reactor 303 within one switching cycle T decreases can be smaller than in the case of FIG. Therefore, it is also suitable when the switching speed of the second semiconductor switching element 307 is not high.
　図４におけるリアクトル３０３の電流波形７１０３は概略波形であるが、本発明の実施の形態１にかかる電力変換装置３０が逆方向に流れる電流量を抑制できていることは分かる。すなわち、本発明の実施の形態１にかかる電力変換装置３０が負荷３０９に供給する電力の変動を抑制できていることは分かる。 The current waveform 7103 of the reactor 303 in FIG. 4 is a schematic waveform, but it can be seen that the power converter 30 according to the first embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, it turns out that the fluctuation | variation of the electric power which the power converter device 30 concerning Embodiment 1 of this invention supplies to the load 309 can be suppressed.
　図５は、本発明の実施の形態１にかかる電力変換装置３０の制御装置３２１の別の変形例が送出する制御信号の波形とリアクトルに流れる電流の波形を示した概略図である。ここでは、第１の半導体スイッチング素子３０４の制御信号３１２の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形７２０１となる。第２の半導体スイッチング素子３０７の制御信号３１４の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形７２０２となる。他に図５には、同期整流動作切り替え信号波形７２０４と、リアクトル３０３の電流波形７２０３とが示されている。リアクトル３０３の電流波形７２０３は、リアクトル３０３に流れる電流の波形を示しているが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 5 is a schematic diagram illustrating a waveform of a control signal sent out by another modification of the control device 321 of the power conversion device 30 according to the first embodiment of the present invention and a waveform of a current flowing through the reactor. Here, the waveform of the control signal 312 of the first semiconductor switching element 304 becomes the switching signal waveform 7201 of the first semiconductor switching element 304. The waveform of the control signal 314 of the second semiconductor switching element 307 becomes the switching signal waveform 7202 of the second semiconductor switching element 307. In addition, FIG. 5 shows a synchronous rectification operation switching signal waveform 7204 and a current waveform 7203 of the reactor 303. Although the current waveform 7203 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　図５のスイッチング信号波形７２０１は、図３のスイッチング信号波形６２０１と同じである。図５のスイッチング信号波形７２０２に関して、図３のスイッチング信号波形６２０２と異なるところのみを説明する。第２の半導体スイッチング素子３０７のスイッチング信号波形７２０２は、第２の半導体スイッチング素子３０７のオフ状態にするタイミングと第１の半導体スイッチング素子３０４をオン状態にするタイミングとが同じである。 The switching signal waveform 7201 in FIG. 5 is the same as the switching signal waveform 6201 in FIG. Only a difference between the switching signal waveform 7202 of FIG. 5 and the switching signal waveform 6202 of FIG. 3 will be described. In the switching signal waveform 7202 of the second semiconductor switching element 307, the timing for turning the second semiconductor switching element 307 off and the timing for turning the first semiconductor switching element 304 on are the same.
　図５におけるリアクトル３０３の電流波形７２０３は概略波形であるが、本発明の実施の形態１にかかる電力変換装置３０は、逆方向に流れる電流量を抑制できる。ただし、図５のような第２の半導体スイッチング素子３０７スイッチング信号波形７２０２とするときは、高速で動作する半導体スイッチング素子を第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７に用いることが望ましい。 Although the current waveform 7203 of the reactor 303 in FIG. 5 is a schematic waveform, the power conversion device 30 according to the first embodiment of the present invention can suppress the amount of current flowing in the reverse direction. However, when the second semiconductor switching element 307 has a switching signal waveform 7202 as shown in FIG. 5, a semiconductor switching element that operates at high speed is used for the first semiconductor switching element 304 and the second semiconductor switching element 307. desirable.
　本発明の実施の形態１では、同期整流を開始するタイミングはスイッチング周期Ｔが切り替わるタイミングと同じとして説明した。同期整流を開始するタイミングはスイッチング周期Ｔの途中であってもよいが、同期整流を開始するタイミングはスイッチング周期Ｔが切り替わるタイミングと同じであることが好ましい。 In the first embodiment of the present invention, the timing at which synchronous rectification is started is described as being the same as the timing at which the switching period T is switched. The timing for starting the synchronous rectification may be in the middle of the switching cycle T, but the timing for starting the synchronous rectification is preferably the same as the timing for switching the switching cycle T.
実施の形態２．
　本発明の実施の形態２では、本発明の実施の形態１と相違する部分について説明し、同一又は対応する部分についての説明は省略する。本発明の実施の形態１で示した電力変換システム３１は、同期整流可能な１石型昇圧回路の入力側に電源３０１が配置され、出力側に電力を消費する負荷３０９が配置されたものであり、電力が一方向に伝達されるものであった。本発明の実施の形態２では、一方方向ではなく双方向に電力が伝達される場合の電力変換装置及び電力変換システムについて説明する。本発明の実施の形態２にかかる電力変換装置は、本発明の実施の形態１にかかる電力変換装置３０の負荷３０９が電源８０９となっている。 Embodiment 2. FIG.
In the second embodiment of the present invention, portions that are different from the first embodiment of the present invention will be described, and descriptions of the same or corresponding portions will be omitted. In the power conversion system 31 shown in the first embodiment of the present invention, a power source 301 is disposed on the input side of a one-stone booster circuit capable of synchronous rectification, and a load 309 that consumes power is disposed on the output side. Yes, power was transmitted in one direction. In the second embodiment of the present invention, a power conversion device and a power conversion system in a case where power is transmitted bidirectionally instead of unidirectionally will be described. In the power conversion device according to the second embodiment of the present invention, the load 309 of the power conversion device 30 according to the first embodiment of the present invention is the power source 809.
　図６は、本発明の実施の形態２にかかる電力変換装置８０を用いて構成された電力変換システム８１を示す概略図である。本発明の実施の形態２にかかる電力変換装置８０が有する回路は、同期整流が可能な１石型昇圧回路であり、本発明の実施の形態１にかかる電力変換装置３０が有する回路と同じである。本発明の実施の形態２にかかる電力変換装置８０が備える回路は、電源８０１と電源８０９とに接続されている。電源８０１の一方の極は、リアクトル３０３の第１の端子と接続され、他方の極は第１の半導体スイッチング素子３０４と接続している。さらに、電源８０１には、第１のコンデンサー３０２が並列に接続されている。電源８０９は、電源８０１のリアクトル３０３の第１の端子と接続している方の極と同じ極性の極側に、第２の整流素子３０６のカソード側が接続されている。 FIG. 6 is a schematic diagram showing a power conversion system 81 configured using the power conversion device 80 according to the second embodiment of the present invention. The circuit included in the power conversion device 80 according to the second embodiment of the present invention is a one-stone booster circuit capable of synchronous rectification, and is the same as the circuit included in the power conversion device 30 according to the first embodiment of the present invention. is there. The circuit included in the power conversion device 80 according to the second embodiment of the present invention is connected to the power source 801 and the power source 809. One pole of the power source 801 is connected to the first terminal of the reactor 303, and the other pole is connected to the first semiconductor switching element 304. Further, a first capacitor 302 is connected to the power source 801 in parallel. In the power source 809, the cathode side of the second rectifier element 306 is connected to the pole side having the same polarity as the pole connected to the first terminal of the reactor 303 of the power source 801.
　本発明の実施の形態２にかかる電力変換装置８０は、その他に、１回のスイッチング周期内におけるリアクトル３０３の電流の平均値を検出する検出装置８１０と、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７を駆動させる駆動信号を送出する駆動装置８２０とを備えている。さらに、第１の半導体スイッチング素子３０４及び第２の半導体スイッチング素子３０７の駆動を制御する制御信号を駆動装置８２０へ送出する制御装置８２１とを備えている。駆動装置８２０は、第１の半導体スイッチング素子３０４の制御端子に対しては、第１の半導体スイッチング素子３０４の駆動信号８１６を送出し、第２の半導体スイッチング素子３０７の制御端子に対しては、第２の半導体スイッチング素子３０７の駆動信号８１７を送出する。 In addition, the power conversion device 80 according to the second exemplary embodiment of the present invention includes a detection device 810 that detects the average value of the current of the reactor 303 within one switching cycle, the first semiconductor switching element 304, and the second And a driving device 820 for sending a driving signal for driving the semiconductor switching element 307. Further, a control device 821 for sending a control signal for controlling driving of the first semiconductor switching element 304 and the second semiconductor switching element 307 to the driving device 820 is provided. The drive device 820 sends a drive signal 816 of the first semiconductor switching element 304 to the control terminal of the first semiconductor switching element 304, and to the control terminal of the second semiconductor switching element 307. A drive signal 817 for the second semiconductor switching element 307 is transmitted.
　制御装置８２１は、検出装置８１０によって検出された１回のスイッチング周期内におけるリアクトル３０３の電流の平均値から、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７とのうちいずれがオフ状態に維持された同期スイッチング素子であるか、及び第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７とのうちいずれが第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子であるかを判断し、同期スイッチング素子判定信号８１２を駆動装置８２０へ送出する。ここで、検出装置８１０によって検出された１回のスイッチング周期内におけるリアクトル３０３の電流の平均値が正の値のときは、電源８０１から電源８０９へと電力を供給している昇圧回路動作であって、オフ状態に維持された同期スイッチング素子は第２の半導体スイッチング素子３０７であり、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子は第１の半導体スイッチング素子３０４である。逆に、検出装置８１０によって検出された１回のスイッチング周期内におけるリアクトル３０３の電流の平均値が負の値のときは、電源８０９から電源８０１へと電力を供給している降圧回路動作であって、オフ状態に維持された同期スイッチング素子は第１の半導体スイッチング素子３０４であり、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子は第２の半導体スイッチング素子３０７である。 Control device 821 determines whether one of first semiconductor switching element 304 and second semiconductor switching element 307 is in an OFF state based on the average value of current in reactor 303 within one switching cycle detected by detection device 810. And the third switching that switches between the third on-state and the third off-state, either the first semiconductor switching element 304 or the second semiconductor switching element 307 The synchronous switching element determination signal 812 is sent to the driving device 820. Here, when the average value of the current of the reactor 303 within a single switching cycle detected by the detection device 810 is a positive value, the operation is a booster circuit supplying power from the power source 801 to the power source 809. Thus, the synchronous switching element maintained in the OFF state is the second semiconductor switching element 307, and the asynchronous switching element that performs the third switching for switching between the third ON state and the third OFF state is the first semiconductor. This is a switching element 304. On the contrary, when the average value of the current of the reactor 303 in one switching cycle detected by the detection device 810 is a negative value, it is the operation of the step-down circuit supplying power from the power source 809 to the power source 801. Thus, the synchronous switching element maintained in the OFF state is the first semiconductor switching element 304, and the asynchronous switching element that performs the third switching for switching between the third ON state and the third OFF state is the second semiconductor. This is a switching element 307.
　さらに、制御装置８２１は、第１の半導体スイッチング素子３０４の駆動を制御する制御信号８１３と、第２の半導体スイッチング素子３０７の駆動を制御する制御信号８１５と、同期整流切り替え信号８１４とを駆動装置８２０へ送出する。 Further, the control device 821 includes a control signal 813 for controlling driving of the first semiconductor switching element 304, a control signal 815 for controlling driving of the second semiconductor switching element 307, and a synchronous rectification switching signal 814. Send to 820.
　すなわち、本発明の実施の形態２にかかる電力変換装置８０は、非同期スイッチング素子が第１の半導体スイッチング素子３０４である場合は、制御装置８２１によって生成された第１の半導体スイッチング素子３０４の制御信号８１３を受けた駆動装置８２０が、第１の半導体スイッチング素子３０４のオン状態とオフ状態を切り替えることによって、電源８０１から出力された電圧よりも高い電圧を電源８０９に伝達することができる。非同期スイッチング素子が第２の半導体スイッチング素子３０７である場合は、制御装置８２１によって生成された第２の半導体スイッチング素子３０７の制御信号８１５を受けた駆動装置８２０が、第２の半導体スイッチング素子３０７のオン状態とオフ状態を切り替えることによって、電源８０９から出力された電圧よりも低い電圧を電源８０１に伝達することができる。 That is, in the power conversion device 80 according to the second exemplary embodiment of the present invention, when the asynchronous switching element is the first semiconductor switching element 304, the control signal of the first semiconductor switching element 304 generated by the control device 821. The driving device 820 that has received 813 can transmit a voltage higher than the voltage output from the power source 801 to the power source 809 by switching between the on state and the off state of the first semiconductor switching element 304. When the asynchronous switching element is the second semiconductor switching element 307, the driving device 820 that has received the control signal 815 of the second semiconductor switching element 307 generated by the control device 821 is connected to the second semiconductor switching element 307. By switching between the on state and the off state, a voltage lower than the voltage output from the power source 809 can be transmitted to the power source 801.
　本発明の実施の形態２にかかる電力変換装置８０は、本発明の実施の形態１にかかる電力変換装置３０と同様に、さらに、入力側電圧検出器３１０と、出力側電圧検出器３１１とを備えている。入力側電圧検出器３１０は、第１のコンデンサー３０２の両端にかかる電圧の値を測定している。出力側電圧検出器３１１は、第２のコンデンサー３０８の両端にかかる電圧の値を測定している。 Similar to the power conversion device 30 according to the first embodiment of the present invention, the power conversion device 80 according to the second embodiment of the present invention further includes an input side voltage detector 310 and an output side voltage detector 311. I have. The input side voltage detector 310 measures the value of the voltage applied to both ends of the first capacitor 302. The output side voltage detector 311 measures the value of the voltage applied to both ends of the second capacitor 308.
　本発明の実施の形態２では、電力が電源８０１から電源８０９へと伝達される場合と、電源８０９から電源８０１へと伝達される場合の双方向を想定している。例えば、電源８０１が蓄電池で電源８０９が直流系統のような場合は、蓄電池を充電する場合には電源８０９から電源８０１へ電力を供給する。また、蓄電池の電力を直流系統へ送る場合は、電源８０１から電源８０９へと電力を伝達する。さらに、電源８０１及び８０９が電動機兼発電機を含むような場合なども考えられる。ここでは特に電源８０１及び８０９が何かについては指定せず、電力変換装置８０に双方向に電力の流れがあることとする。また、以下でも、本発明の実施の形態１と同様に、リアクトル３０３の第１の端子から第２の端子へ電流が流れる方向を正方向（順方向）と呼び、第２の端子から第１の端子へ電流が流れる方向を負方向（逆方向）と呼ぶことにする。したがって、電力が電源８０９から電源８０１へと伝達される場合は、本発明の実施の形態１とは電流の流れる向きが逆であるので、正方向に流れる電流量を抑制することが目的となる。電流の流れる向きが逆であっても、本発明の実施の形態１も本発明の実施の形態２も供給する（伝達する）電力の変動を抑制した電力変換装置を得ることが目的である。 In the second embodiment of the present invention, it is assumed that the power is transmitted from the power source 801 to the power source 809 and bidirectional when the power is transmitted from the power source 809 to the power source 801. For example, when the power source 801 is a storage battery and the power source 809 is a DC system, power is supplied from the power source 809 to the power source 801 when the storage battery is charged. Further, when the power of the storage battery is sent to the DC system, the power is transmitted from the power source 801 to the power source 809. Furthermore, the case where the power sources 801 and 809 include an electric motor / generator may be considered. Here, it is assumed that the power sources 801 and 809 are not specified in particular and the power converter 80 has a bidirectional power flow. Also, in the following, as in the first embodiment of the present invention, the direction in which current flows from the first terminal of the reactor 303 to the second terminal is referred to as a positive direction (forward direction), and the first terminal from the second terminal The direction in which the current flows to the terminal is called the negative direction (reverse direction). Therefore, when power is transmitted from power supply 809 to power supply 801, the direction of current flow is opposite to that of Embodiment 1 of the present invention, and therefore the object is to suppress the amount of current flowing in the positive direction. . It is an object to obtain a power conversion device that suppresses fluctuations in the power supplied (transmitted) by both the first embodiment and the second embodiment of the present invention even when the direction of current flow is reversed.
　図７は、本発明の実施の形態２にかかる電力変換装置８０の制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図７において、領域Ａ２に示す信号波形及び電流波形は、制御装置８２１が第２の半導体スイッチング素子３０７をオフ状態に維持し、かつ第１の半導体スイッチング素子３０４を第３のオン状態と第３のオフ状態とに切り替える第３の切り替えを行う非同期整流の状態を示している。そして、第３のオン状態の時間を第３のオン時間Ｔ１１、第３のオフ状態の時間を第３のオフ時間Ｔ１２としている。ここで、リアクトル３０３に流れる電流は不連続であり、第３のオン時間Ｔ１１よりも第３のオフ時間Ｔ１２の方が長い。また、図７におけるスイッチング周期は、Ｔ１０として示され、第３の切り替えの１周期である。この領域Ａ２の状態から、同期整流の状態へ移行する。 FIG. 7 is a schematic diagram showing the waveform of the control signal sent out by the control device 821 of the power conversion device 80 according to the second embodiment of the present invention and the waveform of the current flowing through the reactor 303. In FIG. 7, the signal waveform and the current waveform shown in the region A <b> 2 indicate that the control device 821 keeps the second semiconductor switching element 307 in the off state and the first semiconductor switching element 304 in the third on state and the third on state. The state of the asynchronous rectification which performs the 3rd switching switched to an OFF state is shown. The third on-state time is defined as a third on-time T11, and the third off-state time is defined as a third off-time T12. Here, the current flowing through the reactor 303 is discontinuous, and the third off time T12 is longer than the third on time T11. Moreover, the switching period in FIG. 7 is indicated as T10 and is one period of the third switching. The state of this area A2 shifts to the state of synchronous rectification.
　図７は、領域Ａ２において、検出装置８１０によって検出された１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値が正の値であり、電源８０１から電源８０９へ電力を伝達しているときの制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示している。ここでは、検出装置８１０によって検出された１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値から、電力の供給方向を制御装置８２１で判断し、それを同期スイッチング素子判定信号８１２によって駆動装置８２０に送ることとしている。 In FIG. 7, in the region A2, the average value of the current flowing through the reactor 303 within one switching period T10 detected by the detection device 810 is a positive value, and power is transmitted from the power source 801 to the power source 809. The waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 are shown. Here, the control device 821 determines the power supply direction from the average value of the current flowing through the reactor 303 within one switching cycle T10 detected by the detection device 810, and this is driven by the synchronous switching element determination signal 812. To the device 820.
　電源８０１から電源８０９へ電力を供給しているとき、同期整流の状態へ移行する前に、オフ状態に維持されている同期スイッチング素子は第２の半導体スイッチング素子３０７であり、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子は第１の半導体スイッチング素子３０４である。 When power is supplied from the power source 801 to the power source 809, the synchronous switching element maintained in the OFF state before the transition to the synchronous rectification state is the second semiconductor switching element 307, and the third ON state The first switching element 304 is the asynchronous switching element that performs the third switching to switch between the first semiconductor switching element 304 and the third OFF state.
　例えば、電源８０１から電源８０９へ電力を供給している場合には、同期スイッチング素子判定信号８１２として１を出力し、電源８０９から電源８０１へ電力を供給している場合には、同期スイッチング素子判定信号８１２として０を出力するなどして判別結果を伝達させることができる。判別結果を伝達することによって、駆動装置８２０は、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれがオフ状態に維持された同期スイッチング素子であるか、及び第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれが第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子であるかが分かる。電力の供給方向の判別は、例えば、本発明の実施の形態２のように、検出器８１０によって１回のスイッチング周期Ｔ１０におけるリアクトル３０３に流れる電流の平均値を検出し、その値が正か負かによって判断することができるが、この限りではない。検出器８１０によってリアクトル３０３に流れる瞬時の電流値を検出し、その電流値情報を取得した制御装置８２１で１回のスイッチング周期Ｔ１０におけるリアクトル３０３に流れる電流の平均値を算出し、その値が正か負かによって電力の供給方向を判別するなどしてもよい。 For example, when power is supplied from the power source 801 to the power source 809, 1 is output as the synchronous switching element determination signal 812, and when power is supplied from the power source 809 to the power source 801, the synchronous switching element determination is performed. The determination result can be transmitted by outputting 0 as the signal 812. By transmitting the determination result, the driving device 820 determines which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is a synchronous switching element maintained in an off state, and the first semiconductor It can be seen which of the switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element that performs a third switching to switch between a third on state and a third off state. For example, as in the second embodiment of the present invention, the power supply direction is determined by detecting the average value of the current flowing through the reactor 303 in one switching cycle T10 by the detector 810, and the value is positive or negative. However, this is not a limitation. The instantaneous current value flowing through the reactor 303 is detected by the detector 810, and the control device 821 that has acquired the current value information calculates the average value of the current flowing through the reactor 303 in one switching cycle T10. The direction of power supply may be determined based on whether the power is negative or negative.
　本発明の実施の形態２にかかる電力変換装置８０の制御装置８２１は、同期整流の状態へ移行する前、すなわち領域Ａ２の状態のときに、検出装置８１０によって検出された１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値から、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれがオフ状態に維持された同期スイッチング素子であるか、及び第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれが第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子であるかを判断する。そして、同期スイッチング素子がオフ状態に維持され、かつ非同期スイッチング素子が第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期整流の状態から、第３の切り替えに同期して、同期スイッチング素子が第４のオン状態と第４のオフ状態とを切り替える第４の切り替えを行う同期整流の状態へ移行する場合に、制御装置８２１は、同期整流の状態における非同期スイッチング素子が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間Ｔ１２よりも短い第４のオン時間Ｔ１３で同期スイッチング素子を第４のオン状態とするように制御することを特徴としている。ここで、第４の切り替えの１周期もＴ１０である。すなわち、第３の切り替えの１周期と第４の切り替えの１周期は同じであるので、同期スイッチング素子のスイッチング周波数と非同期スイッチング素子のスイッチング周波数は等しい。 The control device 821 of the power conversion device 80 according to the second exemplary embodiment of the present invention has one switching cycle T10 detected by the detection device 810 before shifting to the synchronous rectification state, that is, in the state of the region A2. Which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is a synchronous switching element maintained in the OFF state, and the first semiconductor switching It is determined which of the element 304 and the second semiconductor switching element 307 is an asynchronous switching element that performs the third switching for switching between the third on state and the third off state. Then, the synchronous switching element is maintained in the OFF state, and the asynchronous switching element is synchronized with the third switching from the asynchronous rectification state in which the third switching is performed to switch between the third ON state and the third OFF state. Thus, when the synchronous switching element shifts to the synchronous rectification state in which the fourth switching for switching between the fourth on state and the fourth off state is performed, the control device 821 has the asynchronous switching element in the synchronous rectification state. Controlling the synchronous switching element to be in the fourth on state at a fourth on time T13 that is shorter than the third off time T12 indicating the time of the third off state in the third off state. It is a feature. Here, one cycle of the fourth switching is also T10. That is, since one cycle of the third switching is the same as one cycle of the fourth switching, the switching frequency of the synchronous switching element and the switching frequency of the asynchronous switching element are equal.
　図７では、第１の半導体スイッチング素子３０４の制御信号８１３の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形９１０１として示される。第２の半導体スイッチング素子３０７の制御信号８１５の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形９１０２として示されている。他に図７には、同期整流動作切り替え信号波形９１０４と、リアクトル３０３の電流波形９１０３、同期スイッチング素子判定信号波形９１０５とが示される。リアクトル３０３の電流波形７１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。ここで例えば、電源８０１から電源８０９へ電力を供給している場合には、同期スイッチング素子判定信号８１２に１を出力することにしているので、同期スイッチング素子判定信号波形９１０５は、図７に示すような直線となっている。 7, the waveform of the control signal 813 of the first semiconductor switching element 304 is shown as the switching signal waveform 9101 of the first semiconductor switching element 304. The waveform of the control signal 815 of the second semiconductor switching element 307 is shown as the switching signal waveform 9102 of the second semiconductor switching element 307. In addition, FIG. 7 shows a synchronous rectification operation switching signal waveform 9104, a current waveform 9103 of the reactor 303, and a synchronous switching element determination signal waveform 9105. Although the current waveform 7103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line. Here, for example, when power is being supplied from the power source 801 to the power source 809, 1 is output to the synchronous switching element determination signal 812. Therefore, the synchronous switching element determination signal waveform 9105 is shown in FIG. It is a straight line like this.
　本発明の実施の形態２にかかる電力変換装置８０の制御装置８２１は、領域Ａ２の状態から同期整流の状態へ移行する場合に、第１の半導体スイッチング素子３０４が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間Ｔ１２よりも短い第４のオン時間Ｔ１３で第２の半導体スイッチング素子３０７を第４のオン状態とするように制御することを特徴としている。第４のオン時間Ｔ１３は、第３のオフ時間Ｔ１２からデッドタイム期間（１μｓから５μｓ程度）を引いた時間よりも短いものである。 When the control device 821 of the power conversion device 80 according to the second exemplary embodiment of the present invention shifts from the state of the region A2 to the synchronous rectification state, when the first semiconductor switching element 304 is in the third OFF state, The second semiconductor switching element 307 is controlled to be in the fourth on state at the fourth on time T13 that is shorter than the third off time T12 indicating the time of the third off state. The fourth on-time T13 is shorter than the time obtained by subtracting the dead time period (about 1 μs to about 5 μs) from the third off-time T12.
　同期整流は、同期整流動作切り替え信号８１４がオン状態になることによって始まる。同期整流切り替え信号８１４によって同期整流が可能となったところから、第２の半導体スイッチング素子３０７をオン状態にできるようになる。 Synchronous rectification starts when the synchronous rectification operation switching signal 814 is turned on. Since the synchronous rectification is enabled by the synchronous rectification switching signal 814, the second semiconductor switching element 307 can be turned on.
　第２の半導体スイッチング素子３０７をオン状態にしている期間のみ、電流がリアクトル３０３を負方向に流れる。この期間は、本発明の実施の形態２では、第１の半導体スイッチング素子３０４のオフ時間よりも短くなっている。これにより、本発明の実施の形態２にかかる電力変換装置８０は、電流がリアクトル３０３を逆方向に流れる量を抑制することができる。すなわち、電源８０１から電源８０９へ電力を供給する場合、本発明の実施の形態２にかかる電力変換装置８０は、電源８０９に供給する電力の変動を抑制することができる。第３のオフ時間Ｔ１２よりも短くした第４のオン時間Ｔ１３で第２の半導体スイッチング素子３０７をオン状態とする第４の切り替えは複数回あることが好ましく、それによってさらに電流がリアクトル３０３を逆方向に流れる量を抑制することができる。 Only during the period when the second semiconductor switching element 307 is in the ON state, the current flows through the reactor 303 in the negative direction. This period is shorter than the off time of the first semiconductor switching element 304 in the second embodiment of the present invention. Thereby, the power converter device 80 concerning Embodiment 2 of this invention can suppress the quantity which an electric current flows through the reactor 303 to a reverse direction. That is, when power is supplied from the power source 801 to the power source 809, the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 809. It is preferable that the fourth switching for turning on the second semiconductor switching element 307 at the fourth on-time T13 shorter than the third off-time T12 is performed a plurality of times, so that the current further reverses the reactor 303. The amount flowing in the direction can be suppressed.
　本発明の実施の形態２では、制御装置８２１が送出する第２の半導体スイッチング素子３０７の制御信号８１５は、図７の第２の半導体スイッチング素子３０７のスイッチング信号波形９１０２に示すような波形であって、さらに、第１の半導体スイッチング素子３０４のオフ時間Ｔ１２よりも短くした第２の半導体スイッチング素子３０７のオン時間を徐々に長くするという特徴がある。最終的には第２の半導体スイッチング素子３０７のオン時間は、第１の半導体スイッチング素子３０４のオフ時間Ｔ１２と同じ長さにする。すなわち、同期整流の状態に移行後の２回目以降の第４の切り替えにおける第４のオン時間を、移行後の１回目の第４の切り替えにおける第４のオン時間よりも長くする。 In the second embodiment of the present invention, the control signal 815 of the second semiconductor switching element 307 sent out by the control device 821 has a waveform as shown in the switching signal waveform 9102 of the second semiconductor switching element 307 in FIG. Further, there is a feature that the ON time of the second semiconductor switching element 307, which is shorter than the OFF time T12 of the first semiconductor switching element 304, is gradually increased. Finally, the ON time of the second semiconductor switching element 307 is set to be the same as the OFF time T12 of the first semiconductor switching element 304. That is, the fourth on time in the fourth switching after the second time after the transition to the synchronous rectification state is made longer than the fourth on time in the first fourth switching after the transition.
　図７の第２の半導体スイッチング素子３０７のスイッチング信号波形９１０２について、さらに詳しく説明する。まず、図７に示すように、同期整流の状態に移行後の１回目の第２の切り替えにおける第２の半導体スイッチング素子３０７のオン時間を第４のオン時間Ｔ１３とする。もちろん、第４のオン時間Ｔ１３は、第１の半導体スイッチング素子３０４の第３のオフ時間Ｔ１２より短くなる。次のスイッチング周期Ｔ１０、すなわち同期整流の状態に移行後の２回目の第２の切り替えにおける第２の半導体スイッチング素子３０７のオン時間は、第４のオン時間Ｔ１３よりも長いオン時間Ｔ１５とする。そして、また次のスイッチング周期Ｔ１０における第２の半導体スイッチング素子３０７のオン時間は、オン時間Ｔ１５よりも長いオン時間Ｔ１７とする。さらに、また次のスイッチング周期Ｔ１０における第２の半導体スイッチング素子３０７のオン時間は、オン時間Ｔ１７よりも長いオン時間Ｔ１９とする。このようにして、第２の半導体スイッチング素子３０７のオン時間を徐々に長くし、最終的には、第１の半導体スイッチング素子３０４の第１のオフ時間Ｔ１２と同じ長さにする。すなわち、最終的には、第２の半導体スイッチング素子３０７の制御信号８１５は、第１の半導体スイッチング素子３０４の制御信号８１２の反転信号となる。 The switching signal waveform 9102 of the second semiconductor switching element 307 in FIG. 7 will be described in more detail. First, as shown in FIG. 7, the on-time of the second semiconductor switching element 307 in the second switching for the first time after shifting to the synchronous rectification state is set as a fourth on-time T13. Of course, the fourth on-time T13 is shorter than the third off-time T12 of the first semiconductor switching element 304. The on-time of the second semiconductor switching element 307 in the second switching period T10, that is, the second switching after the transition to the synchronous rectification state, is an on-time T15 longer than the fourth on-time T13. The on-time of the second semiconductor switching element 307 in the next switching period T10 is an on-time T17 longer than the on-time T15. Furthermore, the on-time of the second semiconductor switching element 307 in the next switching period T10 is an on-time T19 longer than the on-time T17. In this way, the ON time of the second semiconductor switching element 307 is gradually increased, and finally the same length as the first OFF time T12 of the first semiconductor switching element 304 is set. That is, finally, the control signal 815 of the second semiconductor switching element 307 becomes an inverted signal of the control signal 812 of the first semiconductor switching element 304.
　第１の半導体スイッチング素子３０４も第２の半導体スイッチング素子３０７もオフ状態で、電流が正方向に流れるときは、電流は第２の整流素子３０６を通るため、電圧降下が大きく、電力損失が大きくなってしまう。しかしながら、図７に示したように、第３のオフ時間Ｔ１２よりも短くした第２の半導体スイッチング素子３０７のオン時間を徐々に長くし、最終的には、第３のオフ時間Ｔ１２と同じ長さにすれば、逆方向に流れる電流量を抑制することができ、かつ同期整流を行う本来の目的である電力損失を抑えることができる。第１の半導体スイッチング素子３０４も第２の半導体スイッチング素子３０７もオフ状態で、電流が正方向に流れるということが、最終的にはなくなるからである。 When both the first semiconductor switching element 304 and the second semiconductor switching element 307 are in the OFF state and the current flows in the positive direction, the current flows through the second rectifier element 306, so that the voltage drop is large and the power loss is large. turn into. However, as shown in FIG. 7, the on-time of the second semiconductor switching element 307, which is shorter than the third off-time T12, is gradually lengthened, and finally the same length as the third off-time T12. By so doing, it is possible to suppress the amount of current flowing in the reverse direction and to suppress power loss that is the original purpose of performing synchronous rectification. This is because the first semiconductor switching element 304 and the second semiconductor switching element 307 are in the off state, and the current does not flow in the positive direction in the end.
　第２の半導体スイッチング素子３０７のオン時間を増加させる際の増加量は、回路構成制御の応答速度によって適切な量があると考えられるが、例えば、１秒で第１の半導体スイッチング素子３０４の第３のオフ時間Ｔ１２と同じ長さまで線形的に増加させる方法がある。他にも、０．５秒で２次関数的に増加させる方法なども考えられるが、これらだけに限定されるものではなく、回路に流れる電流や電圧を検出して、第２の半導体スイッチング素子３０７のオン時間を増加させている途中で、第２の半導体スイッチング素子３０７のオン時間を再度減少させることも考えられる。 The amount of increase in increasing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the response speed of the circuit configuration control. For example, the first semiconductor switching element 304 can be increased in one second. There is a method of increasing linearly up to the same length as the off time T12 of 3. In addition, a method of increasing in a quadratic function in 0.5 seconds is also conceivable. However, the method is not limited thereto, and the second semiconductor switching element is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to reduce the ON time of the second semiconductor switching element 307 again while increasing the ON time of 307.
　第２の半導体スイッチング素子３０７のスイッチング信号波形７２０２は、第２の半導体スイッチング素子３０７のオン状態にするタイミングが、第１の半導体スイッチング素子３０４をオフ状態にするタイミングと同じである。第１の半導体スイッチング素子３０４をオフ状態にするタイミングと第２の半導体スイッチング素子３０７のオン状態にするタイミングが同じであるので、電流がリアクトル３０３を負方向に流れる場合、それは必ず、リアクトル３０３に蓄えられたエネルギーを電源８０９へ供給する電流の流れに引き続いて行われる。 In the switching signal waveform 7202 of the second semiconductor switching element 307, the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off. Since the timing at which the first semiconductor switching element 304 is turned off and the timing at which the second semiconductor switching element 307 is turned on are the same, when current flows in the reactor 303 in the negative direction, This is performed following the flow of current for supplying the stored energy to the power source 809.
　第２の半導体スイッチング素子３０７をオン状態にする時間が徐々に長くなっていくと、電流がリアクトル３０３を負方向に流れる時間も徐々に長くなってくる。そのため、１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値は、徐々に低下する。このとき、図７のような第２の半導体スイッチング素子３０７スイッチング信号波形９１０２とすると、電流がリアクトル３０３を負方向に流れる場合は、リアクトル３０３に蓄えられたエネルギーを電源８０９へ供給する電流の流れに引き続いて行われるので、１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値が低下していく割合を小さくすることができる。そのため、第２の半導体スイッチング素子３０７のスイッチング速度が高速でない場合にも適している。 As the time for turning on the second semiconductor switching element 307 is gradually increased, the time for the current to flow through the reactor 303 in the negative direction is also gradually increased. Therefore, the average value of the current flowing through reactor 303 within one switching cycle T10 gradually decreases. At this time, when the second semiconductor switching element 307 switching signal waveform 9102 as shown in FIG. 7 is used, when the current flows through the reactor 303 in the negative direction, the current flow for supplying the energy stored in the reactor 303 to the power source 809. Therefore, the rate at which the average value of the current flowing through the reactor 303 in one switching cycle T10 decreases can be reduced. Therefore, it is also suitable when the switching speed of the second semiconductor switching element 307 is not high.
　図７におけるアクトル３０３の電流波形９１０３は概略波形であるが、本発明の実施の形態２にかかる電力変換装置８０が逆方向に流れる電流量を抑制できていることは分かる。つまり、電源８０１から電源８０９へ電力を供給する場合、本発明の実施の形態２にかかる電力変換装置８０は、電源８０９に供給する電力の変動を抑制することができていることは分かる。 7 is a schematic waveform, it can be seen that the power converter 80 according to the second embodiment of the present invention can suppress the amount of current flowing in the reverse direction. That is, when power is supplied from the power source 801 to the power source 809, it can be seen that the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 809.
　図７で示している制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形は、本発明の実施の形態１における図４と特徴部分は変わらない。これは、電源８０１から電源８０９へ電力を伝達しているとき、非同期整流の状態で、オフ状態に維持されている同期スイッチング素子は第２の半導体スイッチング素子３０７であり、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子は第１の半導体スイッチング素子３０４であるからである。したがって、図７は、図４に同期スイッチング素子判定信号波形９１０５が加わったものと同様である。図７に示した第２の半導体スイッチング素子３０７のスイッチング信号波形９１０２を、図３及び図５のように変形することも可能である。 7 is the same as FIG. 4 in the first embodiment of the present invention in the waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 shown in FIG. This is because when the power is transmitted from the power source 801 to the power source 809, the synchronous switching element maintained in the off state in the asynchronous rectification state is the second semiconductor switching element 307, and the third on state This is because the asynchronous switching element that performs the third switching for switching to the third OFF state is the first semiconductor switching element 304. Accordingly, FIG. 7 is the same as FIG. 4 with the addition of the synchronous switching element determination signal waveform 9105. The switching signal waveform 9102 of the second semiconductor switching element 307 shown in FIG. 7 can be modified as shown in FIGS.
　図８は、本発明の実施の形態２にかかる電力変換装置８０の制御装置８２１の変形例が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図８において、領域Ａ３に示す信号波形及び電流波形は、第１の半導体スイッチング素子３０４がオフ状態に維持され、かつ第２の半導体スイッチング素子３０７が第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期整流の状態を示す。そして、第３のオン状態の時間を第３のオン時間Ｔ１１、第３のオフ状態の時間を第３のオフ時間Ｔ１２としている。ここで、リアクトル３０３に流れる電流は不連続であり、第３のオン時間Ｔ１１よりも第３のオフ時間Ｔ１２の方が長い。この領域Ａ３の状態から、同期整流の状態へ移行する。図８は、領域Ａ３において、１回のスイッチング周期Ｔ１０内におけるリアクトル３０３に流れる電流の平均値が負の値であり、電源８０９から電源８０１へ電力を伝達しているときの制御装置８２１が送出する制御信号の波形とリアクトルに流れる電流の波形を示す。 FIG. 8 is a schematic diagram showing a waveform of a control signal sent out by a modification of the control device 821 of the power conversion device 80 according to the second embodiment of the present invention and a waveform of a current flowing through the reactor 303. In FIG. 8, the signal waveform and the current waveform shown in the region A3 indicate that the first semiconductor switching element 304 is maintained in the off state, and the second semiconductor switching element 307 is in the third on state and the third off state. The state of the asynchronous rectification which performs the 3rd switching which switches is shown. The third on-state time is defined as a third on-time T11, and the third off-state time is defined as a third off-time T12. Here, the current flowing through the reactor 303 is discontinuous, and the third off time T12 is longer than the third on time T11. The state of this area A3 shifts to the state of synchronous rectification. FIG. 8 shows that in the region A3, the average value of the current flowing through the reactor 303 in one switching cycle T10 is a negative value, and the control device 821 sends power from the power source 809 to the power source 801. The waveform of the control signal to be performed and the waveform of the current flowing through the reactor are shown.
　図８では、第１の半導体スイッチング素子３０４の制御信号８１３の波形が、第１の半導体スイッチング素子３０４のスイッチング信号波形９２０１として示される。第２の半導体スイッチング素子３０７の制御信号８１５の波形は、第２の半導体スイッチング素子３０７のスイッチング信号波形９２０２として示される。他に図８には、同期整流動作切り替え信号波形９２０４と、リアクトル３０３の電流波形９２０３、同期スイッチング素子判定信号波形９２０５とが示されている。リアクトル３０３の電流波形９１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。ここで例えば、電源８０９から電源８０１へ電力を供給している場合には、同期スイッチング素子判定信号８１２に０を出力することにしているので、同期スイッチング素子判定信号波形９１０５は、図８に示すような直線となっている。 8, the waveform of the control signal 813 of the first semiconductor switching element 304 is shown as the switching signal waveform 9201 of the first semiconductor switching element 304. The waveform of the control signal 815 of the second semiconductor switching element 307 is shown as the switching signal waveform 9202 of the second semiconductor switching element 307. In addition, FIG. 8 shows a synchronous rectification operation switching signal waveform 9204, a current waveform 9203 of the reactor 303, and a synchronous switching element determination signal waveform 9205. Although the current waveform 9103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line. Here, for example, when power is supplied from the power source 809 to the power source 801, 0 is output to the synchronous switching element determination signal 812. Therefore, the synchronous switching element determination signal waveform 9105 is shown in FIG. It is a straight line like this.
　電源８０９から電源８０１へ電力を供給しているとき、同期整流の状態へ移行する前に、オフ状態に維持されている同期スイッチング素子は第１の半導体スイッチング素子３０４であり、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子は第２の半導体スイッチング素子３０７である。したがって、図８では、図７において第１の半導体スイッチング素子３０４に対して送出していた信号と、第２の半導体スイッチング素子３０７に対して送出していた信号とが入れ替わる。 When power is supplied from the power source 809 to the power source 801, the synchronous switching element maintained in the OFF state before the transition to the synchronous rectification state is the first semiconductor switching element 304, and the third ON state The second semiconductor switching element 307 is the asynchronous switching element that performs the third switching to switch between the third semiconductor switching element 307 and the third OFF state. Therefore, in FIG. 8, the signal sent to the first semiconductor switching element 304 in FIG. 7 and the signal sent to the second semiconductor switching element 307 are interchanged.
　図８の第１の半導体スイッチング素子３０４のスイッチング信号波形９２０１に関して、図７の第２の半導体スイッチング素子３０７のスイッチング信号波形９１０２と異なるところのみを説明する。図８に示すように、第１の半導体スイッチング素子３０４のオン信号は、第２の半導体スイッチング素子３０７のオン信号と、次のスイッチング周期Ｔ１０の第２の半導体スイッチング素子３０７のオン信号との間の中央、すなわち、第２の半導体スイッチング素子３０７のオフ信号の中央に設けている。 Only the difference between the switching signal waveform 9201 of the first semiconductor switching element 304 in FIG. 8 and the switching signal waveform 9102 of the second semiconductor switching element 307 in FIG. 7 will be described. As shown in FIG. 8, the ON signal of the first semiconductor switching element 304 is between the ON signal of the second semiconductor switching element 307 and the ON signal of the second semiconductor switching element 307 in the next switching period T10. At the center of the off signal of the second semiconductor switching element 307.
　図８において、第２の半導体スイッチング素子３０７をオン状態にしてリアクトル３０３にエネルギーを蓄積しているとき、リアクトル３０３に蓄積したエネルギーを電源３０１へ伝達しているとき、及び第２の半導体スイッチング素子３０７がオン状態でリアクトル３０３に負方向の電流が流れるとき、これらのときのリアクトル３０３の電流波形６２０３の傾きも、必ずしも図３に図示した傾きではない。図８は、概略図であるが、本発明の実施の形態２にかかる電力変換装置８０は、電源８０９から電源８０１へ電力を伝達するとき、正方向に流れる電流量を抑制できていることは分かる。つまり、電源８０９から電源８０１へ電力を供給する場合、本発明の実施の形態２にかかる電力変換装置８０は、電源８０１に供給する電力の変動を抑制することができていることは分かる。 In FIG. 8, when the second semiconductor switching element 307 is turned on to store energy in the reactor 303, when the energy stored in the reactor 303 is transmitted to the power supply 301, and the second semiconductor switching element When a current in the negative direction flows through the reactor 303 when 307 is on, the slope of the current waveform 6203 of the reactor 303 at this time is not necessarily the slope shown in FIG. Although FIG. 8 is a schematic diagram, the power conversion device 80 according to the second exemplary embodiment of the present invention can suppress the amount of current flowing in the positive direction when transmitting power from the power source 809 to the power source 801. I understand. That is, when power is supplied from the power source 809 to the power source 801, it can be seen that the power conversion device 80 according to the second embodiment of the present invention can suppress fluctuations in the power supplied to the power source 801.
　図８で示している制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形は、電源３０１から電源３０９へ電力を伝達しているときのものであるので、第１の半導体スイッチング素子３０４に対して送出していた信号と、第２の半導体スイッチング素子３０７に対して送出していた信号とが入れ替わるものであり、本発明の実施の形態１における図３と特徴部分は変わらない。図３に同期スイッチング素子判定信号波形９１０５が加わり、第１の半導体スイッチング素子３０４に対して送出していた信号と、第２の半導体スイッチング素子３０７に対して送出していた信号とを入れ替えたのみである。図８に示した第１の半導体スイッチング素子３０４のスイッチング信号波形９２０１を、図４及び図５の第２の半導体スイッチング素子３０７のスイッチング信号波形のように変形することも可能である。 Since the waveform of the control signal sent out by the control device 821 and the waveform of the current flowing through the reactor 303 shown in FIG. 8 are those when power is transmitted from the power supply 301 to the power supply 309, the first semiconductor switching is performed. The signal transmitted to the element 304 and the signal transmitted to the second semiconductor switching element 307 are interchanged, and the characteristic portion is not different from FIG. 3 in the first embodiment of the present invention. . The synchronous switching element determination signal waveform 9105 is added to FIG. 3, and only the signal sent to the first semiconductor switching element 304 and the signal sent to the second semiconductor switching element 307 are replaced. It is. The switching signal waveform 9201 of the first semiconductor switching element 304 shown in FIG. 8 can be modified like the switching signal waveform of the second semiconductor switching element 307 of FIGS.
　以上のように、双方向に電力を供給することが出来る電力変換装置８０においても、同期スイッチング素子が第１の半導体スイッチング素子３０４であるか第２の半導体スイッチング素子３０７であるかを見極め、非同期整流の状態から同期整流の状態へ移行する場合に、非同期スイッチング素子が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間よりも短い第４のオン時間で同期スイッチング素子を第４のオン状態とするように制御することで、逆方向に流れる電流量を抑制することができる。すなわち、本発明の実施の形態２では、供給する電力の変動を抑制した電力変換装置８０を得ることができる。 As described above, also in the power conversion device 80 that can supply power bidirectionally, it is determined whether the synchronous switching element is the first semiconductor switching element 304 or the second semiconductor switching element 307, and is asynchronous. When shifting from the rectification state to the synchronous rectification state, when the asynchronous switching element is in the third OFF state, it is synchronized with a fourth ON time shorter than the third OFF time indicating the time of the third OFF state. By controlling the switching element to be in the fourth ON state, the amount of current flowing in the reverse direction can be suppressed. That is, in Embodiment 2 of the present invention, it is possible to obtain a power conversion device 80 that suppresses fluctuations in supplied power.
　本発明の実施の形態２では、同期整流を開始するタイミングはスイッチング周期Ｔ１０が切り替わるタイミングと同じとして説明した。同期整流を開始するタイミングはスイッチング周期Ｔ１０の途中であってもよいが、同期整流を開始するタイミングはスイッチング周期Ｔ１０が切り替わるタイミングと同じであることが好ましい。 In the second embodiment of the present invention, the timing for starting the synchronous rectification is described as being the same as the timing for switching the switching cycle T10. The timing for starting the synchronous rectification may be in the middle of the switching cycle T10, but the timing for starting the synchronous rectification is preferably the same as the timing for switching the switching cycle T10.
実施の形態３．
　本発明の実施の形態３では、本発明の実施の形態１及び本発明の実施の形態２と相違する部分について説明し、同一又は対応する部分についての説明は省略する。本発明の実施の形態１及び本発明の実施の形態２では、非同期整流の状態から同期整流の状態へ移行する場合について説明したが、本発明の実施の形態３では同期整流の状態から非同期整流の状態へ移行する場合について説明する。電力の伝達方向は、本発明の実施の形態３では本発明の実施の形態１と同様に、一方向である。 Embodiment 3 FIG.
In the third embodiment of the present invention, portions that are different from the first embodiment of the present invention and the second embodiment of the present invention will be described, and description of the same or corresponding portions will be omitted. In the first embodiment and the second embodiment of the present invention, the case of shifting from the asynchronous rectification state to the synchronous rectification state has been described, but in the third embodiment of the present invention, the asynchronous rectification state is changed to the asynchronous rectification state. A case of shifting to the state will be described. The power transmission direction is one direction in the third embodiment of the present invention, as in the first embodiment of the present invention.
　本発明の実施の形態３では、本発明の実施の形態１で示した電力変換システム３１と同じ図１の電力変換システム３１が使用される。したがって、図１は、本発明の実施の形態３にかかる電力変換装置３０を用いて構成された電力変換システム３１でもある。そのため、本発明の実施の形態３では、本発明の実施の形態１にかかる電力変換システム３１を構成している物と同じ名称及び符号を使用して、同期整流の状態から非同期整流の状態へ移行する場合について説明する。 In the third embodiment of the present invention, the same power conversion system 31 of FIG. 1 as the power conversion system 31 shown in the first embodiment of the present invention is used. Therefore, FIG. 1 is also a power conversion system 31 configured using the power conversion device 30 according to the third embodiment of the present invention. Therefore, in the third embodiment of the present invention, from the state of synchronous rectification to the state of asynchronous rectification, using the same names and symbols as those constituting the power conversion system 31 according to the first embodiment of the present invention. A case of migration will be described.
　本発明の実施の形態３にかかる電力変換装置３０は、同期整流が可能な１石型昇圧回路において、同期整流の状態から非同期整流の状態へ移行する際に起きる課題を解決する。まず、本発明の実施の形態３にかかる電力変換装置３０が解決する課題について説明する。 The power conversion device 30 according to the third embodiment of the present invention solves a problem that occurs when a single rectifier booster circuit capable of synchronous rectification shifts from a synchronous rectification state to an asynchronous rectification state. First, the problem which the power converter device 30 concerning Embodiment 3 of this invention solves is demonstrated.
　図９は、本発明の実施の形態３にかかる電力変換装置３０が解決する課題を説明するための図であり、比較例の電力変換装置の制御装置が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。なお以下では、本発明の実施の形態１にかかる電力変換システム３１を構成している物と同じ名称及び符号を使用して説明する。図９には、第１の半導体スイッチング素子３０４のスイッチング信号波形８１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形８１０２と、同期整流動作切り替え信号波形８１０４と、リアクトル３０３の電流波形８１０３とが示される。リアクトル３０３の電流波形８１０３は、リアクトル３０３に流れる電流の波形を示しているが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 9 is a diagram for explaining a problem to be solved by the power conversion device 30 according to the third embodiment of the present invention. The control signal waveform and the reactor 303 sent out by the control device of the power conversion device of the comparative example are shown in FIG. It is the schematic which showed the waveform of the electric current which flows. In addition, below, it demonstrates using the same name and code | symbol as the thing which comprises the power conversion system 31 concerning Embodiment 1 of this invention. FIG. 9 shows a switching signal waveform 8101 of the first semiconductor switching element 304, a switching signal waveform 8102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 8104, and a current waveform 8103 of the reactor 303. Indicated. Although the current waveform 8103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　図９の領域Ａ４は、第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返し、かつ第２の半導体スイッチング素子３０７が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを繰り返す同期整流の状態を示す。図９の領域Ａ４より先は、第２の半導体スイッチング素子３０７がオフ状態に維持され、かつ第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返す非同期整流の状態を示す。図９の動作を行う比較例の電力変換装置では、同期整流動作切り替え信号３１３がオフ状態になると、第２の半導体スイッチング素子３０７がオフ状態に維持され、かつ第１の半導体スイッチング素子３０４が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返す非同期整流の状態になる。 Region A4 in FIG. 9 repeats the first switching in which the first semiconductor switching element 304 switches between the first on-state and the first off-state, and the second semiconductor switching element 307 is in the second on-state. And a synchronous rectification state in which the second switching for switching between the second off state and the second off state is repeated. Prior to the region A4 in FIG. 9, the first semiconductor switching element 307 is maintained in the OFF state, and the first switching is performed so that the first semiconductor switching element 304 switches between the first ON state and the first OFF state. Shows the state of asynchronous rectification. In the power conversion device of the comparative example that performs the operation of FIG. 9, when the synchronous rectification operation switching signal 313 is turned off, the second semiconductor switching element 307 is maintained in the off state, and the first semiconductor switching element 304 is in the first state. Asynchronous rectification is performed by repeating the first switching for switching between the ON state of 1 and the first OFF state.
　図９では第１のオン時間はＴ２１として示し、第１のオフ時間はＴ２２として示す。また、図９におけるスイッチング周期は、Ｔ２０として示され、第１の半導体スイッチング素子３０４の第１の切り替え及び第２の半導体スイッチング素子３０７の第２の切り替えの１周期である。つまり、第１の半導体スイッチング素子３０４のスイッチング周波数と第２の半導体スイッチング素子３０７のスイッチング周波数は等しい。同期整流の状態において、第２の半導体スイッチング素子３０７のスイッチング信号波形８１０２は、第１の半導体スイッチング素子３０４の反転信号である。 In FIG. 9, the first on-time is indicated as T21, and the first off-time is indicated as T22. Further, the switching period in FIG. 9 is indicated as T20 and is one period of the first switching of the first semiconductor switching element 304 and the second switching of the second semiconductor switching element 307. That is, the switching frequency of the first semiconductor switching element 304 and the switching frequency of the second semiconductor switching element 307 are equal. In the state of synchronous rectification, the switching signal waveform 8102 of the second semiconductor switching element 307 is an inverted signal of the first semiconductor switching element 304.
　図９の動作を行う比較例の電力変換装置において、例えば、第１の半導体スイッチング素子３０４の第１のオン時間Ｔ２１の方が第１のオフ時間Ｔ２２よりも短く、リアクトル３０３に蓄えられるエネルギーが少ない場合を考える。図９の領域Ａ４では、第１の半導体スイッチング素子３０４がオン状態の間に、リアクトル３０３に流れる電流は正方向に増加し、第１の半導体スイッチング素子３０４をオフ状態にすると、リアクトル３０３に流れる電流は減少し０となる。図９の領域Ａ４では、リアクトル３０３に流れる電流が０となった時、第２の半導体スイッチング素子３０７がオン状態であるので、リアクトル３０３に流れる電流は、そのまま負方向に流れる。図９の領域Ａ４では、１回のスイッチング周期Ｔ２０の間に、リアクトル３０３に流れる電流は、正方向と負方向の双方に流れる期間があるが、図９では、電力を電源３０１から負荷３０９へと供給しているので、第１の切り替えの１周期の間にリアクトル３０３に流れる電流の平均値は正である。 In the power conversion device of the comparative example that performs the operation of FIG. 9, for example, the first on-time T21 of the first semiconductor switching element 304 is shorter than the first off-time T22, and the energy stored in the reactor 303 is Consider the case of few. In the region A4 of FIG. 9, the current flowing through the reactor 303 increases in the positive direction while the first semiconductor switching element 304 is on, and flows into the reactor 303 when the first semiconductor switching element 304 is turned off. The current decreases and becomes zero. In the region A4 of FIG. 9, when the current flowing through the reactor 303 becomes 0, the second semiconductor switching element 307 is in the on state, so the current flowing through the reactor 303 flows in the negative direction as it is. In the region A4 in FIG. 9, there is a period in which the current flowing through the reactor 303 flows in both the positive direction and the negative direction during one switching cycle T20. In FIG. 9, power is supplied from the power source 301 to the load 309. Therefore, the average value of the current flowing through the reactor 303 during one cycle of the first switching is positive.
　ここで、図９の動作を行う比較例の電力変換装置において、第２の半導体スイッチング素子３０７がオフ状態となるタイミングで同期整流動作切り替え信号３１３がオフ状態になるとする。すなわち、同期整流の状態から非同期整流の状態に移行する。非同期整流の状態に移行後も、第１の半導体スイッチング素子３０４がオフ状態になってからリアクトル３０３に流れる電流は減少し０となるまでは、リアクトル３０３に流れる電流は同期整流の状態のときと同様である。しかしながら、非同期整流の状態では、第２の半導体スイッチング素子３０７が常にオフ状態であるので、電流がリアクトル３０３を負方向に流れる経路が無い。そのため、第１の半導体スイッチング素子３０４がオフ状態となった後、減少し０となったリアクトル３０３に流れる電流は、一時的に０のままとなり、リアクトル３０３に流れる電流が不連続となることがある。 Here, in the power conversion device of the comparative example that performs the operation of FIG. 9, it is assumed that the synchronous rectification operation switching signal 313 is turned off at the timing when the second semiconductor switching element 307 is turned off. That is, the state is shifted from the synchronous rectification state to the asynchronous rectification state. Even after the transition to the asynchronous rectification state, the current flowing through the reactor 303 remains in the synchronous rectification state until the current flowing through the reactor 303 decreases to zero after the first semiconductor switching element 304 is turned off. It is the same. However, in the asynchronous rectification state, since the second semiconductor switching element 307 is always in the off state, there is no path for current to flow through the reactor 303 in the negative direction. For this reason, after the first semiconductor switching element 304 is turned off, the current flowing through the reactor 303 that has decreased to 0 remains temporarily 0, and the current flowing through the reactor 303 may become discontinuous. is there.
　図９の領域Ａ４では、制御装置が、１回のスイッチング周期Ｔ２０内においてリアクトル３０３に電流が負方向に流れる期間があることを前提に、第１の半導体スイッチング素子３０４の必要な第１のオン時間Ｔ２１を決定していた。しかしながら、同期整流の状態を解消した直後は、電流はリアクトル３０３を負方向に流れないため、第１の半導体スイッチング素子３０４に、同期整流の状態を解消する直前と同じ時間の第１のオン時間Ｔ２１を設けると、リアクトル３０３に流れる１回のスイッチング周期Ｔ２０における電流の平均値が想定よりも増加してしまう。その結果、想定以上の電流を負荷３０９へ供給することが発生したり、負荷３０９の電圧が増加したりしてしまい、保護機能が動作して、図９の比較例の電力変換装置が停止する可能性がある。 In the region A4 of FIG. 9, the control device requires the first on-state of the first semiconductor switching element 304 on the assumption that there is a period in which the current flows through the reactor 303 in the negative direction within one switching cycle T20. Time T21 was determined. However, since the current does not flow negatively through the reactor 303 immediately after canceling the synchronous rectification state, the first on-time of the first semiconductor switching element 304 is the same as that immediately before canceling the synchronous rectification state. If T21 is provided, the average value of the current in one switching cycle T20 flowing through the reactor 303 will increase more than expected. As a result, a current greater than expected may be supplied to the load 309 or the voltage of the load 309 increases, the protection function operates, and the power conversion device of the comparative example in FIG. 9 stops. there is a possibility.
　もちろん、本発明の実施の形態１で説明したように、１回のスイッチング周期Ｔ２０内におけるリアクトル３０３に流れる電流の平均値が想定よりも増加したとき、すなわち負荷３０９に供給したい電力の値よりも出力した電力が高くなってしまったとき、そこから制御装置が、第１のオン時間Ｔ２１を、本来必要な第１の半導体スイッチング素子３０４のオン時間に調整していくこともある。しかしながら、このような１回のスイッチング周期Ｔ２０内におけるリアクトル３０３に流れる電流の平均値が想定よりも増加した状況をすぐに改善することは困難である。 Of course, as described in the first embodiment of the present invention, when the average value of the current flowing through the reactor 303 within one switching cycle T20 is larger than expected, that is, more than the value of the electric power to be supplied to the load 309. When the output power becomes high, the control device may adjust the first on-time T21 to the originally required on-time of the first semiconductor switching element 304 from there. However, it is difficult to immediately improve the situation in which the average value of the current flowing through the reactor 303 within the single switching period T20 has increased more than expected.
　以上のように、同期整流の状態から非同期整流の状態に移行する場合においても、１回のスイッチング周期Ｔ２０内における正方向の電流量が多くなり、想定以上の電流を負荷３０９へ供給することが発生してしまうという課題があった。そのため、図９の動作を行う比較例の電力変換装置は負荷３０９に供給すべき電力を負荷３０９に供給することが出来ず、図９の動作を行う比較例の電力変換装置が負荷３０９に供給する電力に変動が発生してしまうという課題があった。 As described above, even in the case of shifting from the synchronous rectification state to the asynchronous rectification state, the amount of current in the positive direction within one switching cycle T20 increases, and a current larger than expected can be supplied to the load 309. There was a problem that it would occur. Therefore, the power conversion device of the comparative example that performs the operation of FIG. 9 cannot supply the load 309 with the power to be supplied to the load 309, and the power conversion device of the comparative example that performs the operation of FIG. There is a problem that fluctuations occur in the power to be generated.
　次に、本発明の実施の形態３にかかる電力変換装置３０について説明する。図１０は、本発明の実施の形態３にかかる電力変換装置３０の制御装置３２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図１０には、第１の半導体スイッチング素子３０４のスイッチング信号波形１０１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形１０１０２と、同期整流動作切り替え信号波形１０１０４と、リアクトル３０３の電流波形６２０３とが示される。リアクトル３０３の電流波形１０１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。図１０において領域A４に示す信号波形及び電流波形は図９の領域Ａ４の信号波形及び電流波形と同じである。 Next, the power conversion device 30 according to the third embodiment of the present invention will be described. FIG. 10 is a schematic diagram illustrating a waveform of a control signal sent out by the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303. FIG. 10 shows a switching signal waveform 10101 of the first semiconductor switching element 304, a switching signal waveform 10102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 10104, and a current waveform 6203 of the reactor 303. Indicated. Although the current waveform 10103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line. In FIG. 10, the signal waveform and current waveform shown in region A4 are the same as the signal waveform and current waveform in region A4 in FIG.
　この領域Ａ４の状態から、非同期整流の状態へ移行する。本発明の実施の形態３にかかる電力変換装置３０の制御装置３２１は、図１０の領域Ａ４の状態から非同期整流の状態へ移行する間に、第１の半導体スイッチング素子３０４が第１のオフ状態の時に、第１のオフ状態の時間を示す第１のオフ時間Ｔ２２よりも短い第２のオン時間Ｔ２３で第２の半導体スイッチング素子３０７を第２のオン状態とするように制御する期間を設ける。つまり、本発明の実施の形態３では、同期整流の状態を解消した後すぐに非同期整流の状態とするのではなく、同期整流の状態を解消した直後に、同期整流の状態から非同期整流の状態へと移行する期間（以下、移行期間と呼ぶ。）が設けられる。ここで、第２のオン時間Ｔ２３は、第１のオフ時間Ｔ２２からデッドタイム期間（１μｓから５μｓ程度）を引いた時間よりも短いものである。 [Transition from the state of this area A4 to the state of asynchronous rectification. In the control device 321 of the power conversion device 30 according to the third exemplary embodiment of the present invention, the first semiconductor switching element 304 is in the first OFF state during the transition from the state of the region A4 in FIG. 10 to the asynchronous rectification state. At this time, there is provided a period for controlling the second semiconductor switching element 307 to be in the second on state at the second on time T23 shorter than the first off time T22 indicating the time of the first off state. . In other words, in the third embodiment of the present invention, the state of asynchronous rectification is changed from the state of synchronous rectification to the state of asynchronous rectification immediately after the state of synchronous rectification is canceled, instead of the state of asynchronous rectification immediately after the state of synchronous rectification is eliminated. A period for shifting to (hereinafter referred to as a transition period) is provided. Here, the second on-time T23 is shorter than the time obtained by subtracting the dead time period (about 1 μs to 5 μs) from the first off-time T22.
　同期整流の状態を解消した直後から第２の半導体スイッチング素子３０７を常時オフ状態にするのではなく、同期整流の状態を解消した直後に移行期間を設けることによって、同期整流の状態に引き続いて、電流がリアクトル３０３の負方向に流れる時間を一部継続させる。 Instead of always turning off the second semiconductor switching element 307 immediately after canceling the state of synchronous rectification, following the state of synchronous rectification by providing a transition period immediately after canceling the state of synchronous rectification, Part of the time during which the current flows in the negative direction of reactor 303 is continued.
　同期整流の状態を解消した後すぐに非同期整流の状態にすると、１回のスイッチング周期Ｔ２０内におけるリアクトル３０３に流れる電流の平均値は、同期整流の状態を解消する前よりも急激に上昇する。一方、同期整流の状態から非同期整流の状態へ移行する場合に、本発明の実施の形態３のような移行期間を設けると、１回のスイッチング周期Ｔ２０内におけるリアクトル３０３に流れる電流の平均値の上昇を抑制することができる。同期整流の状態を解消しても、電流がリアクトル３０３の負方向に流れる時間を一部継続してから、非同期整流の状態となるからである。よって、本発明の実施の形態３にかかる電力変換装置３０は、供給する電力の変動を抑制することができる。 When the state of asynchronous rectification is made immediately after the state of synchronous rectification is eliminated, the average value of the current flowing through the reactor 303 within one switching cycle T20 increases more rapidly than before the state of synchronous rectification is eliminated. On the other hand, when shifting from the state of synchronous rectification to the state of asynchronous rectification, if a transition period as in the third embodiment of the present invention is provided, the average value of the current flowing through the reactor 303 in one switching cycle T20 The rise can be suppressed. This is because even if the state of the synchronous rectification is eliminated, the state where the current flows in the negative direction of the reactor 303 is partially continued before the state of the asynchronous rectification is entered. Therefore, the power conversion device 30 according to the third embodiment of the present invention can suppress fluctuations in the supplied power.
　移行期間において、第１の半導体スイッチング素子３０４が第１のオフ状態の時に、第１の半導体スイッチング素子３０４の第１のオフ時間Ｔ２２よりも短くした第２の半導体スイッチング素子の第２のオン時間Ｔ２３で第２の半導体スイッチング素子をオン状態とする第２の切り替えは複数回あることが好ましい。これにより、同期整流の状態から非同期整流の状態へ移行するときに、１回のスイッチング周期Ｔ２０内におけるリアクトル３０に流れる電流の平均値の上昇をさらに抑制することができる。 In the transition period, when the first semiconductor switching element 304 is in the first OFF state, the second ON time of the second semiconductor switching element that is shorter than the first OFF time T22 of the first semiconductor switching element 304 It is preferable that the second switching for turning on the second semiconductor switching element at T23 is performed a plurality of times. Thereby, when it transfers to the state of asynchronous rectification from the state of synchronous rectification, the raise of the average value of the electric current which flows into the reactor 30 in one switching period T20 can further be suppressed.
　本発明の実施の形態３では、制御装置３２１が送出する第２の半導体スイッチング素子３０７の制御信号３１４は、図１０に示すような移行期間において、第２の半導体スイッチング素子３０７の第２のオン時間Ｔ２３を徐々に短くする。最終的には、第２の半導体スイッチング素子３０７の第２オン時間Ｔ２３は０となり、第２の半導体スイッチング素子３０７が常にオフ状態となって、移行期間が終了し、非同期整流の状態となる。 In the third embodiment of the present invention, the control signal 314 of the second semiconductor switching element 307 sent out by the control device 321 is the second on-state of the second semiconductor switching element 307 in the transition period as shown in FIG. The time T23 is gradually shortened. Eventually, the second on-time T23 of the second semiconductor switching element 307 becomes 0, the second semiconductor switching element 307 is always turned off, the transition period ends, and the state of asynchronous rectification is entered.
　第２の半導体スイッチング素子３０７のオン時間を減少させる際の変化量は、回路構成や制御の応答速度によって適切な量があると考えられるが、例えば、１ｓで第２の半導体スイッチング素子３０７を常にオフ状態とする非同期整流の状態まで線形的に、第２の半導体スイッチング素子３０７のオン時間を減少させる方法がある。他にも、０．５ｓで２次関数的に減少させる方法なども考えられるが、これらだけに限定されるものではなく、回路に流れる電流や電圧を検出して、第２の半導体スイッチング素子３０７のオン時間を減少させている途中で、第２の半導体スイッチング素子３０７のオン時間を再度増加させることも考えられる。 The amount of change when reducing the on-time of the second semiconductor switching element 307 is considered to be an appropriate amount depending on the circuit configuration and control response speed. For example, the second semiconductor switching element 307 is always set in 1 s. There is a method in which the on-time of the second semiconductor switching element 307 is linearly reduced to the state of asynchronous rectification to be turned off. In addition, a method of reducing it by a quadratic function at 0.5 s is also conceivable. However, the method is not limited to these, and the second semiconductor switching element 307 is detected by detecting the current and voltage flowing in the circuit. It is also conceivable to increase the on-time of the second semiconductor switching element 307 again while the on-time is being reduced.
　さらに、図１０に示すように、第２の半導体スイッチング素子３０７のオン状態にするタイミングも種々考えられ、例えば第２の半導体スイッチング素子３０７のオン状態とするタイミングを遅らせ、かつオフ状態とするタイミングを同じだけ早める方法がある。特に本発明の実施の形態３では、第１の半導体スイッチング素子３０４のオン信号と、次のスイッチング周期Ｔ２０の第１の半導体スイッチング素子３０４のオン信号との間の中央を中心に対称に、第２の半導体スイッチング素子３０７のオン信号を設ける。 Furthermore, as shown in FIG. 10, there are various timings for turning on the second semiconductor switching element 307. For example, the timing for turning on the second semiconductor switching element 307 is delayed and the timing at which the second semiconductor switching element 307 is turned off. There is a way to speed up as much. In particular, in the third embodiment of the present invention, the first semiconductor switching element 304 is turned on symmetrically around the center between the ON signal of the first semiconductor switching element 304 and the ON signal of the first semiconductor switching element 304 in the next switching period T20. An ON signal of the second semiconductor switching element 307 is provided.
　また、本発明の実施の形態３では、図１０に示すように、同期整流の状態を解消した後、第２の半導体スイッチング素子３０７のオン時間は徐々に短くする。したがって、１回のスイッチング周期Ｔ２０内のリアクトル３０３に流れる電流の平均値の上昇は緩やかになる。よって、本発明の実施の形態３にかかる電力変換装置３０は、負荷３０９に供給する電力の変動をさらに抑制することができる。また、１回のスイッチング周期Ｔ２０内のリアクトル３０３に流れる電流の平均値の上昇が緩やかになると、制御装置３２１によって、迅速に負荷３０９への電力の供給量を調整することが可能となる。 Further, in the third embodiment of the present invention, as shown in FIG. 10, after the state of the synchronous rectification is eliminated, the on-time of the second semiconductor switching element 307 is gradually shortened. Therefore, the increase in the average value of the current flowing through reactor 303 within one switching cycle T20 is moderate. Therefore, the power conversion device 30 according to the third embodiment of the present invention can further suppress fluctuations in the power supplied to the load 309. In addition, when the average value of the current flowing through the reactor 303 within one switching cycle T20 gradually increases, the control device 321 can quickly adjust the amount of power supplied to the load 309.
　同期整流の状態から非同期整流の状態への移行は、電源３０１から負荷３０９へ供給する電力が少ない場合などに行う。例えば、電流がリアクトル３０３を正方向に流れるときに、電流が第２の整流素子３０６を通ったときに生じる電力損失と、第２の半導体スイッチング素子３０７の起電力の大きさとを考慮した際に、電流は第２の整流素子３０６を通った方が良いと判断されると、同期整流の状態から非同期整流の状態へと移行する。 The transition from the synchronous rectification state to the asynchronous rectification state is performed when the power supplied from the power supply 301 to the load 309 is small. For example, when considering the power loss that occurs when the current flows through the second rectifying element 306 and the magnitude of the electromotive force of the second semiconductor switching element 307 when the current flows in the positive direction through the reactor 303 When it is determined that the current should pass through the second rectifier element 306, the state shifts from the synchronous rectification state to the asynchronous rectification state.
　図１１は、本発明の実施の形態３にかかる電力変換装置３０の制御装置３２１の変形例が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図１１には、第１の半導体スイッチング素子３０４のスイッチング信号波形１１１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形１１１０２と、同期整流動作切り替え信号波形１１１０４と、リアクトル３０３の電流波形１１１０３とが示される。リアクトル３０３の電流波形１１１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 11 is a schematic diagram illustrating a waveform of a control signal sent by a modification of the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303. FIG. 11 shows a switching signal waveform 11101 of the first semiconductor switching element 304, a switching signal waveform 11102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 11104, and a current waveform 11103 of the reactor 303. Indicated. Although the current waveform 11103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　同期整流の状態を解消した直後の移行期間において、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、図１０と図１１とでは異なる。以下、図１１については、図１０との相違点のみ説明する。 The timing for turning on the second semiconductor switching element 307 is different between FIG. 10 and FIG. 11 in the transition period immediately after the cancellation of the synchronous rectification state. Hereinafter, only differences from FIG. 10 will be described with reference to FIG.
　図１１では、第２の半導体スイッチング素子３０７のスイッチング信号波形１１１０２は、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、第１の半導体スイッチング素子３０４をオフ状態とするタイミングと同じである。なお、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、第１の半導体スイッチング素子３０４をオフ状態にするタイミングと同じという意味には、第２の半導体スイッチング素子３０７をオン状態にするタイミングと第１の半導体スイッチング素子３０４をオフ状態にするタイミングとの間に、デットタイム期間（１μｓから５μｓ程度）を設けた場合、すなわち、厳密に同じではなく、間が数μｓ程度空いた場合も含まれるものである。 In FIG. 11, in the switching signal waveform 11102 of the second semiconductor switching element 307, the timing when the second semiconductor switching element 307 is turned on is the same as the timing when the first semiconductor switching element 304 is turned off. . The timing for turning on the second semiconductor switching element 307 is the same as the timing for turning on the first semiconductor switching element 304 in the meaning that the timing at which the second semiconductor switching element 307 is turned on. When a dead time period (about 1 μs to 5 μs) is provided between the first semiconductor switching element 304 and the timing at which the first semiconductor switching element 304 is turned off, that is, not exactly the same, but there is a gap of about several μs. It is included.
　図１１において、第２の半導体スイッチング素子３０７のオン時間を徐々に短くするにあたっては、第２の半導体スイッチング素子３０７をオフ状態にするタイミングを徐々に早める。図１１のような変形例の場合も、同期整流の状態を解消した後に、電流がリアクトル３０３を負方向に流れることができる期間を設けることで、負荷３０９に供給する電力の変動を抑制することができる。 In FIG. 11, in order to gradually shorten the ON time of the second semiconductor switching element 307, the timing for turning the second semiconductor switching element 307 OFF is gradually advanced. Also in the modified example as shown in FIG. 11, the fluctuation of the power supplied to the load 309 is suppressed by providing a period in which the current can flow negatively through the reactor 303 after the synchronous rectification state is canceled. Can do.
　ただし、図１１と図１０とを比較すると、図１１に示すリアクトル３０３に流れる電流の方が、負方向に流れる電流を減少させる速度が速くなることが分かっている。したがって、図１１に示すような第２の半導体スイッチング素子３０７のスイッチング信号波形１１１０２を使用するときは、スイッチング速度が高速である第２の半導体スイッチング素子３０７を用いることが好ましい。 However, when FIG. 11 and FIG. 10 are compared, it is known that the current flowing through the reactor 303 shown in FIG. 11 is faster in reducing the current flowing in the negative direction. Therefore, when the switching signal waveform 11102 of the second semiconductor switching element 307 as shown in FIG. 11 is used, it is preferable to use the second semiconductor switching element 307 having a high switching speed.
　図１２は、本発明の実施の形態３にかかる電力変換装置３０の制御装置３２１の別の変形例が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図１２には、第１の半導体スイッチング素子３０４のスイッチング信号波形１２１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形１２１０２と、同期整流動作切り替え信号波形１２１０４と、リアクトル３０３の電流波形１２１０３とが示される。リアクトル３０３の電流波形１２１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 12 is a schematic diagram illustrating a waveform of a control signal sent out by another modification of the control device 321 of the power conversion device 30 according to the third embodiment of the present invention and a waveform of a current flowing through the reactor 303. FIG. 12 shows a switching signal waveform 12101 of the first semiconductor switching element 304, a switching signal waveform 12102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 12104, and a current waveform 12103 of the reactor 303. Indicated. Although the current waveform 12103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　同期整流の状態を解消した直後、移行期間において、第２の半導体スイッチング素子３０７をオン状態にするタイミングが、図１２は図１０及び図１１とでは異なる。以下、図１２については、図１０及び図１１との相違点のみ説明する。 Immediately after the state of synchronous rectification is canceled, the timing for turning on the second semiconductor switching element 307 in the transition period is different from that in FIGS. Hereinafter, only differences from FIG. 10 and FIG. 11 will be described with reference to FIG.
　図１２では、第２の半導体スイッチング素子３０７のスイッチング信号波形１２１０２は、第２の半導体スイッチング素子３０７をオフ状態にするタイミングが、第１の半導体スイッチング素子３０４をオン状態とするタイミングと同じである。なお、第２の半導体スイッチング素子３０７をオフ状態にするタイミングが、第１の半導体スイッチング素子３０４をオン状態にするタイミングと同じという意味には、第２の半導体スイッチング素子３０７をオフ状態にするタイミングと第１の半導体スイッチング素子３０４をオン状態にするタイミングとの間に、デットタイム期間（１μｓから５μｓ程度）を設けた場合、すなわち、厳密に同じではなく、間が数μｓ程度空いた場合も含まれるものである。 In FIG. 12, the switching signal waveform 12102 of the second semiconductor switching element 307 has the same timing when the second semiconductor switching element 307 is turned off as the timing when the first semiconductor switching element 304 is turned on. . Note that the timing at which the second semiconductor switching element 307 is turned off means that the timing at which the second semiconductor switching element 307 is turned off is the same as the timing at which the first semiconductor switching element 304 is turned on. When a dead time period (about 1 μs to 5 μs) is provided between the first semiconductor switching element 304 and the timing at which the first semiconductor switching element 304 is turned on, that is, not exactly the same, but there is a gap of about several μs. It is included.
　図１２において、第２の半導体スイッチング素子３０７のオン時間を徐々に短くするにあたっては、第２の半導体スイッチング素子３０７をオン状態にするタイミングを徐々に遅くする。図１２のスイッチング信号１２１０２によれば、第２の半導体スイッチング素子３０７がオン状態である間は必ず電流がリアクトル３０３を負方向に流れるようになる。したがって、図１２のような変形例の場合も、同期整流の状態を解消した後に、電流がリアクトル３０３を負方向に流れることができる期間を設けることで、負荷３０９に供給する電力の変動を抑制することができる。 In FIG. 12, in order to gradually shorten the ON time of the second semiconductor switching element 307, the timing for turning on the second semiconductor switching element 307 is gradually delayed. According to the switching signal 12102 in FIG. 12, the current always flows in the negative direction through the reactor 303 while the second semiconductor switching element 307 is in the ON state. Therefore, even in the modified example as shown in FIG. 12, the fluctuation of the power supplied to the load 309 is suppressed by providing a period in which the current can flow in the negative direction through the reactor 303 after the synchronous rectification state is canceled. can do.
　さらに、図１２と図１０とを比較すると、図１２に示すリアクトル３０３に流れる電流の方が、負方向に流れる電流を減少させる速度が遅くなることが分かっている。したがって、図１２に示すような第２の半導体スイッチング素子３０７のスイッチング信号波形１２１０２を使用するときは、スイッチング速度が低速である第２の半導体スイッチング素子３０７を用いることができる。 Further, comparing FIG. 12 with FIG. 10, it is known that the current flowing through the reactor 303 shown in FIG. 12 is slower in reducing the current flowing in the negative direction. Therefore, when the switching signal waveform 12102 of the second semiconductor switching element 307 as shown in FIG. 12 is used, the second semiconductor switching element 307 having a low switching speed can be used.
　本発明の実施の形態３では、同期整流の状態を解消するタイミングは、スイッチング周期Ｔ２０が切り替わるタイミングと同じとして説明した。同期整流の状態を解消するタイミングはスイッチング周期Ｔ２０の途中であってもよいが、同期整流の状態を解消するタイミングはスイッチング周期Ｔ２０が切り替わるタイミングと同じであることが好ましい。 In the third embodiment of the present invention, the timing for canceling the synchronous rectification state is described as being the same as the timing for switching the switching cycle T20. The timing for canceling the synchronous rectification state may be in the middle of the switching cycle T20, but the timing for canceling the synchronous rectification state is preferably the same as the timing for switching the switching cycle T20.
実施の形態４．
　本発明の実施の形態４では、本発明の実施の形態１から本発明の実施の形態３と相違する部分について説明し、同一又は対応する部分についての説明は省略する。本発明の実施の形態１及び本発明の実施の形態２では、非同期整流の状態から同期整流の状態へ移行する場合について説明したが、本発明の実施の形態４では本発明の実施の形態３と同様に、同期整流の状態から非同期整流の状態へ移行する場合について説明する。電力の伝達方向は、本発明の実施の形態４では本発明の実施の形態２と同様に双方向である。 Embodiment 4 FIG.
In the fourth embodiment of the present invention, parts different from the first to third embodiments of the present invention will be described, and description of the same or corresponding parts will be omitted. In the first embodiment and the second embodiment of the present invention, the case of shifting from the asynchronous rectification state to the synchronous rectification state has been described. However, in the fourth embodiment of the present invention, the third embodiment of the present invention is described. Similarly, a case where the state is shifted from the synchronous rectification state to the asynchronous rectification state will be described. The power transmission direction is bidirectional in the fourth embodiment of the present invention, as in the second embodiment of the present invention.
　本発明の実施の形態４では、本発明の実施の形態２で示した電力変換システム８１と同じ図６の電力変換システム８１が使用される。したがって、図６は、本発明の実施の形態４にかかる電力変換装置８０を用いて構成された電力変換システム８１でもある。そのため、本発明の実施の形態４では、本発明の実施の形態２にかかる電力変換システム８１を構成している物と同じ名称及び符号を使用して、同期整流の状態から非同期整流の状態へ移行する場合について説明する。 In the fourth embodiment of the present invention, the same power conversion system 81 of FIG. 6 as the power conversion system 81 shown in the second embodiment of the present invention is used. Therefore, FIG. 6 is also a power conversion system 81 configured using the power conversion device 80 according to the fourth embodiment of the present invention. Therefore, in the fourth embodiment of the present invention, from the state of synchronous rectification to the state of asynchronous rectification, using the same names and symbols as those constituting the power conversion system 81 according to the second embodiment of the present invention. A case of migration will be described.
　本発明の実施の形態４では、本発明の実施の形態２と同様に、電力が電源８０１から電源８０９へと伝達される場合と、電源８０９から電源８０１へと伝達される場合の双方向を想定している。また、以下でも、本発明の実施の形態１から本発明の実施の形態３と同様に、リアクトル３０３の第１の端子から第２の端子へ電流が流れる方向を正方向（順方向）と呼び、第２の端子から第１の端子へ電流が流れる方向を負方向（逆方向）と呼ぶことにする。したがって、電力が電源８０９から電源８０１へと伝達される場合においては、同期整流の状態を解消した後、リアクトル３０３に流れる電流の平均値の下降（リアクトル３０３を負方向に流れる電流の平均値の上昇）を抑制することが目的となる。しかしながら、電力を伝達する向きが逆方向となることがあっても、本発明の実施の形態４も供給する（伝達する）電力の変動を抑制した電力変換装置を得ることが目的であることは、本発明の実施の形態１から本発明の実施の形態３と同じである。 In the fourth embodiment of the present invention, as in the second embodiment of the present invention, bidirectional operation is performed when power is transmitted from the power source 801 to the power source 809 and when power is transmitted from the power source 809 to the power source 801. Assumed. In the following, the direction in which current flows from the first terminal of the reactor 303 to the second terminal is referred to as the positive direction (forward direction) as in the first to third embodiments of the present invention. The direction in which current flows from the second terminal to the first terminal is referred to as the negative direction (reverse direction). Therefore, in the case where power is transmitted from power source 809 to power source 801, after the state of synchronous rectification is canceled, the average value of the current flowing through reactor 303 decreases (the average value of the current flowing through reactor 303 in the negative direction). The purpose is to suppress the rise). However, the object is to obtain a power conversion device that suppresses fluctuations in the power that is supplied (transmitted) in the fourth embodiment of the present invention even when the direction in which the power is transmitted is reversed. This is the same as Embodiment 1 to Embodiment 3 of the present invention.
　図１３は、本発明の実施の形態４にかかる電力変換装置８０の制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。図１３には、第１の半導体スイッチング素子３０４のスイッチング信号波形１３１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形１３１０２と、同期整流動作切り替え信号波形１３１０４と、リアクトル３０３の電流波形１３１０３と、同期スイッチング素子判定信号波形１３１０５とが示される。リアクトル３０３の電流波形１３１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。 FIG. 13 is a schematic diagram illustrating a waveform of a control signal sent out by the control device 821 of the power conversion device 80 according to the fourth embodiment of the present invention and a waveform of a current flowing through the reactor 303. FIG. 13 includes a switching signal waveform 13101 of the first semiconductor switching element 304, a switching signal waveform 13102 of the second semiconductor switching element 307, a synchronous rectification operation switching signal waveform 13104, a current waveform 13103 of the reactor 303, A synchronous switching element determination signal waveform 13105 is shown. Although the current waveform 13103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line.
　図１３において、領域Ａ５に示す信号波形及び電流波形は、制御装置８２１が第１の半導体スイッチング素子３０４を第３のオン状態と第３のオフ状態とに切り替える第３の切り替えを繰り返させ、かつ第３の切り替えに同期して、第２の半導体スイッチング素子３０７を第４のオン状態と第４のオフ状態とを切り替える第４の切り替えを繰り返させる同期整流の状態を示す。図１３では、第３のオン時間をＴ３１、第３のオフ時間をＴ３２として示す。また、図１３におけるスイッチング周期は、Ｔ３０として示され、第３の切り替え及び第４の切り替えの１周期である。つまり、第１の半導体スイッチング素子３０４の周波数と第２の半導体スイッチング素子３０７の周波数は等しい。第２の半導体スイッチング素子３０７のスイッチング信号波形１３１０２は、第１の半導体スイッチング素子３０４の反転信号である。 In FIG. 13, the signal waveform and the current waveform shown in the region A5 cause the control device 821 to repeat the third switching for switching the first semiconductor switching element 304 between the third on state and the third off state, and The state of synchronous rectification in which the fourth switching for switching the second semiconductor switching element 307 between the fourth on state and the fourth off state is repeated in synchronization with the third switching is shown. In FIG. 13, the third on-time is shown as T31, and the third off-time is shown as T32. Moreover, the switching period in FIG. 13 is shown as T30, and is one period of the third switching and the fourth switching. That is, the frequency of the first semiconductor switching element 304 and the frequency of the second semiconductor switching element 307 are equal. A switching signal waveform 13102 of the second semiconductor switching element 307 is an inverted signal of the first semiconductor switching element 304.
　図１３は、領域Ａ５において、検出装置８１０によって検出された１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値が正の値であるので、電源８０１から電源８０９へ電力を伝達しているときの制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示す。つまり、図１３の同期スイッチング素子判定信号波形１３１０５は、同期スイッチング素子判定信号８１２として１を出力する。本発明の実施の形態２において説明したように、例えば、制御装置８２１は、電源８０１から電源８０９へ電力を供給している場合には、同期スイッチング素子判定信号８１２として１を出力し、電源８０９から電源８０１へ電力を供給している場合には、同期スイッチング素子判定信号８１２として０を出力するからである。 FIG. 13 shows that in region A5, the average value of the current flowing through the reactor 303 within one switching cycle T30 detected by the detection device 810 is a positive value, so that power is transmitted from the power source 801 to the power source 809. 6 shows a waveform of a control signal sent out by the control device 821 and a waveform of a current flowing through the reactor 303. That is, the synchronous switching element determination signal waveform 13105 in FIG. 13 outputs 1 as the synchronous switching element determination signal 812. As described in Embodiment 2 of the present invention, for example, when the power is supplied from the power source 801 to the power source 809, the control device 821 outputs 1 as the synchronous switching element determination signal 812, and the power source 809 This is because 0 is output as the synchronous switching element determination signal 812 when power is supplied from the power source 801 to the power source 801.
　本発明の実施の形態４では、同期整流の状態である領域Ａ５の状態から、非同期整流の状態へ移行する。本発明の実施の形態４のように電力の伝達が双方向である場合、まず、同期整流の状態を解消し非同期整流の状態とするために、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のいずれのスイッチング信号波形を変更させるか判断する。本発明の実施の形態４では、同期整流の状態から非同期整流の状態へ移行するときに、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちスイッチング信号波形が変更される方を、同期スイッチング素子と呼び、他方を、非同期スイッチング素子と呼ぶ。図１３において、同期スイッチング素子は第２の半導体スイッチング素子３０７であり、非同期スイッチング素子は第１の半導体スイッチング素子３０４である。 In the fourth embodiment of the present invention, the state of the region A5 which is the state of synchronous rectification is shifted to the state of asynchronous rectification. When power is transmitted bidirectionally as in the fourth embodiment of the present invention, first, the first semiconductor switching element 304 and the second semiconductor are set in order to cancel the synchronous rectification state and enter the asynchronous rectification state. It is determined which switching signal waveform of the switching element 307 is to be changed. In the fourth embodiment of the present invention, when switching from the synchronous rectification state to the asynchronous rectification state, the switching signal waveform of the first semiconductor switching element 304 and the second semiconductor switching element 307 is changed. Are called synchronous switching elements, and the other is called asynchronous switching elements. In FIG. 13, the synchronous switching element is the second semiconductor switching element 307, and the asynchronous switching element is the first semiconductor switching element 304.
　本発明の実施の形態４にかかる電力変換装置８０の検出装置８１０は、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値を検出する。制御装置８２１は、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値を駆動装置８２０に伝達する。この動作によって、駆動装置８２０は、第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれが非同期スイッチング素子であるか、及び第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうちいずれが同期スイッチング素子であるか判断する。さらに、駆動装置８２０は、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値から、電力の供給方向も判断する。 The detection device 810 of the power conversion device 80 according to the fourth embodiment of the present invention detects the average value of the current flowing through the reactor 303 within one switching cycle T30. Control device 821 transmits the average value of the current flowing through reactor 303 within one switching cycle T30 to drive device 820. By this operation, the driving device 820 determines which one of the first semiconductor switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element, and the first semiconductor switching element 304 and the second semiconductor switching element. It is determined which of 307 is a synchronous switching element. Further, drive device 820 also determines the direction of power supply from the average value of the current flowing through reactor 303 within one switching cycle T30.
　電力の供給方向の判別は、例えば、検出器８１０によって１回のスイッチング周期Ｔ１０におけるリアクトル３０３に流れる電流の平均値を検出し、その値が正か負かによって判断することができるが、他の判別方法でも構わない。本発明の実施の形態４では、検出器８１０によってリアクトル３０３に流れる瞬時の電流値を検出し、その電流値情報を取得した制御装置８２１で１回のスイッチング周期Ｔ１０におけるリアクトル３０３に流れる電流の平均値を算出し、その値が正か負かによって電力の供給方向を判別する。第１の半導体スイッチング素子３０４と第２の半導体スイッチング素子３０７のうち、いずれが非同期スイッチング素子であるか、及びいずれが同期スイッチング素子であるか判断する手段も電力の供給方向の判別と同様に行う。ただし、上述した内容に限られることはない。 The power supply direction can be determined by, for example, detecting the average value of the current flowing through the reactor 303 in one switching cycle T10 by the detector 810 and determining whether the value is positive or negative. A discrimination method may be used. In the fourth embodiment of the present invention, the instantaneous current value flowing through the reactor 303 is detected by the detector 810, and the average of the current flowing through the reactor 303 in one switching cycle T10 is detected by the control device 821 that has acquired the current value information. A value is calculated, and the power supply direction is determined depending on whether the value is positive or negative. The means for determining which of the first semiconductor switching element 304 and the second semiconductor switching element 307 is an asynchronous switching element and which is a synchronous switching element is performed in the same manner as the determination of the power supply direction. . However, the contents are not limited to those described above.
　非同期整流の状態では、同期スイッチング素子である第２の半導体スイッチング素子３０７がオフ状態に維持され、非同期スイッチング素子である第１の半導体スイッチング素子３０４が第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを繰り返す。 In the state of asynchronous rectification, the second semiconductor switching element 307 that is a synchronous switching element is maintained in an off state, and the first semiconductor switching element 304 that is an asynchronous switching element is in a third on state and a third off state. The third switching for switching is repeated.
　本発明の実施の形態４にかかる電力変換装置８０の制御装置８２１は、図１３の領域Ａ５の状態から非同期整流の状態へ移行する間に、非同期スイッチング素子が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間Ｔ３２よりも短い第４のオン時間Ｔ３３で同期スイッチング素子を第４のオン状態とするように制御する期間（移行期間）を設ける。つまり、同期整流の状態を解消した後すぐに非同期整流の状態とするのではなく、同期整流の状態を解消した直後に、移行期間が設けられていることを示す。ここで、第４のオン時間Ｔ３３は、第３のオフ時間Ｔ３２からデッドタイム期間（１μｓから５μｓ程度）を引いた時間よりも短いものである。 The control device 821 of the power conversion device 80 according to the fourth exemplary embodiment of the present invention operates when the asynchronous switching element is in the third OFF state during the transition from the state of the region A5 in FIG. 13 to the asynchronous rectification state. A period (transition period) is provided in which the synchronous switching element is controlled to be in the fourth on state at a fourth on time T33 that is shorter than the third off time T32 indicating the time of three off states. That is, it indicates that the transition period is provided immediately after the state of the synchronous rectification is canceled, not the state of the asynchronous rectification immediately after the state of the synchronous rectification is canceled. Here, the fourth on-time T33 is shorter than the time obtained by subtracting the dead time period (about 1 μs to about 5 μs) from the third off-time T32.
　同期整流を解消した直後から非同期スイッチング素子を常時オフ状態にするのではなく、移行期間を設けることによって、電流がリアクトル３０３の負方向に流れる時間を同期整流の状態を解消した直後に作る。つまり、同期整流の状態に引き続いて、電流がリアクトル３０３の負方向に流れる時間を一部継続させる。本発明の実施の形態３と同様に、同期整流の状態から非同期整流の状態へ移行する場合に、図１３のような移行期間を設けると、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値の上昇を抑制することができるため、本発明の実施の形態４にかかる電力変換装置８０は、供給する（伝達する）電力の変動を抑制することができる。 Instead of always turning off the asynchronous switching element immediately after eliminating the synchronous rectification, the transition period is provided so that the time during which the current flows in the negative direction of the reactor 303 is created immediately after the state of the synchronous rectification is eliminated. That is, part of the time during which the current flows in the negative direction of the reactor 303 is continued following the synchronous rectification state. Similarly to the third embodiment of the present invention, when the transition from the synchronous rectification state to the asynchronous rectification state is made, if a transition period as shown in FIG. 13 is provided, the current flowing through the reactor 303 within one switching cycle T30 Therefore, the power conversion device 80 according to the fourth embodiment of the present invention can suppress fluctuations in supplied (transmitted) power.
　移行期間において、第１の半導体スイッチング素子３０４が第３のオフ状態の時に、第１の半導体スイッチング素子３０４の第３のオフ時間Ｔ３２よりも短くした第２の半導体スイッチング素子３０７の第４のオン時間Ｔ３３で第２の半導体スイッチング素子をオン状態とする第４の切り替えは複数回あることが好ましい。これにより、同期整流の状態から非同期整流の状態へ移行するときに、１回のスイッチング周期Ｔ３０内におけるリアクトル３０に流れる電流の平均値の上昇をさらに抑制することができる。 In the transition period, when the first semiconductor switching element 304 is in the third OFF state, the fourth ON state of the second semiconductor switching element 307 that is shorter than the third OFF time T32 of the first semiconductor switching element 304 is set. It is preferable that the fourth switching for turning on the second semiconductor switching element at time T33 is performed a plurality of times. Thereby, when it transfers to the state of asynchronous rectification from the state of synchronous rectification, the raise of the average value of the electric current which flows into the reactor 30 in one switching period T30 can further be suppressed.
　本発明の実施の形態４では、制御装置８２１が送出する第２の半導体スイッチング素子３０７の制御信号８１５は、図１３の第２の半導体スイッチング素子３０７のスイッチング信号波形１３１０２に示すような波形であって、第１の半導体スイッチング素子３０４の第３のオフ時間Ｔ３２よりも短くした第２の半導体スイッチング素子３０７の第４のオン時間Ｔ３３を徐々に短くする。最終的には、第２の半導体スイッチング素子３０７の第４オン時間Ｔ３３は０となり、第２の半導体スイッチング素子３０７が常にオフ状態となって、移行期間が終了し、非同期整流の状態となる。 In Embodiment 4 of the present invention, the control signal 815 of the second semiconductor switching element 307 sent out by the control device 821 has a waveform as shown in the switching signal waveform 13102 of the second semiconductor switching element 307 in FIG. Thus, the fourth on-time T33 of the second semiconductor switching element 307, which is shorter than the third off-time T32 of the first semiconductor switching element 304, is gradually shortened. Eventually, the fourth on-time T33 of the second semiconductor switching element 307 becomes 0, the second semiconductor switching element 307 is always turned off, the transition period ends, and the state of asynchronous rectification is entered.
　第２の半導体スイッチング素子３０７のオン時間を減少させる際の変化量は、回路構成や制御の応答速度によって適切な量があると考えられる。例としては、本発明の実施の形態３において上述した通りである。 It is considered that there is an appropriate amount of change when the on-time of the second semiconductor switching element 307 is decreased depending on the circuit configuration and control response speed. An example is as described above in the third embodiment of the present invention.
　さらに、実施の形態３と同様に、第２の半導体スイッチング素子３０７のオン状態にするタイミングも種々考えられ、本発明の実施の形態４では、第１の半導体スイッチング素子３０４のオン信号と、次のスイッチング周期Ｔ３０の第１の半導体スイッチング素子３０４のオン信号との間の中央を中心として対称に、第２の半導体スイッチング素子３０７のオン信号を設ける。図１３に示した第２の半導体スイッチング素子３０７のスイッチング信号波形１３１０２は、図１１及び図１２のように変形することも可能である。 Further, similarly to the third embodiment, various timings for turning on the second semiconductor switching element 307 can be considered. In the fourth embodiment of the present invention, the ON signal of the first semiconductor switching element 304 and the next The ON signal of the second semiconductor switching element 307 is provided symmetrically about the center between the ON signal of the first semiconductor switching element 304 and the switching period T30. The switching signal waveform 13102 of the second semiconductor switching element 307 shown in FIG. 13 can be modified as shown in FIGS.
　図１４は、本発明の実施の形態４にかかる電力変換装置８０の制御装置８２１の変形例が送出する制御信号の波形とリアクトル３０３に流れる電流の波形を示した概略図である。本発明の実施の形態４の変形例は、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値が負の値であり、電源８０９から電源８０１へ電力を伝達する場合である。図１４には、第１の半導体スイッチング素子３０４のスイッチング信号波形１４１０１と、第２の半導体スイッチング素子３０７のスイッチング信号波形１４１０２と、同期整流動作切り替え信号波形１４１０４と、リアクトル３０３の電流波形１４１０３と、同期スイッチング素子判定信号波形１４１０５とが示される。リアクトル３０３の電流波形１４１０３は、リアクトル３０３に流れる電流の波形を示すが、これは概略波形であって、本来はこのように直線のみで表されるものではない。以下、図１４については、図１３との相違点のみ説明する。 FIG. 14 is a schematic diagram illustrating a waveform of a control signal sent by a modification of the control device 821 of the power conversion device 80 according to the fourth embodiment of the present invention and a waveform of a current flowing through the reactor 303. A modification of the fourth embodiment of the present invention is a case where the average value of the current flowing through reactor 303 in one switching cycle T30 is a negative value, and power is transmitted from power supply 809 to power supply 801. In FIG. 14, the switching signal waveform 14101 of the first semiconductor switching element 304, the switching signal waveform 14102 of the second semiconductor switching element 307, the synchronous rectification operation switching signal waveform 14104, the current waveform 14103 of the reactor 303, A synchronous switching element determination signal waveform 14105 is shown. Although the current waveform 14103 of the reactor 303 shows the waveform of the current flowing through the reactor 303, this is a schematic waveform and is not originally represented by only a straight line. Hereinafter, only differences from FIG. 13 will be described with reference to FIG.
　図１４において、領域Ａ５に示す信号波形及び電流波形は、図１３と同様に、同期整流の状態を示す。図１４は、領域Ａ５において、検出装置８１０によって検出された１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値が負の値であるので、電源８０９から電源８０１へ電力を伝達しているときの制御装置８２１が送出する制御信号の波形とリアクトル３０３に流れる電流波形を示す。つまり、図１４の同期スイッチング素子判定信号波形１４１０５は、同期スイッチング素子判定信号８１２として０を出力する。 14, the signal waveform and current waveform shown in region A5 indicate the state of synchronous rectification, as in FIG. 13. FIG. 14 shows that in region A5, the average value of the current flowing through the reactor 303 within one switching cycle T30 detected by the detection device 810 is a negative value, so that power is transmitted from the power source 809 to the power source 801. The waveform of the control signal sent out by the control device 821 and the current waveform flowing through the reactor 303 are shown. That is, the synchronous switching element determination signal waveform 14105 in FIG. 14 outputs 0 as the synchronous switching element determination signal 812.
　図１４において、第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを繰り返す非同期スイッチング素子は、第２の半導体スイッチング素子３０７である。第３の切り替えに同期して、第４のオン状態と第４のオフ状態とを切り替える第４の切り替えを繰り返す同期スイッチング素子は、第１の半導体スイッチング素子３０４である。つまり、図１４では、図１３において第１の半導体スイッチング素子３０４に対して送出していた信号と、第２の半導体スイッチング素子３０７に対して送出していた信号とが入れ替わる。 In FIG. 14, the asynchronous switching element that repeats the third switching for switching between the third on state and the third off state is the second semiconductor switching element 307. The synchronous switching element that repeats the fourth switching that switches between the fourth on state and the fourth off state in synchronization with the third switching is the first semiconductor switching element 304. That is, in FIG. 14, the signal sent to the first semiconductor switching element 304 in FIG. 13 and the signal sent to the second semiconductor switching element 307 are switched.
　本発明の実施の形態４にかかる電力変換装置８０の制御装置８２１は、本発明の実施の形態４の変形例においても、図１４の領域Ａ５の状態から非同期整流の状態へ移行する間に、非同期スイッチング素子が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間Ｔ３２よりも短い第４のオン時間Ｔ３３で同期スイッチング素子を第４のオン状態とするように制御する期間（移行期間）を設ける。つまり、同期整流の状態を解消した後すぐに非同期整流の状態とするのではなく、同期整流の状態を解消した直後に、移行期間が設けられていることを示す。ここで、第４のオン時間Ｔ３３は、第３のオフ時間Ｔ３２からデッドタイム期間（１μｓから５μｓ程度）を引いた時間よりも短いものである。 The control device 821 of the power conversion device 80 according to the fourth exemplary embodiment of the present invention also changes the state of the region A5 in FIG. 14 to the asynchronous rectification state in the modified example of the fourth exemplary embodiment of the present invention. When the asynchronous switching element is in the third OFF state, the synchronous switching element is set to the fourth ON state at a fourth ON time T33 that is shorter than the third OFF time T32 indicating the time of the third OFF state. A control period (transition period) is provided. That is, it indicates that the transition period is provided immediately after the state of the synchronous rectification is canceled, not the state of the asynchronous rectification immediately after the state of the synchronous rectification is canceled. Here, the fourth on-time T33 is shorter than the time obtained by subtracting the dead time period (about 1 μs to about 5 μs) from the third off-time T32.
　同期整流を解消した直後から非同期スイッチング素子を常時オフ状態にするのではなく、同期整流の状態を解消した直後に移行期間を設けることによって、同期整流の状態に引き続いて、電流がリアクトル３０３の正方向に流れる時間を一部継続させる。 Instead of always turning off the asynchronous switching element immediately after the cancellation of the synchronous rectification, a transition period is provided immediately after the cancellation of the synchronous rectification state. Continue part of the time flowing in the direction.
　同期整流の状態を解消した後すぐに非同期整流の状態にすると、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値は、同期整流の状態を解消する前よりも急激に下降する。一方、同期整流の状態から非同期整流の状態へ移行する場合に、図１４のような移行期間を設けると、１回のスイッチング周期Ｔ３０内におけるリアクトル３０３に流れる電流の平均値の下降を抑制することができる。同期整流の状態を解消しても、電流がリアクトル３０３の正方向に流れる時間を一部継続してから、非同期整流の状態となるからである。よって、本発明の実施の形態４にかかる電力変換装置８０は、供給する（伝達する）電力の変動を抑制することができる。 When the state of asynchronous rectification is made immediately after the state of synchronous rectification is eliminated, the average value of the current flowing through the reactor 303 within one switching cycle T30 falls more rapidly than before the state of synchronous rectification is eliminated. On the other hand, when shifting from the state of synchronous rectification to the state of asynchronous rectification, if a transition period as shown in FIG. 14 is provided, the decrease in the average value of the current flowing through the reactor 303 within one switching cycle T30 is suppressed. Can do. This is because even if the state of the synchronous rectification is canceled, a part of the time during which the current flows in the positive direction of the reactor 303 is continued before the state of asynchronous rectification is entered. Therefore, the power conversion device 80 according to the fourth embodiment of the present invention can suppress fluctuations in the supplied (transmitted) power.
　本発明の実施の形態４の変形例においても、第１の半導体スイッチング素子３０４のオン状態にするタイミングは種々考えられ、図１４では、第１の半導体スイッチング素子３０４をオン状態とするタイミングと第２の半導体スイッチング素子３０７をオフ状態とするタイミングとを同じとする。図１４に示した第１の半導体スイッチング素子３０４のスイッチング信号波形１４１０１は、図１０及び図１２の第２の半導体スイッチング素子３０７のスイッチング信号波形のように変形することも可能である。 Also in the modification of the fourth embodiment of the present invention, various timings for turning on the first semiconductor switching element 304 can be considered. In FIG. The timing at which the semiconductor switching element 307 is turned off is the same. The switching signal waveform 14101 of the first semiconductor switching element 304 shown in FIG. 14 can be modified like the switching signal waveform of the second semiconductor switching element 307 of FIGS.
　以上のように、双方向に電力を供給することが出来る電力変換装置８０においても、まず、同期スイッチング素子が第１の半導体スイッチング素子３０４であるか第２の半導体スイッチング素子３０７であるかを見極める。そして、同期整流の状態から非同期整流の状態へ移行する場合において、同期整流の状態を解消した後、同期整流の状態から非同期整流の状態へ移行する間に、非同期スイッチング素子が第３のオフ状態の時に、第３のオフ状態の時間を示す第３のオフ時間よりも短い第４のオン時間で同期スイッチング素子を第４のオン状態とするように制御する期間を設ける。これにより、本発明の実施の形態４では、供給する電力の変動を抑制した電力変換装置８０を得ることができる。 As described above, also in the power conversion device 80 that can supply power bidirectionally, first, it is determined whether the synchronous switching element is the first semiconductor switching element 304 or the second semiconductor switching element 307. . Then, in the transition from the synchronous rectification state to the asynchronous rectification state, after the synchronous rectification state is canceled, the asynchronous switching element is switched to the third off state during the transition from the synchronous rectification state to the asynchronous rectification state. At this time, a period for controlling the synchronous switching element to be in the fourth on-state with a fourth on-time shorter than the third off-time indicating the time of the third off-state is provided. Thereby, in Embodiment 4 of this invention, the power converter device 80 which suppressed the fluctuation | variation of the electric power to supply can be obtained.
　本発明の実施の形態４では、同期整流の状態を解消するタイミングは、スイッチング周期Ｔ２０が切り替わるタイミングと同じとして説明した。同期整流の状態を解消するタイミングはスイッチング周期Ｔ２０の途中であってもよいが、同期整流の状態を解消するタイミングはスイッチング周期Ｔ２０が切り替わるタイミングと同じであることが好ましい。 In the fourth embodiment of the present invention, the timing for canceling the synchronous rectification state is described as being the same as the timing for switching the switching cycle T20. The timing for canceling the synchronous rectification state may be in the middle of the switching cycle T20, but the timing for canceling the synchronous rectification state is preferably the same as the timing for switching the switching cycle T20.
　なお、図３から図５、図７、図８、図１０から図１４は、概略図であり、図３から図５、図７、図８、図１０から図１４において、デッドタイム期間は図示省略されている。 3 to 5, FIG. 7, FIG. 8, and FIG. 10 to FIG. 14 are schematic diagrams. In FIG. 3 to FIG. 5, FIG. 7, FIG. It is omitted.
　また、上記の各実施の形態において、第１の半導体スイッチング素子３０４、第２の半導体スイッチング素子３０７、第１の整流素子３０５及び第２の整流素子３０６として、ワイドバンドギャップ半導体によって形成された素子を適用すると、さらにスイッチング損失や導通損失が低減する。これにより、電力変換装置の電力供給を一層の高効率にできることは言うまでもない。ワイドバンドギャップ半導体としては、例えば、炭化珪素、窒化ガリウム系材料、ダイヤモンドなどがある。 In each of the above embodiments, the first semiconductor switching element 304, the second semiconductor switching element 307, the first rectifying element 305, and the second rectifying element 306 are elements formed of a wide band gap semiconductor. When is applied, switching loss and conduction loss are further reduced. Thus, it goes without saying that the power supply of the power converter can be made more efficient. Examples of wide band gap semiconductors include silicon carbide, gallium nitride-based materials, and diamond.
　このようなワイドバンドギャップ半導体によって形成された素子は、耐電圧性が高く、許容電流密度も高いため、小型化が可能である。これら小型化された素子を用いることにより、これらの素子を組み込んだ半導体モジュールの小型化が可能となる。また、耐熱性も高いため、放熱フィンの小型化、半導体モジュールの一層の小型化が可能になる。さらに電力損失が低いため、素子自身の特性の高効率化が可能であり、延いては半導体モジュールの高効率化が可能になる。 An element formed of such a wide band gap semiconductor has high voltage resistance and high allowable current density, and thus can be miniaturized. By using these miniaturized elements, a semiconductor module incorporating these elements can be miniaturized. Further, since the heat resistance is also high, it is possible to reduce the size of the radiating fin and further reduce the size of the semiconductor module. Furthermore, since the power loss is low, it is possible to increase the efficiency of the characteristics of the element itself, and further increase the efficiency of the semiconductor module.
　なお、本発明は、発明の範囲内において、各実施の形態を自由に組み合わせることや、各実施の形態を適宜、変形、省略することが可能である。 In the present invention, the embodiments can be freely combined within the scope of the invention, and the embodiments can be appropriately modified or omitted.
３０，８０　電力変換装置
３１，８１　電力変換システム
３０１，８０１，８０９　電源
３０２　第１のコンデンサー
３０３　リアクトル
３０４　第１の半導体スイッチング素子
３０５　第１の整流素子
３０６　第２の整流素子
３０７　第２の半導体スイッチング素子
３０８　第２のコンデンサー
３０９　負荷
３１０　入力側電圧検出器
３１１　出力側電圧検出器
３１２，８１２　第１の半導体スイッチング素子の制御信号
３１３，８１４　同期整流動作切り替え信号
３１４，８１５　第２の半導体スイッチング素子の制御信号
３１５，８１６　第１の半導体スイッチング素子の駆動信号
３１６，８１７　第２の半導体スイッチング素子の駆動信号
３２０，８２０　駆動装置
３２１，８２１　制御装置
８１０　検出装置
５２０１，６２０１，７１０１，７２０１，８１０１，９１０１，９２０１，１０１０１，１１１０１，１２１０１，１３１０１，１４１０１　第１の半導体スイッチング素子のスイッチング信号波形
５２０２，６２０２，７１０２，７２０２，８１０２，９１０２，９２０２，１０１０２，１１１０２，１２１０２，１３１０２，１４１０２　第２の半導体スイッチング素子のスイッチング信号波形
５２０３，６２０３，７１０３，７２０３，８１０３，９１０３，９２０３，１０１０３，１１１０３，１２１０３，１３１０３，１４１０３　リアクトルの電流波形
５２０４，６２０４，７１０４，７２０４，８１０４，９１０４，９２０４，１０１０４，１１１０４，１２１０４，１３１０４，１４１０４　同期整流動作切り替え信号波形
９１０５，９２０５，１３１０５，１４１０５　同期スイッチング素子判定信号波形 30, 80 Power conversion device 31, 81 Power conversion system 301, 801, 809 Power supply 302 First capacitor 303 Reactor 304 First semiconductor switching element 305 First rectifier element 306 Second rectifier element 307 Second semiconductor switching Element 308 Second capacitor 309 Load 310 Input side voltage detector 311 Output side voltage detectors 312 and 812 Control signal 313 and 814 of first semiconductor switching element Synchronous rectification operation switching signal 314 and 815 of second semiconductor switching element Control signals 315, 816 Drive signals 316, 817 for the first semiconductor switching elements Drive signals 320, 820 for the second semiconductor switching elements Drive devices 321, 821 Control device 810 Detection devices 5201, 6201, 7101, 7201, 8101 9101, 9201, 10101, 11101, 12101, 13101, 14101 Switching signal waveforms of the first semiconductor switching element 5202, 6202, 7102, 7202, 8102, 9102, 9202, 10102, 11102, 12102, 13102, 14102 Second semiconductor Switching signal waveform 5203, 6203, 7103, 7203, 8103, 9103, 9203, 10103, 11103, 12103, 13103, 14103 of the switching element Current waveform 5204, 6204, 7104, 7204, 8104, 9104, 9204, 10104, 11104 of the reactor , 12104, 13104, 14104 Synchronous rectification operation switching signal waveform 9105, 9205, 13105, 14105 Ching element judgment signal waveform

Claims (14)

  1. 　第１の端子と第２の端子とを有し、前記第１の端子が電源の正極と接続されたリアクトルと、
    　前記リアクトルの前記第２の端子と前記電源の負極との間に接続された第１の半導体スイッチング素子と、
    　前記リアクトルの前記第２の端子と負荷の正側との間に接続され、前記第２の端子から送出された電流を前記負荷に送出するように整流する整流素子と、
    　前記整流素子に並列に接続された第２の半導体スイッチング素子と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子を駆動させる駆動信号を送出する駆動装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子の駆動を制御する制御信号を前記駆動装置へ送出する制御装置と、
    　を備え、
    　前記第２の半導体スイッチング素子がオフ状態に維持され、かつ前記第１の半導体スイッチング素子が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを行う非同期整流の状態から、前記第１の切り替えに同期して、前記第２の半導体スイッチング素子が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを行う同期整流の状態へ移行する場合に、
    　前記制御装置は、前記同期整流の状態において前記第１の半導体スイッチング素子が前記第１のオフ状態の時に、前記第１のオフ状態の時間を示す第１のオフ時間よりも短い第２のオン時間で前記第２の半導体スイッチング素子を前記第２のオン状態とするように制御すること、
    　を特徴とした電力変換装置。     A reactor having a first terminal and a second terminal, wherein the first terminal is connected to a positive electrode of a power source;
    A first semiconductor switching element connected between the second terminal of the reactor and a negative electrode of the power source;
    A rectifying element connected between the second terminal of the reactor and a positive side of a load and rectifying the current sent from the second terminal so as to send the current to the load;
    A second semiconductor switching element connected in parallel to the rectifying element;
    A driving device for transmitting a driving signal for driving the first semiconductor switching element and the second semiconductor switching element;
    A control device for sending a control signal for controlling driving of the first semiconductor switching element and the second semiconductor switching element to the driving device;
    With
    From the state of asynchronous rectification in which the second semiconductor switching element is maintained in an off state and the first semiconductor switching element performs a first switching to switch between a first on state and a first off state, In synchronization with the first switching, when the second semiconductor switching element shifts to a synchronous rectification state in which a second switching is performed to switch between a second on state and a second off state.
    When the first semiconductor switching element is in the first off state in the synchronous rectification state, the control device has a second on time shorter than a first off time indicating a time of the first off state. Controlling the second semiconductor switching element to be in the second ON state over time;
    The power converter characterized by this.
  2. 　第１の端子と第２の端子とを有し、前記第１の端子が電源の正極と接続されたリアクトルと、
    　前記リアクトルの前記第２の端子と前記電源の負極との間に接続された第１の半導体スイッチング素子と、
    　前記リアクトルの前記第２の端子と負荷の正側との間に接続され、前記第２の端子から送出された電流を前記負荷に送出するように整流する整流素子と、
    　前記整流素子に並列に接続された第２の半導体スイッチング素子と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子を駆動させる駆動信号を送出する駆動装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子の駆動を制御する制御信号を前記駆動装置へ送出する制御装置と、
    　を備え、
    　前記第１の半導体スイッチング素子が第１のオン状態と第１のオフ状態とを切り替える第１の切り替えを繰り返し、かつ前記第１の切り替えに同期して、前記第２の半導体スイッチング素子が第２のオン状態と第２のオフ状態とを切り替える第２の切り替えを繰り返す同期整流の状態から、前記第２の半導体スイッチング素子がオフ状態に維持され、かつ前記第１の半導体スイッチング素子が前記第１の切り替えを繰り返す非同期整流の状態へ移行する間に、
    　前記制御装置は、前記第１の半導体スイッチング素子が前記第１のオフ状態の時に、前記第１のオフ状態の時間を示す第１のオフ時間よりも短い第２のオン時間で前記第２の半導体スイッチング素子を前記第２のオン状態とするように制御する期間を設けること、
    　を特徴とした電力変換装置。     A reactor having a first terminal and a second terminal, wherein the first terminal is connected to a positive electrode of a power source;
    A first semiconductor switching element connected between the second terminal of the reactor and a negative electrode of the power source;
    A rectifying element connected between the second terminal of the reactor and a positive side of a load and rectifying the current sent from the second terminal so as to send the current to the load;
    A second semiconductor switching element connected in parallel to the rectifying element;
    A driving device for transmitting a driving signal for driving the first semiconductor switching element and the second semiconductor switching element;
    A control device for sending a control signal for controlling driving of the first semiconductor switching element and the second semiconductor switching element to the driving device;
    With
    The first semiconductor switching element repeats the first switching for switching between the first on state and the first off state, and the second semiconductor switching element is second in synchronization with the first switching. The second semiconductor switching element is maintained in the OFF state from the synchronous rectification state in which the second switching for switching between the ON state and the second OFF state is repeated, and the first semiconductor switching element is the first semiconductor switching element. During the transition to the state of asynchronous rectification that repeats switching,
    When the first semiconductor switching element is in the first OFF state, the control device has a second ON time shorter than a first OFF time indicating a time of the first OFF state. Providing a period for controlling the semiconductor switching element to be in the second ON state;
    The power converter characterized by this.
  3. 　前記第２のオン時間は、前記第１のオフ時間からデッドタイム期間を引いた時間よりも短いこと、
    　を特徴とした請求項１又は請求項２に記載の電力変換装置。     The second on time is shorter than the first off time minus a dead time period;
    The power converter according to claim 1 or 2, characterized by the above.
  4. 　さらに前記制御装置は、前記移行後に、前記第１のオフ状態の時間を示す第１のオフ時間よりも短い第２のオン時間で前記第２の半導体スイッチング素子を前記第２のオン状態とする前記第２の切り替えが、複数回あるように制御すること、
    　を特徴とした請求項１から請求項３のいずれか１項に記載の電力変換装置。     Further, after the transition, the control device sets the second semiconductor switching element to the second on state with a second on time shorter than the first off time indicating the time of the first off state. Controlling the second switching to be performed a plurality of times,
    The power conversion device according to any one of claims 1 to 3, wherein:
  5. 　さらに前記制御装置は、前記移行後の２回目以降の前記第２の切り替えにおける前記第２のオン時間を、前記移行後の１回目の前記第２の切り替えにおける前記第２のオン時間よりも長くするように制御すること、
    　を特徴とした請求項４に記載の電力変換装置。     Further, the control device makes the second on-time in the second switching after the second time after the transition longer than the second on-time at the first second switching after the transition. To control,
    The power converter according to claim 4 characterized by things.
  6. 　さらに前記制御装置は、前記第２の半導体スイッチング素子をオン状態にするタイミングを、前記リアクトルに流れる電流が前記第１の端子から前記第２の端子の向きに流れている間になるように制御すること、
    　を特徴とした請求項１から請求項５のいずれか１項に記載の電力変換装置。     Further, the control device controls the timing for turning on the second semiconductor switching element so that the current flowing through the reactor flows from the first terminal to the second terminal. To do,
    The power conversion device according to any one of claims 1 to 5, wherein:
  7. 　さらに前記制御装置は、前記第２の半導体スイッチング素子のオン状態にするタイミングが、前記第１の半導体スイッチング素子がオフ状態にしたタイミングと同じになるように制御すること、
    　を特徴とした請求項１から請求項５のいずれか１項に記載の電力変換装置。     Further, the control device performs control so that a timing at which the second semiconductor switching element is turned on is the same as a timing at which the first semiconductor switching element is turned off,
    The power conversion device according to any one of claims 1 to 5, wherein:
  8. 　第１の端子と第２の端子とを有し、前記第１の端子が第１の電源の一方の極と接続されたリアクトルと、
    　前記リアクトルの前記第２の端子と前記第１の電源の他方の極との間に接続された第１の半導体スイッチング素子と、
    　前記リアクトルの前記第２の端子と第２の電源の前記第１の電源の一方の極と同じ極性の極側との間に接続され、前記第２の端子から送出された電流を前記負荷に送出するように整流する整流素子と、
    　前記整流素子に並列に接続された第２の半導体スイッチング素子と、
    　前記リアクトルに流れる電流値を検出する検出装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子を駆動させる駆動信号を送出する駆動装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子の駆動を制御する制御信号を前記駆動装置へ送出する制御装置と、
    　を備え、
    　前記制御装置は、
    　前記電流値から、前記第１の半導体スイッチング素子と前記第２の半導体スイッチング素子とのうちいずれがオフ状態に維持された同期スイッチング素子であるか、及び前記第１の半導体スイッチング素子と前記第２の半導体スイッチング素子とのうちいずれが第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期スイッチング素子であるかを判断し、
    　前記同期スイッチング素子がオフ状態に維持され、かつ前記非同期スイッチング素子が第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを行う非同期整流の状態から、前記第３の切り替えに同期して、前記同期スイッチング素子が第４のオン状態と第４のオフ状態とを切り替える第４の切り替えを行う同期整流の状態へ移行する場合に、
    　前記制御装置は、前記同期整流の状態において前記非同期スイッチング素子が前記第３のオフ状態の時に、前記第３のオフ状態の時間を示す第３のオフ時間よりも短い第４のオン時間で前記同期スイッチング素子を前記第４のオン状態とするように制御すること、
    　を特徴とした電力変換装置。     A reactor having a first terminal and a second terminal, wherein the first terminal is connected to one pole of a first power source;
    A first semiconductor switching element connected between the second terminal of the reactor and the other pole of the first power source;
    Connected between the second terminal of the reactor and a pole side of the same polarity as one pole of the first power source of a second power source, the current sent from the second terminal to the load A rectifying element that rectifies so as to be sent out;
    A second semiconductor switching element connected in parallel to the rectifying element;
    A detection device for detecting a current value flowing through the reactor;
    A driving device for transmitting a driving signal for driving the first semiconductor switching element and the second semiconductor switching element;
    A control device for sending a control signal for controlling driving of the first semiconductor switching element and the second semiconductor switching element to the driving device;
    With
    The controller is
    Based on the current value, which of the first semiconductor switching element and the second semiconductor switching element is a synchronous switching element maintained in an OFF state, and the first semiconductor switching element and the second semiconductor switching element Which of the semiconductor switching elements is an asynchronous switching element that performs a third switching to switch between the third on-state and the third off-state,
    The synchronous switching element is maintained in the OFF state, and the asynchronous switching element is synchronized with the third switching from the asynchronous rectification state in which the asynchronous switching element performs the third switching for switching between the third ON state and the third OFF state. When the synchronous switching element shifts to a synchronous rectification state in which a fourth switching is performed to switch between a fourth on state and a fourth off state,
    When the asynchronous switching element is in the third OFF state in the synchronous rectification state, the control device has a fourth ON time shorter than a third OFF time indicating a time of the third OFF state. Controlling the synchronous switching element to be in the fourth ON state;
    The power converter characterized by this.
  9. 　第１の端子と第２の端子とを有し、前記第１の端子が第１の電源の一方の極と接続されたリアクトルと、
    　前記リアクトルの前記第２の端子と前記第１の電源の他方の極との間に接続された第１の半導体スイッチング素子と、
    　前記リアクトルの前記第２の端子と第２の電源の前記第１の電源の一方の極と同じ極性の極側との間に接続され、前記第２の端子から送出された電流を前記負荷に送出するように整流する整流素子と、
    　前記整流素子に並列に接続された第２の半導体スイッチング素子と、
    　前記リアクトルに流れる電流値を検出する検出装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子を駆動させる駆動信号を送出する駆動装置と、
    　前記第１の半導体スイッチング素子及び前記第２の半導体スイッチング素子の駆動を制御する制御信号を前記駆動装置へ送出する制御装置と、
    　を備え、
    　前記制御装置は、
    　前記電流値から、前記第１の半導体スイッチング素子と前記第２の半導体スイッチング素子とのうちいずれが第３のオン状態と第３のオフ状態とを切り替える第３の切り替えを繰り返す非同期スイッチング素子であるか、及び前記第１の半導体スイッチング素子と前記第２の半導体スイッチング素子とのうちいずれが第４のオン状態と第４のオフ状態とを切り替える第４の切り替えを繰り返す同期スイッチング素子であるかを判断し、
    　前記非同期スイッチング素子が前記第３の切り替えを繰り返し、かつ前記第３の切り替えに同期して、前記同期スイッチング素子が前記第４の切り替えを繰り返す同期整流の状態から、前記非同期スイッチング素子が前記第３の切り替えを繰り返し、かつ前記同期スイッチング素子がオフ状態に維持される非同期整流の状態へ移行する間に、
    　前記制御装置は、前記非同期スイッチング素子が前記第３のオフ状態の時に、前記第３のオフ状態の時間を示す第３のオフ時間よりも短い第４のオン時間で前記同期スイッチング素子を前記第４のオン状態とするように制御する期間を設けること、
    　を特徴とした電力変換装置。     A reactor having a first terminal and a second terminal, wherein the first terminal is connected to one pole of a first power source;
    A first semiconductor switching element connected between the second terminal of the reactor and the other pole of the first power source;
    Connected between the second terminal of the reactor and a pole side of the same polarity as one pole of the first power source of a second power source, the current sent from the second terminal to the load A rectifying element that rectifies so as to be sent out;
    A second semiconductor switching element connected in parallel to the rectifying element;
    A detection device for detecting a current value flowing through the reactor;
    A driving device for transmitting a driving signal for driving the first semiconductor switching element and the second semiconductor switching element;
    A control device for sending a control signal for controlling driving of the first semiconductor switching element and the second semiconductor switching element to the driving device;
    With
    The controller is
    Any one of the first semiconductor switching element and the second semiconductor switching element is an asynchronous switching element that repeats a third switching to switch between a third on state and a third off state based on the current value. And which of the first semiconductor switching element and the second semiconductor switching element is a synchronous switching element that repeats a fourth switching that switches between a fourth on-state and a fourth off-state. Judgment
    From the state of synchronous rectification in which the asynchronous switching element repeats the third switching and is synchronized with the third switching, and the synchronous switching element repeats the fourth switching, the asynchronous switching element is And switching to the asynchronous rectification state in which the synchronous switching element is maintained in the off state,
    When the asynchronous switching element is in the third OFF state, the control device causes the synchronous switching element to be in the fourth OFF time, which is shorter than a third OFF time indicating the time of the third OFF state. Providing a period of control so as to be in the ON state of 4,
    The power converter characterized by this.
  10. 　前記第４のオン時間は、前記第３のオフ時間からデッドタイム期間を引いた時間よりも短いこと、
    　を特徴とした請求項８又は請求項９に記載の電力変換装置。     The fourth on-time is shorter than a time obtained by subtracting a dead time period from the third off-time;
    The power converter according to claim 8 or 9, characterized by the above.
  11. 　さらに前記制御装置は、前記移行後に、前記第３のオフ状態の時間を示す第３のオフ時間よりも短い第４のオン時間で前記同期スイッチング素子を前記第４のオン状態とする前記第４の切り替えが、複数回あるように制御すること、
    　を特徴とした請求項８から請求項１０のいずれか１項に記載の電力変換装置。     Further, after the transition, the control device sets the synchronous switching element to the fourth on state with a fourth on time shorter than a third off time indicating the time of the third off state. Control to switch multiple times,
    The power conversion device according to any one of claims 8 to 10, wherein:
  12. 　さらに前記制御装置は、前記移行後の２回目以降の前記第４の切り替えにおける前記第４のオン時間は、前記移行後の１回目の前記第４の切り替えにおける前記第４のオン時間よりも長くするように制御すること、
    　を特徴とした請求項１１に記載の電力変換装置。     Further, the control device has a fourth on-time in the fourth switching after the second time after the transition is longer than the fourth on-time in the first switching after the transition. To control,
    The power converter according to claim 11 characterized by things.
  13. 　さらに前記制御装置は、前記同期スイッチング素子のオン状態にするタイミングが、前記リアクトルに流れる電流が前記第１の端子と前記第２の端子との間に流れている間になるように制御すること、
    　を特徴とした請求項８から請求項１２のいずれか１項に記載の電力変換装置。     Further, the control device controls the timing to turn on the synchronous switching element so that the current flowing through the reactor is between the first terminal and the second terminal. ,
    The power conversion device according to any one of claims 8 to 12, characterized by:
  14. 　さらに前記制御装置は、前記同期スイッチング素子のオン状態にするタイミングが、前記非同期スイッチング素子がオフ状態にしたタイミングと同じになるように制御すること、
    　を特徴とした請求項８から請求項１２のいずれか１項に記載の電力変換装置。     Further, the control device performs control so that the timing when the synchronous switching element is turned on is the same as the timing when the asynchronous switching element is turned off,
    The power conversion device according to any one of claims 8 to 12, characterized by:
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