WO2021255849A1 - Power conversion apparatus, motor drive device, and air conditioner - Google Patents

Power conversion apparatus, motor drive device, and air conditioner Download PDF

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Publication number
WO2021255849A1
WO2021255849A1 PCT/JP2020/023725 JP2020023725W WO2021255849A1 WO 2021255849 A1 WO2021255849 A1 WO 2021255849A1 JP 2020023725 W JP2020023725 W JP 2020023725W WO 2021255849 A1 WO2021255849 A1 WO 2021255849A1
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WIPO (PCT)
Prior art keywords
voltage
current
power supply
switching element
polarity
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PCT/JP2020/023725
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French (fr)
Japanese (ja)
Inventor
厚司 土谷
和徳 畠山
啓介 植村
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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 JP2022531161A priority Critical patent/JP7455207B2/en
Priority to PCT/JP2020/023725 priority patent/WO2021255849A1/en
Publication of WO2021255849A1 publication Critical patent/WO2021255849A1/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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present disclosure relates to a power converter, a motor drive device, and an air conditioner that convert AC power into DC power.
  • Patent Document 1 describes a power conversion circuit having a configuration in which a series circuit of a first switching element and a second switching element and a series circuit of a first diode and a second diode are connected in parallel to each other.
  • a power conversion device comprising the above is disclosed.
  • An AC power supply is connected between the connection points of the first and second switching elements and the connection points of the first and second diodes via a reactor, and the first switching element and the first diode are connected.
  • a smoothing capacitor is connected between the connection point of the above and the connection point of the second switching element and the second diode.
  • the first switching element and the first diode are elements connected to the positive electrode side of the smoothing capacitor
  • the second switching element and the second diode are elements connected to the negative electrode side of the smoothing capacitor.
  • the series circuit by the first and second diodes is connected to the side of the smoothing capacitor more than the series circuit by the first and second switching elements.
  • a current detection unit for detecting the current for charging the smoothing capacitor is provided between the second diode and the negative electrode side of the smoothing capacitor. Further, one of both ends of the current detection unit is connected to GND.
  • Patent Document 1 does not consider reverse power flow to the AC power supply and an arm short circuit in which the switching elements of the upper and lower arms are turned on at the same time.
  • Reverse power flow to the AC power supply may cause distortion due to harmonics in the power supply voltage.
  • the reverse power flow to the AC power supply is an operation of returning the electric energy charged in the smoothing capacitor to the AC power supply side, which may reduce the efficiency of the power conversion device.
  • An arm short circuit shortens the life of the switching element and may damage the switching element.
  • the present disclosure has been made in view of the above, and an object of the present disclosure is to obtain a power conversion device capable of controlling to suppress reverse power flow to an AC power supply and an arm short circuit.
  • the power conversion device includes a reactor in which one end is connected to an AC power supply and a first voltage of AC output from the AC power supply is applied. And a converter circuit having a second leg and converting a first voltage into a second DC voltage.
  • the first switching element of the upper arm and the second switching element of the lower arm are connected in series, and the connection point between the first switching element and the second switching element is the other end of the reactor.
  • the second leg is connected in parallel with the first leg, the third switching element of the upper arm and the fourth switching element of the lower arm are connected in series, and the third switching element and the fourth switching are connected.
  • the connection point with the element is connected to the AC power supply.
  • the power converter has a capacitor that smoothes the second voltage, a first voltage detector that detects the first voltage, and a first current that detects a first current of both polarities flowing between the converter circuit and the capacitor. It is equipped with a current detector. When the polarity of the first current determined based on the detection signal of the first current and the polarity of the first voltage determined based on the detection signal of the first voltage do not match, the first to fourth switching elements operate. Stop.
  • FIG. 1 is a circuit diagram showing the configuration of the power conversion device 100 according to the first embodiment.
  • the power conversion device 100 according to the first embodiment converts the AC power supplied from the AC power supply 1 into DC power and supplies it to the load 500.
  • An example of a load 500 is a motor built into a blower or compressor of an air conditioner.
  • the power conversion device 100 includes a reactor 2, a converter circuit 3, a capacitor 4, and a control unit 8. Further, the power converter 100 includes a voltage detector 5 which is a first voltage detector, a voltage detector 7 which is a second voltage detector, a current detector 10 which is a first current detector, and the like. It includes a current detector 6 which is a second current detector, and a zero cross detector 9.
  • the current detector 10 includes a shunt resistor 11 and a current detection conversion unit 12.
  • One end of the reactor 2 is connected to one end of the AC power supply 1, and the other end of the reactor 2 is connected to the converter circuit 3.
  • the converter circuit 3 converts the AC voltage output from the AC power supply 1 into a DC voltage.
  • the converter circuit 3 includes a first leg 31 and a second leg 32.
  • the first leg 31 and the second leg 32 are connected in parallel.
  • the switching element 311 of the upper arm and the switching element 312 of the lower arm are connected in series.
  • the switching element 321 of the upper arm and the switching element 322 of the lower arm are connected in series.
  • the switching element 311 may be referred to as a "first switching element”
  • the switching element 312 may be referred to as a "second switching element”.
  • the switching element 321 may be referred to as a "third switching element”
  • the switching element 322 may be referred to as a "fourth switching element".
  • connection point 3a between the switching element 311 and the switching element 312 in the first leg 31.
  • connection point 3b between the switching element 321 and the switching element 322 is connected to the other end of the AC power supply 1.
  • the connection points 3a and 3b form an AC terminal.
  • the reactor 2 is connected between one end of the AC power supply 1 and the connection point 3a, but is connected between the other end of the AC power supply 1 and the connection point 3b. May be good.
  • the AC voltage output from the AC power supply 1 is called the "power supply voltage”.
  • the power supply voltage may be referred to as a "first voltage”, and the cycle of the power supply voltage may be referred to as a "power supply cycle”.
  • the switching element 311 includes a transistor Q1 and a diode D1 connected in antiparallel to the transistor Q1.
  • the switching element 312 includes a transistor Q2 and a diode D2 connected in antiparallel to the transistor Q2.
  • the switching element 321 includes a transistor Q3 and a diode D3 connected in antiparallel to the transistor Q3.
  • the switching element 322 includes a transistor Q4 and a diode D4 connected in antiparallel to the transistor Q4.
  • FIG. 1 exemplifies a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor: MOSFET) for each of the transistors Q1, Q2, Q3, and Q4, but is not limited to MOSFETs.
  • MOSFET Metal Oxide Semiconductor Field Effect Transistor
  • a MOSFET is a switching element capable of passing a current in both directions between a drain and a source. Any semiconductor element can be used as long as it is a semiconductor element capable of bidirectionally flowing a current between the first terminal corresponding to the drain and the second terminal corresponding to the source, that is, a bidirectional element.
  • antiparallel means that the first terminal corresponding to the drain of the MOSFET and the cathode of the diode are connected, and the second terminal corresponding to the source of the MOSFET and the anode of the diode are connected.
  • diode a parasitic diode contained in the MOSFET itself may be used. Parasitic diodes are also called body diodes.
  • At least one of the switching elements 311, 312, 321, 322 is not limited to the MOSFET formed of the silicon-based material, but is formed of a wide bandgap semiconductor such as silicon carbide, gallium nitride, gallium oxide or diamond. It may be a MOSFET.
  • wide bandgap semiconductors have higher withstand voltage and heat resistance than silicon semiconductors. Therefore, by using a wide bandgap semiconductor for at least one of the switching elements 311, 312, 321, 322, the withstand voltage resistance and the allowable current density of the switching element are increased, and the semiconductor module incorporating the switching element can be miniaturized. Can be changed.
  • the capacitor 4 is connected to the DC bus 16a on the high potential side.
  • the DC bus 16a is drawn from the connection point 3c between the switching element 311 in the first leg 31 and the switching element 321 in the second leg 32.
  • the other end of the capacitor 4 is connected to the DC bus 16b on the low potential side.
  • the DC bus 16b is drawn from the connection point 3d between the switching element 312 in the first leg 31 and the switching element 322 in the second leg 32.
  • the connection points 3c and 3d form a DC terminal.
  • the output voltage of the converter circuit 3 is applied to both ends of the capacitor 4.
  • the capacitor 4 is a smoothing capacitor that smoothes the output voltage of the converter circuit 3.
  • the voltage smoothed by the capacitor 4 may be referred to as "bus voltage”. Further, the bus voltage may be referred to as a "second voltage”.
  • the bus voltage is also the voltage applied to the load 500.
  • the voltage detector 5 detects the power supply voltage Vs and outputs the detection signal of the power supply voltage Vs to the control unit 8.
  • the voltage detector 7 detects the bus voltage Vdc and outputs the detection signal of the bus voltage Vdc to the control unit 8.
  • the shunt resistor 11 is arranged on the DC bus 16b.
  • the connection portion between the shunt resistor 11 and the negative electrode side terminal of the capacitor 4 is connected to GND.
  • the shunt resistor 11 detects the current Id flowing between the negative electrode side terminal of the capacitor 4 and the connection point 3d of the converter circuit 3, and outputs the detection signal of the current Id to the current detection conversion unit 12.
  • the current detection conversion unit 12 converts the detection signal of the current Id into a signal capable of discriminating between positive and negative polarities and outputs the signal to the control unit 8.
  • the current detector 10 provided with the shunt resistor 11 and the current detection conversion unit 12 detects the current Id of both polarities flowing between the converter circuit 3 and the capacitor 4, and sends the detection signal of the current Id to the control unit 8. Output.
  • the current Id may be referred to as a "first current”.
  • the detailed contents of the current detection conversion unit 12 will be described later.
  • the current detector 6 detects the power supply current Is flowing in and out of the AC power supply 1.
  • the power supply current Is is also the reactor current flowing through the reactor 2. In FIG. 1, the direction in which the arrow points is the positive direction of the power supply current Is.
  • the current detector 6 outputs a detection signal of the power supply current Is to the control unit 8.
  • An example of the current detector 6 is a current transformer (CT).
  • CT current transformer
  • the power supply current Is may be referred to as a "second current”.
  • the zero-cross detection unit 9 outputs a “High” or “Low” power supply polarity signal according to the power supply voltage Vs to the control unit 8.
  • the polarity of the power supply voltage Vs is abbreviated as "power supply polarity”.
  • FIG. 2 is a diagram showing a power supply polarity signal output by the zero-cross detection unit 9 of the power conversion device 100 according to the first embodiment.
  • the zero cross detection unit 9 outputs a “Low” signal when the power supply voltage Vs is positive, and outputs a “High” signal when the power supply voltage Vs is negative.
  • the zero cross detection unit 9 outputs a “High” signal when the power supply voltage Vs is positive, and outputs a “Low” signal when the power supply voltage Vs is negative. It may be configured to output.
  • the control unit 8 constitutes a converter circuit 3 based on the detection signal of the voltage detector 5, the detection signal of the current detector 6, the detection signal of the voltage detector 7, the power supply polarity signal, and the detection signal of the current detector 10.
  • Control signals S1 to S4 for controlling each switching element are generated.
  • the control signal S1 is a control signal for controlling the continuity of the transistor Q1
  • the control signal S2 is a control signal for controlling the continuity of the transistor Q2.
  • the control signal S3 is a control signal for controlling the continuity of the transistor Q3, and the control signal S4 is a control signal for controlling the continuity of the transistor Q4. More detailed operation of the control unit 8 will be described later.
  • the processor 8a is a calculation means called a microprocessor, a microcomputer, a microcomputer, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or the like.
  • the memory 8b may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Project ROM), or an EEPROM (registered trademark).
  • the memory 8b stores a program that executes the functions of the control unit 8 described above and the functions of the control unit 8 described later.
  • the processor 8a exchanges necessary information via an interface including an analog-to-digital converter and a digital-to-digital converter (not shown), and the processor 8a executes a program stored in the memory 8b to perform necessary processing.
  • the calculation result by the processor 8a is stored in the memory 8b.
  • FIG. 3 is a diagram showing the timing at which each switching element of the converter circuit 3 conducts in the power conversion device 100 according to the first embodiment.
  • 4 to 9 are diagrams showing first to sixth examples of current paths that may occur in the converter circuit 3 in the power conversion device according to the first embodiment, respectively.
  • FIG. 3 shows the waveforms of the power supply voltage Vs and the power supply current Is.
  • the horizontal axis of FIG. 3 represents time.
  • current synchronization "311” and “312” are current synchronization in which the switching elements 311, 312 are controlled to be turned on or off according to the polarity of the power supply current Is. It is shown that it is a switching element of.
  • voltage synchronization "321” and “322” indicate that the switching elements 321 and 322 are voltage synchronization switching elements whose on or off is controlled according to the power supply polarity. ..
  • Ith represents a current threshold value.
  • the control unit 8 controls the switching element 322 to be on and the switching element 321 to be turned off. Further, when the power supply polarity is negative, the control unit 8 controls the switching element 321 to be on and the switching element 322 to be turned off.
  • the timing at which the switching element 322 is turned from on to off and the timing at which the switching element 321 is turned from off to on are the same timing, but the timing is not limited to this.
  • the control unit 8 may provide a dead time during which the switching elements 321 and 322 are both turned off between the timing at which the switching element 322 is turned from on to off and the timing at which the switching element 321 is turned from off to on.
  • the control unit 8 provides a dead time during which the switching elements 321 and 322 are both turned off between the timing at which the switching element 321 is turned from on to off and the timing at which the switching element 322 is turned from off to on. May be good.
  • the current path when the power supply polarity is positive and the absolute value of the power supply current Is is less than the current threshold value Is is shown by a thick line.
  • the switching element 311 is not controlled to be ON. Therefore, the power supply current Is flows on the diode D1 side in the switching element 311 and flows on the transistor Q4 side in the switching element 322.
  • the control unit 8 controls the switching element 311 to be turned on when the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is.
  • the current path in this case is shown by a thick line.
  • control unit 8 controls the switching element 311 to be turned off when the absolute value of the power supply current Is becomes smaller and the absolute value of the power supply current Is becomes smaller than the current threshold value Is.
  • the current path when the power supply polarity is negative and the absolute value of the power supply current Is is less than the current threshold value Is is shown by a thick line.
  • the switching element 312 is not controlled to be ON. Therefore, the power supply current Is flows on the diode D2 side in the switching element 312, and flows on the transistor Q3 side in the switching element 321.
  • the control unit 8 controls the switching element 312 to be turned on when the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is.
  • the current path in this case is shown by a thick line.
  • control unit 8 controls the switching element 312 to be turned off when the absolute value of the power supply current Is becomes smaller and the absolute value of the power supply current Is becomes smaller than the current threshold value Is.
  • control for turning on switching elements connected in parallel when a current is flowing through the diode of each switching element is called “synchronous rectification”.
  • the control that leaves the corresponding switching element off is called “full-wave rectification”. Since the voltage drop due to the on-resistance of the transistor is smaller than the voltage drop in the forward direction of the diode, the loss in each switching element can be reduced by performing synchronous rectification. As a result, the efficiency of the power conversion device 100 can be improved.
  • the power conversion device 100 can perform power factor improvement control and bus voltage boost control of the AC power supply 1.
  • the converter circuit 3 performs an operation called a power short circuit.
  • FIG. 8 shows an example of a power supply short-circuit operation when the power supply voltage Vs is positive. From the state of FIG. 5, the switching element 322 is controlled from on to off, and the switching element 321 is controlled from off to on. Then, the power supply current Is flows in the order of the reactor 2, the switching element 311 and the switching element 321. At this time, electric energy is stored in the reactor 2.
  • the period in which the power supply current Is flows can be extended, so that the power factor of the AC power supply 1 can be improved. Further, if the capacitor 4 is charged by using the electric energy stored in the reactor 2, the bus voltage can be boosted.
  • FIG. 9 shows an example of a power supply short-circuit operation when the power supply voltage Vs is negative. From the state of FIG. 7, the switching element 321 is controlled from on to off, and the switching element 322 is controlled from off to on. Then, the power supply current Is flows in the order of the switching element 322, the switching element 312, and the reactor 2. At this time, electric energy is stored in the reactor 2. If the power supply short-circuit operation is performed, the period in which the power supply current Is flows can be extended, so that the power factor of the AC power supply 1 can be improved. Further, if the capacitor 4 is charged by using the electric energy stored in the reactor 2, the bus voltage can be boosted.
  • FIG. 10 is a diagram showing a connection relationship between the current detection and conversion unit 12 according to the first embodiment and an external component.
  • FIG. 11 is a diagram showing an example of the internal configuration of the current detection conversion unit 12 according to the first embodiment.
  • the external components are designated by the same reference numerals as those in FIG.
  • the current detection conversion unit 12 includes a level shift circuit 14.
  • the level shift circuit 14 shifts the level of the shunt resistance voltage Vsh so that the shunt resistance voltage Vsh, which is the detection voltage detected by the shunt resistance 11, becomes a level that can be input to the processor 8a.
  • the shunt resistance voltage Vsh is a voltage generated in the shunt resistor 11 by the current Id flowing in the shunt resistor 11.
  • the detected value of the current flowing from the connection point 3d side to the negative electrode side terminal of the capacitor 4 is a positive voltage.
  • the detected value of the current flowing from the negative electrode side terminal of the capacitor 4 to the connection point 3d side is the negative electrode voltage.
  • a typical example of the processor 8a is a microcomputer.
  • a microcomputer is assumed as the processor 8a.
  • the voltage output from the level shift circuit 14 and input to the processor 8a is referred to as "microcomputer input voltage” and is referred to as "Vsh_micon”.
  • the microcomputer is generally designed to detect a positive voltage of about 0 to 5 [V], but it does not support detecting a negative voltage.
  • the microcomputer since the shunt resistor 11 generates a voltage of both polarities, the microcomputer needs to accept the voltage of both polarities. Therefore, the current detection conversion unit 12 is provided with a level shift circuit 14. For example, when the maximum value of the input voltage to the microcomputer is 5 [V], the level shift circuit 14 has an offset of about 2.5 [V] to set the zero point. Then, the level shift circuit 14 outputs 0 to 2.5 [V] as a negative voltage and 2.5 to 5 [V] as a positive voltage to the microcomputer.
  • the level shift circuit 14 can be configured by a differential amplification unit 14a and an offset voltage generation unit 14b.
  • the differential amplification unit 14a includes an operational amplifier 15a and resistors R3 to R6 which are resistance elements.
  • the offset voltage generation unit 14b includes an operational amplifier 15b and resistors R1 and R2 which are resistance elements.
  • the negative terminal (-), which is the reference terminal of the operational amplifier 15a, is grounded via the resistor R4.
  • the shunt resistance voltage Vsh detected by the shunt resistor 11 is input to the positive terminal (+), which is the signal input terminal of the operational amplifier 15a, via the resistor R3.
  • the amplification factor of the operational amplifier 15a is determined based on the ratio of the resistance values of the resistors R4 and R6. That is, the amplification factor of the operational amplifier 15a can be changed by changing the ratio of the resistance values of the resistors R4 and R6.
  • the negative terminal (-) of the operational amplifier 15b is connected to the output terminal of the operational amplifier 15b to form a voltage follower circuit. Further, the voltage divider voltage divided by the resistors R1 and R2 is input to the positive terminal (+) of the operational amplifier 15b. When the resistance values of the resistors R1 and R2 are equal, a voltage of 2.5 [V] is input to the positive terminal (+) of the operational amplifier 15b. From the output terminal of the operational amplifier 15b, the same voltage as the voltage dividing voltage input to the positive terminal (+) of the operational amplifier 15b is output. This voltage is output as an offset voltage from the offset voltage generation unit 14b.
  • the offset voltage output from the offset voltage generation unit 14b is input to the positive terminal (+) of the operational amplifier 15a via the resistor R5. With this configuration, an offset voltage is superimposed on the shunt resistance voltage Vsh and input to the positive terminal (+) of the operational amplifier 15a.
  • the level shift circuit 14 has the offset voltage generation unit 14b that generates the offset voltage that shifts the level of the detection voltage of the shunt resistor 11, and the differential amplification that increases the difference voltage between the detection voltage and the offset voltage.
  • a unit 14a is provided.
  • the circuit configuration in FIG. 11 is an example, and the circuit configuration is not limited to this. If the stability of the circuit operation can be ensured by the characteristics of the operational amplifier 15a of the differential amplification unit 14a, the relationship between the resistance values of the resistors R3 and R5 and the shunt resistor 11, the operational amplifier 15b operating as the voltage follower circuit may be omitted. .. That is, the offset voltage generation unit 14b may be composed of only the voltage dividing circuits of the resistors R1 and R2.
  • the configuration is not limited to this.
  • a configuration may be used in which 0 to 2.5 [V] is input to the microcomputer as a positive voltage and 2.5 to 5 [V] is input to the microcomputer as a negative voltage.
  • the positive / negative inversion process may be performed in the microcomputer, and it is not necessary to significantly change the process in the microcomputer.
  • FIG. 12 is a diagram showing specific waveform examples of the shunt resistance voltage Vsh and the microcomputer input voltage Vsh_micon when the current in the path shown in FIGS. 4 to 7 flows.
  • the horizontal axis represents time.
  • the offset voltage Vsh_offset is 2.5 [V].
  • the microcomputer input voltage Vsh_micon is detected as a voltage that changes from 0 [V] to the offset voltage Vsh_offset, which is 2.5 [V], as shown in the upper part of FIG. ..
  • the power conversion device 100 according to the first embodiment controls to suppress reverse power flow to the AC power supply 1 and short circuit of the arm. Therefore, in the present specification, two “abnormal states”, “first abnormal state” and “second abnormal state”, are defined.
  • the first abnormal state is a state in which reverse power flow to the AC power supply 1 is occurring.
  • the second abnormal state is a state in which an "arm short circuit” occurs in any of the legs of the converter circuit 3.
  • “reverse power flow to AC power supply 1” can be paraphrased as "power supply regeneration”. In the following description, the expression “power regeneration” is used.
  • FIG. 13 is a diagram showing various operation waveforms when the power conversion device 100 according to the first embodiment performs a full-wave rectification operation or a synchronous rectification operation.
  • the waveforms of the power supply voltage Vs, the power supply current Is, the power supply polarity signal Sig (Vs), the shunt resistance voltage Vsh, and the microcomputer input voltage Vsh_micon are shown in order from the upper part. The characteristics of the individual waveforms have already been described, and the description thereof is omitted here.
  • FIG. 14 is a diagram showing various operation waveforms when the power conversion device 100 according to the first embodiment performs a synchronous rectification operation and a power supply short circuit operation.
  • the types of operation waveforms are the same as those in FIG. In FIG. 14, the power supply short-circuit operation is performed a plurality of times over a half cycle of the power supply cycle.
  • the polarity of the shunt resistance voltage Vsh is positive, and the waveform of the microcomputer input voltage Vsh_micon is also a voltage value equal to or less than the offset voltage Vsh_offset.
  • FIG. 15 is a diagram showing changes in the operation waveform when the first abnormal state occurs in the power conversion device 100 according to the first embodiment.
  • a control signal S1 for controlling the continuity of the switching element 311 and a control signal S2 for controlling the continuity of the switching element 312 are added. ..
  • FIG. 15 shows an operation waveform when the on-width T2 of the control signal S1 is wider than the flow section T1 of the power supply current Is.
  • the on-width T2 is wider than the flow section T1
  • power supply regeneration occurs in the portion indicated by the broken line circle, and the polarity of the power supply current Is is reversed.
  • the waveform of the shunt resistance voltage Vsh is inverted in the portion indicated by the broken line ellipse.
  • the microcomputer input voltage Vsh_micon is a voltage that exceeds the offset voltage Vsh_offset.
  • FIG. 16 is a diagram showing an example of a current path when the power conversion device 100 according to the first embodiment is in the first abnormal state.
  • the section in which the power supply current Is does not flow is a section in which the bus voltage Vdc is larger than the power supply voltage Vs. Therefore, as shown in FIG. 15, when the switching element 311 is controlled to be ON in the section where the power supply current Is does not flow, the power supply regeneration in which the electric charge of the capacitor 4 flows into the AC power supply 1 occurs.
  • the power supply current Is due to power supply regeneration flows in the order of the switching element 311, the reactor 2, the AC power supply 1, the switching element 322, and the shunt resistor 11. Since the power supply current Is due to power supply regeneration flows from the connection point 3d side to the negative electrode side terminal of the capacitor 4, the shunt resistance voltage Vsh becomes a positive voltage.
  • FIG. 17 is a diagram showing an example of a current path when the power conversion device 100 according to the first embodiment is in the second abnormal state.
  • a set of switching elements 321 and 322 causes an arm short circuit.
  • the shunt resistor 11 is steep because there is no circuit element other than the shunt resistor 11 between the positive electrode side terminal and the negative electrode side terminal of the capacitor 4. Current flows. Further, since the current due to the arm short circuit flows from the connection point 3d side to the negative electrode side terminal of the capacitor 4, the shunt resistance voltage Vsh becomes a positive electrode voltage.
  • FIG. 18 is a diagram showing an example of a waveform of the shunt resistance voltage Vsh when power regeneration and arm short circuit occur in the power conversion device 100 of the first embodiment.
  • FIG. 18 shows a state in which a power supply regeneration occurs at time t1 and the power supply regeneration is periodically repeated, and a state in which an arm short circuit occurs at time t2 and the arm short circuit is periodically repeated.
  • the reactor 2 is an element having a high impedance among the circuit elements of the converter circuit 3. Therefore, the rate of change of the abnormal current flowing in the first abnormal state is smaller than the rate of change of the abnormal current flowing in the second abnormal state. Therefore, the distinction between the first abnormal state and the second abnormal state can be made based on the rate of change of the current.
  • the rate of change in current is generally described as "di / dt".
  • the current Id is converted into a shunt resistance voltage Vsh by the shunt resistor 11. Therefore, using the determination index of "di / dt" is equivalent to using the determination index of "dv / dt", which is the rate of change in voltage.
  • the method for determining the abnormal state will be described.
  • the following methods are common to the determination of the first abnormal state and the second abnormal state. That is, the following method is a method for discriminating between the first abnormal state and the second abnormal state without distinguishing between them.
  • FIG. 19 is a diagram used for explaining an abnormal state determination method in the power conversion device 100 according to the first embodiment.
  • the waveform of the polarity determination voltage Vp is shown instead of the waveforms of the control signals S1 and S2.
  • the polarity determination voltage Vp is defined by the following equation (1).
  • Vp (Vsh_micon-Vsh_offset) x sig (Vs) ... (1)
  • the code of the value of the polarity determination voltage Vp is described together with the waveform of the polarity determination voltage Vp.
  • the sign of the polarity judgment voltage Vp at the place where the power supply regeneration occurs is "minus (-)", whereas the polarity judgment at the place where the power supply regeneration does not occur.
  • the sign of the voltage Vp is "plus (+)”.
  • the sign of the polarity determination voltage Vp in the place where the power supply regeneration occurs is "plus (+)”
  • the sign of the polarity determination voltage Vp is “minus ( ⁇ )”. Therefore, it can be determined whether or not the power conversion device 100 is in an abnormal state based on the following determination conditions.
  • FIG. 20 is a flowchart for explaining a processing procedure for determining an abnormal state in the power conversion device 100 according to the first embodiment.
  • the current detector 10 detects the current Id (step S101), and the voltage detector 5 detects the power supply voltage Vs (step S102).
  • the control unit 8 calculates the polarity determination voltage Vp based on the polarity of the current Id determined based on the detected value of the current Id and the polarity of the power supply voltage Vs determined based on the detected value of the power supply voltage Vs (step S103). .. As described above, the polarity determination voltage Vp can be calculated using the above equation (1). Information on the polarity of the power supply voltage Vs is obtained from the power supply polarity signal Sig (Vs), and information on the polarity of the current Id is obtained by "Vsh_micon-Vsh_offset" which is a difference value between the microcomputer input voltage Vsh_micon and the offset voltage Vsh_offset. Be done.
  • the control unit 8 determines whether the polarity of the current Id and the polarity of the power supply voltage Vs match or do not match based on the polarity determination voltage Vp (step S104). When the mutual polarities match, that is, when the polarities of the current Id and the polarities of the power supply voltage Vs match (steps S105, Yes), the control unit 8 continues the normal operation (step S106). ). After that, the processes of steps S101 to S105 are repeated.
  • step S105 when the polarities do not match each other, that is, when the polarities of the current Id and the polarities of the power supply voltage Vs do not match (steps S105, No), the power conversion device 100 is the first control unit 8. It is determined that the first or second abnormal state is present (step S107).
  • the control unit 8 calculates the rate of change dI / dt of the current Id (step S108).
  • the control unit 8 compares the rate of change of the current Id with the determination value (step S109). When the rate of change of the current Id is equal to or less than the determination value (step S109, No), the control unit 8 determines that the power conversion device 100 is in the first abnormal state (step S110), and each of the power conversion devices 100 The switching control for the switching element is stopped (step S111). After that, the processes of steps S101 to S109 are repeated.
  • step S111 the power conversion device 100 shifts from the synchronous rectification operation to the full-wave rectification operation.
  • the application example of the power conversion device 100 is an air conditioner, the operation efficiency is lowered, but the operation of the device can be continued.
  • step S109 when the rate of change of the current Id exceeds the determination value (step S109, Yes), the control unit 8 determines that the power conversion device 100 is in the second abnormal state (step S112). , The operation of the power conversion device 100 and the load 500 is stopped (step S113), and the processing of the flowchart of FIG. 20 is completed.
  • step S109 the case where the rate of change of the current Id is equal to the determination value is determined as "No", but it may be determined as "Yes”. That is, the case where the rate of change of the current Id is equal to the determination value may be determined by either "Yes” or "No".
  • the processing procedure is more complicated than that in FIG. 20, but there is an effect that the operation of the power conversion device 100 and the load 500 can be stopped quickly.
  • the power conversion device detects the first current of both polarities flowing between the converter circuit and the capacitor and the first voltage output from the AC power supply 1. Further, the power conversion device is provided in the converter circuit when the polarity of the first current determined based on the detection signal of the first current and the polarity of the first voltage determined based on the detection signal of the first voltage do not match.
  • the first to fourth switching elements are configured to stop operating. This has the effect of enabling control to suppress reverse power flow to the AC power supply and short circuit of the arm.
  • the processor of the control unit is a microcomputer, it is possible to detect the first current of both polarities by providing a level shift circuit in the current detector.
  • Embodiment 2 The power conversion device described in the first embodiment can be used as a motor drive device for supplying DC power to the inverter.
  • a motor drive device for supplying DC power to the inverter.
  • FIG. 21 is a diagram showing a configuration example of the motor drive device 101 according to the second embodiment.
  • the motor drive device 101 according to the second embodiment is configured by using the power conversion device 100 shown in the first embodiment.
  • an inverter 500a is connected to the power conversion device 100.
  • the power conversion device 100 is a device that converts AC power into DC power.
  • the inverter 500a is a device that converts DC power output from the power conversion device 100 into AC power.
  • a motor 500b is connected to the output side of the inverter 500a.
  • the inverter 500a drives the motor 500b by supplying the converted AC power to the motor 500b.
  • the motor drive device 101 shown in FIG. 21 can be applied to a blower of an air conditioner and a compressor of an air conditioner.
  • FIG. 22 is a diagram showing an example in which the motor drive device 101 shown in FIG. 21 is applied to an air conditioner.
  • a motor 500b is connected to the output side of the motor drive device 101, and the motor 500b is connected to the compression element 504.
  • the compressor 505 includes a motor 500b and a compression element 504.
  • the refrigeration cycle unit 506 is configured to include a four-way valve 506a, an indoor heat exchanger 506b, an expansion valve 506c, and an outdoor heat exchanger 506d.
  • the flow path of the refrigerant circulating inside the air conditioner is from the compression element 504 via the four-way valve 506a, the indoor heat exchanger 506b, the expansion valve 506c, the outdoor heat exchanger 506d, and again via the four-way valve 506a. , It is configured to return to the compression element 504.
  • the motor drive device 101 receives AC power from the AC power supply 1 and rotates the motor 500b.
  • the compression element 504 executes a compression operation of the refrigerant by rotating the motor 500b, and circulates the refrigerant inside the refrigeration cycle unit 506.
  • the power conversion device according to the first embodiment is used because the power conversion device according to the first embodiment is used. It is possible to enjoy the effects that it possesses.
  • the configuration shown in the above embodiment is an example, and can be combined with another known technique, or a part of the configuration may be omitted or changed without departing from the gist. It is possible.

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Abstract

This power conversion apparatus (100) comprises a reactor (2) to which a power supply voltage Vs is applied, and a converter circuit (3) that converts the power supply voltage Vs to a bus voltage Vdc. The converter circuit (3) comprises four switching elements (311 to 322). A connection point (3a) of the switching elements (311, 312) is connected to one end of an AC power supply (1) with the reactor (2) interposed therebetween, and a connection point (3b) of the switching elements (321, 322) is connected to the other end of the AC power supply (1). The power conversion apparatus (100) comprises a voltage detector (5) that detects the power supply voltage Vs, and a current detector (10) that detects the current Id of both polarities flowing between the converter circuit (3) and a capacitor (4). When there is a mismatch between the polarity of the current Id determined based on the detection signal of the current Id, and the polarity of the power supply voltage Vs determined based on the detection signal of the power supply voltage Vs, the operation of the switching elements (311 to 322) is stopped.

Description

電力変換装置、モータ駆動装置及び空気調和機Power converter, motor drive and air conditioner
　本開示は、交流電力を直流電力に変換する電力変換装置、モータ駆動装置及び空気調和機に関する。 The present disclosure relates to a power converter, a motor drive device, and an air conditioner that convert AC power into DC power.
　下記特許文献１には、第１のスイッチング素子と第２のスイッチング素子との直列回路と、第１のダイオードと第２のダイオードとの直列回路とが互いに並列に接続される構成の電力変換回路を備えた電力変換装置が開示されている。第１及び第２のスイッチング素子の接続点と、第１及第２のダイオードの接続点との間には、リアクタを介して交流電源が接続され、第１のスイッチング素子と第１のダイオードとの接続点と、第２のスイッチング素子と第２のダイオードとの接続点との間には、平滑コンデンサが接続されている。 The following Patent Document 1 describes a power conversion circuit having a configuration in which a series circuit of a first switching element and a second switching element and a series circuit of a first diode and a second diode are connected in parallel to each other. A power conversion device comprising the above is disclosed. An AC power supply is connected between the connection points of the first and second switching elements and the connection points of the first and second diodes via a reactor, and the first switching element and the first diode are connected. A smoothing capacitor is connected between the connection point of the above and the connection point of the second switching element and the second diode.
　第１のスイッチング素子及び第１のダイオードは平滑コンデンサの正極側に接続される素子であり、第２のスイッチング素子及び第２のダイオードは平滑コンデンサの負極側に接続される素子である。第１及び第２のダイオードによる直列回路は、第１及び第２のスイッチング素子による直列回路よりも、平滑コンデンサの側に接続されている。また、第２のダイオードと平滑コンデンサの負極側との間には、平滑コンデンサに電荷をチャージする電流を検出するための電流検出部が設けられている。更に、電流検出部の両端部のうちの何れか一方は、ＧＮＤに接続されている。 The first switching element and the first diode are elements connected to the positive electrode side of the smoothing capacitor, and the second switching element and the second diode are elements connected to the negative electrode side of the smoothing capacitor. The series circuit by the first and second diodes is connected to the side of the smoothing capacitor more than the series circuit by the first and second switching elements. Further, a current detection unit for detecting the current for charging the smoothing capacitor is provided between the second diode and the negative electrode side of the smoothing capacitor. Further, one of both ends of the current detection unit is connected to GND.
特開２０１７－３４８２９号公報Japanese Unexamined Patent Publication No. 2017-34829
　しかしながら、特許文献１には、交流電源への逆潮流、及び上下アームのスイッチング素子が同時にオンするアーム短絡についての考慮はなされていない。交流電源への逆潮流は、電源電圧に高調波による歪みを発生させるおそれがある。また、交流電源への逆潮流は、平滑コンデンサにチャージされた電気エネルギーを交流電源側に戻してしまう動作であり、電力変換装置の効率を低下させるおそれがある。アーム短絡は、スイッチング素子の寿命を低下させ、スイッチング素子を損傷させるおそれがある。 However, Patent Document 1 does not consider reverse power flow to the AC power supply and an arm short circuit in which the switching elements of the upper and lower arms are turned on at the same time. Reverse power flow to the AC power supply may cause distortion due to harmonics in the power supply voltage. Further, the reverse power flow to the AC power supply is an operation of returning the electric energy charged in the smoothing capacitor to the AC power supply side, which may reduce the efficiency of the power conversion device. An arm short circuit shortens the life of the switching element and may damage the switching element.
　また、特許文献１に記載の構成では、何れか一方の極性の電流しか検出できない。このため、特許文献１に記載の電力変換装置では、電流検出部の検出値に基づいて、交流電源への逆潮流及びアーム短絡を抑止する制御を行うことは困難である。 Further, in the configuration described in Patent Document 1, only the current of one of the polarities can be detected. Therefore, in the power conversion device described in Patent Document 1, it is difficult to control the reverse power flow to the AC power supply and the short circuit of the arm based on the detection value of the current detection unit.
　本開示は、上記に鑑みてなされたものであって、交流電源への逆潮流及びアーム短絡を抑止する制御を可能とする電力変換装置を得ることを目的とする。 The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain a power conversion device capable of controlling to suppress reverse power flow to an AC power supply and an arm short circuit.
　上述した課題を解決し、目的を達成するため、本開示に係る電力変換装置は、一端が交流電源に接続され、交流電源から出力される交流の第１電圧が印加されるリアクタと、第１及び第２のレグを有し、第１電圧を直流の第２電圧に変換するコンバータ回路と、を備える。第１のレグは、上アームの第１のスイッチング素子と下アームの第２のスイッチング素子とが直列に接続され、第１のスイッチング素子と第２のスイッチング素子との接続点がリアクタの他端に接続される。第２のレグは、第１のレグと並列に接続され、上アームの第３のスイッチング素子と下アームの第４のスイッチング素子とが直列に接続され、第３のスイッチング素子と第４のスイッチング素子との接続点が交流電源に接続される。また、電力変換装置は、第２電圧を平滑するコンデンサと、第１電圧を検出する第１の電圧検出器と、コンバータ回路とコンデンサとの間に流れる両極性の第１電流を検出する第１の電流検出器と、を備える。第１電流の検出信号に基づいて定まる第１電流の極性と、第１電圧の検出信号に基づいて定まる第１電圧の極性とが不一致の場合、第１から第４のスイッチング素子は、動作を停止する。 In order to solve the above-mentioned problems and achieve the object, the power conversion device according to the present disclosure includes a reactor in which one end is connected to an AC power supply and a first voltage of AC output from the AC power supply is applied. And a converter circuit having a second leg and converting a first voltage into a second DC voltage. In the first leg, the first switching element of the upper arm and the second switching element of the lower arm are connected in series, and the connection point between the first switching element and the second switching element is the other end of the reactor. Connected to. The second leg is connected in parallel with the first leg, the third switching element of the upper arm and the fourth switching element of the lower arm are connected in series, and the third switching element and the fourth switching are connected. The connection point with the element is connected to the AC power supply. Further, the power converter has a capacitor that smoothes the second voltage, a first voltage detector that detects the first voltage, and a first current that detects a first current of both polarities flowing between the converter circuit and the capacitor. It is equipped with a current detector. When the polarity of the first current determined based on the detection signal of the first current and the polarity of the first voltage determined based on the detection signal of the first voltage do not match, the first to fourth switching elements operate. Stop.
　本開示に係る電力変換装置によれば、交流電源への逆潮流及びアーム短絡を抑止する制御が可能になるという効果を奏する。 According to the power conversion device according to the present disclosure, there is an effect that control for suppressing reverse power flow to the AC power supply and short circuit of the arm becomes possible.
実施の形態１に係る電力変換装置の構成を示す回路図A circuit diagram showing the configuration of the power conversion device according to the first embodiment. 実施の形態１に係る電力変換装置のゼロクロス検出部が出力する電源極性信号を示す図The figure which shows the power supply polarity signal output by the zero cross detection part of the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路の各スイッチング素子が導通するタイミングを示す図The figure which shows the timing which each switching element of a converter circuit conducts in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第１の例を示す図The figure which shows the 1st example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第２の例を示す図The figure which shows the 2nd example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第３の例を示す図The figure which shows the 3rd example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第４の例を示す図The figure which shows the 4th example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第５の例を示す図The figure which shows the 5th example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置においてコンバータ回路に生じ得る電流経路の第６の例を示す図The figure which shows the sixth example of the current path which can occur in the converter circuit in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電流検出変換部と外部の構成要素との間の接続関係を示す図The figure which shows the connection relationship between the current detection conversion part which concerns on Embodiment 1 and an external component. 実施の形態１に係る電流検出変換部の内部の構成例を示す図The figure which shows the structural example of the inside of the current detection conversion part which concerns on Embodiment 1. 図４から図７に示す経路の電流が流れた場合におけるシャント抵抗電圧及びマイコン入力電圧の具体的な波形例を示す図The figure which shows the specific waveform example of the shunt resistance voltage and the microcomputer input voltage when the current of the path shown in FIG. 4 to FIG. 7 flows. 実施の形態１に係る電力変換装置が全波整流動作又は同期整流動作を実施している場合の各種の動作波形を示す図The figure which shows various operation waveforms when the power conversion apparatus which concerns on Embodiment 1 performs a full-wave rectification operation or a synchronous rectification operation. 実施の形態１に係る電力変換装置が同期整流動作及び電源短絡動作を実施している場合の各種の動作波形を示す図The figure which shows various operation waveforms when the power conversion apparatus which concerns on Embodiment 1 performs a synchronous rectification operation and a power supply short-circuit operation. 実施の形態１に係る電力変換装置に第１の異常状態が生じたときの動作波形の変化を示す図The figure which shows the change of the operation waveform when the first abnormal state occurs in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置が第１の異常状態であるときの電流経路の例を示す図The figure which shows the example of the current path when the power conversion apparatus which concerns on Embodiment 1 is a 1st abnormal state. 実施の形態１に係る電力変換装置が第２の異常状態であるときの電流経路の例を示す図The figure which shows the example of the current path when the power conversion apparatus which concerns on Embodiment 1 is a 2nd abnormal state. 実施の形態１の電力変換装置において電源回生とアーム短絡とが生じた場合のシャント抵抗電圧の波形例を示す図The figure which shows the waveform example of the shunt resistance voltage when the power supply regeneration and the arm short circuit occur in the power conversion apparatus of Embodiment 1. 実施の形態１に係る電力変換装置における異常状態の判定手法の説明に供する図The figure which provides the explanation of the abnormality state determination method in the power conversion apparatus which concerns on Embodiment 1. 実施の形態１に係る電力変換装置における異常状態判定の処理手順の説明に供するフローチャートA flowchart used to explain the processing procedure for determining an abnormal state in the power conversion device according to the first embodiment. 実施の形態２に係るモータ駆動装置の構成例を示す図The figure which shows the structural example of the motor drive device which concerns on Embodiment 2. 図２１に示したモータ駆動装置を空気調和機に適用した例を示す図The figure which shows the example which applied the motor drive device shown in FIG. 21 to an air conditioner.
　以下に添付図面を参照し、本開示の実施の形態に係る電力変換装置、モータ駆動装置及び空気調和機について詳細に説明する。 The power conversion device, the motor drive device, and the air conditioner according to the embodiment of the present disclosure will be described in detail with reference to the attached drawings below.
実施の形態１．
　図１は、実施の形態１に係る電力変換装置１００の構成を示す回路図である。実施の形態１に係る電力変換装置１００は、交流電源１から供給される交流電力を直流電力に変換して負荷５００に供給する。負荷５００の例は、空気調和機の送風機又は圧縮機に内蔵されるモータである。 Embodiment 1.
FIG. 1 is a circuit diagram showing the configuration of the power conversion device 100 according to the first embodiment. The power conversion device 100 according to the first embodiment converts the AC power supplied from the AC power supply 1 into DC power and supplies it to the load 500. An example of a load 500 is a motor built into a blower or compressor of an air conditioner.
　実施の形態１に係る電力変換装置１００は、図１に示すように、リアクタ２と、コンバータ回路３と、コンデンサ４と、制御部８とを備える。また、電力変換装置１００は、第１の電圧検出器である電圧検出器５と、第２の電圧検出器である電圧検出器７と、第１の電流検出器である電流検出器１０と、第２の電流検出器である電流検出器６と、ゼロクロス検出部９とを備える。電流検出器１０は、シャント抵抗１１と、電流検出変換部１２とを備える。 As shown in FIG. 1, the power conversion device 100 according to the first embodiment includes a reactor 2, a converter circuit 3, a capacitor 4, and a control unit 8. Further, the power converter 100 includes a voltage detector 5 which is a first voltage detector, a voltage detector 7 which is a second voltage detector, a current detector 10 which is a first current detector, and the like. It includes a current detector 6 which is a second current detector, and a zero cross detector 9. The current detector 10 includes a shunt resistor 11 and a current detection conversion unit 12.
　リアクタ２の一端は交流電源１の一端に接続され、リアクタ２の他端はコンバータ回路３に接続される。コンバータ回路３は、交流電源１から出力される交流電圧を直流電圧に変換する。 One end of the reactor 2 is connected to one end of the AC power supply 1, and the other end of the reactor 2 is connected to the converter circuit 3. The converter circuit 3 converts the AC voltage output from the AC power supply 1 into a DC voltage.
　コンバータ回路３は、第１のレグ３１と、第２のレグ３２とを備える。第１のレグ３１と第２のレグ３２とは、並列に接続されている。第１のレグ３１では、上アームのスイッチング素子３１１と、下アームのスイッチング素子３１２とが直列に接続されている。第２のレグ３２では、上アームのスイッチング素子３２１と、下アームのスイッチング素子３２２とが直列に接続されている。なお、スイッチング素子３１１を「第１のスイッチング素子」と呼び、スイッチング素子３１２を「第２のスイッチング素子」と呼ぶ場合がある。また、スイッチング素子３２１を「第３のスイッチング素子」と呼び、スイッチング素子３２２を「第４のスイッチング素子」と呼ぶ場合がある。 The converter circuit 3 includes a first leg 31 and a second leg 32. The first leg 31 and the second leg 32 are connected in parallel. In the first leg 31, the switching element 311 of the upper arm and the switching element 312 of the lower arm are connected in series. In the second leg 32, the switching element 321 of the upper arm and the switching element 322 of the lower arm are connected in series. The switching element 311 may be referred to as a "first switching element", and the switching element 312 may be referred to as a "second switching element". Further, the switching element 321 may be referred to as a "third switching element", and the switching element 322 may be referred to as a "fourth switching element".
　リアクタ２の他端は、第１のレグ３１におけるスイッチング素子３１１とスイッチング素子３１２との接続点３ａに接続されている。スイッチング素子３２１とスイッチング素子３２２との接続点３ｂは、交流電源１の他端に接続されている。コンバータ回路３において、接続点３ａ，３ｂは、交流端子を構成する。 The other end of the reactor 2 is connected to the connection point 3a between the switching element 311 and the switching element 312 in the first leg 31. The connection point 3b between the switching element 321 and the switching element 322 is connected to the other end of the AC power supply 1. In the converter circuit 3, the connection points 3a and 3b form an AC terminal.
　なお、図１において、リアクタ２は、交流電源１の一端と、接続点３ａとの間に接続されているが、交流電源１の別の一端と、接続点３ｂとの間に接続されていてもよい。 In FIG. 1, the reactor 2 is connected between one end of the AC power supply 1 and the connection point 3a, but is connected between the other end of the AC power supply 1 and the connection point 3b. May be good.
　交流電源１から出力される交流電圧を「電源電圧」と呼ぶ。なお、電源電圧を「第１電圧」と呼び、電源電圧の周期を「電源周期」と呼ぶ場合がある。 The AC voltage output from the AC power supply 1 is called the "power supply voltage". The power supply voltage may be referred to as a "first voltage", and the cycle of the power supply voltage may be referred to as a "power supply cycle".
　スイッチング素子３１１は、トランジスタＱ１と、トランジスタＱ１に逆並列に接続されるダイオードＤ１とを含む。スイッチング素子３１２は、トランジスタＱ２と、トランジスタＱ２に逆並列に接続されるダイオードＤ２とを含む。スイッチング素子３２１は、トランジスタＱ３と、トランジスタＱ３に逆並列に接続されるダイオードＤ３とを含む。スイッチング素子３２２は、トランジスタＱ４と、トランジスタＱ４に逆並列に接続されるダイオードＤ４とを含む。 The switching element 311 includes a transistor Q1 and a diode D1 connected in antiparallel to the transistor Q1. The switching element 312 includes a transistor Q2 and a diode D2 connected in antiparallel to the transistor Q2. The switching element 321 includes a transistor Q3 and a diode D3 connected in antiparallel to the transistor Q3. The switching element 322 includes a transistor Q4 and a diode D4 connected in antiparallel to the transistor Q4.
　図１では、トランジスタＱ１，Ｑ２，Ｑ３，Ｑ４のそれぞれに金属酸化物半導体電界効果トランジスタ（Ｍｅｔａｌ　Ｏｘｉｄｅ　Ｓｅｍｉｃｏｎｄｕｃｔｏｒ　Ｆｉｅｌｄ　Ｅｆｆｅｃｔ　Ｔｒａｎｓｉｓｔｏｒ：ＭＯＳＦＥＴ）を例示しているが、ＭＯＳＦＥＴに限定されない。ＭＯＳＦＥＴは、ドレインとソースとの間で双方向に電流を流すことができるスイッチング素子である。ドレインに相当する第１端子とソースに相当する第２端子との間で双方向に電流を流すことができる半導体素子、即ち双方向素子であれば、どのような半導体素子でもよい。 FIG. 1 exemplifies a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor: MOSFET) for each of the transistors Q1, Q2, Q3, and Q4, but is not limited to MOSFETs. A MOSFET is a switching element capable of passing a current in both directions between a drain and a source. Any semiconductor element can be used as long as it is a semiconductor element capable of bidirectionally flowing a current between the first terminal corresponding to the drain and the second terminal corresponding to the source, that is, a bidirectional element.
　また、逆並列とは、ＭＯＳＦＥＴのドレインに相当する第１端子とダイオードのカソードとが接続され、ＭＯＳＦＥＴのソースに相当する第２端子とダイオードのアノードとが接続されることを意味する。なお、ダイオードは、ＭＯＳＦＥＴ自身が内部に有する寄生ダイオードを用いてもよい。寄生ダイオードは、ボディダイオードとも呼ばれる。 Also, antiparallel means that the first terminal corresponding to the drain of the MOSFET and the cathode of the diode are connected, and the second terminal corresponding to the source of the MOSFET and the anode of the diode are connected. As the diode, a parasitic diode contained in the MOSFET itself may be used. Parasitic diodes are also called body diodes.
　また、スイッチング素子３１１，３１２，３２１，３２２のうちの少なくとも１つは、シリコン系材料により形成されたＭＯＳＦＥＴに限定されず、炭化珪素、窒化ガリウム、酸化ガリウム又はダイヤモンドといったワイドバンドギャップ半導体により形成されたＭＯＳＦＥＴでもよい。 Further, at least one of the switching elements 311, 312, 321, 322 is not limited to the MOSFET formed of the silicon-based material, but is formed of a wide bandgap semiconductor such as silicon carbide, gallium nitride, gallium oxide or diamond. It may be a MOSFET.
　一般的にワイドバンドギャップ半導体は、シリコン半導体に比べて耐電圧及び耐熱性が高い。そのため、スイッチング素子３１１，３１２，３２１，３２２のうちの少なくとも１つにワイドバンドギャップ半導体を用いることにより、スイッチング素子の耐電圧性及び許容電流密度が高くなり、スイッチング素子を組み込んだ半導体モジュールを小型化できる。 Generally, wide bandgap semiconductors have higher withstand voltage and heat resistance than silicon semiconductors. Therefore, by using a wide bandgap semiconductor for at least one of the switching elements 311, 312, 321, 322, the withstand voltage resistance and the allowable current density of the switching element are increased, and the semiconductor module incorporating the switching element can be miniaturized. Can be changed.
　コンデンサ４の一端は、高電位側の直流母線１６ａに接続されている。直流母線１６ａは、第１のレグ３１におけるスイッチング素子３１１と、第２のレグ３２におけるスイッチング素子３２１との接続点３ｃから引き出されている。コンデンサ４の他端は、低電位側の直流母線１６ｂに接続されている。直流母線１６ｂは、第１のレグ３１におけるスイッチング素子３１２と、第２のレグ３２におけるスイッチング素子３２２との接続点３ｄから引き出されている。コンバータ回路３において、接続点３ｃ，３ｄは、直流端子を構成する。 One end of the capacitor 4 is connected to the DC bus 16a on the high potential side. The DC bus 16a is drawn from the connection point 3c between the switching element 311 in the first leg 31 and the switching element 321 in the second leg 32. The other end of the capacitor 4 is connected to the DC bus 16b on the low potential side. The DC bus 16b is drawn from the connection point 3d between the switching element 312 in the first leg 31 and the switching element 322 in the second leg 32. In the converter circuit 3, the connection points 3c and 3d form a DC terminal.
　コンバータ回路３の出力電圧は、コンデンサ４の両端に印加される。コンデンサ４は、コンバータ回路３の出力電圧を平滑する平滑コンデンサである。なお、コンデンサ４で平滑された電圧を「母線電圧」と呼ぶ場合がある。また、母線電圧を「第２電圧」と呼ぶ場合がある。母線電圧は、負荷５００への印加電圧でもある。 The output voltage of the converter circuit 3 is applied to both ends of the capacitor 4. The capacitor 4 is a smoothing capacitor that smoothes the output voltage of the converter circuit 3. The voltage smoothed by the capacitor 4 may be referred to as "bus voltage". Further, the bus voltage may be referred to as a "second voltage". The bus voltage is also the voltage applied to the load 500.
　電圧検出器５は、電源電圧Ｖｓを検出し、電源電圧Ｖｓの検出信号を制御部８に出力する。電圧検出器７は、母線電圧Ｖｄｃを検出し、母線電圧Ｖｄｃの検出信号を制御部８に出力する。 The voltage detector 5 detects the power supply voltage Vs and outputs the detection signal of the power supply voltage Vs to the control unit 8. The voltage detector 7 detects the bus voltage Vdc and outputs the detection signal of the bus voltage Vdc to the control unit 8.
　シャント抵抗１１は、直流母線１６ｂに配置される。シャント抵抗１１とコンデンサ４の負極側端子との接続部はＧＮＤに接続されている。シャント抵抗１１は、コンデンサ４の負極側端子とコンバータ回路３の接続点３ｄとの間に流れる電流Ｉｄを検出し、電流Ｉｄの検出信号を電流検出変換部１２に出力する。電流検出変換部１２は、電流Ｉｄの検出信号を正又は負の極性を判別可能な信号に変換して制御部８に出力する。即ち、シャント抵抗１１及び電流検出変換部１２を備えた電流検出器１０は、コンバータ回路３とコンデンサ４との間に流れる両極性の電流Ｉｄを検出し、電流Ｉｄの検出信号を制御部８に出力する。電流Ｉｄを「第１電流」と呼ぶ場合がある。電流検出変換部１２の詳細な内容は、後述する。 The shunt resistor 11 is arranged on the DC bus 16b. The connection portion between the shunt resistor 11 and the negative electrode side terminal of the capacitor 4 is connected to GND. The shunt resistor 11 detects the current Id flowing between the negative electrode side terminal of the capacitor 4 and the connection point 3d of the converter circuit 3, and outputs the detection signal of the current Id to the current detection conversion unit 12. The current detection conversion unit 12 converts the detection signal of the current Id into a signal capable of discriminating between positive and negative polarities and outputs the signal to the control unit 8. That is, the current detector 10 provided with the shunt resistor 11 and the current detection conversion unit 12 detects the current Id of both polarities flowing between the converter circuit 3 and the capacitor 4, and sends the detection signal of the current Id to the control unit 8. Output. The current Id may be referred to as a "first current". The detailed contents of the current detection conversion unit 12 will be described later.
　電流検出器６は、交流電源１に流出入する電源電流Ｉｓを検出する。電源電流Ｉｓは、リアクタ２に流れるリアクタ電流でもある。図１において、矢印が向いている方向を電源電流Ｉｓの正方向とする。電流検出器６は、電源電流Ｉｓの検出信号を制御部８に出力する。電流検出器６の一例は、変流器（Ｃｕｒｒｅｎｔ　Ｔｒａｎｓｆｏｒｍｅｒ：ＣＴ）である。なお、説明の簡便化のため、電源電流Ｉｓを「第２電流」と呼ぶ場合がある。 The current detector 6 detects the power supply current Is flowing in and out of the AC power supply 1. The power supply current Is is also the reactor current flowing through the reactor 2. In FIG. 1, the direction in which the arrow points is the positive direction of the power supply current Is. The current detector 6 outputs a detection signal of the power supply current Is to the control unit 8. An example of the current detector 6 is a current transformer (CT). For the sake of simplicity of explanation, the power supply current Is may be referred to as a "second current".
　ゼロクロス検出部９は、電源電圧Ｖｓに応じた“Ｈｉｇｈ”又は“Ｌｏｗ”の電源極性信号を制御部８に出力する。なお、以下では、説明の簡便化のため、電源電圧Ｖｓの極性を「電源極性」と略す。 The zero-cross detection unit 9 outputs a “High” or “Low” power supply polarity signal according to the power supply voltage Vs to the control unit 8. In the following, for the sake of simplicity of explanation, the polarity of the power supply voltage Vs is abbreviated as "power supply polarity".
　図２は、実施の形態１に係る電力変換装置１００のゼロクロス検出部９が出力する電源極性信号を示す図である。図２に示すように、ゼロクロス検出部９は、電源電圧Ｖｓが正極性のときは“Ｌｏｗ”の信号を出力し、電源電圧Ｖｓが負極性のときは“Ｈｉｇｈ”の信号を出力する。なお、図２の例に限定されず、ゼロクロス検出部９は、電源電圧Ｖｓが正極性のときに“Ｈｉｇｈ”の信号を出力し、電源電圧Ｖｓが負極性のときに“Ｌｏｗ”の信号を出力するように構成されていてもよい。 FIG. 2 is a diagram showing a power supply polarity signal output by the zero-cross detection unit 9 of the power conversion device 100 according to the first embodiment. As shown in FIG. 2, the zero cross detection unit 9 outputs a “Low” signal when the power supply voltage Vs is positive, and outputs a “High” signal when the power supply voltage Vs is negative. Not limited to the example of FIG. 2, the zero cross detection unit 9 outputs a “High” signal when the power supply voltage Vs is positive, and outputs a “Low” signal when the power supply voltage Vs is negative. It may be configured to output.
　制御部８は、電圧検出器５の検出信号、電流検出器６の検出信号、電圧検出器７の検出信号、電源極性信号及び電流検出器１０の検出信号に基づいて、コンバータ回路３を構成する各スイッチング素子を制御するための制御信号Ｓ１～Ｓ４を生成する。制御信号Ｓ１はトランジスタＱ１の導通を制御するための制御信号であり、制御信号Ｓ２はトランジスタＱ２の導通を制御するための制御信号である。制御信号Ｓ３はトランジスタＱ３の導通を制御するための制御信号であり、制御信号Ｓ４はトランジスタＱ４の導通を制御するための制御信号である。制御部８の更に詳細な動作は後述する。 The control unit 8 constitutes a converter circuit 3 based on the detection signal of the voltage detector 5, the detection signal of the current detector 6, the detection signal of the voltage detector 7, the power supply polarity signal, and the detection signal of the current detector 10. Control signals S1 to S4 for controlling each switching element are generated. The control signal S1 is a control signal for controlling the continuity of the transistor Q1, and the control signal S2 is a control signal for controlling the continuity of the transistor Q2. The control signal S3 is a control signal for controlling the continuity of the transistor Q3, and the control signal S4 is a control signal for controlling the continuity of the transistor Q4. More detailed operation of the control unit 8 will be described later.
　制御部８において、プロセッサ８ａは、マイクロプロセッサ、マイクロコンピュータ、マイコン、ＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）、ＤＳＰ（Ｄｉｇｉｔａｌ　Ｓｉｇｎａｌ　Ｐｒｏｃｅｓｓｏｒ）などと称される演算手段である。メモリ８ｂは、ＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）、ＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、フラッシュメモリ、ＥＰＲＯＭ（Ｅｒａｓａｂｌｅ　Ｐｒｏｇｒａｍｍａｂｌｅ　ＲＯＭ）、ＥＥＰＲＯＭ（登録商標）（Ｅｌｅｃｔｒｉｃａｌｌｙ　ＥＰＲＯＭ）といった不揮発性又は揮発性の半導体メモリを例示できる。 In the control unit 8, the processor 8a is a calculation means called a microprocessor, a microcomputer, a microcomputer, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or the like. The memory 8b may be a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Project ROM), or an EEPROM (registered trademark).
　メモリ８ｂには、上述した制御部８の機能、及び後述する制御部８の機能を実行するプログラムが格納されている。プロセッサ８ａは、図示しないアナログディジタル変換器及びディジタルアナログ変換器を含むインタフェースを介して必要な情報を授受し、メモリ８ｂに格納されたプログラムをプロセッサ８ａが実行することにより、所要の処理を行う。プロセッサ８ａによる演算結果は、メモリ８ｂに記憶される。 The memory 8b stores a program that executes the functions of the control unit 8 described above and the functions of the control unit 8 described later. The processor 8a exchanges necessary information via an interface including an analog-to-digital converter and a digital-to-digital converter (not shown), and the processor 8a executes a program stored in the memory 8b to perform necessary processing. The calculation result by the processor 8a is stored in the memory 8b.
　次に、実施の形態１に係る電力変換装置１００の基本的な動作について、図３から図９の図面を参照して説明する。図３は、実施の形態１に係る電力変換装置１００において、コンバータ回路３の各スイッチング素子が導通するタイミングを示す図である。また、図４から図９は、それぞれ実施の形態１に係る電力変換装置において、コンバータ回路３に生じ得る電流経路の第１から第６の例を示す図である。 Next, the basic operation of the power conversion device 100 according to the first embodiment will be described with reference to the drawings of FIGS. 3 to 9. FIG. 3 is a diagram showing the timing at which each switching element of the converter circuit 3 conducts in the power conversion device 100 according to the first embodiment. 4 to 9 are diagrams showing first to sixth examples of current paths that may occur in the converter circuit 3 in the power conversion device according to the first embodiment, respectively.
　図３の上段部には、電源電圧Ｖｓ及び電源電流Ｉｓの各波形が示されている。図３の横軸は、時間を表している。また、図３の下段部において、“電流同期”、“３１１”及び“３１２”とあるのは、スイッチング素子３１１，３１２が、電源電流Ｉｓの極性に応じてオン又はオフが制御される電流同期のスイッチング素子であることを示している。また、“電圧同期”、“３２１”及び“３２２”とあるのは、スイッチング素子３２１，３２２が、電源極性に応じてオン又はオフが制御される電圧同期のスイッチング素子であることを示している。更に、図３において、“Ｉｔｈ”は電流閾値を表している。 The upper part of FIG. 3 shows the waveforms of the power supply voltage Vs and the power supply current Is. The horizontal axis of FIG. 3 represents time. Further, in the lower part of FIG. 3, "current synchronization", "311" and "312" are current synchronization in which the switching elements 311, 312 are controlled to be turned on or off according to the polarity of the power supply current Is. It is shown that it is a switching element of. Further, "voltage synchronization", "321" and "322" indicate that the switching elements 321 and 322 are voltage synchronization switching elements whose on or off is controlled according to the power supply polarity. .. Further, in FIG. 3, “Ith” represents a current threshold value.
　制御部８は、電源極性が正の場合、スイッチング素子３２２をオンに制御し、スイッチング素子３２１をオフに制御する。また、制御部８は、電源極性が負の場合、スイッチング素子３２１をオンに制御し、スイッチング素子３２２をオフに制御する。なお、図３では、スイッチング素子３２２がオンからオフになるタイミングと、スイッチング素子３２１がオフからオンになるタイミングとが同じタイミングであるが、これに限定されない。制御部８は、スイッチング素子３２２がオンからオフになるタイミングと、スイッチング素子３２１がオフからオンになるタイミングとの間に、スイッチング素子３２１，３２２が共にオフになるデッドタイムを設けてもよい。同様に、制御部８は、スイッチング素子３２１がオンからオフになるタイミングと、スイッチング素子３２２がオフからオンになるタイミングとの間に、スイッチング素子３２１，３２２が共にオフになるデッドタイムを設けてもよい。 When the power supply polarity is positive, the control unit 8 controls the switching element 322 to be on and the switching element 321 to be turned off. Further, when the power supply polarity is negative, the control unit 8 controls the switching element 321 to be on and the switching element 322 to be turned off. In FIG. 3, the timing at which the switching element 322 is turned from on to off and the timing at which the switching element 321 is turned from off to on are the same timing, but the timing is not limited to this. The control unit 8 may provide a dead time during which the switching elements 321 and 322 are both turned off between the timing at which the switching element 322 is turned from on to off and the timing at which the switching element 321 is turned from off to on. Similarly, the control unit 8 provides a dead time during which the switching elements 321 and 322 are both turned off between the timing at which the switching element 321 is turned from on to off and the timing at which the switching element 322 is turned from off to on. May be good.
　図４には、電源極性が正であり、且つ、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ未満の場合の電流経路が太線で示されている。電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ未満の場合、スイッチング素子３１１はオンに制御されていない。このため、電源電流Ｉｓは、スイッチング素子３１１においてはダイオードＤ１側を流れ、スイッチング素子３２２においてはトランジスタＱ４側を流れる。 In FIG. 4, the current path when the power supply polarity is positive and the absolute value of the power supply current Is is less than the current threshold value Is is shown by a thick line. When the absolute value of the power supply current Is is less than the current threshold value Is, the switching element 311 is not controlled to be ON. Therefore, the power supply current Is flows on the diode D1 side in the switching element 311 and flows on the transistor Q4 side in the switching element 322.
　制御部８は、電源極性が正の場合、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ以上になると、スイッチング素子３１１をオンに制御する。図５には、この場合の電流経路が太線で示されている。電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ以上になると、スイッチング素子３１１はオンに制御されるので、電源電流Ｉｓは、スイッチング素子３１１においても、トランジスタＱ１側を流れるようになる。 When the power supply polarity is positive, the control unit 8 controls the switching element 311 to be turned on when the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is. In FIG. 5, the current path in this case is shown by a thick line. When the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is, the switching element 311 is controlled to be ON, so that the power supply current Is also flows on the transistor Q1 side in the switching element 311.
　その後、制御部８は、電源電流Ｉｓの絶対値が小さくなり、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈよりも小さくなると、スイッチング素子３１１をオフに制御する。 After that, the control unit 8 controls the switching element 311 to be turned off when the absolute value of the power supply current Is becomes smaller and the absolute value of the power supply current Is becomes smaller than the current threshold value Is.
　図６には、電源極性が負であり、且つ、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ未満の場合の電流経路が太線で示されている。電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ未満の場合、スイッチング素子３１２はオンに制御されていない。このため、電源電流Ｉｓは、スイッチング素子３１２においてはダイオードＤ２側を流れ、スイッチング素子３２１においてはトランジスタＱ３側を流れる。 In FIG. 6, the current path when the power supply polarity is negative and the absolute value of the power supply current Is is less than the current threshold value Is is shown by a thick line. When the absolute value of the power supply current Is is less than the current threshold value Is, the switching element 312 is not controlled to be ON. Therefore, the power supply current Is flows on the diode D2 side in the switching element 312, and flows on the transistor Q3 side in the switching element 321.
　制御部８は、電源極性が負の場合、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ以上になると、スイッチング素子３１２をオンに制御する。図７には、この場合の電流経路が太線で示されている。電源電流Ｉｓの絶対値が電流閾値Ｉｔｈ以上になると、スイッチング素子３１２はオンに制御されるので、電源電流Ｉｓは、スイッチング素子３１２においても、トランジスタＱ２側を流れるようになる。 When the power supply polarity is negative, the control unit 8 controls the switching element 312 to be turned on when the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is. In FIG. 7, the current path in this case is shown by a thick line. When the absolute value of the power supply current Is becomes equal to or higher than the current threshold value Is, the switching element 312 is controlled to be ON, so that the power supply current Is also flows on the transistor Q2 side in the switching element 312.
　その後、制御部８は、電源電流Ｉｓの絶対値が小さくなり、電源電流Ｉｓの絶対値が電流閾値Ｉｔｈよりも小さくなると、スイッチング素子３１２をオフに制御する。 After that, the control unit 8 controls the switching element 312 to be turned off when the absolute value of the power supply current Is becomes smaller and the absolute value of the power supply current Is becomes smaller than the current threshold value Is.
　図５及び図７のように、各スイッチング素子のダイオードに電流が流れているときに、並列接続されるスイッチング素子をオンにする制御は「同期整流」と呼ばれる。なお、この同期整流と区別するため、該当するスイッチング素子をオフのままとする制御を「全波整流」と呼ぶ。トランジスタのオン抵抗による電圧降下は、ダイオードの順方向の電圧降下よりも小さいので、同期整流を行うことで、各スイッチング素子での損失を低減することができる。これにより、電力変換装置１００の高効率化を図ることができる。 As shown in FIGS. 5 and 7, control for turning on switching elements connected in parallel when a current is flowing through the diode of each switching element is called "synchronous rectification". In order to distinguish it from this synchronous rectification, the control that leaves the corresponding switching element off is called "full-wave rectification". Since the voltage drop due to the on-resistance of the transistor is smaller than the voltage drop in the forward direction of the diode, the loss in each switching element can be reduced by performing synchronous rectification. As a result, the efficiency of the power conversion device 100 can be improved.
　なお、電力変換装置１００が交流電力から直流電力への電力変換を行う過程で、交流電源１の力率改善制御及び母線電圧の昇圧制御を行うことが可能である。力率改善制御及び昇圧制御を行う場合、コンバータ回路３は、電源短絡と称される動作を行う。図８には、電源電圧Ｖｓが正極性の場合の電源短絡動作の一例が示されている。図５の状態から、スイッチング素子３２２をオンからオフに制御し、スイッチング素子３２１をオフからオンに制御する。すると、電源電流Ｉｓは、リアクタ２、スイッチング素子３１１及びスイッチング素子３２１の順で流れる。このとき、リアクタ２に電気エネルギーが蓄積される。電源短絡動作を行えば、電源電流Ｉｓが流れる期間を拡大できるので、交流電源１の力率を改善することが可能となる。また、リアクタ２に蓄積された電気エネルギーを利用してコンデンサ４を充電すれば、母線電圧の昇圧が可能となる。 In the process of power conversion from AC power to DC power, the power conversion device 100 can perform power factor improvement control and bus voltage boost control of the AC power supply 1. When performing power factor improvement control and boost control, the converter circuit 3 performs an operation called a power short circuit. FIG. 8 shows an example of a power supply short-circuit operation when the power supply voltage Vs is positive. From the state of FIG. 5, the switching element 322 is controlled from on to off, and the switching element 321 is controlled from off to on. Then, the power supply current Is flows in the order of the reactor 2, the switching element 311 and the switching element 321. At this time, electric energy is stored in the reactor 2. If the power supply short-circuit operation is performed, the period in which the power supply current Is flows can be extended, so that the power factor of the AC power supply 1 can be improved. Further, if the capacitor 4 is charged by using the electric energy stored in the reactor 2, the bus voltage can be boosted.
　図９には、電源電圧Ｖｓが負極性の場合の電源短絡動作の一例が示されている。図７の状態から、スイッチング素子３２１をオンからオフに制御し、スイッチング素子３２２をオフからオンに制御する。すると、電源電流Ｉｓは、スイッチング素子３２２、スイッチング素子３１２及びリアクタ２の順で流れる。このとき、リアクタ２に電気エネルギーが蓄積される。電源短絡動作を行えば、電源電流Ｉｓが流れる期間を拡大できるので、交流電源１の力率を改善することが可能となる。また、リアクタ２に蓄積された電気エネルギーを利用してコンデンサ４を充電すれば、母線電圧の昇圧が可能となる。 FIG. 9 shows an example of a power supply short-circuit operation when the power supply voltage Vs is negative. From the state of FIG. 7, the switching element 321 is controlled from on to off, and the switching element 322 is controlled from off to on. Then, the power supply current Is flows in the order of the switching element 322, the switching element 312, and the reactor 2. At this time, electric energy is stored in the reactor 2. If the power supply short-circuit operation is performed, the period in which the power supply current Is flows can be extended, so that the power factor of the AC power supply 1 can be improved. Further, if the capacitor 4 is charged by using the electric energy stored in the reactor 2, the bus voltage can be boosted.
　次に、実施の形態１に係る電流検出変換部１２について説明する。図１０は、実施の形態１に係る電流検出変換部１２と外部の構成要素との間の接続関係を示す図である。図１１は、実施の形態１に係る電流検出変換部１２の内部の構成例を示す図である。なお、図１０及び図１１において、外部の構成要素には、図１と同一の符号を付している。 Next, the current detection conversion unit 12 according to the first embodiment will be described. FIG. 10 is a diagram showing a connection relationship between the current detection and conversion unit 12 according to the first embodiment and an external component. FIG. 11 is a diagram showing an example of the internal configuration of the current detection conversion unit 12 according to the first embodiment. In FIGS. 10 and 11, the external components are designated by the same reference numerals as those in FIG.
　図１０に示すように、電流検出変換部１２は、レベルシフト回路１４を備える。レベルシフト回路１４は、シャント抵抗１１によって検出された検出電圧であるシャント抵抗電圧Ｖｓｈがプロセッサ８ａに入力可能なレベルとなるように、シャント抵抗電圧Ｖｓｈのレベルをシフトさせる。シャント抵抗電圧Ｖｓｈは、シャント抵抗１１に流れる電流Ｉｄによってシャント抵抗１１に生ずる電圧である。図１に示すように、コンデンサ４の負極側端子はＧＮＤに接続されているので、接続点３ｄ側からコンデンサ４の負極側端子に流れる電流の検出値は、正極性の電圧となる。これとは逆に、コンデンサ４の負極側端子から接続点３ｄ側に流れる電流の検出値は、負極性の電圧となる。 As shown in FIG. 10, the current detection conversion unit 12 includes a level shift circuit 14. The level shift circuit 14 shifts the level of the shunt resistance voltage Vsh so that the shunt resistance voltage Vsh, which is the detection voltage detected by the shunt resistance 11, becomes a level that can be input to the processor 8a. The shunt resistance voltage Vsh is a voltage generated in the shunt resistor 11 by the current Id flowing in the shunt resistor 11. As shown in FIG. 1, since the negative electrode side terminal of the capacitor 4 is connected to GND, the detected value of the current flowing from the connection point 3d side to the negative electrode side terminal of the capacitor 4 is a positive voltage. On the contrary, the detected value of the current flowing from the negative electrode side terminal of the capacitor 4 to the connection point 3d side is the negative electrode voltage.
　プロセッサ８ａの典型的な例は、マイコンである。実施の形態１に係る電力変換装置１００では、プロセッサ８ａとしてマイコンを想定する。以下、レベルシフト回路１４から出力されてプロセッサ８ａに入力される電圧を「マイコン入力電圧」と呼び、「Ｖｓｈ_ｍｉｃｏｎ」と表記する。 A typical example of the processor 8a is a microcomputer. In the power conversion device 100 according to the first embodiment, a microcomputer is assumed as the processor 8a. Hereinafter, the voltage output from the level shift circuit 14 and input to the processor 8a is referred to as "microcomputer input voltage" and is referred to as "Vsh_micon".
　マイコンは、一般的に０～５［Ｖ］程度の正の電圧を検出するようにできているが、負の電圧を検出することには対応していない。一方、前述したように、シャント抵抗１１には両極性の電圧が発生するので、マイコンは、両極性の電圧を受け入れる必要がある。このため、電流検出変換部１２には、レベルシフト回路１４が設けられている。レベルシフト回路１４は、例えばマイコンへの入力電圧の最大値が５［Ｖ］の場合には、２．５［Ｖ］程度のオフセットを持たせてゼロ点とする。そして、レベルシフト回路１４は、０～２．５［Ｖ］までを負極性の電圧とし、２．５～５［Ｖ］までを正極性の電圧としてマイコンへ出力する。 The microcomputer is generally designed to detect a positive voltage of about 0 to 5 [V], but it does not support detecting a negative voltage. On the other hand, as described above, since the shunt resistor 11 generates a voltage of both polarities, the microcomputer needs to accept the voltage of both polarities. Therefore, the current detection conversion unit 12 is provided with a level shift circuit 14. For example, when the maximum value of the input voltage to the microcomputer is 5 [V], the level shift circuit 14 has an offset of about 2.5 [V] to set the zero point. Then, the level shift circuit 14 outputs 0 to 2.5 [V] as a negative voltage and 2.5 to 5 [V] as a positive voltage to the microcomputer.
　レベルシフト回路１４は、図１１に示すように、差動増幅部１４ａと、オフセット電圧生成部１４ｂとによって構成することができる。差動増幅部１４ａは、図示のように、オペアンプ１５ａと、抵抗素子である抵抗Ｒ３～Ｒ６とを備える。オフセット電圧生成部１４ｂは、オペアンプ１５ｂと、抵抗素子である抵抗Ｒ１，Ｒ２とを備える。 As shown in FIG. 11, the level shift circuit 14 can be configured by a differential amplification unit 14a and an offset voltage generation unit 14b. As shown in the figure, the differential amplification unit 14a includes an operational amplifier 15a and resistors R3 to R6 which are resistance elements. The offset voltage generation unit 14b includes an operational amplifier 15b and resistors R1 and R2 which are resistance elements.
　オペアンプ１５ａの基準端子である負側端子（－）は、抵抗Ｒ４を介して接地される。シャント抵抗１１で検出されたシャント抵抗電圧Ｖｓｈは、抵抗Ｒ３を介してオペアンプ１５ａの信号入力端子である正側端子（＋）に入力される。抵抗Ｒ４，Ｒ６の抵抗値の比に基づいて、オペアンプ１５ａの増幅率が決定される。即ち、抵抗Ｒ４，Ｒ６の抵抗値の比を変えることで、オペアンプ１５ａの増幅率を変更することが可能である。 The negative terminal (-), which is the reference terminal of the operational amplifier 15a, is grounded via the resistor R4. The shunt resistance voltage Vsh detected by the shunt resistor 11 is input to the positive terminal (+), which is the signal input terminal of the operational amplifier 15a, via the resistor R3. The amplification factor of the operational amplifier 15a is determined based on the ratio of the resistance values of the resistors R4 and R6. That is, the amplification factor of the operational amplifier 15a can be changed by changing the ratio of the resistance values of the resistors R4 and R6.
　オフセット電圧生成部１４ｂにおいて、オペアンプ１５ｂの負側端子（－）は、オペアンプ１５ｂの出力端子と接続されて、ボルテージフォロワ回路を構成する。また、オペアンプ１５ｂの正側端子（＋）には、抵抗Ｒ１，Ｒ２で分圧された分圧電圧が入力される。抵抗Ｒ１，Ｒ２の抵抗値が等しい場合、オペアンプ１５ｂの正側端子（＋）には、２．５［Ｖ］の電圧が入力される。オペアンプ１５ｂの出力端子からは、オペアンプ１５ｂの正側端子（＋）に入力される分圧電圧と同じ電圧が出力される。この電圧がオフセット電圧として、オフセット電圧生成部１４ｂから出力される。 In the offset voltage generation unit 14b, the negative terminal (-) of the operational amplifier 15b is connected to the output terminal of the operational amplifier 15b to form a voltage follower circuit. Further, the voltage divider voltage divided by the resistors R1 and R2 is input to the positive terminal (+) of the operational amplifier 15b. When the resistance values of the resistors R1 and R2 are equal, a voltage of 2.5 [V] is input to the positive terminal (+) of the operational amplifier 15b. From the output terminal of the operational amplifier 15b, the same voltage as the voltage dividing voltage input to the positive terminal (+) of the operational amplifier 15b is output. This voltage is output as an offset voltage from the offset voltage generation unit 14b.
　オフセット電圧生成部１４ｂから出力されるオフセット電圧は、抵抗Ｒ５を介してオペアンプ１５ａの正側端子（＋）に入力される。この構成により、オペアンプ１５ａの正側端子（＋）には、シャント抵抗電圧Ｖｓｈにオフセット電圧が重畳されて入力される。 The offset voltage output from the offset voltage generation unit 14b is input to the positive terminal (+) of the operational amplifier 15a via the resistor R5. With this configuration, an offset voltage is superimposed on the shunt resistance voltage Vsh and input to the positive terminal (+) of the operational amplifier 15a.
　以上のように、レベルシフト回路１４は、シャント抵抗１１の検出電圧のレベルをシフトさせるオフセット電圧を生成するオフセット電圧生成部１４ｂと、検出電圧とオフセット電圧との差電圧を増複する差動増幅部１４ａとを備える。これにより、前述したレベルシフト回路１４によるレベルシフト機能が実現できる。 As described above, the level shift circuit 14 has the offset voltage generation unit 14b that generates the offset voltage that shifts the level of the detection voltage of the shunt resistor 11, and the differential amplification that increases the difference voltage between the detection voltage and the offset voltage. A unit 14a is provided. As a result, the level shift function by the level shift circuit 14 described above can be realized.
　なお、図１１の回路構成は一例であり、これに限定されない。差動増幅部１４ａのオペアンプ１５ａの特性、抵抗Ｒ３，Ｒ５及びシャント抵抗１１の抵抗値の関係等によって、回路動作の安定化を担保できれば、ボルテージフォロワ回路として動作するオペアンプ１５ｂを省略してもよい。即ち、オフセット電圧生成部１４ｂは、抵抗Ｒ１，Ｒ２の分圧回路のみで構成されていてもよい。 Note that the circuit configuration in FIG. 11 is an example, and the circuit configuration is not limited to this. If the stability of the circuit operation can be ensured by the characteristics of the operational amplifier 15a of the differential amplification unit 14a, the relationship between the resistance values of the resistors R3 and R5 and the shunt resistor 11, the operational amplifier 15b operating as the voltage follower circuit may be omitted. .. That is, the offset voltage generation unit 14b may be composed of only the voltage dividing circuits of the resistors R1 and R2.
　また、図１１は、オフセット電圧が２．５［Ｖ］である場合に、０～２．５［Ｖ］までを負極性の電圧とし、２．５～５［Ｖ］までを正極性の電圧としてマイコンへ入力する構成であるが、これに限定されない。０～２．５［Ｖ］までを正極性の電圧、２．５～５［Ｖ］までを負極性の電圧としてマイコンへ入力する構成でもよい。この構成の場合、マイコン内で正負反転の処理を行えばよく、マイコン内の処理を大きく変更する必要はない。 Further, in FIG. 11, when the offset voltage is 2.5 [V], 0 to 2.5 [V] is a negative voltage, and 2.5 to 5 [V] is a positive voltage. However, the configuration is not limited to this. A configuration may be used in which 0 to 2.5 [V] is input to the microcomputer as a positive voltage and 2.5 to 5 [V] is input to the microcomputer as a negative voltage. In the case of this configuration, the positive / negative inversion process may be performed in the microcomputer, and it is not necessary to significantly change the process in the microcomputer.
　図１２は、図４から図７に示す経路の電流が流れた場合におけるシャント抵抗電圧Ｖｓｈ及びマイコン入力電圧Ｖｓｈ_ｍｉｃｏｎの具体的な波形例を示す図である。図１２において、横軸は時間を表している。また、オフセット電圧Ｖｓｈ_ｏｆｆｓｅｔは、２．５［Ｖ］としている。 FIG. 12 is a diagram showing specific waveform examples of the shunt resistance voltage Vsh and the microcomputer input voltage Vsh_micon when the current in the path shown in FIGS. 4 to 7 flows. In FIG. 12, the horizontal axis represents time. The offset voltage Vsh_offset is 2.5 [V].
　図４から図７に示す電流経路の場合、シャント抵抗電圧Ｖｓｈは、図１２の下段部にも示されるような負極性の電圧となる。このため、マイコン入力電圧Ｖｓｈ_ｍｉｃｏｎは、図１２の上段部に示されるように、２．５［Ｖ］であるオフセット電圧Ｖｓｈ_ｏｆｆｓｅｔを基準に、０［Ｖ］までの間で変化する電圧として検出される。 In the case of the current path shown in FIGS. 4 to 7, the shunt resistance voltage Vsh is a negative voltage as shown in the lower part of FIG. Therefore, the microcomputer input voltage Vsh_micon is detected as a voltage that changes from 0 [V] to the offset voltage Vsh_offset, which is 2.5 [V], as shown in the upper part of FIG. ..
　次に、実施の形態１に係る電力変換装置１００の要部の動作について説明する。前述したように、実施の形態１に係る電力変換装置１００は、交流電源１への逆潮流及びアーム短絡を抑止する制御を行う。そこで、本明細書においては、「第１の異常状態」及び「第２の異常状態」という２つの「異常状態」を定義する。第１の異常状態は、交流電源１への逆潮流が生じている状態である。第２の異常状態は、コンバータ回路３の各レグの何れかに「アーム短絡」が生じている状態である。なお、「交流電源１への逆潮流」は、「電源回生」と言い替えることもできる。以下の説明では、「電源回生」という表現を使用する。 Next, the operation of the main part of the power conversion device 100 according to the first embodiment will be described. As described above, the power conversion device 100 according to the first embodiment controls to suppress reverse power flow to the AC power supply 1 and short circuit of the arm. Therefore, in the present specification, two "abnormal states", "first abnormal state" and "second abnormal state", are defined. The first abnormal state is a state in which reverse power flow to the AC power supply 1 is occurring. The second abnormal state is a state in which an "arm short circuit" occurs in any of the legs of the converter circuit 3. In addition, "reverse power flow to AC power supply 1" can be paraphrased as "power supply regeneration". In the following description, the expression "power regeneration" is used.
　図１３は、実施の形態１に係る電力変換装置１００が全波整流動作又は同期整流動作を実施している場合の各種の動作波形を示す図である。図１３には、上段部から順に、電源電圧Ｖｓ、電源電流Ｉｓ、電源極性信号Ｓｉｇ（Ｖｓ）、シャント抵抗電圧Ｖｓｈ及びマイコン入力電圧Ｖｓｈ_ｍｉｃｏｎの波形が示されている。個々の波形の特徴は既に説明した通りであり、ここでの説明は省略する。 FIG. 13 is a diagram showing various operation waveforms when the power conversion device 100 according to the first embodiment performs a full-wave rectification operation or a synchronous rectification operation. In FIG. 13, the waveforms of the power supply voltage Vs, the power supply current Is, the power supply polarity signal Sig (Vs), the shunt resistance voltage Vsh, and the microcomputer input voltage Vsh_micon are shown in order from the upper part. The characteristics of the individual waveforms have already been described, and the description thereof is omitted here.
　図１４は、実施の形態１に係る電力変換装置１００が同期整流動作及び電源短絡動作を実施している場合の各種の動作波形を示す図である。動作波形の種類は、図１３と同じである。図１４では、電源周期の半周期に亘って、電源短絡動作が複数回実施されている。これにより、電源電流Ｉｓの波形は正弦波に近くなり、交流電源１の力率が改善されていることが分かる。なお、シャント抵抗電圧Ｖｓｈの極性は正極性であり、マイコン入力電圧Ｖｓｈ_ｍｉｃｏｎの波形も、オフセット電圧Ｖｓｈ_ｏｆｆｓｅｔ以下の電圧値となっている。 FIG. 14 is a diagram showing various operation waveforms when the power conversion device 100 according to the first embodiment performs a synchronous rectification operation and a power supply short circuit operation. The types of operation waveforms are the same as those in FIG. In FIG. 14, the power supply short-circuit operation is performed a plurality of times over a half cycle of the power supply cycle. As a result, it can be seen that the waveform of the power supply current Is becomes close to a sine wave, and the power factor of the AC power supply 1 is improved. The polarity of the shunt resistance voltage Vsh is positive, and the waveform of the microcomputer input voltage Vsh_micon is also a voltage value equal to or less than the offset voltage Vsh_offset.
　図１５は、実施の形態１に係る電力変換装置１００に第１の異常状態が生じたときの動作波形の変化を示す図である。図１５においては、図１３及び図１４の動作波形に加え、スイッチング素子３１１の導通を制御するための制御信号Ｓ１と、スイッチング素子３１２の導通を制御するための制御信号Ｓ２とが追加されている。 FIG. 15 is a diagram showing changes in the operation waveform when the first abnormal state occurs in the power conversion device 100 according to the first embodiment. In FIG. 15, in addition to the operation waveforms of FIGS. 13 and 14, a control signal S1 for controlling the continuity of the switching element 311 and a control signal S2 for controlling the continuity of the switching element 312 are added. ..
　図１５には、電源電流Ｉｓの通流区間Ｔ１よりも、制御信号Ｓ１のオン幅Ｔ２の方が広くなった場合の動作波形が示されている。通流区間Ｔ１よりもオン幅Ｔ２が広くなると、破線の円で示される部分において電源回生が生じており、電源電流Ｉｓの極性が反転している。このとき、破線の楕円で示される部分においては、シャント抵抗電圧Ｖｓｈの波形が反転している。また、マイコン入力電圧Ｖｓｈ_ｍｉｃｏｎは、オフセット電圧Ｖｓｈ_ｏｆｆｓｅｔを超えた電圧となる。なお、図１５では、電源極性が正である電源半周期の区間のみに破線の円及び楕円を示しているが、電源極性が負である電源半周期の区間においても、電源回生が生じている。 FIG. 15 shows an operation waveform when the on-width T2 of the control signal S1 is wider than the flow section T1 of the power supply current Is. When the on-width T2 is wider than the flow section T1, power supply regeneration occurs in the portion indicated by the broken line circle, and the polarity of the power supply current Is is reversed. At this time, the waveform of the shunt resistance voltage Vsh is inverted in the portion indicated by the broken line ellipse. Further, the microcomputer input voltage Vsh_micon is a voltage that exceeds the offset voltage Vsh_offset. In addition, in FIG. 15, although the broken line circle and the ellipse are shown only in the section of the power supply half cycle in which the power supply polarity is positive, the power supply regeneration occurs also in the section of the power supply half cycle in which the power supply polarity is negative. ..
　図１６は、実施の形態１に係る電力変換装置１００が第１の異常状態であるときの電流経路の例を示す図である。電源電流Ｉｓが通流しない区間は、電源電圧Ｖｓよりも母線電圧Ｖｄｃの方が大きい区間である。このため、図１５に示されるように、電源電流Ｉｓが通流しない区間において、スイッチング素子３１１がオンに制御されると、コンデンサ４の電荷が交流電源１に流れ込む電源回生が生起する。電源回生による電源電流Ｉｓは、スイッチング素子３１１、リアクタ２、交流電源１、スイッチング素子３２２及びシャント抵抗１１の順で流れる。電源回生による電源電流Ｉｓは、接続点３ｄ側からコンデンサ４の負極側端子に流れるので、シャント抵抗電圧Ｖｓｈは、正極性の電圧となる。 FIG. 16 is a diagram showing an example of a current path when the power conversion device 100 according to the first embodiment is in the first abnormal state. The section in which the power supply current Is does not flow is a section in which the bus voltage Vdc is larger than the power supply voltage Vs. Therefore, as shown in FIG. 15, when the switching element 311 is controlled to be ON in the section where the power supply current Is does not flow, the power supply regeneration in which the electric charge of the capacitor 4 flows into the AC power supply 1 occurs. The power supply current Is due to power supply regeneration flows in the order of the switching element 311, the reactor 2, the AC power supply 1, the switching element 322, and the shunt resistor 11. Since the power supply current Is due to power supply regeneration flows from the connection point 3d side to the negative electrode side terminal of the capacitor 4, the shunt resistance voltage Vsh becomes a positive voltage.
　次に、第２の異常状態について説明する。図１７は、実施の形態１に係る電力変換装置１００が第２の異常状態であるときの電流経路の例を示す図である。図１７では、スイッチング素子３２１，３２２の組がアーム短絡を起こした場合を想定している。スイッチング素子３２１，３２２の組がアーム短絡を起こした場合、コンデンサ４の正極側端子と負極側端子との間には、シャント抵抗１１以外の回路要素が存在しないので、シャント抵抗１１には急峻な電流が流れる。また、アーム短絡による電流は、接続点３ｄ側からコンデンサ４の負極側端子に流れるので、シャント抵抗電圧Ｖｓｈは、正極性の電圧となる。 Next, the second abnormal state will be described. FIG. 17 is a diagram showing an example of a current path when the power conversion device 100 according to the first embodiment is in the second abnormal state. In FIG. 17, it is assumed that a set of switching elements 321 and 322 causes an arm short circuit. When the set of switching elements 321 and 322 causes an arm short circuit, the shunt resistor 11 is steep because there is no circuit element other than the shunt resistor 11 between the positive electrode side terminal and the negative electrode side terminal of the capacitor 4. Current flows. Further, since the current due to the arm short circuit flows from the connection point 3d side to the negative electrode side terminal of the capacitor 4, the shunt resistance voltage Vsh becomes a positive electrode voltage.
　図１８は、実施の形態１の電力変換装置１００において、電源回生とアーム短絡とが生じた場合のシャント抵抗電圧Ｖｓｈの波形例を示す図である。図１８には、時刻ｔ１において電源回生が生じ、この電源回生が周期的に繰り返される様子と、時刻ｔ２においてアーム短絡が生じ、このアーム短絡が周期的に繰り返される様子とが示されている。 FIG. 18 is a diagram showing an example of a waveform of the shunt resistance voltage Vsh when power regeneration and arm short circuit occur in the power conversion device 100 of the first embodiment. FIG. 18 shows a state in which a power supply regeneration occurs at time t1 and the power supply regeneration is periodically repeated, and a state in which an arm short circuit occurs at time t2 and the arm short circuit is periodically repeated.
　電源回生が生じる第１の異常状態では、図１６に示したように、リアクタ２を介して電流が流れる。これに対し、アーム短絡が生じる第２の異常状態では、図１７に示したように、リアクタ２を介さずに電流が流れる。リアクタ２は、コンバータ回路３の回路素子の中では、インピーダンスの高い素子である。このため、第１の異常状態時に流れる異常電流の変化率は、第２の異常状態時に流れる異常電流の変化率よりも小さい。従って、第１の異常状態と第２の異常状態との区別は、電流の変化率に基づいて行うことができる。 In the first abnormal state where power supply regeneration occurs, a current flows through the reactor 2 as shown in FIG. On the other hand, in the second abnormal state where an arm short circuit occurs, as shown in FIG. 17, a current flows without going through the reactor 2. The reactor 2 is an element having a high impedance among the circuit elements of the converter circuit 3. Therefore, the rate of change of the abnormal current flowing in the first abnormal state is smaller than the rate of change of the abnormal current flowing in the second abnormal state. Therefore, the distinction between the first abnormal state and the second abnormal state can be made based on the rate of change of the current.
　なお、電流の変化率は、一般的に「ｄｉ／ｄｔ」と記載される。実施の形態１に係る電力変換装置１００では、電流Ｉｄをシャント抵抗１１によって、シャント抵抗電圧Ｖｓｈに変換する。従って、「ｄｉ／ｄｔ」という判定指標を用いることは、電圧の変化率である「ｄｖ／ｄｔ」という判定指標を用いることと等価である。 The rate of change in current is generally described as "di / dt". In the power conversion device 100 according to the first embodiment, the current Id is converted into a shunt resistance voltage Vsh by the shunt resistor 11. Therefore, using the determination index of "di / dt" is equivalent to using the determination index of "dv / dt", which is the rate of change in voltage.
　次に、異常状態の判定手法について説明する。以下の手法は、第１の異常状態及び第２の異常状態の判別に共通する手法である。即ち、以下の手法は、第１の異常状態であるか、第２の異常状態であるかを区別せずに判別する手法である。 Next, the method for determining the abnormal state will be described. The following methods are common to the determination of the first abnormal state and the second abnormal state. That is, the following method is a method for discriminating between the first abnormal state and the second abnormal state without distinguishing between them.
　図１９は、実施の形態１に係る電力変換装置１００における異常状態の判定手法の説明に使用する図である。図１９においては、図１５に示す７つの波形の中で、制御信号Ｓ１，Ｓ２の波形に代えて、極性判定電圧Ｖｐの波形が示されている。実施の形態１では、極性判定電圧Ｖｐを、以下の（１）式で定義する。 FIG. 19 is a diagram used for explaining an abnormal state determination method in the power conversion device 100 according to the first embodiment. In FIG. 19, among the seven waveforms shown in FIG. 15, the waveform of the polarity determination voltage Vp is shown instead of the waveforms of the control signals S1 and S2. In the first embodiment, the polarity determination voltage Vp is defined by the following equation (1).
　Ｖｐ＝(Ｖｓｈ_ｍｉｃｏｎ－Ｖｓｈ_ｏｆｆｓｅｔ)×ｓｉｇ(Ｖｓ)　…（１） Vp = (Vsh_micon-Vsh_offset) x sig (Vs) ... (1)
　図１９の下段部には、極性判定電圧Ｖｐの波形と共に、極性判定電圧Ｖｐの値の符号が記載されている。電源極性が正の電源半周期において、電源回生が生じている箇所における極性判定電圧Ｖｐの符号は、“マイナス（－）”になっているのに対し、電源回生が生じていない箇所における極性判定電圧Ｖｐの符号は、“プラス（＋）”になっている。また、電源極性が負の電源半周期において、電源回生が生じている箇所における極性判定電圧Ｖｐの符号は、“プラス（＋）”になっているのに対し、電源回生が生じていない箇所における極性判定電圧Ｖｐの符号は、“マイナス（－）”になっている。従って、以下の判定条件に基づいて、電力変換装置１００が異常状態であるか否かを判定することができる。 In the lower part of FIG. 19, the code of the value of the polarity determination voltage Vp is described together with the waveform of the polarity determination voltage Vp. In the power supply half cycle where the power supply polarity is positive, the sign of the polarity judgment voltage Vp at the place where the power supply regeneration occurs is "minus (-)", whereas the polarity judgment at the place where the power supply regeneration does not occur. The sign of the voltage Vp is "plus (+)". Further, in the power supply half cycle in which the power supply polarity is negative, the sign of the polarity determination voltage Vp in the place where the power supply regeneration occurs is "plus (+)", whereas in the place where the power supply regeneration does not occur. The sign of the polarity determination voltage Vp is “minus (−)”. Therefore, it can be determined whether or not the power conversion device 100 is in an abnormal state based on the following determination conditions.
　・Ｖｓ＞０、且つ、Ｖｐ＜０の場合、又はＶｓ＜０、且つ、Ｖｐ＞０の場合
　異常状態であると判定
　・上記以外の場合
　異常状態ではないと判定 ・ If Vs> 0 and Vp <0, or if Vs <0 and Vp> 0, it is judged to be in an abnormal state. ・ In cases other than the above, it is judged not to be in an abnormal state.
　次に、異常状態判定の処理手順について説明する。図２０は、実施の形態１に係る電力変換装置１００における異常状態判定の処理手順の説明に供するフローチャートである。 Next, the processing procedure for determining the abnormal state will be described. FIG. 20 is a flowchart for explaining a processing procedure for determining an abnormal state in the power conversion device 100 according to the first embodiment.
　電流検出器１０は電流Ｉｄを検出し（ステップＳ１０１）、電圧検出器５は電源電圧Ｖｓを検出する（ステップＳ１０２）。 The current detector 10 detects the current Id (step S101), and the voltage detector 5 detects the power supply voltage Vs (step S102).
　制御部８は、電流Ｉｄの検出値に基づいて定まる電流Ｉｄの極性と、電源電圧Ｖｓの検出値に基づいて定まる電源電圧Ｖｓの極性とに基づいて極性判定電圧Ｖｐを演算する（ステップＳ１０３）。前述の通り、極性判定電圧Ｖｐは、上記（１）式を用いて演算することができる。電源電圧Ｖｓの極性に関する情報は電源極性信号Ｓｉｇ（Ｖｓ）で得られ、電流Ｉｄの極性に関する情報は、マイコン入力電圧Ｖｓｈ_ｍｉｃｏｎとオフセット電圧Ｖｓｈ_ｏｆｆｓｅｔとの間の差分値である「Ｖｓｈ_ｍｉｃｏｎ－Ｖｓｈ_ｏｆｆｓｅｔ」で得られる。 The control unit 8 calculates the polarity determination voltage Vp based on the polarity of the current Id determined based on the detected value of the current Id and the polarity of the power supply voltage Vs determined based on the detected value of the power supply voltage Vs (step S103). .. As described above, the polarity determination voltage Vp can be calculated using the above equation (1). Information on the polarity of the power supply voltage Vs is obtained from the power supply polarity signal Sig (Vs), and information on the polarity of the current Id is obtained by "Vsh_micon-Vsh_offset" which is a difference value between the microcomputer input voltage Vsh_micon and the offset voltage Vsh_offset. Be done.
　制御部８は、極性判定電圧Ｖｐに基づいて電流Ｉｄの極性と電源電圧Ｖｓの極性の一致、不一致を判定する（ステップＳ１０４）。相互の極性が一致している場合、即ち電流Ｉｄの極性と電源電圧Ｖｓの極性とが一致している場合（ステップＳ１０５，Ｙｅｓ）、制御部８は、平常時の動作を継続する（ステップＳ１０６）。以降、ステップＳ１０１からステップＳ１０５の処理が繰り返される。 The control unit 8 determines whether the polarity of the current Id and the polarity of the power supply voltage Vs match or do not match based on the polarity determination voltage Vp (step S104). When the mutual polarities match, that is, when the polarities of the current Id and the polarities of the power supply voltage Vs match (steps S105, Yes), the control unit 8 continues the normal operation (step S106). ). After that, the processes of steps S101 to S105 are repeated.
　一方、ステップＳ１０５において、相互の極性が不一致の場合、即ち電流Ｉｄの極性と電源電圧Ｖｓの極性とが一致していない場合（ステップＳ１０５，Ｎｏ）、制御部８は、電力変換装置１００が第１又は第２の異常状態であると判定する（ステップＳ１０７）。 On the other hand, in step S105, when the polarities do not match each other, that is, when the polarities of the current Id and the polarities of the power supply voltage Vs do not match (steps S105, No), the power conversion device 100 is the first control unit 8. It is determined that the first or second abnormal state is present (step S107).
　制御部８は、電流Ｉｄの変化率ｄＩ／ｄｔを演算する（ステップＳ１０８）。制御部８は、電流Ｉｄの変化率を判定値と比較する（ステップＳ１０９）。電流Ｉｄの変化率が判定値以下である場合（ステップＳ１０９，Ｎｏ）、制御部８は、電力変換装置１００が第１の異常状態であると判定し（ステップＳ１１０）、電力変換装置１００の各スイッチング素子に対するスイッチング制御を停止する（ステップＳ１１１）。以降、ステップＳ１０１からステップＳ１０９の処理が繰り返される。ステップＳ１１１の処理により、電力変換装置１００は、同期整流動作から全波整流動作に移行する。電力変換装置１００の適用例が空気調和機である場合、運転効率は低下するが、装置の運転は継続することが可能である。 The control unit 8 calculates the rate of change dI / dt of the current Id (step S108). The control unit 8 compares the rate of change of the current Id with the determination value (step S109). When the rate of change of the current Id is equal to or less than the determination value (step S109, No), the control unit 8 determines that the power conversion device 100 is in the first abnormal state (step S110), and each of the power conversion devices 100 The switching control for the switching element is stopped (step S111). After that, the processes of steps S101 to S109 are repeated. By the process of step S111, the power conversion device 100 shifts from the synchronous rectification operation to the full-wave rectification operation. When the application example of the power conversion device 100 is an air conditioner, the operation efficiency is lowered, but the operation of the device can be continued.
　また、ステップＳ１０９において、電流Ｉｄの変化率が判定値を超えている場合（ステップＳ１０９，Ｙｅｓ）、制御部８は、電力変換装置１００が第２の異常状態であると判定し（ステップＳ１１２）、電力変換装置１００及び負荷５００の動作を停止して（ステップＳ１１３）、図２０のフローチャートの処理を終了する。 Further, in step S109, when the rate of change of the current Id exceeds the determination value (step S109, Yes), the control unit 8 determines that the power conversion device 100 is in the second abnormal state (step S112). , The operation of the power conversion device 100 and the load 500 is stopped (step S113), and the processing of the flowchart of FIG. 20 is completed.
　なお、上記ステップＳ１０９の処理では、電流Ｉｄの変化率が判定値に等しい場合を“Ｎｏ”と判定しているが、“Ｙｅｓ”と判定してもよい。即ち、電流Ｉｄの変化率が判定値に等しい場合を“Ｙｅｓ”又は“Ｎｏ”の何れで判定してもよい。 In the process of step S109, the case where the rate of change of the current Id is equal to the determination value is determined as "No", but it may be determined as "Yes". That is, the case where the rate of change of the current Id is equal to the determination value may be determined by either "Yes" or "No".
　また、図２０のフローチャートでは、第１又は第２の異常状態であるかを判定してから、第１の異常状態と第２の異常状態との切り分けを行っているが、これに限定されない。電流Ｉｄの変化率ｄＩ／ｄｔを先に演算し、変化率ｄＩ／ｄｔに基づいて第２の異常状態であるか否かを判定し、その後に第１の異常状態であるか否かの判定を行ってもよい。このフローの場合、処理手順は図２０のものよりも複雑になるが、電力変換装置１００及び負荷５００の動作を迅速に停止できるという効果がある。 Further, in the flowchart of FIG. 20, after determining whether it is the first or second abnormal state, the first abnormal state and the second abnormal state are separated, but the present invention is not limited to this. The rate of change dI / dt of the current Id is calculated first, and based on the rate of change dI / dt, it is determined whether or not it is in the second abnormal state, and then it is determined whether or not it is in the first abnormal state. May be done. In the case of this flow, the processing procedure is more complicated than that in FIG. 20, but there is an effect that the operation of the power conversion device 100 and the load 500 can be stopped quickly.
　以上説明したように、実施の形態１に係る電力変換装置は、コンバータ回路とコンデンサとの間に流れる両極性の第１電流と、交流電源１から出力される第１電圧を検出する。また、電力変換装置は、第１電流の検出信号に基づいて定まる第１電流の極性と、第１電圧の検出信号に基づいて定まる第１電圧の極性とが不一致の場合、コンバータ回路に具備される第１から第４のスイッチング素子が動作を停止するように構成されている。これにより、交流電源への逆潮流及びアーム短絡を抑止する制御が可能になるという効果が得られる。 As described above, the power conversion device according to the first embodiment detects the first current of both polarities flowing between the converter circuit and the capacitor and the first voltage output from the AC power supply 1. Further, the power conversion device is provided in the converter circuit when the polarity of the first current determined based on the detection signal of the first current and the polarity of the first voltage determined based on the detection signal of the first voltage do not match. The first to fourth switching elements are configured to stop operating. This has the effect of enabling control to suppress reverse power flow to the AC power supply and short circuit of the arm.
　なお、実施の形態１に係る電力変換装置において、制御部のプロセッサがマイコンである場合、電流検出器にレベルシフト回路を設けることで、両極性の第１電流を検出することが可能となる。 In the power conversion device according to the first embodiment, when the processor of the control unit is a microcomputer, it is possible to detect the first current of both polarities by providing a level shift circuit in the current detector.
実施の形態２．
　実施の形態１で説明した電力変換装置は、インバータに直流電力を供給するモータ駆動装置として用いることができる。以下、実施の形態１に係る電力変換装置１００のモータ駆動装置への適用例を説明する。 Embodiment 2.
The power conversion device described in the first embodiment can be used as a motor drive device for supplying DC power to the inverter. Hereinafter, an example of application of the power conversion device 100 according to the first embodiment to a motor drive device will be described.
　図２１は、実施の形態２に係るモータ駆動装置１０１の構成例を示す図である。図２１に示されるように、実施の形態２に係るモータ駆動装置１０１は、実施の形態１に示した電力変換装置１００を用いて構成されている。図２１において、電力変換装置１００には、インバータ５００ａが接続されている。前述したように、電力変換装置１００は、交流電力を直流電力に変換する装置である。また、インバータ５００ａは、電力変換装置１００から出力される直流電力を交流電力に変換する装置である。 FIG. 21 is a diagram showing a configuration example of the motor drive device 101 according to the second embodiment. As shown in FIG. 21, the motor drive device 101 according to the second embodiment is configured by using the power conversion device 100 shown in the first embodiment. In FIG. 21, an inverter 500a is connected to the power conversion device 100. As described above, the power conversion device 100 is a device that converts AC power into DC power. Further, the inverter 500a is a device that converts DC power output from the power conversion device 100 into AC power.
　インバータ５００ａの出力側には、モータ５００ｂが接続されている。インバータ５００ａは、変換した交流電力をモータ５００ｂに供給することでモータ５００ｂを駆動する。 A motor 500b is connected to the output side of the inverter 500a. The inverter 500a drives the motor 500b by supplying the converted AC power to the motor 500b.
　図２１に示すモータ駆動装置１０１は、空気調和機の送風機、及び空気調和機の圧縮機に適用することが可能である。 The motor drive device 101 shown in FIG. 21 can be applied to a blower of an air conditioner and a compressor of an air conditioner.
　図２２は、図２１に示したモータ駆動装置１０１を空気調和機に適用した例を示す図である。モータ駆動装置１０１の出力側にはモータ５００ｂが接続されており、モータ５００ｂは、圧縮要素５０４に連結されている。圧縮機５０５は、モータ５００ｂと圧縮要素５０４とを備える。冷凍サイクル部５０６は、四方弁５０６ａ、室内熱交換器５０６ｂ、膨張弁５０６ｃ及び室外熱交換器５０６ｄを含む態様で構成されている。 FIG. 22 is a diagram showing an example in which the motor drive device 101 shown in FIG. 21 is applied to an air conditioner. A motor 500b is connected to the output side of the motor drive device 101, and the motor 500b is connected to the compression element 504. The compressor 505 includes a motor 500b and a compression element 504. The refrigeration cycle unit 506 is configured to include a four-way valve 506a, an indoor heat exchanger 506b, an expansion valve 506c, and an outdoor heat exchanger 506d.
　空気調和機の内部を循環する冷媒の流路は、圧縮要素５０４から、四方弁５０６ａ、室内熱交換器５０６ｂ、膨張弁５０６ｃ、室外熱交換器５０６ｄを経由し、再び四方弁５０６ａを経由して、圧縮要素５０４へ戻る態様で構成されている。モータ駆動装置１０１は、交流電源１より交流電力の供給を受け、モータ５００ｂを回転させる。圧縮要素５０４は、モータ５００ｂが回転することによって、冷媒の圧縮動作を実行し、冷媒を冷凍サイクル部５０６の内部で循環させる。 The flow path of the refrigerant circulating inside the air conditioner is from the compression element 504 via the four-way valve 506a, the indoor heat exchanger 506b, the expansion valve 506c, the outdoor heat exchanger 506d, and again via the four-way valve 506a. , It is configured to return to the compression element 504. The motor drive device 101 receives AC power from the AC power supply 1 and rotates the motor 500b. The compression element 504 executes a compression operation of the refrigerant by rotating the motor 500b, and circulates the refrigerant inside the refrigeration cycle unit 506.
　以上のように、実施の形態２に係るモータ駆動装置及び空気調和機によれば、実施の形態１に係る電力変換装置を用いて構成されているので、実施の形態１に係る電力変換装置が具備する効果を享受することが可能となる。 As described above, according to the motor drive device and the air conditioner according to the second embodiment, the power conversion device according to the first embodiment is used because the power conversion device according to the first embodiment is used. It is possible to enjoy the effects that it possesses.
　以上の実施の形態に示した構成は、一例を示すものであり、別の公知の技術と組み合わせることも可能であるし、要旨を逸脱しない範囲で、構成の一部を省略、変更することも可能である。 The configuration shown in the above embodiment is an example, and can be combined with another known technique, or a part of the configuration may be omitted or changed without departing from the gist. It is possible.
　１　交流電源、２　リアクタ、３　コンバータ回路、３ａ，３ｂ，３ｃ，３ｄ　接続点、４　コンデンサ、５，７　電圧検出器、６，１０　電流検出器、８　制御部、８ａ　プロセッサ、８ｂ　メモリ、９　ゼロクロス検出部、１１　シャント抵抗、１２　電流検出変換部、１４　レベルシフト回路、１４ａ　差動増幅部、１４ｂ　オフセット電圧生成部、１５ａ，１５ｂ　オペアンプ、１６ａ，１６ｂ　直流母線、３１　第１のレグ、３２　第２のレグ、１００　電力変換装置、１０１　モータ駆動装置、３１１，３１２，３２１，３２２　スイッチング素子、５００　負荷、５００ａ　インバータ、５００ｂ　モータ、５０４　圧縮要素、５０５　圧縮機、５０６　冷凍サイクル部、５０６ａ　四方弁、５０６ｂ　室内熱交換器、５０６ｃ　膨張弁、５０６ｄ　室外熱交換器、Ｄ１，Ｄ２，Ｄ３，Ｄ４　ダイオード、Ｑ１，Ｑ２，Ｑ３，Ｑ４　トランジスタ、Ｒ１，Ｒ２，Ｒ３，Ｒ４，Ｒ５，Ｒ６　抵抗。 1 AC power supply, 2 reactor, 3 converter circuit, 3a, 3b, 3c, 3d connection point, 4 capacitor, 5,7 voltage detector, 6,10 current detector, 8 control unit, 8a processor, 8b memory, 9 zero cross Detection unit, 11 shunt resistance, 12 current detection conversion unit, 14 level shift circuit, 14a differential amplification unit, 14b offset voltage generation unit, 15a, 15b operational amplifier, 16a, 16b DC bus, 31 first leg, 32 second Leg, 100 power converter, 101 motor drive, 311, 312, 321, 322 switching element, 500 load, 500a inverter, 500b motor, 504 compression element, 505 compressor, 506 refrigeration cycle section, 506a four-way valve, 506b Indoor heat exchanger, 506c expansion valve, 506d outdoor heat exchanger, D1, D2, D3, D4 diode, Q1, Q2, Q3, Q4 transistor, R1, R2, R3, R4, R5, R6 resistance.

Claims (8)

  1. 　一端が交流電源に接続され、前記交流電源から出力される交流の第１電圧が印加されるリアクタと、上アームの第１のスイッチング素子と下アームの第２のスイッチング素子とが直列に接続され、前記第１のスイッチング素子と前記第２のスイッチング素子との接続点が前記リアクタの他端に接続される第１のレグと、前記第１のレグと並列に接続され、上アームの第３のスイッチング素子と下アームの第４のスイッチング素子とが直列に接続され、前記第３のスイッチング素子と前記第４のスイッチング素子との接続点が前記交流電源に接続される第２のレグと、を有し、前記第１電圧を直流の第２電圧に変換するコンバータ回路と、
    　前記第２電圧を平滑するコンデンサと、
    　前記第１電圧を検出する第１の電圧検出器と、
    　前記コンバータ回路と前記コンデンサとの間に流れる両極性の第１電流を検出する第１の電流検出器と、
    　を備え、
    　前記第１電流の検出信号に基づいて定まる前記第１電流の極性と、前記第１電圧の検出信号に基づいて定まる前記第１電圧の極性とが不一致の場合、前記第１から第４のスイッチング素子は動作を停止する
    　電力変換装置。     One end is connected to an AC power supply, and the reactor to which the first AC voltage output from the AC power supply is applied, and the first switching element of the upper arm and the second switching element of the lower arm are connected in series. The first leg in which the connection point between the first switching element and the second switching element is connected to the other end of the reactor is connected in parallel with the first leg, and the third leg of the upper arm is connected. A second leg in which the switching element of the above and the fourth switching element of the lower arm are connected in series, and the connection point between the third switching element and the fourth switching element is connected to the AC power supply. A converter circuit that converts the first voltage into a second DC voltage.
    A capacitor that smoothes the second voltage and
    The first voltage detector that detects the first voltage and
    A first current detector that detects a first current of both polarities flowing between the converter circuit and the capacitor,
    Equipped with
    When the polarity of the first current determined based on the detection signal of the first current and the polarity of the first voltage determined based on the detection signal of the first voltage do not match, the first to fourth switchings are performed. The element is a power conversion device that stops its operation.
  2. 　前記第１電流の極性と前記第１電圧の極性とが不一致であり、且つ、前記第１電流の変化率が判定値を超えた場合、前記コンバータ回路は動作を停止する
    　請求項１に記載の電力変換装置。     The converter circuit stops operating when the polarity of the first current and the polarity of the first voltage do not match and the rate of change of the first current exceeds the determination value. Power converter.
  3. 　前記第１電流の極性に関する情報と、前記第１電圧の極性に関する情報とに基づいて極性判定電圧を演算する制御部を備え、
    　前記制御部は、前記極性判定電圧に基づいて、前記第１から第４のスイッチング素子の導通を制御する
    　請求項１又は２に記載の電力変換装置。     A control unit for calculating the polarity determination voltage based on the information regarding the polarity of the first current and the information regarding the polarity of the first voltage is provided.
    The power conversion device according to claim 1 or 2, wherein the control unit controls the continuity of the first to fourth switching elements based on the polarity determination voltage.
  4. 　前記第１の電流検出器は、
    　前記第１電流を検出するシャント抵抗と、
    　前記シャント抵抗の検出信号を正又は負の極性を判別可能な信号に変換して前記制御部に出力する電流検出変換部と、
    　を備えている
    　請求項３に記載の電力変換装置。     The first current detector is
    The shunt resistor that detects the first current and
    A current detection and conversion unit that converts the shunt resistance detection signal into a signal that can discriminate between positive and negative polarities and outputs it to the control unit.
    The power conversion device according to claim 3.
  5. 　前記電流検出変換部は、
    　前記シャント抵抗によって検出された検出電圧が前記制御部のプロセッサに入力可能なレベルとなるように、前記検出電圧のレベルをシフトさせるレベルシフト回路を備えている
    　請求項４に記載の電力変換装置。     The current detection conversion unit is
    The power conversion device according to claim 4, further comprising a level shift circuit that shifts the level of the detected voltage so that the detected voltage detected by the shunt resistance becomes a level that can be input to the processor of the control unit.
  6. 　前記レベルシフト回路は、
    　前記検出電圧のレベルをシフトさせるオフセット電圧を生成するオフセット電圧生成部と、
    　前記検出電圧と前記オフセット電圧との差電圧を増複する差動増幅部と、
    　を備えている
    　請求項５に記載の電力変換装置。     The level shift circuit is
    An offset voltage generator that generates an offset voltage that shifts the level of the detected voltage,
    A differential amplifier that increases or decreases the difference voltage between the detected voltage and the offset voltage,
    The power conversion device according to claim 5.
  7. 　請求項１から６の何れか１項に記載の電力変換装置と、
    　前記電力変換装置から出力される直流電力を交流電力に変換するインバータと
    　を備えるモータ駆動装置。     The power conversion device according to any one of claims 1 to 6.
    A motor drive device including an inverter that converts DC power output from the power conversion device into AC power.
  8. 　請求項７に記載のモータ駆動装置を備える空気調和機。 An air conditioner including the motor drive device according to claim 7.
PCT/JP2020/023725 2020-06-17 2020-06-17 Power conversion apparatus, motor drive device, and air conditioner WO2021255849A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010104088A (en) * 2008-10-21 2010-05-06 Seiko Epson Corp Rectification control device, full-wave rectification circuit, power receiving device, electronic apparatus, contactless power transmission system, and rectification control method
JP2013198388A (en) * 2012-03-23 2013-09-30 Shindengen Electric Mfg Co Ltd Synchronous-rectification type bridge
WO2020066030A1 (en) * 2018-09-28 2020-04-02 三菱電機株式会社 Dc power supply device, motor drive device, blower, compressor and air conditioner

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010104088A (en) * 2008-10-21 2010-05-06 Seiko Epson Corp Rectification control device, full-wave rectification circuit, power receiving device, electronic apparatus, contactless power transmission system, and rectification control method
JP2013198388A (en) * 2012-03-23 2013-09-30 Shindengen Electric Mfg Co Ltd Synchronous-rectification type bridge
WO2020066030A1 (en) * 2018-09-28 2020-04-02 三菱電機株式会社 Dc power supply device, motor drive device, blower, compressor and air conditioner

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