JP2005176567A - Two-system changeover feeding device, uninterruptible power supply, and two-system changeover feeding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of a device while suppressing a transient current. <P>SOLUTION: A first feed-controlling means 72 controls gate signals in such a way that, when the output of the gate signals to switching elements 31, 32 is started, the period of supplying energy accumulated in an input coil 12 to the common wirings 14, 16 becomes shorter. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a two-system switching power supply device that switches two systems of power and supplies them to a load device, an uninterruptible power supply that supplies power to a load device by switching between power from a power supply and power from a battery, and two-system switching power supply Regarding the method.

  Patent Document 1 discloses an uninterruptible power supply that switches between power from an input power supply and power from a battery and supplies the power to load equipment. This uninterruptible power supply rectifies the AC voltage of the input power supply through a noise filter, a rectifying stack, a choke coil, a diode, and a capacitor, and supplies this rectified and smoothed DC voltage to a DC / DC converter.

  This uninterruptible power supply also turns off the power MOS-FET between the rectifier stack and the capacitor to protect the circuit against a sudden overvoltage abnormality of the input power supply, and the battery pack as the main power supply Make a backup. Furthermore, this uninterruptible power supply device turns on the power MOS-FET to supply commercial power when the input power returns to the normal voltage.

JP-A-8-182221 (Embodiment of the Invention, Drawing)

  By the way, when the diode is eliminated from the uninterruptible power supply of Patent Document 1, when switching from the power supply state from the battery to the power supply state from the input power supply, DC / DC is used in a period until energy is accumulated in the choke coil. A transient current flows from the converter side to the input power supply side.

  However, when such a diode for preventing backflow is provided, the power from the input power supply is always supplied to the load device via the diode. As a result, in the conventional uninterruptible power supply, a loss at the diode always occurs, and the efficiency is reduced by the amount of the loss.

  The present invention has been made in view of the above problems, and obtains a two-system switching power supply apparatus, an uninterruptible power supply apparatus, and a two-system switching power supply method capable of increasing the efficiency of the apparatus while suppressing a transient current. For the purpose.

  A two-system switching power supply device according to the present invention is connected to an input terminal, an input coil connected to the input terminal, a first power supply circuit having a switching element connected to the input coil, and the first power supply circuit. The common wiring, the second power supply circuit connected to the common wiring, and the gate signal for switching the switching element to output energy, and the energy is stored in the input coil and the stored energy is supplied to the common wiring. And a switching means for switching between power feeding by the first power feeding circuit and power feeding by the second power feeding circuit. The power supply control means uses the energy accumulated in the input coil when starting the output of the gate signal when the power supply by the second power supply circuit is switched from the power supply by the second power supply circuit to the power supply by the first power supply circuit. The gate signal is controlled so that the period for supplying to the common wiring side is shorter than that in the steady state.

  If this configuration is adopted, when the power feeding control means starts to output the gate signal, the gate signal is controlled so that the period during which the energy stored in the input coil is supplied to the common wiring side is shorter than in the normal state. When the switching means switches from feeding by the second feeding circuit to feeding by the first feeding circuit, even if the common wiring is at a predetermined potential due to feeding by the second feeding circuit, Transient current that flows from the common wiring to the input terminal during a period until sufficient energy is accumulated in the input coil can be reduced.

  Therefore, it is not necessary to provide a backflow prevention diode for preventing a transient current from the common wiring to the input terminal between the switching element and the common wiring. By eliminating this backflow prevention diode, the efficiency of the device can be improved. Can be planned.

  The two-system switching power supply device according to the present invention includes an input terminal to which an alternating voltage is applied, an input coil connected to the input terminal, two common wires on the positive side and the negative side, and an input coil and a positive side. A first power supply circuit having a first switching element between the common wiring and a second switching element between the input coil and the negative common wiring; and a second power supply circuit connected to the two common wirings A power supply circuit, power supply control means for outputting two gate signals for switching the first switching element and the second switching element to be alternately turned on within a half cycle of the AC voltage, and a first power supply circuit. Switching means for switching between power feeding and power feeding by the second power feeding circuit. The power supply control means uses the energy accumulated in the input coil when starting the output of the gate signal when the power supply by the second power supply circuit is switched from the power supply by the second power supply circuit to the power supply by the first power supply circuit. The gate signal is controlled so that the period for supplying to the common wiring side is shorter than that in the steady state.

  If this configuration is adopted, when the power supply control means starts outputting the gate signal, the gate signal is controlled so that the period for supplying the energy stored in the input coil to the common wiring side is shortened. Is switched from power feeding by the second power feeding circuit to power feeding by the first power feeding circuit, the common wiring is at a predetermined potential because the power is fed by the second power feeding circuit, and the AC voltage Even if two gate signals for switching the first switching element and the second switching element to be alternately turned on within a half cycle are output, they are common in a period until sufficient energy is accumulated in the input coil. The transient current that flows from the wiring to the input terminal can be reduced.

  Therefore, it is not necessary to provide a backflow prevention diode for preventing a transient current from the common wiring to the input terminal between the switching element and the common wiring. By eliminating this backflow prevention diode, the efficiency of the device can be improved. Can be planned.

  The uninterruptible power supply according to the present invention includes, in addition to any one of the configurations of the uninterruptible power supply described above, a switch connected between the input terminal and the input coil, and between the input terminal and the input coil. And an input current detector for detecting an input current flowing through the current limit control means for opening the switch when the input current exceeds a predetermined current limit current.

  If this configuration is adopted, the transient current at the time of switching from power feeding by the second power feeding circuit to power feeding by the first power feeding circuit is suppressed, so even if the input voltage is large or near the peak voltage of the input voltage Even if the switching control is started from, the cumulative value of the transient current can be kept smaller than the current limit current value. As a result, the current limit control unit can be prevented from opening the switch without limiting the input voltage input to the input terminal when the power supply control unit starts outputting the gate signal. .

  The uninterruptible power supply according to the present invention includes an input terminal to which an AC voltage is applied, an input coil connected to the input terminal, a first common wiring, a second common wiring, an input coil, and a first common wiring. A first power supply circuit having a first switching element and a second switching element between the input coil and the second common wiring; a battery; a first common wiring; a second common wiring; and a battery. A second power feeding circuit, and a first power feeding control means for outputting two gate signals for switching the first switching element and the second switching element to be alternately turned on within a half cycle of the AC voltage; A second power supply control means for supplying electric power stored in the battery from the second power supply circuit to the first common wiring and the second common wiring; power supply by the first power supply circuit; and a second power supply circuit. Having a switching means for switching a power feeding. The first power supply control means is input to the input terminal when starting the output of the gate signal when the switching means switches from the power supply by the second power supply circuit to the power supply by the first power supply circuit. During the period when the alternating voltage is positive, the period during which the first switching element is on is shorter than during the steady state, and during the period when the alternating voltage input to the input terminal is negative, the second switching element is on. The gate signal is controlled so that the period of the state is shorter than the steady state.

  If this configuration is adopted, the first power supply control means is the time when the output of the gate signal is started and the AC voltage input to the input terminal is positive, the first switching element is The gate signal is controlled so that the ON period is shorter than the steady state. Therefore, in this period, although the first switching element is in the on state, the period in which the first switching element is in the on state is shortened, so that the transient current from the first common wiring to the input terminal can be reduced.

  The first power supply control means is a period when the second switching element is in an on state when the output of the gate signal is started and the AC voltage input to the input terminal is negative. The gate signal is controlled so as to be shorter than the normal time. Therefore, in this period, although the second switching element is in the on state, the period in which the second switching element is in the on state is shortened, so that the reverse transient current from the second common line to the input terminal can be reduced. . That is, the transient current can be reduced no matter what timing the gate signal output is started.

  Therefore, a backflow prevention diode for preventing a transient current from the first common wiring to the input terminal is provided between the first switching element and the first common wiring, or between the second switching element and the second common wiring. There is no need to provide a backflow prevention diode between the second common wiring and the input terminal to prevent reverse current flow between them, and the efficiency of the device is improved by not providing these backflow prevention diodes. be able to.

  Another uninterruptible power supply according to the present invention includes an input current detector that detects an input current flowing between the input terminal and the input coil in addition to the configuration of the other uninterruptible power supply described above. The first power supply control means includes a current amplitude control unit that outputs a current command value, a sine wave generation circuit that outputs a sine wave synchronized with the input voltage, and a current command value or a command value based on the current command value. A first instantaneous multiplier that multiplies the signal by a sine wave, an instantaneous subtractor that subtracts the input current from the calculation result of the first instantaneous multiplier, and a current that calculates an instantaneous current command value according to the output of the instantaneous subtractor Compensation calculator, instantaneous soft start control unit that sequentially outputs a value that decreases from a value greater than 1 to 1 when starting the output of the gate signal, and the output value of the instantaneous soft start control unit for the instantaneous current command value A second instantaneous multiplier for multiplying, a comparator that compares the value including the output value of the second instantaneous multiplier with the waveform data of the triangular wave, and outputs a pulse having a pulse width according to the comparison result as a gate signal; Invert the output of the comparator Having an inverting circuit for outputting a gate signal.

  If this configuration is adopted, the first power supply control means is the time when the output of the gate signal is started and the AC voltage input to the input terminal is positive, the larger the transient current is. The ON period of the first switching element is shortened. Therefore, not only can the transient current flowing during the on-period of the first switching element be simply reduced, but also the current flowing during the on-period of the second switching element can be increased and offset.

  Further, the first power supply control means is configured to start the output of the gate signal, and during the period in which the AC voltage input to the input terminal is negative, the second reverse current increases as the reverse current increases. The ON period of the switching element is shortened. Therefore, not only can the transient current flowing during the ON period of the second switching element be simply reduced, but also the current flowing during the ON period of the first switching element can be increased and offset.

  In the other uninterruptible power supply according to the present invention, in addition to the configuration of the other uninterruptible power supply described above, the current amplitude control unit includes an average voltage of the first common wiring, an average voltage of the second common wiring, and a target average. A current having a voltage compensation arithmetic unit that outputs a current command value corresponding to the difference from the voltage, and outputting a value that increases from a predetermined value of 0 or more to less than 1 when starting to output a gate signal An amplitude soft start control unit; and a soft start multiplier that multiplies the current command value by an output value of the current amplitude soft start control unit and outputs the product to the first instantaneous multiplier.

  If this configuration is adopted, the effective control unit throttles the current command value when starting the output of the gate signal, so that the transient current that flows in accordance with the current command value can be narrowed down.

  The two-system switching power feeding method according to the present invention includes a first power feeding circuit that stores energy in an input coil by switching a switching element and supplies the stored energy to a common wiring, and power to the common wiring. A two-system switching power supply method that supplies power from two systems to a common wiring by switching the second power supply circuit to be supplied. When starting the switching operation of the switching element, the energy stored in the input coil is common. Control is performed so that the period of time supplied to the wiring side is shorter than that in the steady state.

  If this method is adopted, when the output of the gate signal is started, the gate signal is controlled so that the period during which the energy stored in the input coil is supplied to the common wiring side is shorter than in the normal state. When switching from power feeding by the second power feeding circuit to power feeding by the first power feeding circuit, even if the common wiring is at a predetermined potential due to power feeding by the second power feeding circuit, it is sufficient for the input coil. Transient current that flows from the common wiring to the input terminal during the period until energy is stored can be reduced.

  Therefore, it is not necessary to provide a backflow prevention diode for preventing a transient current from the common wiring to the input terminal between the switching element and the common wiring. By eliminating this backflow prevention diode, the efficiency of the device can be improved. Can be planned.

  In the present invention, the efficiency of the apparatus can be increased while suppressing the transient current.

  Hereinafter, a two-system switching power supply apparatus, an uninterruptible power supply apparatus, and a two-system switching power supply method according to the best mode for carrying out the present invention will be described based on the drawings. Note that the two-system switching power supply device will be described by taking an uninterruptible power supply device that switches between power from the power supply device and power from the battery and supplies it to the load device as an example. The two-system switching power supply method will be described by taking the operation of the uninterruptible power supply as an example.

  FIG. 1 is a connection diagram showing an uninterruptible power supply 1 and an apparatus connected to the uninterruptible power supply 1 according to an embodiment of the present invention.

  The uninterruptible power supply 1 according to this embodiment has a pair of input terminals 2 and 3. An AC power supply device 4 such as a commercial AC power supply is connected to the pair of input terminals 2 and 3. The commercial AC power supply outputs AC power having an AC voltage with an amplitude of about 280 V at a predetermined frequency such as 50 Hz or 60 Hz. AC power having this AC voltage is supplied to the pair of input terminals 2 and 3.

  One input terminal 2 of the pair of input terminals 2 and 3 is connected to one end of the switch 11. The switch 11 is closed when an open / close signal is input, and is opened when no open / close signal is input. The other input terminal 3 of the pair of input terminals 2 and 3 is connected to the ground 10 of the uninterruptible power supply 1. One input terminal 2 and the other input terminal 3 are input terminals.

  The other end of the switch 11 is connected to one end of the input coil 12. The input coil 12 accumulates energy in accordance with changes in the current flowing through it. The energy stored in the input coil 12 is finally supplied to a load device 7 to be described later. Therefore, in the uninterruptible power supply 1, a coil using thick wiring is used as the input coil 12 so that a large amount of energy can be efficiently supplied.

  The other end of the input coil 12 is connected to a rectifier circuit 13 as a first power feeding circuit. The rectifier circuit 13 includes a first transistor 31 as a switching element or a first switching element, a second transistor 32 as a switching element or a second switching element, a first diode 33, and a second diode 34. Have. As the first transistor 31 and the second transistor 32, for example, transistors capable of flowing a current of about several tens of amperes between the collector and the emitter are used. Examples of such a transistor capable of flowing a large current include an IGBT (Insulated Gate Bipolar Transistor), a thyristor, and an FET (Field Effect Transistor). In addition, as the first diode 33 and the second diode 34, for example, a diode capable of flowing a current of about several tens of amperes from the anode to the cathode is used.

  The emitter of the first transistor 31 and the collector of the second transistor 32 are connected to the other end of the input coil 12. The anode of the first diode 33 is connected to the emitter of the first transistor 31, and the cathode of the first diode 33 is connected to the collector of the first transistor 31. The anode of the second diode 34 is connected to the emitter of the second transistor 32, and the cathode of the second diode 34 is connected to the collector of the second transistor 32.

  The collector of the first transistor 31 of the rectifier circuit 13 is connected to the plus rail wiring 14 in the pair of rail wirings 14 and 16. The plus rail wiring 14 is connected to one end of the plus capacitor 15. The other end of the plus capacitor 15 is connected to the ground 10. The emitter of the second transistor 32 of the rectifier circuit 13 is connected to the negative rail wiring 16. The minus rail wiring 16 is connected to one end of the minus capacitor 17. The other end of the negative capacitor 17 is connected to the ground 10. The positive rail wiring 14 is a common wiring or a first common wiring, and the negative rail wiring 16 is a common wiring or a second common wiring.

  The plus rail wiring 14 and the minus rail wiring 16 are connected to a charge / discharge circuit 18 as a second power feeding circuit. The charge / discharge circuit 18 includes a charge / discharge transistor (not shown), is connected to the battery 19, and inputs / outputs power to / from the battery 19.

  Further, the plus rail wiring 14 and the minus rail wiring 16 are connected to the inverter circuit 20. The inverter circuit 20 has an inverter transistor (not shown) and is connected to a low-pass filter circuit 21.

  The low pass filter circuit 21 includes an output coil 41 and an output capacitor 42. One end of the output coil 41 is connected to the inverter circuit 20. The other end of the output coil 41 is connected to one end of the output capacitor 42. The other end of the output capacitor 42 is connected to the ground 10. Note that the output coil 41 and the output capacitor 42 of the low-pass filter circuit 21 may be selected so as to attenuate the frequency component of 50 Hz or 60 Hz, for example.

  The other end of the output coil 41 of the low-pass filter circuit 21 is connected to one output terminal 5 of the pair of output terminals 5 and 6. The other output terminal 6 of the pair of output terminals 5 and 6 is connected to the ground 10.

  A load device 7 such as a computer or a laser printer is connected to the pair of output terminals 5 and 6. The load device 7 operates by being supplied with AC power having an AC voltage with an amplitude of about 280 V at a predetermined frequency such as 50 Hz or 60 Hz.

  The uninterruptible power supply 1 according to this embodiment includes an input voltage detector 51, an input current detector 52, a plus rail voltage detector 53, and a minus rail voltage detector 54.

  The input voltage detector 51 detects the voltage of one input terminal 2 on the basis of the voltage level of the other input terminal 3 (= the voltage level of the ground 10), and outputs a voltage having a level corresponding to the magnitude of the detected voltage. Output as detection input voltage.

  The input current detector 52 detects a current flowing between one input terminal 2 and the input coil 12 with a detection coil or the like, and outputs a voltage excited in the detection coil by the current as a detection voltage of the input current. .

  The plus rail voltage detector 53 detects the voltage of the plus rail wiring 14 on the basis of the voltage level of the ground 10, and outputs a voltage having a level corresponding to the magnitude of the detected voltage as a detected plus rail voltage.

  The minus rail voltage detector 54 detects the voltage level of the ground 10 with reference to the voltage of the minus rail wiring 16, and outputs a voltage having a level corresponding to the magnitude of the detected voltage as a detected minus rail voltage. As the absolute value of the voltage of the minus rail wiring 16 increases, the detected minus rail voltage output by the minus rail voltage detector 54 also increases.

  These input voltage detector 51, input current detector 52, plus rail voltage detector 53, and minus rail voltage detector 54 are connected to a DSP (Digital Signal Processor) 61. The DSP 61 is a kind of microprocessor, and generates various control signals by digital signal processing. Note that the DSP 61 that can be used for the uninterruptible power supply 1 and the like and that supports a large current currently samples and outputs an input signal at an operating frequency of about 400 k to about 1 MHz. Those that can control the signal are available.

  The DSP 61 periodically samples the detection input voltage to generate a digital value of the detection input voltage, and periodically samples the detection voltage of the input current to obtain the digital value of the detection voltage of the input current. A second AD converter 63 to be generated, a third AD converter 64 that periodically samples the detection plus rail voltage to generate a digital value of the detection plus rail voltage, and a detection minus by periodically sampling the detection minus rail voltage. And a fourth AD converter 65 for generating a digital value of the rail voltage.

  The DSP 61 includes a current limit control unit 71 as a current limit control unit, a first power supply control unit or a rectifier control unit 72 as a power supply control unit, and a charge / discharge control as a second power supply control unit. Part 73, inverter control part 74, and mode control part 75 as switching means. These current limit control unit 71, rectifier control unit 72, charge / discharge control unit 73, inverter control unit 74, and mode control unit 75 are controlled by a microprocessor (not shown) of DSP 61 stored in a memory (not shown). It is realized by executing the program.

  The current limit control unit 71 monitors the detection voltage of the input current generated by the second AD converter 63. When the magnitude of the input current is smaller than the predetermined current limit current value, the current limit control unit 71 outputs a switching signal to the switch 11, and the magnitude of the input current is the predetermined current limit current. When the value exceeds the value, the output of the switching signal to the switch 11 is stopped.

  FIG. 2 is a detailed block diagram showing the rectifier control unit 72 and its peripheral part in FIG. The rectifier control unit 72 includes a current amplitude control unit 81 that outputs a current command value, and an instantaneous control unit 82 that outputs a gate signal composed of a plurality of pulses based on the current command value.

  The current amplitude control unit 81 includes a plus filter 91, a minus filter 92, an average value calculator including an adder 93 and a half amplifier 94, a target rail voltage register 95, an effective subtractor 96, and a voltage compensation calculation. And a limiter 98.

  The plus filter 91 removes the noise component of the detected plus rail voltage output from the third AD converter 64. The minus filter 92 removes the noise component of the detected minus rail voltage output from the fourth AD converter 65. The adder 93 adds the filtered detection plus rail voltage and the filtered detection minus rail voltage. The half amplifier 94 outputs half the value of the operation result of the adder 93. Therefore, the half-amplifier 94 outputs an average value of the detected plus rail voltage and the detected minus rail voltage (hereinafter referred to as an average value of the rail voltage).

  The target rail voltage register 95 stores a target rail voltage that is a target value of an average value of rail voltages. The effective subtractor 96 subtracts the average value of the rail voltage from the target rail voltage. The voltage compensation calculator 97 calculates a voltage compensation value corresponding to the differential voltage value by a primary IIR (Infinite-Duration Impulse Response) filter calculation process. The limiter 98 replaces the current command value with “0” when the current command value as the calculation result of the voltage compensation calculator 97 is a negative value.

  The instantaneous control unit 82 includes a current amplitude soft start control unit 99, a soft start multiplier 100, a sine wave generation circuit 111, an instantaneous amplifier 112, a first instantaneous multiplier 113, an instantaneous subtractor 114, a current Compensation computing unit 115, instantaneous soft start control unit 116, second instantaneous multiplier 117, instantaneous adder 118, rectifier triangular wave generator 119 as a triangular wave generator, and rectifier comparison as a comparator And 120.

  The current amplitude soft start control unit 99 includes a current amplitude soft start register 101 and a current amplitude register updater 102. The current amplitude soft start register 101 stores a value of “0” or more and “1” or less. The current amplitude register updater 102 updates the value of the current amplitude soft start register 101. Specifically, the current amplitude register updater 102 steps the value of the current amplitude soft start register 101 by a plurality of discrete values from “0” or a predetermined value close to “0” to “1”. Increase. The soft start multiplier 100 multiplies the output value of the limiter 98 by the value stored in the current amplitude soft start register 101.

  The sine wave generation circuit 111 outputs a sine wave having a magnitude of 1 in synchronization with the detection input voltage output from the first AD converter 62. In practice, the sine wave generation circuit 111 sequentially outputs a plurality of values obtained by sampling the sine wave for each operating frequency of the DSP 61 for each operating frequency of the DSP 61. The instantaneous amplifier 112 amplifies the output value of the sine wave generation circuit 111 at a predetermined magnification.

  The first instantaneous multiplier 113 multiplies the output value of the soft start multiplier 100 of the current amplitude soft start control unit 99 by the output value of the sine wave generation circuit 111. The instantaneous subtractor 114 subtracts the output value of the second AD converter 63 from the output value of the first instantaneous multiplier 113. The current compensation calculator 115 calculates an instantaneous current command value corresponding to the output of the instantaneous subtractor 114.

  The instantaneous soft start control unit 116 includes an instantaneous soft start register 121 and an instantaneous register updater 122. The instantaneous soft start register 121 stores a value of “1” or more. The instantaneous register updater 122 updates the value of the instantaneous soft start register 121. Specifically, the instantaneous register updater 122 gradually decreases the value of the instantaneous soft start register 121 by a plurality of discrete values from a predetermined value larger than “1” to “1”. The second instantaneous multiplier 117 multiplies the output value of the current compensation calculator 115 by the value stored in the instantaneous soft start register 121.

  The instantaneous adder 118 adds the instantaneous current command value to the output value of the second instantaneous multiplier 117. The rectifier triangle wave generator 119 generates waveform data according to the waveform of the triangle wave. The rectifier comparator 120 compares the output value of the instantaneous adder 118 with the value of the waveform data, and outputs a pulse having a pulse width corresponding to the comparison result.

  This train of pulses is input as a gate signal to the gate of the first transistor 31 of the rectifier circuit 13 and to the first inverting circuit 131 as an inverting circuit. The first inversion circuit 131 inverts the high level and low level of the gate signal and outputs the result to the gate of the second transistor 32.

  The charge / discharge control unit 73 in the DSP 61 outputs a gate signal for charging and a gate signal for discharging. These gate signals are input to the gate of a charge / discharge transistor (not shown) of the charge / discharge circuit 18. The charging / discharging circuit 18 outputs a charging voltage to the battery 19 based on the potential difference between the pair of rail wirings 14 and 16 by performing switching control of the charging / discharging transistor with a charging gate signal. The charge / discharge circuit 18 outputs the discharge voltage to the pair of rail wires 14 and 16 based on the stored voltage of the battery 19 by switching control of the charge / discharge transistor with the gate signal for discharge.

  The inverter control unit 74 in the DSP 61 outputs a gate signal. This gate signal is input to the gate of an inverter transistor (not shown) of the inverter circuit 20. The inverter circuit 20 outputs an AC voltage to the low-pass filter circuit 21 based on the potential difference between the pair of rail wires 14 and 16 by switching control of the inverter transistor with the gate signal.

  The mode control unit 75 in the DSP 61 outputs an activation signal to each of the rectifier control unit 72, the charge / discharge control unit 73, and the inverter control unit 74. The rectifier control unit 72, the charge / discharge control unit 73, and the inverter control unit 74 operate when a start signal is input, and stop when the start signal is not input.

  Next, the operation of the uninterruptible power supply 1 will be described.

  An AC power supply device 4 is connected to the pair of input terminals 2 and 3 of the uninterruptible power supply device 1. A load device 7 is connected to the pair of output terminals 5 and 6. When the central processing unit of the DSP 61 executes the control program, a current limit control unit 71, a rectifier control unit 72, a charge / discharge control unit 73, an inverter control unit 74, and a mode control unit 75 are realized.

  When the uninterruptible power supply 1 is started, the mode control unit 75 outputs a start signal to the rectifier control unit 72, a start signal to the charge / discharge control unit 73, and a start signal to the inverter control unit 74. Absent. Therefore, the rectifier control unit 72, the charge / discharge control unit 73, and the inverter control unit 74 are stopped. Further, since the rectifier control unit 72 is stopped, the input current is 0 A (ampere). Further, the current limit control unit 71 outputs an opening / closing signal, and the switch 11 is open. The AC voltage supplied to the pair of input terminals 2 and 3 is applied to the rectifier circuit 13.

  First, the mode control unit 75 controls the activation signal to the charge / discharge control unit 73 to a high level. When the start signal is controlled to a high level, the charge / discharge control unit 73 applies a discharge voltage based on the stored voltage of the battery 19 from the charge / discharge circuit 18 to the plus rail wiring 14 and the minus rail wiring 16. The plus capacitor 15 and the minus capacitor 17 are charged to this discharge voltage.

  Further, the charge / discharge control unit 73 reads the values of the detected plus rail voltage and the detected minus rail voltage, and the charge / discharge circuit 18 so that the average value of the detected plus rail voltage and the detected minus rail voltage becomes a predetermined target rail voltage. The switching element is controlled. Thereby, the voltage of the plus rail wiring 14 is controlled to the target rail voltage, and the magnitude of the voltage of the minus rail wiring 16 is controlled to the target rail voltage.

  After controlling the activation signal to the charge / discharge control unit 73 to a high level, the mode control unit 75 generates a pair of signals based on the detected plus rail voltage of the third AD converter 64 and the detected minus rail voltage of the fourth AD converter 65. It is determined whether or not the potential difference between the rail wires 14 and 16 is a predetermined target rail-to-rail voltage. When the potential difference between the pair of rail wires 14 and 16 is a predetermined target rail-to-rail voltage, the mode control unit 75 controls the activation signal to the inverter control unit 74 to a high level.

  When the activation signal is controlled to a high level, the inverter control unit 74 outputs a gate signal to the gate of the inverter transistor of the inverter circuit 20. Thereby, the inverter circuit 20 outputs the electric power from the rail wirings 14 and 16 with an alternating voltage. The low-pass filter circuit 21 removes harmonic components of the AC voltage as the second AC voltage output from the inverter circuit 20. Therefore, the low-pass filter circuit 21 outputs an AC voltage having the same frequency as the detected input voltage. AC power having this AC voltage is supplied to the load device 7 through the pair of output terminals 5 and 6.

  The inverter control unit 74 controls the switching element of the inverter circuit 20 so that the effective value of the AC voltage output from the pair of output terminals 5 and 6 becomes a predetermined target output voltage. Thus, an alternating voltage having the target output voltage as an effective value is output from the pair of output terminals 5 and 6. The load device 7 is supplied with AC power having this good effective value.

  Subsequently, the mode control unit 75 determines whether the AC power supplied to the pair of input terminals 2 and 3 is normal power based on the detected input voltage of the first AD converter 62. When the AC power supplied to the pair of input terminals 2 and 3 is normal power, the mode control unit 75 controls the activation signal to the rectifier control unit 72 to a high level and The activation signal to the discharge control unit 73 is controlled to a low level. When the activation signal is controlled to a low level, the charge / discharge control unit 73 stops outputting the gate signal to the transistor of the charge / discharge circuit 18. Further, the current limit control unit 71 controls the switching signal to close the switch 11. At this time, since the rail voltage is higher than the input voltage, no inrush current flows even when the switch 11 is closed.

  When the activation signal is controlled to a high level, the current amplitude control unit 81 and the instantaneous control unit 82 of the rectifier control unit 72 start their operations.

  In the current amplitude control unit 81, an average value of the detected plus rail voltage and the detected minus rail voltage in a period corresponding to one cycle of the detected input voltage by the plus filter 91, the minus filter 92, the adder 93, and the half amplifier 94. Is output as the average value of the rail voltage.

  Then, a current command value is calculated from the average value of the rail voltage and the target rail voltage by the target rail voltage register 95, the effective subtractor 96, the voltage compensation calculator 97, and the limiter 98. The current command value output from the limiter 98 is updated every cycle of the detected input voltage. Therefore, the current command value is a value that compensates for the voltage difference between the average value of the rail voltage in the previous cycle of the detected input voltage and the target rail voltage, and a period corresponding to the cycle of the detected input voltage. During this period, the limiter 98 outputs the signal.

  As described above, the current amplitude control unit 81 updates the current command value for each cycle of the detected input voltage.

  In the instantaneous control unit 82, the sine wave generation circuit 111 outputs a sine wave having a magnitude of 1 in synchronization with the detected input voltage output from the first AD converter 62.

  On the other hand, the current amplitude register updater 102 stores “0” or a value close to “0” as an initial value in the current amplitude soft start register 101. Further, the current amplitude register updater 102 increases the value of the current amplitude soft start register 101 step by step by a plurality of discrete values from the initial value to “1” every predetermined time. The update period of the current amplitude soft start register 101 may be a time corresponding to several tens of periods of PWM (Pulse Width Modulation) control, for example. The soft start multiplier 100 multiplies the current command value by the value of the current amplitude soft start register 101. Therefore, the soft start multiplier 100 outputs a current command value smaller than the current command value immediately after startup, and when the value of the current amplitude soft start register 101 becomes “1” after several tens of cycles of PWM control, the limiter 98. The current command value output from is output as it is.

  The first instantaneous multiplier 113 of the instantaneous control unit 82 multiplies the current command value from the soft start multiplier 100 by the output value of the sine wave generation circuit 111. Therefore, the first instantaneous multiplier 113 outputs a value that changes according to a sine wave waveform having the magnitude of the current command value.

  The instantaneous subtractor 114 subtracts the detected voltage value of the input current output from the second AD converter 63 from the output value of the first instantaneous multiplier 113. The current compensation calculator 115 calculates an instantaneous current command value corresponding to the output value of the instantaneous subtractor 114 and outputs it to the second instantaneous multiplier 117.

  On the other hand, the instantaneous register updater 122 stores a value larger than “1” as an initial value in the instantaneous soft start register 121. In addition, the instantaneous register updater 122 decreases the value of the instantaneous soft start register 121 step by step by a plurality of discrete values from the initial value to “1” every predetermined period. Similar to the current amplitude soft start register 101, the update period of the instantaneous soft start register 121 may be a time corresponding to several tens of cycles of PWM control, for example. Therefore, the second instantaneous multiplier 117 outputs an instantaneous current command value that is larger than the instantaneous current command value output from the current compensation calculator 115 immediately after startup, and after several cycles of the detected input voltage, the instantaneous soft start register 121. When the value becomes “1”, the instantaneous current command value output from the current compensation calculator 115 is output as it is.

  The instantaneous amplifier 112 amplifies the output value of the sine wave generation circuit 111 by a predetermined magnification, and the instantaneous adder 118 adds the output value of the instantaneous amplifier 112 to the output value of the second instantaneous multiplier 117. . The output value of the instantaneous adder 118 changes every cycle of the operating frequency of the DSP 61. The rectifier comparator 120 compares the output value of the instantaneous adder 118 with the value of the waveform data from the rectifier triangle wave generator 119 at that time, and outputs a pulse having a pulse width corresponding to the comparison result. To do.

  By the way, the digital calculation processing by the instantaneous control unit 82 is repeatedly executed for each cycle corresponding to the operating frequency of the DSP 61. Therefore, during the period of the AC voltage of the commercial AC power, the rectifier control unit 72 outputs a PWM control gate signal composed of a plurality of pulses. In the gate signal for PWM control, the pulse width of each pulse is controlled for each period described above. The gate signal is at a high level during a period in which a pulse is output, and the gate signal is at a low level during a period between pulses.

  This gate signal is input to the gate of the first transistor 31 of the rectifier circuit 13. The first transistor 31 is turned on when the gate signal is at high level, that is, when a pulse of the gate signal is input, and when the gate signal is at low level, that is, the potential between the pulse of the gate signal is Turns off when input. By switching the first transistor 31 between the on state and the off state, energy is stored in the input coil 12 during the period in which the first transistor 31 is on. If the voltage obtained by adding the voltage induced in the input coil 12 at the time of switching by the accumulated energy and the input voltage is higher than the charging voltage of the minus capacitor 17, the energy accumulated in the input coil 12 causes the second diode 34 to be transmitted. To the negative rail wiring 16. The minus capacitor 17 is gradually charged by the energy supplied from the input coil 12, and the absolute value of the voltage of the minus rail wiring 16 increases.

  The second transistor 32 is turned on and inverted when the gate signal inverted by the first inverting circuit 131 is at a high level, that is, when the potential between the pulses is input in terms of the gate signal. When the gate signal is at a low level, that is, a gate signal, a pulse is input, and the gate signal is turned off. By switching the second transistor 32 between the on state and the off state, energy is accumulated in the input coil 12 during the period in which the second transistor 32 is in the on state. If the voltage obtained by adding the voltage induced in the input coil 12 at the time of switching by the accumulated energy and the input voltage is higher than the charging voltage of the plus capacitor 15, the energy accumulated in the input coil 12 causes the first diode 33. To the plus rail wiring 14. The plus capacitor 15 is gradually charged by the energy supplied from the input coil 12, and the voltage of the plus rail wiring 14 rises.

  Thus, the first transistor 31 and the second transistor 32 are alternately turned on according to the pulse pattern of the gate signal.

  As described above, the rectifier circuit 13 mainly charges the plus capacitor 15 during the period in which the sine wave output from the sine wave generation circuit 111 becomes a positive voltage in synchronization with the input voltage, and the sine wave The negative capacitor 17 is mainly charged during a period in which becomes a negative voltage.

  In addition, when the average value of the detected plus rail voltage and the detected minus rail voltage is lower than the target rail voltage, the rectifier control unit 72 generates a pulse of the gate signal pulse during a period when the detected input voltage is a positive voltage. While increasing the width, the pulse width of the pulse of the gate signal in the period when the detected input voltage is a negative voltage is decreased. When this average value is higher than the target rail voltage, the rectifier control unit 72 reduces the pulse width of the pulse of the gate signal during the period when the detection input voltage is a positive voltage, and also detects the detection input voltage. Increases the pulse width of the pulse of the gate signal in a period in which becomes a negative voltage. Thereby, the voltage of the plus rail wiring 14 and the absolute value of the voltage of the minus rail wiring 16 are controlled to the target rail voltage.

  Therefore, even if the charge / discharge control unit 73 is stopped, the potential difference between the pair of rail wires 14 and 16 is controlled to a predetermined potential difference by the power supplied from the rectifier circuit 13, and the inverter circuit 20 Electric power is continuously supplied to the load device 7 based on the potential difference between the rail wires 14 and 16.

  As described above, in the uninterruptible power supply 1 according to this embodiment, at the time of activation, first, power based on the stored power of the battery 19 is supplied to the capacitors 15 and 17 connected to the pair of rail wires 14 and 16. Then, the rail wirings 14 and 16 are controlled to a desired target rail voltage, and then the supply source is switched from the battery 19 to the rectifier circuit 13.

  When the above series of start-up processes is completed, the mode control unit 75 periodically monitors the detected input voltage of the first AD converter 62. When determining that the input power is not in a normal state based on the value of the detected input voltage, the mode control unit 75 controls the activation signal to the charge / discharge control unit 73 to a high level, and the rectifier control unit. The activation signal to 72 is controlled to a low level. Thereby, instead of the output voltage of the rectifier circuit 13, the discharge voltage output from the charge / discharge circuit 18 is supplied to the plus rail wiring 14 and the minus rail wiring 16, and the plus rail wiring 14 and the minus rail wiring 16 The potential difference is maintained.

  Thereafter, when the AC power supplied to the pair of input terminals 2 and 3 returns to normal power, the mode control unit 75 controls the start signal to the rectifier control unit 72 to a high level and charge / discharge control. The activation signal to the unit 73 is controlled to a low level. As a result, power can be supplied again from the rectifier circuit 13 to the pair of rail wires 14 and 16.

  When the mode control unit 75 determines that the storage voltage of the battery 19 has become equal to or lower than the predetermined target storage voltage, the mode control unit 75 confirms that the activation signal to the rectifier control unit 72 is at a high level, The activation signal to the discharge control unit 73 is controlled to a high level. The charge / discharge circuit 18 generates a charging voltage based on the potential difference between the plus rail wiring 14 and the minus rail wiring 16. With this charging voltage, the battery 19 is charged to the target storage voltage.

  As described above, during the period in which the AC power supplied to the pair of input terminals 2 and 3 is not determined to be normal while maintaining the stored voltage of the battery 19 at a predetermined target stored voltage or higher, the stored power of the battery 19 By supplying the AC power based on the power to the load device 7, the uninterruptible power supply 1 can maintain the period of the abnormal state even if the AC power supplied to the pair of input terminals 2 and 3 becomes abnormal. Including, it is possible to continuously supply AC power to the load device 7.

  While the power supply to the load device 7 is controlled, the current limit control unit 71 monitors the detection voltage of the input current generated by the second AD converter 63. When the input current becomes equal to or greater than a predetermined current limit current value, the current limit control unit 71 stops outputting the opening / closing signal. Therefore, the switch 11 is opened and power is not supplied from the pair of input terminals 2 and 3. Thereby, the electric current more than a current limit electric current value does not flow into the uninterruptible power supply device 1 or the load apparatus 7.

  By the way, in the uninterruptible power supply 1 of this embodiment, when the first transistor 31 is on, a current flows from the plus rail wiring 14 to the one input terminal 2 via the first transistor 31. There is no backflow prevention diode for preventing the leakage.

  However, since such a backflow prevention diode is not provided, switching between the first transistor 31 and the second transistor 32 is performed after the pair of rail wirings 14 and 16 are controlled to a predetermined voltage by the discharge voltage from the battery 19. When the control is started, a transient current flows from the plus rail wiring 14 to the one input terminal 2 at the start-up for the following reason.

  The timing for starting the switching control between the first transistor 31 and the second transistor 32 after controlling the pair of rail wirings 14 and 16 to a predetermined voltage with the discharge voltage from the battery 19 is the same as that of the present embodiment. There are times when the system is started up or when the battery power supply is restored to the rectifier power supply when the input power is abnormal.

  When the first transistor 31 is turned on in a state where the plus capacitor 15 is charged to a plus voltage higher than the voltage of one input terminal 2, one side is connected from the plus capacitor 15 via the first transistor 31. A transient current tends to flow toward the input terminal 2. If energy is sufficiently stored in the input coil 12, it does not flow into one input terminal 2. However, immediately after starting the rectifier circuit 13, sufficient energy is not accumulated in the input coil 12. Therefore, a transient current flows from the plus rail wiring 14 toward the one input terminal 2.

  The transient current flowing through the first transistor 31 becomes maximum when the first transistor 31 is turned on when the input voltage is near a negative peak voltage. Further, the transient current becomes larger as the amplitude of the input voltage is larger as 280V as in this embodiment.

  Further, this transient current flows every time the first transistor 31 is turned on until sufficient energy is accumulated in the input coil 12. Therefore, when the first transistor 31 and the second transistor 32 are alternately turned on as in this embodiment, for example, the amplitude of the input voltage is 280 V and the input voltage is negative. When the switching control of the first transistor 31 is started from the timing near the peak voltage, this transient current is cumulatively added, so that the cumulative value of the transient current becomes very large. In some cases, the accumulated value of the current is greater than or equal to the current limit current value.

  As described above, when the cumulative value of the transient current exceeds the current limit current value, the output of the switching signal is stopped and the switch 11 is opened. As a result, one input terminal 2 is disconnected from the rectifier circuit 13, and the input power input to the pair of input terminals 2 and 3 cannot be supplied to the load device 7.

  Therefore, in the uninterruptible power supply 1 of this embodiment, the current amplitude soft start control unit 99 that narrows down the current command value output from the current amplitude control unit 81 immediately after startup, and the current compensation calculator 115 output immediately after startup. And an instantaneous soft start control unit 116 that amplifies the instantaneous current command value to be generated.

  The current amplitude soft start control unit 99 decreases the current command value output from the current amplitude control unit 81 immediately after startup. Therefore, the amplitude of the sine wave output from the first instantaneous multiplier 113 immediately after startup is reduced, and the total ON period of the first transistor 31 during the period when the sine wave is negative can be reduced. The cumulative value of can be reduced.

  The first AD converter 61 detects the transient current as a negative value. Therefore, the output value of the instantaneous subtractor 114 increases by the amount of the transient current, and the current compensation calculator 115 outputs the instantaneous current command value so as to compensate the transient current. Moreover, the instantaneous soft start control unit 116 amplifies the instantaneous current command value output from the current compensation calculator 115 immediately after startup. Therefore, immediately after startup, the total ON period of the second transistor 32 in the period in which the previous sine wave is negative is increased, and the cumulative value of the current input from one input terminal 2 in accordance with the switching of the second transistor 32. And the accumulated value of the transient current can be offset by the accumulated value of this current.

  In the uninterruptible power supply 1 of this embodiment, the current amplitude soft start control unit 99 reduces the cumulative value of the transient current and the instantaneous soft start control unit 116 cancels the transient current accumulated value. Even if the amplitude of the input voltage is 280 V and the switching control of the first transistor 31 is started from the timing near the negative peak voltage of the input voltage, the magnitude of the cumulative value of the transient current is set to the current limit. It can be kept smaller than the current value.

  In the uninterruptible power supply 1 of this embodiment, when the second transistor 32 is in an ON state, a current flows from one input terminal 2 to the negative rail wiring 16 via the first transistor 31. Although no backflow prevention diode is provided to prevent this, a transient current is suppressed in the same manner as described above. In other words, in the uninterruptible power supply device of this embodiment, the current amplitude soft start control unit 99 reduces the cumulative value of the transient current and the instantaneous soft start control unit 116 cancels the cumulative value of the transient current. Even if the amplitude of the voltage is 280 V and the switching control of the second transistor 32 is started from the timing near the positive peak voltage of the input voltage, the magnitude of the accumulated value of the reverse transient current is It can be kept smaller than the current limit current value.

  As described above, in the uninterruptible power supply according to this embodiment, the rectifier control unit 72 is the time when the output of the gate signal is started and the detected input voltage is positive. The gate signal is controlled so that the period during which the first transistor 31 is in the on state is shorter than in the steady state. Therefore, in this period, although the first transistor 31 is in the on state, the period in which the first transistor 31 is in the on state is shortened, so that the reverse transient current can be reduced.

  Further, the rectifier control unit 72 is configured to shorten the period during which the second transistor 32 is in the on state when the output of the gate signal is started and the detected input voltage is negative. Control the gate signal. Therefore, in this period, although the second transistor 32 is in the on state, the period in which the second transistor 32 is in the on state is shortened, so that the reverse transient current can be reduced.

  That is, in the uninterruptible power supply according to this embodiment, when the rectifier control unit 72 starts to output the gate signal, the energy stored in the input coil 12 is supplied to the pair of rail wirings 14 and 16 side. Since the gate signal is controlled so as to shorten the period to be performed, the power is supplied by the charge / discharge control unit 73 when the mode control unit 75 switches from the power supply by the charge / discharge control unit 73 to the power supply by the rectifier circuit 13. Thus, even if the pair of rail wirings 14 and 16 have a predetermined potential difference, the pair of rail wirings 14 and 16 to the pair of input terminals 2 and 3 during a period until sufficient energy is accumulated in the input coil 12. The transient current that flows into the can be reduced.

  Accordingly, a reverse current prevention diode for preventing this transient current is provided between the first transistor 31 and the plus rail wiring 14, or a reverse current transient is provided between the second transistor 32 and the minus rail wiring 16. Therefore, it is not necessary to provide a backflow prevention diode for preventing the problem, and the high efficiency of the apparatus is realized.

  In particular, in the uninterruptible power supply according to this embodiment, the rectifier control unit 72 is the time when the output of the gate signal is started and the detected input voltage is positive, the larger the transient current is. The on period of the first transistor 31 is shortened. Therefore, not only the transient current flowing during the ON period of the first transistor 31 is simply reduced, but also the current flowing during the ON period of the second transistor 32 is increased to cancel this. In addition, when the output of the gate signal is started and the detected input voltage is negative, the rectifier control unit 72 shortens the ON period of the second transistor 32 as the reverse transient current increases. doing. Therefore, not only the reverse transient current flowing during the ON period of the second transistor 32 is simply reduced, but also the current flowing during the ON period of the first transistor 31 is increased to cancel this.

  In the uninterruptible power supply according to this embodiment, the effective control unit narrows down the current command value when starting the output of the gate signal, thereby narrowing down the transient current that flows according to the current command value. ing.

  As a result, in the uninterruptible power supply according to this embodiment, even if the amplitude of the input voltage is large and the switching control is started from around the peak voltage of the input voltage, the cumulative value of the transient current is small. The current limit current value will never be exceeded. Therefore, the current limit control unit 71 can be prevented from opening the switch 11 without limiting the input voltage when the rectifier control unit 72 starts outputting the gate signal. Therefore, power supply by the rectifier circuit 13 can be performed by switching from power supply by the charge / discharge circuit 18 to power supply by the rectifier circuit 13.

  The above embodiment is a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  In the said embodiment, the uninterruptible power supply device has the rectifier circuit 13 as an AC / DC conversion circuit, and the inverter circuit 20 as an orthogonal transformation circuit. In addition to this, for example, even in an uninterruptible power supply device having a first AC conversion circuit and a second AC conversion circuit, by applying the present invention, a transient current can be generated without providing a backflow prevention diode. Can be suppressed.

  In the said embodiment, the uninterruptible power supply device 1 which switches the electric power feeding by the rectifier circuit 13 and the electric power feeding by the charging / discharging circuit 18 is made into the example. In addition to this, for example, a two-system switching power supply device that switches between two systems of power by switching between a first power supply circuit and a second power supply circuit and supplies the power to a load device, the first power supply circuit Even if the switching element connected to the input coil is subjected to switching control, by applying the present invention, the transient current can be suppressed without providing a backflow prevention diode.

  In the above embodiment, the instantaneous control unit 82 is provided with the current amplitude soft start control unit 99 and the instantaneous soft start control unit 116, thereby reducing the magnitude of the current command value and shortening the time during which the transient current flows. And the transient current is canceled out. As a result, the cumulative value of the transient current is prevented from exceeding the current limit current value. In addition, for example, only one of the current amplitude soft start control unit 99 and the instantaneous soft start control unit 116 may be provided. Further, when the output of the gate signal is started, the gate signal may be generated so as to shorten the time during which the transient current flows uniformly for a certain time. Further, instead of preventing the accumulated value of the transient current from exceeding the current limit current value, the transient current may be simply suppressed.

  In the above embodiment, a signal obtained by simply inverting the gate signal for the first transistor 31 is used as the gate signal for the second transistor 32. Two gate signals may be generated so as to provide a dead time during which both are turned off during the on period.

FIG. 1 is a connection diagram showing an uninterruptible power supply according to an embodiment of the present invention and devices connected to the uninterruptible power supply. FIG. 2 is a detailed block diagram showing the rectifier control unit and its peripheral part in FIG.

Explanation of symbols

1 Uninterruptible power supply 2 One input terminal (input terminal)
3 The other input terminal (input terminal)
11 Switch 12 Input coil 13 Rectifier circuit (first feeding circuit)
14 Plus rail wiring (common wiring, first common wiring)
16 Negative rail wiring (common wiring, second common wiring)
18 Charging / discharging circuit (second feeding circuit)
19 Battery 31 First transistor (switching element, first switching element)
32 Second transistor (switching element, second switching element)
33 First diode 34 Second diode 52 Input current detector 71 Current limit control section (current limit control means)
72 Rectifier control unit (first power supply control means, power supply control means)
73 Charge / Discharge Control Unit (Second Power Supply Control Unit)
75 Mode controller (switching means)
81 Current Amplitude Control Unit 97 Voltage Compensation Operation Unit 99 Current Amplitude Soft Start Control Unit 100 Soft Start Multiplier 111 Sine Wave Generation Circuit 113 First Instantaneous Multiplier 114 Instantaneous Subtractor 115 Current Compensation Operation Unit 116 Instantaneous Soft Start Control Unit 117 Second instantaneous multiplier 119 Rectifier triangle wave generator (triangle wave generator)
120 Rectifier comparator (comparator)
131 First inverting circuit (inverting circuit)

Claims (7)

An input terminal;
An input coil connected to the input terminal;
A first power supply circuit having a switching element connected to the input coil;
Common wiring connected to the first power supply circuit;
A second power supply circuit connected to the common wiring;
Power supply control means for storing energy in the input coil and supplying the stored energy to the common wiring by outputting a gate signal for switching the switching element.
Switching means for switching between feeding by the first feeding circuit and feeding by the second feeding circuit;
The power feeding control means is stored in the input coil when starting the output of the gate signal when the switching means switches from power feeding by the second power feeding circuit to power feeding by the first power feeding circuit. 2. The dual power switching device, wherein the gate signal is controlled so that a period during which energy is supplied to the common wiring side is shorter than that in a steady state. An input terminal to which an alternating voltage is applied;
An input coil connected to the input terminal;
Two common wires on the positive and negative sides,
A first power supply circuit having a first switching element between the input coil and the positive common wiring and a second switching element between the input coil and the negative common wiring;
A second power supply circuit connected to the two common wires;
Power supply control means for outputting two gate signals for switching the first switching element and the second switching element to be alternately turned on within a half cycle of the AC voltage;
Switching means for switching between feeding by the first feeding circuit and feeding by the second feeding circuit;
The power feeding control means is stored in the input coil when starting the output of the gate signal when the switching means switches from power feeding by the second power feeding circuit to power feeding by the first power feeding circuit. 2. The dual power switching device, wherein the gate signal is controlled so that a period during which energy is supplied to the common wiring side is shorter than that in a steady state. A switch connected between the input terminal and the input coil;
An input current detector for detecting an input current flowing between the input terminal and the input coil;
The dual-system switching power feeding device according to claim 1 or 2, further comprising: current limit control means for opening the switch when the input current exceeds a predetermined current limit current. An input terminal to which an alternating voltage is applied;
An input coil connected to the input terminal;
The first common wiring;
A second common wiring;
A first power feeding circuit having a first switching element between the input coil and the first common wiring and a second switching element between the input coil and the second common wiring;
Battery,
A second power feeding circuit connected to the first common wiring, the second common wiring and the battery;
First power supply control means for outputting two gate signals for switching the first switching element and the second switching element to be alternately turned on within a half cycle of the AC voltage;
Second power supply control means for supplying the power stored in the battery from the second power supply circuit to the first common wiring and the second common wiring;
Switching means for switching between feeding by the first feeding circuit and feeding by the second feeding circuit;
When the first power supply control means starts output of the gate signal when the switching means is switched from power supply by the second power supply circuit to power supply by the first power supply circuit, the first power supply control means is connected to the input terminal. In the period in which the input AC voltage is positive, the period in which the first switching element is on is shorter than in the steady state, and in the period in which the AC voltage input to the input terminal is negative, An uninterruptible power supply, wherein the gate signal is controlled so that a period during which the two switching elements are in an on state is shorter than that in a steady state. An input current detector for detecting an input current flowing between the input terminal and the input coil;
The first power supply control means includes a current amplitude control unit that outputs a current command value, a sine wave generation circuit that outputs a sine wave synchronized with an input voltage, and the current command value or a command value based on the current command value A first instantaneous multiplier that multiplies the sine wave by the instantaneous subtractor that subtracts the input current from the calculation result of the first instantaneous multiplier, and an instantaneous current command value according to the output of the instantaneous subtractor A current compensation computing unit that computes a value, an instantaneous soft start control unit that sequentially outputs a value that decreases from 1 to 1 when starting the output of the gate signal, and the instantaneous soft The second instantaneous multiplier for multiplying the output value of the start control unit, the value including the output value of the second instantaneous multiplier and the waveform data of the triangular wave are compared, and the pulse having the pulse width corresponding to the comparison result is As a gate signal A comparator for force, uninterruptible power supply of claim 4, wherein the having an inverting circuit for outputting as the gate signal inverts the output of the comparator. The current amplitude control unit includes a voltage compensation arithmetic unit that outputs a current command value according to a difference between an average voltage of the first common wiring and an average voltage of the second common wiring and a target average voltage, and
A current amplitude soft start control unit that outputs a value that increases from a predetermined value of 0 or more and less than 1 to 1 when starting the output of the gate signal;
A soft start multiplier that multiplies the output value of the current amplitude soft start control unit by the current command value and outputs to the first instantaneous multiplier;
The uninterruptible power supply according to claim 5. A first feeding circuit that accumulates energy in the input coil by switching the switching element and supplies the accumulated energy to the common wiring, and a second feeding circuit that supplies power to the common wiring, It is a two-system switching power supply method for supplying power from the two systems to the common wiring by switching,
A dual-system switching power feeding method, wherein when the switching operation of the switching element is started, a period in which the energy stored in the input coil is supplied to the common wiring side is controlled to be shorter than that in a steady state.

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