WO2018037591A1 - Power conversion system and arc-extinguishing method for bidirectional switch - Google Patents

Power conversion system and arc-extinguishing method for bidirectional switch Download PDF

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Publication number
WO2018037591A1
WO2018037591A1 PCT/JP2017/005928 JP2017005928W WO2018037591A1 WO 2018037591 A1 WO2018037591 A1 WO 2018037591A1 JP 2017005928 W JP2017005928 W JP 2017005928W WO 2018037591 A1 WO2018037591 A1 WO 2018037591A1
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power
voltage
power supply
power conversion
switch
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PCT/JP2017/005928
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French (fr)
Japanese (ja)
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文生 米田
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パナソニックＩｐマネジメント株式会社
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Publication of WO2018037591A1 publication Critical patent/WO2018037591A1/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
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a power conversion system connected between a DC power supply and a grid power supply, and to a method of extinguishing a bidirectional switch.
  • UPS Uninterruptible Power Supply
  • a thyristor (SCR: Silicon Controlled Rectifier (R)) is widely used as an AC switch of an uninterruptible power supply. When used as a bi-directional switch, two thyristors per phase are connected in parallel in opposite directions and used.
  • a thyristor is superior in terms of overcurrent tolerance, loss (efficiency), and cost as compared to other representative power semiconductor switches, IGBTs (Insulated Gate Bipolar Transistors), but does not have a self-arc-extinguishing function. That is, the arc can not be turned off unless the current flowing to the thyristor becomes zero.
  • IGBTs Insulated Gate Bipolar Transistors
  • the thyristor can not extinguish unless the current is zero, it does not always extinguish when the off signal is input to the gate electrode. If current is flowing at that time, it does not extinguish until the current disappears. Therefore, it is conceivable to apply a reverse bias voltage to the AC switch in order to forcibly extinguish the arc at the timing when the off signal is input to the gate electrode.
  • a reverse bias voltage to the AC switch in order to forcibly extinguish the arc at the timing when the off signal is input to the gate electrode.
  • grid commercial power grid
  • the voltage on the UPS side of the AC switch is set higher than the voltage on the grid side.
  • the voltage on the UPS side of the AC switch is set lower than the voltage on the grid side.
  • a current sensor for detecting the current flowing through the AC switch is provided, and the output voltage of the inverter in the UPS is adjusted according to the direction of the current flowing through the AC switch to conduct the thyristor
  • a method of applying a reverse voltage to the current source has been proposed (see, for example, Patent Document 1). By applying the reverse voltage, the thyristor can be forcibly extinguished at any timing.
  • the direction of the current may be erroneously detected by the current sensor.
  • the reverse voltage is not applied to the AC switch, and the thyristor can not be forcibly extinguished at any timing.
  • the present invention has been made in view of these circumstances, and an object thereof is to provide a power conversion system capable of forcibly extinguishing a semiconductor switch having no self-extinguishing ability at any timing, and extinguishing a bidirectional switch. To provide a way.
  • a power conversion system includes a power conversion device connected between a DC power supply and a grid power supply, and both inserted between the power conversion device and the grid power supply.
  • a bidirectional switch comprising two semiconductor switches which are directional switches and do not have a self-extinguishing ability and are connected in parallel in opposite directions.
  • the power conversion device turns off the gate signals of the two semiconductor switches, A voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more are alternately output at least once.
  • 2 (a) to 2 (c) are diagrams for explaining the connection form of the UPS. It is a figure which shows the example of a detailed structure of the control part which concerns on embodiment of this invention. It is a figure which shows an example of the behavior of the various waveforms in, when the power converter device switches from grid connection operation to a stand-alone operation. It is a figure which shows another example of the behavior of the various waveforms in, when the power converter device switches from grid connection operation to a stand-alone operation.
  • FIG. 1 is a diagram for explaining a power storage system according to an embodiment of the present invention.
  • the storage system includes storage unit 1 and a power conversion system.
  • the power conversion system includes a power conversion device 10, an AC switch 20, and a voltage detection circuit 30. This power storage system may be single phase or three phase.
  • Power storage unit 1 is configured of a plurality of power storage cells connected in series or in series and parallel.
  • a lithium ion storage battery, a nickel hydrogen storage battery, a lead storage battery, an electric double layer capacitor, a lithium ion capacitor, etc. can be used for the storage cell.
  • Power converter 10 is installed between power storage unit 1 and a commercial grid power supply (hereinafter referred to as grid power supply 2).
  • the power converter 10 is a power conditioner with a UPS function.
  • Power conversion device 10 converts DC power discharged from power storage unit 1 into AC power of a predetermined voltage or current, and outputs the AC power to AC wiring. Further, power conversion device 10 converts AC power input from system power supply 2 via AC wiring into DC power of a predetermined voltage or current, and charges power storage unit 1.
  • the power converter 10 includes a bidirectional DC-DC converter 11, a bidirectional inverter 12, and a control unit 13.
  • Each of the bidirectional DC-DC converter 11 and the bidirectional inverter 12 includes, for example, a bridge circuit in which four or six switching elements are bridge-connected. By controlling the duty ratio of the switching element, the input and output of each of the bidirectional DC-DC converter 11 and the bidirectional inverter 12 can be adjusted.
  • an IGBT or a MOSFET Metal-Oxide-Semiconductor Field-Effect Transistor
  • Bidirectional DC-DC converter 11 performs constant current (CC) charging / discharging or constant voltage (CV) charging / discharging according to the drive signal supplied from control unit 13.
  • the bidirectional inverter 12 converts direct current power input from the direct current bus into alternating current power of a predetermined voltage or current according to a drive signal supplied from the control unit 13. Further, AC power supplied from the system power supply 2 is converted into DC power of a predetermined voltage.
  • the power conversion device 10 can also be configured with only the bidirectional inverter 12 and the control unit 13.
  • the control unit 13 controls the bidirectional DC-DC converter 11 and the bidirectional inverter 12.
  • the configuration of the control unit 13 can be realized by cooperation of hardware resources and software resources, or hardware resources only.
  • hardware resources analog elements, microcomputers, DSPs, ROMs, RAMs, FPGAs, and other LSIs can be used.
  • Programs such as firmware can be used as software resources.
  • a specific configuration example of the control unit 13 will be described later.
  • An AC switch 20 is inserted into an AC wiring that connects the power conversion device 10 and the system power supply 2.
  • the AC switch 20 is configured by connecting in parallel two semiconductor switches (for example, thyristors) that do not have a self-extinguishing ability per phase.
  • the alternating current switch 20 can be configured with one triac per phase. The following description assumes an example using a thyristor.
  • the specific load 3 a is connected to an AC path between the power conversion device 10 and the AC switch 20.
  • a general load 3 b is connected to an AC path between the AC switch 20 and the system power supply 2.
  • the specific load 3a is an important load selected by the user, and includes, for example, a server, a PC, and a communication device. In the case of a server installed in a data center, switching to a backup power supply without interruption is required at the time of a power failure of the system power supply 2.
  • the specific load 3a is a load that can continue to receive power supply using the storage unit 1 as a backup power source even when the power failure of the system power source 2 occurs.
  • the general load 3 b is a load whose power supply is stopped when the grid power supply 2 fails. At the time of a power failure of the system power supply 2, since the AC switch 20 is controlled to be in the OFF state, the power supplied from the storage unit 1 is supplied only to the specific load 3a.
  • the voltage detection circuit 30 detects the voltage of the AC path between the AC switch 20 and the system power supply 2, and outputs the voltage to the control unit 13 of the power conversion device 10.
  • the voltage detection circuit 30 can be configured, for example, using an operational amplifier and an A / D converter.
  • the power conversion system shown in FIG. 1 constitutes a UPS of line interactive system (also referred to as parallel processing system).
  • UPS line interactive system
  • the system power supply 2 At the time of a power failure of the system power supply 2, it is possible to start the supply of backup power from the storage unit 1 to the specific load 3a with a momentary power failure period of 1/4 cycle or less.
  • FIG. 2 (a) to 2 (c) are diagrams for explaining the connection form of the UPS.
  • FIG. 2 (a) shows the connection form of the always commercial power feeding system
  • FIG. 2 (b) shows the connection form of the always inverter feed system
  • FIG. 2 (c) shows the connection form of the line interactive system.
  • the system power supply 2 and the inverter 10b can be selectively connected to the load 3 via the power supply switch 20a.
  • the power supply switching device 20a connects the system power supply 2 and the load 3.
  • the power supply switching device 20 a connects the load 3 to the inverter 10 b connected to the storage unit 1.
  • Power storage unit 1 is configured to be constantly chargeable from system power supply 2 via AC-DC converter 10a. In the regular commercial power supply system, power loss due to power conversion does not normally occur, but a momentary interruption occurs at power supply switching.
  • the always-inverter feeding method shown in FIG. 2 (b) has a configuration without a power switch or an AC switch. Normally, AC power supplied from the system power supply 2 is converted to DC power by the AC-DC converter 10 c and supplied to the inverter 10 b and the storage unit 1.
  • the inverter 10 b converts DC power supplied from the AC-DC converter 10 c into AC power and supplies the AC power to the load 3.
  • the inverter 10 b converts DC power supplied from the storage unit 1 into AC power and supplies the AC power to the load 3.
  • power loss occurs due to power conversion in normal times, but momentary interruption does not occur at the time of power supply switching.
  • AC power is normally supplied from the system power supply 2 to the load 3 via the AC switch 20.
  • Power conversion device 10 can discharge from storage unit 1 to an AC path between AC switch 20 and load 3 or charge storage portion 1 from the AC path.
  • the power conversion device 10 converts DC power supplied from the storage unit 1 into AC power and supplies the AC power to the load 3.
  • the circuit configuration shown in FIG. 2C is equivalent to the circuit configuration in which the general load 3b is ignored in the circuit configuration shown in FIG.
  • the line interactive system can be operated with either commercial power supply or inverter power supply at all times.
  • the switching time is shorter compared to the regular commercial power supply system, and the loss in normal mode is smaller than that in the continuous inverter power system.
  • power quality improvement such as load cut applications such as peak cut and peak shift, active filter for power, etc. It can also be used for applications.
  • by supplying power from the power conversion device 10 instantaneously when the grid deviates from the predetermined voltage / frequency range a certain power quality can be guaranteed for the load 3.
  • the alternating current switch 20 is configured by connecting the first thyristor S1 and the second thyristor S2 in parallel in the reverse direction. Therefore, forced arcing can not be reliably performed only by setting the gate terminals of the first thyristor S1 and the second thyristor S2 to the low level.
  • a mechanism for surely forcing the thyristor out at any timing is introduced.
  • FIG. 3 is a diagram showing a detailed configuration example of the control unit 13 according to the embodiment of the present invention.
  • Control unit 13 includes a system power supply abnormality detection unit 131, a reverse voltage command value generation unit 132, an addition unit 133, an output voltage / current detection unit 134, an operation amount generation unit 135, and a drive unit 136.
  • FIG. 3 as the configuration of the control unit 13, only the configuration related to the forcible extinction of the thyristor at the time of system failure is depicted.
  • the system power supply abnormality detection unit 131 detects whether the system voltage detected by the voltage detection circuit 30 falls within a predetermined voltage range and a predetermined frequency range.
  • the system power supply 2 is determined to be normal, and when it deviates from the predetermined voltage range and the predetermined frequency range, the system power supply 2 is determined to be abnormal.
  • the predetermined voltage range is set to, for example, 195-210 V
  • the predetermined frequency range is set to, for example, 49.5-50.5 Hz.
  • the system power supply abnormality detection unit 131 When the detected system voltage is normal, the system power supply abnormality detection unit 131 outputs an ON signal to the AC switch 20 and outputs a system normal signal to the reverse voltage command value generation unit 132. On the other hand, when the system voltage is abnormal, an off signal is output to the AC switch 20, and a system abnormality signal is output to the reverse voltage command value generation unit 132.
  • the reverse voltage command value generation unit 132 When the reverse voltage command value generation unit 132 receives the system abnormality signal from the system power supply abnormality detection unit 131, the amplitude of the output voltage of the bidirectional inverter 12 corresponding to the system voltage is compared with the instantaneous value of the system voltage for a certain period. Then, it swings up and down to generate a reverse voltage command value for applying a reverse voltage to both the first thyristor S1 and the second thyristor S2. Reverse voltage command value generation unit 132 outputs the generated reverse voltage command value to addition unit 133.
  • the adding unit 133 sets a value obtained by adding the system voltage detected by the voltage detection circuit 30 and the reverse voltage command value supplied from the reverse voltage command value generating unit 132 as the output voltage target value V2ref, to the operation amount generating unit 135. Output to Since the reverse voltage command value supplied from reverse voltage command value generation unit 132 is zero except for a fixed period after abnormality of system power supply 2 is detected, addition unit 133 outputs the system voltage as it is. Output as the target value V2ref.
  • the output voltage / current detection unit 134 detects the output voltage / output current of the bidirectional inverter 12 and outputs the detection result to the operation amount generation unit 135.
  • the operation amount generation unit 135 generates an operation amount for performing grid connection operation (operation in current control mode) when the system power supply 2 is normal, and stand-alone operation (operation in voltage control mode) when the system power supply 2 is abnormal. Generate an operation amount to
  • the operation amount generation unit 135 operates in the current control mode during grid-connected operation (normal operation). Therefore, the target value of the output voltage is ignored, and the operation is performed in accordance with the target value of the output current generated in the operation amount generation unit 135.
  • the target value of the output current at the time of grid connection operation is the instantaneous value of the sine wave from positive to negative in the direction and magnitude of the effective value according to the application of normal use such as load leveling and power quality improvement. Is set.
  • the operation amount generation unit 135 operates in the voltage control mode during the independent operation (during system abnormality). Therefore, the target value of the output current is ignored and operates according to the target value of the output voltage.
  • the target value of the output voltage during the stand-alone operation is an output that is input from the addition unit 133 for a predetermined period (less than 1 ms) after switching from the grid connection operation to the stand-alone operation in a state where the system voltage has not disappeared Although it operates according to target value V2ref of voltage, it is generated inside operation amount generation unit 135 after lapse of a predetermined period after the system voltage has disappeared or after switching from grid-connected operation to stand-alone operation. Operate according to the target value of the output voltage.
  • the target value of the output current and output voltage generated in the operation amount generation unit 135 applied outside the predetermined period after switching from the grid connection operation to the stand-alone operation is the forced extinction of the thyristor at the time of the system failure. It is not directly related to the arc. Therefore, I omit the details here.
  • the drive unit 136 generates a drive signal based on the operation amount generated by the operation amount generation unit 135 and drives the switching element of the main circuit of the bidirectional inverter 12.
  • the drive unit 136 includes, for example, a comparator that compares the operation amount with a carrier wave (triangular wave), and the comparator outputs a PWM signal corresponding to the comparison result of the operation amount with the carrier as a drive signal to the gate terminal of the switching element.
  • FIG. 4 and FIG. 5 are diagrams showing an example of behavior of various waveforms when the power conversion device 10 switches from grid-connected operation to self-sustaining operation.
  • the on signal is input to the AC switch 20, and the first thyristor S1 and the second thyristor S2 are in conduction.
  • a current Iscr flows from the system power supply 2 to the specific load 3a via the first thyristor S1 and the second thyristor S2.
  • the power conversion device 10 outputs a voltage V2 corresponding to the grid voltage V1 at an output current setting of zero.
  • the bidirectional inverter 12 is switched to operate so that the current becomes zero (current control mode).
  • the above output current setting is not limited to zero. It may be a setting other than zero according to the application of normal use such as load leveling and power quality improvement.
  • the system interconnection operation is switched to a standalone operation, and an off signal is input to the AC switch 20.
  • the power conversion device 10 has a voltage higher by a predetermined value Vr1 (for example, 3 V) or more than the detected system voltage and a voltage lower than the detected system voltage by a predetermined value Vr2 (for example 3 V) Alternately at least once.
  • Vr1 for example, 3 V
  • Vr2 for example 3 V
  • a voltage higher than the predetermined value Vr1 is output first. Due to this voltage, the voltage at the cathode terminal of the second thyristor S2 becomes higher than the voltage at the anode terminal, the current Iscr flowing through the second thyristor S2 stops, and the second thyristor S2 is forced to extinguish.
  • the predetermined period T1 is larger than the sum of the turn-off times of the first thyristor S1 and the second thyristor S2, and is set to a value sufficiently smaller than the cycle of the system voltage. Normally, this value is less than 1 ms even in consideration of the response of the bidirectional inverter 12, and can be set to a value sufficiently smaller than the cycle of the grid voltage.
  • the predetermined values Vr1 and Vr2 are command values of reverse voltages to be applied to the first thyristor S1 or the second thyristor S2. It is desirable that this command value be as small as possible if it is possible to actually apply a reverse voltage greater than or equal to zero volts to both thyristors.
  • the voltage is set to, for example, 3 V in consideration of the response of the bidirectional inverter 12.
  • the power conversion device 10 After the AC switch 20 is turned off, the power conversion device 10 outputs a prescribed AC voltage V2 generated by itself. That is, the bidirectional inverter 12 is switched (voltage control mode) to maintain the output of the specified AC voltage against the fluctuation of the specific load 3a.
  • the reverse voltage is applied to both the first thyristor S1 and the second thyristor S2 connected in parallel in the reverse direction. Can be applied.
  • the AC switch 20 configured of the first thyristor S1 and the second thyristor S2 can be forcedly extinguished at an arbitrary timing.
  • the power conversion device 10 can also be used for power quality improvement such as normal load leveling, power active filter, power factor improvement, sag compensation, phase adjustment and the like.
  • a several electrical storage system is provided in parallel and it parallels Redundant operation may be performed.
  • a power generation system such as a photovoltaic power generation system, a fuel cell system, or an engine power generation system may be connected in parallel with the power storage system.
  • the embodiment may be specified by the following items.
  • a bidirectional switch (20) configured to be connected to the When the detected voltage of the path between the bidirectional switch (20) and the system power supply (2) deviates from a predetermined voltage range and / or a predetermined frequency range, the two semiconductor switches (S1, S2)
  • the power converter (20) alternately outputs a voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more alternately at least once while turning off the gate signal.
  • the DC power supply (1) is a storage unit (1), A load (3a) is connected to a path between the power converter (10) and the bidirectional switch (20),
  • the power converter (10) is An inverter which converts DC power discharged from the storage unit (1) into AC power and outputs the AC power, and converts AC power input from the system power supply into DC power to charge the storage unit (1) 12) and
  • the inverter (12) is driven in the grid connection mode when the detection voltage falls within the predetermined voltage range and / or the predetermined frequency range, and the detection voltage is set to the predetermined voltage range and / or the predetermined frequency range.
  • the power conversion system according to item 1 comprising: According to this, when the system voltage is abnormal, stable voltage can be supplied to the load (3a) by switching to the stand-alone mode. [Item 3]
  • the control unit (13) controls the inverter (12) so that the output voltage of the inverter (12) corresponds to the system voltage in the grid connection mode, and the output current of the inverter (12) is zero.
  • the power conversion system according to item 2 characterized in that it is driven. According to this, when the system power supply (2) is abnormal, it is possible to switch to the backup power supply instantly.
  • a general load (3b) is connected to the path between the bi-directional switch (20) and the system power supply (2),
  • the power according to item 2 or 3 wherein the load (3a) connected to the path between the power conversion device (10) and the bidirectional switch (20) is a specific load (3a) Conversion system. According to this, at the time of a power failure of the system power supply (2), the specific load (3a) can be preferentially backed up.
  • the specific load (3a) can be preferentially backed up.
  • the power conversion system according to any one of items 1 to 4, wherein the semiconductor switches (S1, S2) are thyristors (S1, S2).
  • a power converter (10) connected to a DC power supply (1) and a bi-directional switch (20) inserted between the system power supply (2), and two semiconductor switches (S1) having no self-extinguishing capability , S2) is a method of extinguishing a bidirectional switch (20) configured to be connected in parallel in the reverse direction,
  • the two semiconductor switches (S1, S2) The gate signal is turned off, and a voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more are alternately output from the power conversion device (10) at least once.
  • 1 storage unit 2 power sources, 3 loads, 3a specific load, 3b general load, 10 power converters, 10a AC-DC converter, 10b inverter, 10c AC-DC converter, 11 bidirectional DC-DC converter, 12 bidirectional Inverter, 13 control unit, 20 AC switch, 20a power switch, S1 first thyristor, S2 second thyristor, 30 voltage detection circuit, 131 system power failure detection unit, 132 reverse voltage command value generation unit, 133 addition unit, 134 Output voltage / current detection unit, 135 operation amount generation unit, 136 drive unit.
  • the present invention is applicable to a storage system.

Abstract

A bidirectional switch (20) inserted between a power conversion device (10) and a system power source (2) is configured by connecting two semiconductor switches (S1, S2) having no self arc-extinguishing capability in parallel in opposing directions. When the detected voltage of a path between the bidirectional switch (20) and the system power source (2) deviates from a prescribed voltage range and a prescribed frequency range, the gate signals of the two semiconductor switches (S1, S2) are turned off, and the power conversion device (10) alternately outputs a voltage higher by a prescribed value than the detected voltage and a voltage lower by a prescribed value than the detected voltage at least once.

Description

電力変換システム、及び双方向スイッチの消弧方法Power conversion system and method of extinguishing bidirectional switch
　本発明は、直流電源と系統電源の間に接続される電力変換システム、及び双方向スイッチの消弧方法に関する。 The present invention relates to a power conversion system connected between a DC power supply and a grid power supply, and to a method of extinguishing a bidirectional switch.
　近年、蓄電システムが普及してきている。蓄電システムは、負荷のピークカットやバックアップに使用することができる。蓄電システムの中には、無停電電源装置（ＵＰＳ:Uninterruptible Power Supply)としての機能を兼ね備えるものもある。 In recent years, storage systems have become widespread. The storage system can be used for peak cut and backup of load. Some storage systems have a function as an uninterruptible power supply (UPS: Uninterruptible Power Supply).
　無停電電源装置の交流スイッチとしてサイリスタ（ＳＣＲ:Silicon Controlled Rectifier（登録商標))が普及している。双方向スイッチとして使用する場合、１相あたり２つのサイリスタが逆向きに並列に接続されて使用される。サイリスタは、他の代表的なパワー半導体スイッチであるＩＧＢＴ(Insulated Gate Bipolar Transistor）と比較して、過電流耐量、損失（効率）、コストの点で優れているが、自己消弧機能が無い。即ち、サイリスタに流れる電流がゼロにならないと消弧（ターンオフ）できない。従来、共振を利用した強制消弧回路を主回路に組み込んでいたが、回路が大型化する。 A thyristor (SCR: Silicon Controlled Rectifier (R)) is widely used as an AC switch of an uninterruptible power supply. When used as a bi-directional switch, two thyristors per phase are connected in parallel in opposite directions and used. A thyristor is superior in terms of overcurrent tolerance, loss (efficiency), and cost as compared to other representative power semiconductor switches, IGBTs (Insulated Gate Bipolar Transistors), but does not have a self-arc-extinguishing function. That is, the arc can not be turned off unless the current flowing to the thyristor becomes zero. Conventionally, a forced arc extinguishing circuit utilizing resonance has been incorporated into the main circuit, but the circuit becomes larger.
　上述のようにサイリスタは電流がゼロにならないと消弧できないため、ゲート電極にオフ信号を入力したタイミングで、必ず消弧するとは限らない。その時点で電流が流れている場合、電流がなくなるまで消弧しない。そこで、ゲート電極にオフ信号を入力したタイミングで強制的に消弧させるために、交流スイッチに逆バイアス電圧を印加することが考えられる。例えば、交流スイッチにおいて商用電力系統（以下適宜、系統という）側からＵＰＳ側の方向に電流が流れている場合、交流スイッチのＵＰＳ側の電圧を系統側の電圧より高く設定する。一方、ＵＰＳ側から系統側に電流が流れている場合、交流スイッチのＵＰＳ側の電圧を系統側の電圧より低く設定する。 As described above, since the thyristor can not extinguish unless the current is zero, it does not always extinguish when the off signal is input to the gate electrode. If current is flowing at that time, it does not extinguish until the current disappears. Therefore, it is conceivable to apply a reverse bias voltage to the AC switch in order to forcibly extinguish the arc at the timing when the off signal is input to the gate electrode. For example, when a current is flowing from the commercial power grid (hereinafter referred to as grid) side to the UPS side in the AC switch, the voltage on the UPS side of the AC switch is set higher than the voltage on the grid side. On the other hand, when the current flows from the UPS side to the grid side, the voltage on the UPS side of the AC switch is set lower than the voltage on the grid side.
　この制御を実現するために、交流スイッチに流れる電流を検出するための電流センサを設け、交流スイッチに流れる電流の向きに応じて、ＵＰＳ内のインバータの出力電圧を調整し、導通しているサイリスタに逆電圧を印加する方法が提案されている（例えば、特許文献１参照）。逆電圧を印加することにより、任意のタイミングでサイリスタを強制消弧させることができる。 In order to realize this control, a current sensor for detecting the current flowing through the AC switch is provided, and the output voltage of the inverter in the UPS is adjusted according to the direction of the current flowing through the AC switch to conduct the thyristor A method of applying a reverse voltage to the current source has been proposed (see, for example, Patent Document 1). By applying the reverse voltage, the thyristor can be forcibly extinguished at any timing.
特開２００３－８７９９９号公報JP 2003-87999 A
　しかしながら上記方法では、サイリスタに流れる電流が少ない場合や、サイリスタに高調波成分を含む電流が流れている場合、電流センサで電流の向きを誤検出する可能性がある。この場合、交流スイッチに逆電圧が印加されないことになり、サイリスタを任意のタイミングで強制消弧させることができない。 However, in the above method, when the current flowing through the thyristor is small or when the current including the harmonic component is flowing through the thyristor, the direction of the current may be erroneously detected by the current sensor. In this case, the reverse voltage is not applied to the AC switch, and the thyristor can not be forcibly extinguished at any timing.
　本発明はこうした状況に鑑みなされたものであり、その目的は、自己消弧能力を持たない半導体スイッチを、任意のタイミングで強制消弧させることができる電力変換システム、及び双方向スイッチの消弧方法を提供することにある。 The present invention has been made in view of these circumstances, and an object thereof is to provide a power conversion system capable of forcibly extinguishing a semiconductor switch having no self-extinguishing ability at any timing, and extinguishing a bidirectional switch. To provide a way.
　上記課題を解決するために、本発明のある態様の電力変換システムは、直流電源と系統電源の間に接続される電力変換装置と、前記電力変換装置と前記系統電源の間に挿入される双方向スイッチであり、自己消弧能力を持たない２つの半導体スイッチが逆向きに並列に接続されて構成される双方向スイッチと、を備える。前記双方向スイッチと前記系統電源の間の経路の検出電圧が、所定の電圧範囲、所定の周波数範囲を逸脱したとき、前記２つの半導体スイッチのゲート信号をオフするとともに、前記電力変換装置は、前記検出電圧より所定値以上高い電圧と、前記検出電圧より所定値以上低い電圧を交互に少なくとも１回出力する。 In order to solve the above problems, a power conversion system according to an aspect of the present invention includes a power conversion device connected between a DC power supply and a grid power supply, and both inserted between the power conversion device and the grid power supply. A bidirectional switch comprising two semiconductor switches which are directional switches and do not have a self-extinguishing ability and are connected in parallel in opposite directions. When the detection voltage of the path between the bidirectional switch and the system power supply deviates from a predetermined voltage range and a predetermined frequency range, the power conversion device turns off the gate signals of the two semiconductor switches, A voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more are alternately output at least once.
　本発明によれば、自己消弧能力を持たない半導体スイッチを、任意のタイミングで強制消弧させることができる。 According to the present invention, it is possible to forcibly extinguish a semiconductor switch that does not have the self-extinguishing ability at any timing.
本発明の実施の形態に係る蓄電システムを説明するための図である。It is a figure for demonstrating the electrical storage system which concerns on embodiment of this invention. 図２（ａ）－（ｃ）は、ＵＰＳの接続形態を説明するための図である。2 (a) to 2 (c) are diagrams for explaining the connection form of the UPS. 本発明の実施の形態に係る制御部の詳細な構成例を示す図である。It is a figure which shows the example of a detailed structure of the control part which concerns on embodiment of this invention. 電力変換装置が系統連系運転から自立運転に切り替わる際における、各種波形の振る舞いの一例を示す図である。It is a figure which shows an example of the behavior of the various waveforms in, when the power converter device switches from grid connection operation to a stand-alone operation. 電力変換装置が系統連系運転から自立運転に切り替わる際における、各種波形の振る舞いの別の例を示す図である。It is a figure which shows another example of the behavior of the various waveforms in, when the power converter device switches from grid connection operation to a stand-alone operation.
　図１は、本発明の実施の形態に係る蓄電システムを説明するための図である。蓄電システムは、蓄電部１及び電力変換システムを備える。電力変換システムは電力変換装置１０、交流スイッチ２０及び電圧検出回路３０を含む。この蓄電システムは、単相であっても、三相であっても構わない。 FIG. 1 is a diagram for explaining a power storage system according to an embodiment of the present invention. The storage system includes storage unit 1 and a power conversion system. The power conversion system includes a power conversion device 10, an AC switch 20, and a voltage detection circuit 30. This power storage system may be single phase or three phase.
　蓄電部１は、直列または直並列接続された複数の蓄電セルにより構成される。蓄電セルには、リチウムイオン蓄電池、ニッケル水素蓄電池、鉛蓄電池、電気二重層キャパシタ、リチウムイオンキャパシタ等を使用することができる。 Power storage unit 1 is configured of a plurality of power storage cells connected in series or in series and parallel. A lithium ion storage battery, a nickel hydrogen storage battery, a lead storage battery, an electric double layer capacitor, a lithium ion capacitor, etc. can be used for the storage cell.
　電力変換装置１０は、蓄電部１と商用系統電源（以下、系統電源２という）の間に設置される。電力変換装置１０は、ＵＰＳ機能付きのパワーコンディショナである。電力変換装置１０は、蓄電部１から放電される直流電力を、所定の電圧または電流の交流電力に変換し、交流配線に出力する。また電力変換装置１０は、系統電源２から交流配線を介して入力される交流電力を所定の電圧または電流の直流電力に変換し、蓄電部１に充電する。 Power converter 10 is installed between power storage unit 1 and a commercial grid power supply (hereinafter referred to as grid power supply 2). The power converter 10 is a power conditioner with a UPS function. Power conversion device 10 converts DC power discharged from power storage unit 1 into AC power of a predetermined voltage or current, and outputs the AC power to AC wiring. Further, power conversion device 10 converts AC power input from system power supply 2 via AC wiring into DC power of a predetermined voltage or current, and charges power storage unit 1.
　電力変換装置１０は、双方向ＤＣ－ＤＣコンバータ１１、双方向インバータ１２及び制御部１３を含む。双方向ＤＣ－ＤＣコンバータ１１及び双方向インバータ１２はそれぞれ、例えば、４つ又は６つのスイッチング素子をブリッジ接続したブリッジ回路を含む。当該スイッチング素子のデューティ比を制御することにより、双方向ＤＣ－ＤＣコンバータ１１及び双方向インバータ１２のそれぞれの入出力を調整することができる。スイッチング素子には例えば、ＩＧＢＴ又はＭＯＳＦＥＴ（Metal-Oxide-Semiconductor Field-Effect Transistor)を使用することができる。 The power converter 10 includes a bidirectional DC-DC converter 11, a bidirectional inverter 12, and a control unit 13. Each of the bidirectional DC-DC converter 11 and the bidirectional inverter 12 includes, for example, a bridge circuit in which four or six switching elements are bridge-connected. By controlling the duty ratio of the switching element, the input and output of each of the bidirectional DC-DC converter 11 and the bidirectional inverter 12 can be adjusted. For example, an IGBT or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) can be used as the switching element.
　双方向ＤＣ－ＤＣコンバータ１１は、制御部１３から供給される駆動信号に応じて、蓄電部１を定電流（ＣＣ）充電／放電、または定電圧（ＣＶ）充電／放電する。双方向インバータ１２は、制御部１３から供給される駆動信号に応じて、直流バスから入力される直流電力を所定の電圧または電流の交流電力に変換する。また系統電源２から供給される交流電力を所定の電圧の直流電力に変換する。なお、電池の充放電制御を双方向インバータ１２で行うことで、電力変換装置１０は、双方向インバータ１２と制御部１３のみの構成も可能である。 Bidirectional DC-DC converter 11 performs constant current (CC) charging / discharging or constant voltage (CV) charging / discharging according to the drive signal supplied from control unit 13. The bidirectional inverter 12 converts direct current power input from the direct current bus into alternating current power of a predetermined voltage or current according to a drive signal supplied from the control unit 13. Further, AC power supplied from the system power supply 2 is converted into DC power of a predetermined voltage. By performing charge and discharge control of the battery with the bidirectional inverter 12, the power conversion device 10 can also be configured with only the bidirectional inverter 12 and the control unit 13.
　制御部１３は双方向ＤＣ－ＤＣコンバータ１１及び双方向インバータ１２を制御する。制御部１３の構成は、ハードウェア資源とソフトウェア資源の協働、またはハードウェア資源のみにより実現できる。ハードウェア資源としてアナログ素子、マイクロコンピュータ、ＤＳＰ、ＲＯＭ、ＲＡＭ、ＦＰＧＡ、その他のＬＳＩを利用できる。ソフトウェア資源としてファームウェア等のプログラムを利用できる。制御部１３の具体的な構成例は後述する。 The control unit 13 controls the bidirectional DC-DC converter 11 and the bidirectional inverter 12. The configuration of the control unit 13 can be realized by cooperation of hardware resources and software resources, or hardware resources only. As hardware resources, analog elements, microcomputers, DSPs, ROMs, RAMs, FPGAs, and other LSIs can be used. Programs such as firmware can be used as software resources. A specific configuration example of the control unit 13 will be described later.
　電力変換装置１０と系統電源２を繋ぐ交流配線に交流スイッチ２０が挿入される。交流スイッチ２０は、１相あたり自己消弧能力を持たない２つの半導体スイッチ（例えば、サイリスタ）が逆向きに並列に接続されて構成される。また、双方向スイッチとして知られているトライアックを使用すれば、交流スイッチ２０は、１相あたり１つのトライアックでも構成可能である。以下の説明ではサイリスタを使用する例を想定する。 An AC switch 20 is inserted into an AC wiring that connects the power conversion device 10 and the system power supply 2. The AC switch 20 is configured by connecting in parallel two semiconductor switches (for example, thyristors) that do not have a self-extinguishing ability per phase. Also, using a triac known as a bi-directional switch, the alternating current switch 20 can be configured with one triac per phase. The following description assumes an example using a thyristor.
　電力変換装置１０と交流スイッチ２０間の交流経路に特定負荷３ａが接続される。交流スイッチ２０と系統電源２間の交流経路に一般負荷３ｂが接続される。特定負荷３ａはユーザが選択した重要負荷であり、例えば、サーバ、ＰＣ、通信機器などが挙げられる。データセンタに設置されたサーバの場合、系統電源２の停電時、バックアップ電源への無瞬断での切替が求められる。 The specific load 3 a is connected to an AC path between the power conversion device 10 and the AC switch 20. A general load 3 b is connected to an AC path between the AC switch 20 and the system power supply 2. The specific load 3a is an important load selected by the user, and includes, for example, a server, a PC, and a communication device. In the case of a server installed in a data center, switching to a backup power supply without interruption is required at the time of a power failure of the system power supply 2.
　特定負荷３ａは、系統電源２の停電時にも、蓄電部１をバックアップ電源として電力供給を受け続けることができる負荷である。一般負荷３ｂは系統電源２の停電時、電力供給が停止する負荷である。系統電源２の停電時、交流スイッチ２０がオフ状態に制御されるため、蓄電部１から供給される電力が特定負荷３ａのみに供給される。 The specific load 3a is a load that can continue to receive power supply using the storage unit 1 as a backup power source even when the power failure of the system power source 2 occurs. The general load 3 b is a load whose power supply is stopped when the grid power supply 2 fails. At the time of a power failure of the system power supply 2, since the AC switch 20 is controlled to be in the OFF state, the power supplied from the storage unit 1 is supplied only to the specific load 3a.
　電圧検出回路３０は、交流スイッチ２０と系統電源２間の交流経路の電圧を検出し、電力変換装置１０の制御部１３に出力する。電圧検出回路３０は例えば、演算増幅器とＡ／Ｄ変換器を用いて構成することができる。 The voltage detection circuit 30 detects the voltage of the AC path between the AC switch 20 and the system power supply 2, and outputs the voltage to the control unit 13 of the power conversion device 10. The voltage detection circuit 30 can be configured, for example, using an operational amplifier and an A / D converter.
　図１に示す電力変換システムは、ラインインタラクティブ方式（パラレルプロセシング方式ともいう）のＵＰＳを構成している。系統電源２の停電時、瞬停期間が１／４サイクル以下で、蓄電部１から特定負荷３ａにバックアップ電力の供給を開始することができる。 The power conversion system shown in FIG. 1 constitutes a UPS of line interactive system (also referred to as parallel processing system). At the time of a power failure of the system power supply 2, it is possible to start the supply of backup power from the storage unit 1 to the specific load 3a with a momentary power failure period of 1/4 cycle or less.
　図２（ａ）－（ｃ）は、ＵＰＳの接続形態を説明するための図である。図２（ａ）は常時商用給電方式の接続形態を示し、図２（ｂ）は常時インバータ給電方式の接続形態を示し、図２（ｃ）はラインインタラクティブ方式の接続形態を示している。 2 (a) to 2 (c) are diagrams for explaining the connection form of the UPS. FIG. 2 (a) shows the connection form of the always commercial power feeding system, FIG. 2 (b) shows the connection form of the always inverter feed system, and FIG. 2 (c) shows the connection form of the line interactive system.
　図２（ａ）に示す常時商用給電方式では、負荷３に対して電源切替器２０ａを介して、系統電源２とインバータ１０ｂが選択的に接続可能な構成である。平常時、電源切替器２０ａは系統電源２と負荷３を接続する。系統電源２の停電時、電源切替器２０ａは蓄電部１に接続されたインバータ１０ｂと、負荷３を接続する。蓄電部１は、系統電源２からＡＣ－ＤＣコンバータ１０ａを介して常時充電可能な構成である。常時商用給電方式では平常時、電力変換による電力ロスが発生しないが、電源切替時に瞬断が発生する。 In the continuous commercial power supply system shown in FIG. 2A, the system power supply 2 and the inverter 10b can be selectively connected to the load 3 via the power supply switch 20a. Normally, the power supply switching device 20a connects the system power supply 2 and the load 3. At the time of a power failure of the system power supply 2, the power supply switching device 20 a connects the load 3 to the inverter 10 b connected to the storage unit 1. Power storage unit 1 is configured to be constantly chargeable from system power supply 2 via AC-DC converter 10a. In the regular commercial power supply system, power loss due to power conversion does not normally occur, but a momentary interruption occurs at power supply switching.
　図２（ｂ）に示す常時インバータ給電方式は、電源切替器や交流スイッチがない構成である。平常時、系統電源２から供給される交流電力は、ＡＣ－ＤＣコンバータ１０ｃで直流電力に変換され、インバータ１０ｂ及び蓄電部１に供給される。インバータ１０ｂはＡＣ－ＤＣコンバータ１０ｃから供給される直流電力を交流電力に変換して負荷３に供給する。系統電源２の停電時、インバータ１０ｂは蓄電部１から供給される直流電力を交流電力に変換して負荷３に供給する。常時インバータ給電方式では平常時、電力変換による電力ロスが発生するが、電源切替時に瞬断が発生しない。 The always-inverter feeding method shown in FIG. 2 (b) has a configuration without a power switch or an AC switch. Normally, AC power supplied from the system power supply 2 is converted to DC power by the AC-DC converter 10 c and supplied to the inverter 10 b and the storage unit 1. The inverter 10 b converts DC power supplied from the AC-DC converter 10 c into AC power and supplies the AC power to the load 3. At the time of power failure of the system power supply 2, the inverter 10 b converts DC power supplied from the storage unit 1 into AC power and supplies the AC power to the load 3. In the constant inverter power supply system, power loss occurs due to power conversion in normal times, but momentary interruption does not occur at the time of power supply switching.
　図２（ｃ）に示すラインインタラクティブ方式では、平常時、系統電源２から交流スイッチ２０を介して負荷３に交流電力が供給される。電力変換装置１０は蓄電部１から、交流スイッチ２０と負荷３間の交流経路に放電、または当該交流経路から蓄電部１に充電することができる。系統電源２の停電時、電力変換装置１０は蓄電部１から供給される直流電力を交流電力に変換して負荷３に供給する。図２（ｃ）に示す回路構成は、図１に示した回路構成において一般負荷３ｂを無視した回路構成と等価である。 In the line interactive system shown in FIG. 2C, AC power is normally supplied from the system power supply 2 to the load 3 via the AC switch 20. Power conversion device 10 can discharge from storage unit 1 to an AC path between AC switch 20 and load 3 or charge storage portion 1 from the AC path. At the time of a power failure of the system power supply 2, the power conversion device 10 converts DC power supplied from the storage unit 1 into AC power and supplies the AC power to the load 3. The circuit configuration shown in FIG. 2C is equivalent to the circuit configuration in which the general load 3b is ignored in the circuit configuration shown in FIG.
　ラインインタラクティブ方式は、常時商用給電でも、常時インバータ給電でも運用可能である。常時商用給電で運用した場合、常時商用給電方式に比べて切替時間が短く、常時インバータ給電方式に比べて平常時の損失が少ない。また、平常時は、交流スイッチ２０を介して、系統電源２と電力変換装置１０が並列接続されるため、ピークカットやピークシフトなどの負荷平準化用途や、電力用アクティブフィルタなどの電力品質改善用途等にも利用が可能である。またさらに、系統が所定の電圧・周波数の範囲を逸脱した場合に瞬時に電力変換装置１０側から給電することで、負荷３に対し、一定の電力品質を保証することができる。 The line interactive system can be operated with either commercial power supply or inverter power supply at all times. When operated with regular commercial power supply, the switching time is shorter compared to the regular commercial power supply system, and the loss in normal mode is smaller than that in the continuous inverter power system. Moreover, since the system power supply 2 and the power conversion device 10 are connected in parallel via the AC switch 20 during normal operation, power quality improvement such as load cut applications such as peak cut and peak shift, active filter for power, etc. It can also be used for applications. Furthermore, by supplying power from the power conversion device 10 instantaneously when the grid deviates from the predetermined voltage / frequency range, a certain power quality can be guaranteed for the load 3.
　上述のように本実施の形態では交流スイッチ２０を、第１サイリスタＳ１と第２サイリスタＳ２を逆向きに並列に接続して構成する。従って、第１サイリスタＳ１と第２サイリスタＳ２のゲート端子をローレベルにしただけでは、確実に強制消弧することはできない。以下、交流スイッチ２０に強制的に逆電圧を印加する構成を追加することにより、任意のタイミングで確実にサイリスタを強制消弧する仕組みを導入する。 As described above, in the present embodiment, the alternating current switch 20 is configured by connecting the first thyristor S1 and the second thyristor S2 in parallel in the reverse direction. Therefore, forced arcing can not be reliably performed only by setting the gate terminals of the first thyristor S1 and the second thyristor S2 to the low level. Hereinafter, by adding a configuration for forcibly applying a reverse voltage to the alternating current switch 20, a mechanism for surely forcing the thyristor out at any timing is introduced.
　図３は、本発明の実施の形態に係る制御部１３の詳細な構成例を示す図である。制御部１３は、系統電源異常検出部１３１、逆電圧指令値発生部１３２、加算部１３３、出力電圧・電流検出部１３４、操作量生成部１３５及び駆動部１３６を含む。なお図３では制御部１３の構成として、系統異常時のサイリスタの強制消弧に関連する構成のみを描いている。 FIG. 3 is a diagram showing a detailed configuration example of the control unit 13 according to the embodiment of the present invention. Control unit 13 includes a system power supply abnormality detection unit 131, a reverse voltage command value generation unit 132, an addition unit 133, an output voltage / current detection unit 134, an operation amount generation unit 135, and a drive unit 136. In FIG. 3, as the configuration of the control unit 13, only the configuration related to the forcible extinction of the thyristor at the time of system failure is depicted.
　系統電源異常検出部１３１は、電圧検出回路３０により検出された系統電圧が、所定の電圧範囲、所定の周波数範囲に収まるか否か検出する。検出された系統電圧が、所定の電圧範囲、所定の周波数範囲に収まるとき系統電源２を正常と判定し、所定の電圧範囲、所定の周波数範囲を逸脱するとき系統電源２を異常と判定する。例えば系統電源２の公称電圧が２００Ｖ、公称周波数が５０Ｈｚのとき、所定の電圧範囲は例えば１９５－２１０Ｖの範囲、所定の周波数範囲は例えば４９．５－５０．５Ｈｚの範囲に設定される。 The system power supply abnormality detection unit 131 detects whether the system voltage detected by the voltage detection circuit 30 falls within a predetermined voltage range and a predetermined frequency range. When the detected system voltage falls within a predetermined voltage range and a predetermined frequency range, the system power supply 2 is determined to be normal, and when it deviates from the predetermined voltage range and the predetermined frequency range, the system power supply 2 is determined to be abnormal. For example, when the nominal voltage of the system power supply 2 is 200 V and the nominal frequency is 50 Hz, the predetermined voltage range is set to, for example, 195-210 V, and the predetermined frequency range is set to, for example, 49.5-50.5 Hz.
　系統電源異常検出部１３１は、検出された系統電圧が正常なときは、交流スイッチ２０にオン信号を、逆電圧指令値発生部１３２に系統正常信号を出力する。一方、系統電圧が異常なときは、交流スイッチ２０にオフ信号を、逆電圧指令値発生部１３２に系統異常信号を出力する。 When the detected system voltage is normal, the system power supply abnormality detection unit 131 outputs an ON signal to the AC switch 20 and outputs a system normal signal to the reverse voltage command value generation unit 132. On the other hand, when the system voltage is abnormal, an off signal is output to the AC switch 20, and a system abnormality signal is output to the reverse voltage command value generation unit 132.
　逆電圧指令値発生部１３２は、系統電源異常検出部１３１から系統異常信号を受け取ると、系統電圧と対応している双方向インバータ１２の出力電圧の振幅を一定期間、系統電圧の瞬時値に対して上下に振り、第１サイリスタＳ１及び第２サイリスタＳ２の両方に逆電圧を印加するための逆電圧指令値を発生させる。逆電圧指令値発生部１３２は発生させた逆電圧指令値を加算部１３３に出力する。加算部１３３は、電圧検出回路３０により検出された系統電圧と、逆電圧指令値発生部１３２から供給される逆電圧指令値とを加算した値を出力電圧目標値Ｖ２ｒｅｆとして、操作量生成部１３５に出力する。なお、系統電源２の異常が検出されてから一定期間の間以外は、逆電圧指令値発生部１３２から供給される逆電圧指令値はゼロになるため、加算部１３３は系統電圧をそのまま出力電圧目標値Ｖ２ｒｅｆとして出力する。 When the reverse voltage command value generation unit 132 receives the system abnormality signal from the system power supply abnormality detection unit 131, the amplitude of the output voltage of the bidirectional inverter 12 corresponding to the system voltage is compared with the instantaneous value of the system voltage for a certain period. Then, it swings up and down to generate a reverse voltage command value for applying a reverse voltage to both the first thyristor S1 and the second thyristor S2. Reverse voltage command value generation unit 132 outputs the generated reverse voltage command value to addition unit 133. The adding unit 133 sets a value obtained by adding the system voltage detected by the voltage detection circuit 30 and the reverse voltage command value supplied from the reverse voltage command value generating unit 132 as the output voltage target value V2ref, to the operation amount generating unit 135. Output to Since the reverse voltage command value supplied from reverse voltage command value generation unit 132 is zero except for a fixed period after abnormality of system power supply 2 is detected, addition unit 133 outputs the system voltage as it is. Output as the target value V2ref.
　出力電圧・電流検出部１３４は、双方向インバータ１２の出力電圧・出力電流を検出して、操作量生成部１３５に出力する。操作量生成部１３５は、系統電源２が正常なときには系統連系運転（電流制御モードで運転）するための操作量を生成し、系統電源２が異常なときには自立運転（電圧制御モードで運転）するための操作量を生成する。 The output voltage / current detection unit 134 detects the output voltage / output current of the bidirectional inverter 12 and outputs the detection result to the operation amount generation unit 135. The operation amount generation unit 135 generates an operation amount for performing grid connection operation (operation in current control mode) when the system power supply 2 is normal, and stand-alone operation (operation in voltage control mode) when the system power supply 2 is abnormal. Generate an operation amount to
　操作量生成部１３５は、系統連系運転時（平常時）、電流制御モードで動作する。そのため、出力電圧の目標値は無視され、操作量生成部１３５内部で生成している出力電流の目標値に従って動作する。なお、系統連系運転時の出力電流の目標値は、負荷平準化や電力品質改善等、平常時の用途に応じて、実効値の向きと大きさが正から負までの正弦波の瞬時値が設定される。 The operation amount generation unit 135 operates in the current control mode during grid-connected operation (normal operation). Therefore, the target value of the output voltage is ignored, and the operation is performed in accordance with the target value of the output current generated in the operation amount generation unit 135. In addition, the target value of the output current at the time of grid connection operation is the instantaneous value of the sine wave from positive to negative in the direction and magnitude of the effective value according to the application of normal use such as load leveling and power quality improvement. Is set.
　一方、操作量生成部１３５は、自立運転時（系統異常時）、電圧制御モードで動作する。そのため、前記の出力電流の目標値は無視され、出力電圧の目標値に従って動作する。自立運転時の出力電圧の目標値は、系統の電圧が消失していない状態において、系統連系運転から自立運転に切り替わってから所定の期間（１ｍｓ未満）だけ、加算部１３３から入力される出力電圧の目標値Ｖ２ｒｅｆに従って動作するが、系統の電圧が消失している場合、もしくは、系統連系運転から自立運転に切り替わってから所定の期間経過後は、操作量生成部１３５内部で生成している出力電圧の目標値に従って動作する。 On the other hand, the operation amount generation unit 135 operates in the voltage control mode during the independent operation (during system abnormality). Therefore, the target value of the output current is ignored and operates according to the target value of the output voltage. The target value of the output voltage during the stand-alone operation is an output that is input from the addition unit 133 for a predetermined period (less than 1 ms) after switching from the grid connection operation to the stand-alone operation in a state where the system voltage has not disappeared Although it operates according to target value V2ref of voltage, it is generated inside operation amount generation unit 135 after lapse of a predetermined period after the system voltage has disappeared or after switching from grid-connected operation to stand-alone operation. Operate according to the target value of the output voltage.
　なお、系統連系運転から自立運転に切り替わってから所定の期間以外に適用される操作量生成部１３５内部で生成している出力電流・出力電圧の目標値は、系統異常時のサイリスタの強制消弧には直接関連していない。そのため、ここではその詳細を割愛する。 The target value of the output current and output voltage generated in the operation amount generation unit 135 applied outside the predetermined period after switching from the grid connection operation to the stand-alone operation is the forced extinction of the thyristor at the time of the system failure. It is not directly related to the arc. Therefore, I omit the details here.
　駆動部１３６は、操作量生成部１３５により生成された操作量をもとに駆動信号を生成し、双方向インバータ１２の主回路のスイッチング素子を駆動する。駆動部１３６は例えば、当該操作量と搬送波（三角波）を比較するコンパレータを含み、当該コンパレータは、当該操作量と搬送波の比較結果に応じたＰＷＭ信号を駆動信号として上記スイッチング素子のゲート端子に出力する。 The drive unit 136 generates a drive signal based on the operation amount generated by the operation amount generation unit 135 and drives the switching element of the main circuit of the bidirectional inverter 12. The drive unit 136 includes, for example, a comparator that compares the operation amount with a carrier wave (triangular wave), and the comparator outputs a PWM signal corresponding to the comparison result of the operation amount with the carrier as a drive signal to the gate terminal of the switching element. Do.
　図４、図５は、電力変換装置１０が系統連系運転から自立運転に切り替わる際における、各種波形の振る舞いの一例を示す図である。系統連系運転時は、交流スイッチ２０にオン信号が入力され、第１サイリスタＳ１及び第２サイリスタＳ２が導通している。図４に示す例では系統電源２から第１サイリスタＳ１及び第２サイリスタＳ２を介して特定負荷３ａに電流Ｉｓｃｒが流れている。電力変換装置１０は、出力電流設定ゼロで、系統電圧Ｖ１に対応する電圧Ｖ２を出力する。即ち、系統電源２の異常に備えて、電流がゼロになるように双方向インバータ１２をスイッチング動作させる（電流制御モード）。なお、前記の出力電流設定はゼロに限定したものではない。負荷平準化や電力品質改善等、平常時の用途に合わせ、ゼロ以外の設定でも構わない。 FIG. 4 and FIG. 5 are diagrams showing an example of behavior of various waveforms when the power conversion device 10 switches from grid-connected operation to self-sustaining operation. During grid-connected operation, the on signal is input to the AC switch 20, and the first thyristor S1 and the second thyristor S2 are in conduction. In the example shown in FIG. 4, a current Iscr flows from the system power supply 2 to the specific load 3a via the first thyristor S1 and the second thyristor S2. The power conversion device 10 outputs a voltage V2 corresponding to the grid voltage V1 at an output current setting of zero. That is, in preparation for an abnormality in the system power supply 2, the bidirectional inverter 12 is switched to operate so that the current becomes zero (current control mode). The above output current setting is not limited to zero. It may be a setting other than zero according to the application of normal use such as load leveling and power quality improvement.
　系統電源２の異常が検出されると、系統連系運転から自立運転に切り替わり、交流スイッチ２０にオフ信号が入力される。それと同時に所定期間のＴ１だけ、電力変換装置１０は、検出された系統電圧より所定値Ｖｒ１（例えば、３Ｖ）以上高い電圧と、検出された系統電圧より所定値Ｖｒ２（例えば、３Ｖ）以上低い電圧を交互に少なくとも１回出力する。所定値Ｖｒ１以上高い電圧と、所定値Ｖｒ２以上低い電圧を出力する順番は、どちらが先でもよい。（図４、図５） When an abnormality in the system power supply 2 is detected, the system interconnection operation is switched to a standalone operation, and an off signal is input to the AC switch 20. At the same time, the power conversion device 10 has a voltage higher by a predetermined value Vr1 (for example, 3 V) or more than the detected system voltage and a voltage lower than the detected system voltage by a predetermined value Vr2 (for example 3 V) Alternately at least once. The order of outputting the voltage higher than the predetermined value Vr1 or more and the voltage lower than the predetermined value Vr2 may be earlier. (Figure 4, Figure 5)
　図４に示す例では所定値Ｖｒ１以上高い電圧を先に出力している。この電圧により第２サイリスタＳ２のカソード端子の電圧がアノード端子の電圧より高くなり、第２サイリスタＳ２を流れる電流Ｉｓｃｒが停止し、第２サイリスタＳ２が強制消弧する。 In the example shown in FIG. 4, a voltage higher than the predetermined value Vr1 is output first. Due to this voltage, the voltage at the cathode terminal of the second thyristor S2 becomes higher than the voltage at the anode terminal, the current Iscr flowing through the second thyristor S2 stops, and the second thyristor S2 is forced to extinguish.
　なお、系統連系運転から自立運転に切り替わる直前の状態において、電力変換装置１０から第１サイリスタＳ１を介して、系統電源２に電流Ｉｓｃｒが流れている場合は、所定値Ｖｒ２以上低い電圧が出力されることにより、第１サイリスタＳ１のアノード端子の電圧がカソード端子の電圧より低くなる。これにより第１サイリスタＳ１を流れる電流Ｉｓｃｒが停止し、第１サイリスタＳ１が強制消弧する。 When the current Iscr flows from the power conversion device 10 to the system power supply 2 from the power conversion device 10 via the first thyristor S1, a voltage lower than the predetermined value Vr2 is output immediately before switching from the grid connection operation to the stand-alone operation. As a result, the voltage at the anode terminal of the first thyristor S1 becomes lower than the voltage at the cathode terminal. As a result, the current Iscr flowing through the first thyristor S1 is stopped, and the first thyristor S1 is forcibly extinguished.
　所定期間Ｔ１は、第１サイリスタＳ１と第２サイリスタＳ２のターンオフ時間の合計値より大きく、系統電圧の周期に比べて、十分に小さい値に設定する。通常この値は、双方向インバータ１２の応答を考慮しても１ｍｓ未満であり、系統電圧の周期に比べて十分に小さい値に設定できる。 The predetermined period T1 is larger than the sum of the turn-off times of the first thyristor S1 and the second thyristor S2, and is set to a value sufficiently smaller than the cycle of the system voltage. Normally, this value is less than 1 ms even in consideration of the response of the bidirectional inverter 12, and can be set to a value sufficiently smaller than the cycle of the grid voltage.
　所定値Ｖｒ１、Ｖｒ２は、第１サイリスタＳ１もしくは第２サイリスタＳ２に加える逆電圧の指令値である。この指令値は、実際に両サイリスタにゼロボルト以上の逆電圧を加えることができれば、できるだけ小さな値が望ましい。本発明の実施の形態では双方向インバータ１２の応答を考慮してたとえば３Ｖに設定する。 The predetermined values Vr1 and Vr2 are command values of reverse voltages to be applied to the first thyristor S1 or the second thyristor S2. It is desirable that this command value be as small as possible if it is possible to actually apply a reverse voltage greater than or equal to zero volts to both thyristors. In the embodiment of the present invention, the voltage is set to, for example, 3 V in consideration of the response of the bidirectional inverter 12.
　電力変換装置１０は、交流スイッチ２０がオフした後、自己が生成する規定の交流電圧Ｖ２を出力する。即ち、特定負荷３ａの変動に対して規定の交流電圧の出力を維持するよう、双方向インバータ１２をスイッチング動作させる（電圧制御モード）。 After the AC switch 20 is turned off, the power conversion device 10 outputs a prescribed AC voltage V2 generated by itself. That is, the bidirectional inverter 12 is switched (voltage control mode) to maintain the output of the specified AC voltage against the fluctuation of the specific load 3a.
　以上説明したように本実施の形態によれば、電力変換装置１０の出力電圧を上下に振ることにより、逆向きに並列に接続された第１サイリスタＳ１及び第２サイリスタＳ２の両方に逆電圧を印加することができる。これにより、第１サイリスタＳ１及び第２サイリスタＳ２で構成される交流スイッチ２０を任意のタイミングで強制消弧させることができる。 As described above, according to the present embodiment, by swinging the output voltage of the power conversion device 10 up and down, the reverse voltage is applied to both the first thyristor S1 and the second thyristor S2 connected in parallel in the reverse direction. Can be applied. Thus, the AC switch 20 configured of the first thyristor S1 and the second thyristor S2 can be forcedly extinguished at an arbitrary timing.
　その際、交流スイッチ２０に流れる電流を検出しないため、第１サイリスタＳ１または第２サイリスタＳ２に流れる電流が少ない場合や、高調波電流を含んだ電流が第１サイリスタＳ１または第２サイリスタＳ２に流れていた場合でも、第１サイリスタＳ１及び第２サイリスタＳ２の両方を確実に強制消弧させることができる。また、共振を用いた強制消弧回路を用いる必要がないため、回路の大型化を防止することができる。また電力変換装置１０は、平常時の負荷平準化、電力用アクティブフィルタ、力率改善、瞬低補償、調相などの電力品質改善にも使用可能である。 At that time, since the current flowing to the AC switch 20 is not detected, the current flowing to the first thyristor S1 or the second thyristor S2 is small, or the current including the harmonic current flows to the first thyristor S1 or the second thyristor S2 Even in this case, both the first thyristor S1 and the second thyristor S2 can be surely extinguished forcibly. In addition, since it is not necessary to use a forced arc extinguishing circuit using resonance, it is possible to prevent an increase in size of the circuit. The power conversion device 10 can also be used for power quality improvement such as normal load leveling, power active filter, power factor improvement, sag compensation, phase adjustment and the like.
　以上、本発明を実施の形態をもとに説明した。実施の形態は例示であり、それらの各構成要素や各処理プロセスの組み合わせにいろいろな変形例が可能なこと、またそうした変形例も本発明の範囲にあることは当業者に理解されるところである。 The present invention has been described above based on the embodiments. The embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .
　上述の実施の形態では、特定負荷３ａをバックアップするための電源として、蓄電部１と電力変換装置１０を備える蓄電システムを１つ設ける例を説明したが、複数の蓄電システムを並列に設けて並列冗長運転させてもよい。さらに蓄電システムと並列に、太陽光発電システム、燃料電池システム、エンジン発電システム等の発電システムを接続してもよい。 Although the above-mentioned embodiment demonstrated the example which provides one electrical storage system provided with the electrical storage part 1 and the power converter 10 as a power supply for backing up the specific load 3a, a several electrical storage system is provided in parallel and it parallels Redundant operation may be performed. Furthermore, a power generation system such as a photovoltaic power generation system, a fuel cell system, or an engine power generation system may be connected in parallel with the power storage system.
　なお、実施の形態は、以下の項目によって特定されてもよい。 The embodiment may be specified by the following items.
［項目１］
　直流電源（１）と系統電源（２）の間に接続される電力変換装置（１０）と、
　前記電力変換装置（１０）と前記系統電源（２）の間に挿入される双方向スイッチ（２０）であり、自己消弧能力を持たない２つの半導体スイッチ（Ｓ１、Ｓ２）が逆向きに並列に接続されて構成される双方向スイッチ（２０）と、を備え、
　前記双方向スイッチ（２０）と前記系統電源（２）の間の経路の検出電圧が、所定の電圧範囲及び／又は所定の周波数範囲を逸脱したとき、前記２つの半導体スイッチ（Ｓ１、Ｓ２）のゲート信号をオフするとともに、前記電力変換装置（２０）は、前記検出電圧より所定値以上高い電圧と、前記検出電圧より所定値以上低い電圧を交互に少なくとも１回出力することを特徴とする電力変換システム。
　これによれば、系統電圧が所定の電圧範囲及び／又は所定の周波数範囲を逸脱したとき、自己消弧能力を持たない２つの半導体スイッチ（Ｓ１、Ｓ２）を強制消弧させることができる。
［項目２］
　前記直流電源（１）は蓄電部（１）であり、
　前記電力変換装置（１０）と前記双方向スイッチ（２０）の間の経路に負荷（３ａ）が接続され、
　前記電力変換装置（１０）は、
　前記蓄電部（１）から放電される直流電力を交流電力に変換して出力するとともに、前記系統電源から入力される交流電力を直流電力に変換して前記蓄電部（１）を充電するインバータ（１２）と、
　前記検出電圧が前記所定の電圧範囲及び／又は所定の周波数範囲に収まるとき系統連系モードで前記インバータ（１２）を駆動し、前記検出電圧が前記所定の電圧範囲及び／又は所定の周波数範囲を逸脱するとき自立モードで前記インバータ（１２）を駆動する制御部（１３）と、
　を含むことを特徴とする項目１に記載の電力変換システム。
　これによれば、系統電圧が異常なとき、自立モードに切り替えることにより、負荷（３ａ）に安定した電圧を供給することができる。
［項目３］
　前記制御部（１３）は、前記系統連系モードにおいて、前記インバータ（１２）の出力電圧が系統電圧に対応し、前記インバータ（１２）の出力電流がゼロになるよう、前記インバータ（１２）を駆動することを特徴とする項目２に記載の電力変換システム。
　これによれば、系統電源（２）が異常のとき瞬時にバックアップ電源に切り替えることができる。
［項目４］
　前記双方向スイッチ（２０）と前記系統電源（２）の間の経路に一般負荷（３ｂ）が接続され、
　前記電力変換装置（１０）と前記双方向スイッチ（２０）の間の経路に接続される前記負荷（３ａ）は、特定負荷（３ａ）であることを特徴とする項目２または３に記載の電力変換システム。
　これによれば、系統電源（２）の停電時、特定負荷（３ａ）を優先的にバックアップすることができる。
［項目５］
　前記半導体スイッチ（Ｓ１、Ｓ２）はサイリスタ（Ｓ１、Ｓ２）であることを特徴とする項目１から４のいずれかに記載の電力変換システム。
　これによれば、系統電圧が所定の電圧範囲及び／又は所定の周波数範囲を逸脱したとき、サイリスタ（Ｓ１、Ｓ２）を強制消弧させることができる。
［項目６］
　直流電源（１）に接続される電力変換装置（１０）と、系統電源（２）の間に挿入される双方向スイッチ（２０）であり、自己消弧能力を持たない２つの半導体スイッチ（Ｓ１、Ｓ２）が逆向きに並列に接続されて構成される双方向スイッチ（２０）の消弧方法であって、
　前記双方向スイッチ（２０）と前記系統電源（２）の間の経路の検出電圧が、所定の電圧範囲及び／又は所定の周波数範囲を逸脱したとき、前記２つの半導体スイッチ（Ｓ１、Ｓ２）のゲート信号をオフするとともに、前記電力変換装置（１０）から、前記検出電圧より所定値以上高い電圧と、前記検出電圧より所定値以上低い電圧を交互に少なくとも１回出力することを特徴とする双方向スイッチの消弧方法。
　これによれば、系統電圧が所定の電圧範囲及び／又は所定の周波数範囲を逸脱したとき、自己消弧能力を持たない２つの半導体スイッチ（Ｓ１、Ｓ２）を強制消弧させることができる。 [Item 1]
A power converter (10) connected between the DC power supply (1) and the system power supply (2);
It is a bidirectional switch (20) inserted between the power converter (10) and the system power supply (2), and two semiconductor switches (S1, S2) having no self-extinguishing ability are connected in parallel in opposite directions. A bidirectional switch (20) configured to be connected to the
When the detected voltage of the path between the bidirectional switch (20) and the system power supply (2) deviates from a predetermined voltage range and / or a predetermined frequency range, the two semiconductor switches (S1, S2) The power converter (20) alternately outputs a voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more alternately at least once while turning off the gate signal. Conversion system.
According to this, when the grid voltage deviates from the predetermined voltage range and / or the predetermined frequency range, it is possible to forcibly extinguish the two semiconductor switches (S1, S2) having no self-extinguishing ability.
[Item 2]
The DC power supply (1) is a storage unit (1),
A load (3a) is connected to a path between the power converter (10) and the bidirectional switch (20),
The power converter (10) is
An inverter which converts DC power discharged from the storage unit (1) into AC power and outputs the AC power, and converts AC power input from the system power supply into DC power to charge the storage unit (1) 12) and
The inverter (12) is driven in the grid connection mode when the detection voltage falls within the predetermined voltage range and / or the predetermined frequency range, and the detection voltage is set to the predetermined voltage range and / or the predetermined frequency range. A control unit (13) for driving said inverter (12) in free standing mode when deviating;
The power conversion system according to item 1, comprising:
According to this, when the system voltage is abnormal, stable voltage can be supplied to the load (3a) by switching to the stand-alone mode.
[Item 3]
The control unit (13) controls the inverter (12) so that the output voltage of the inverter (12) corresponds to the system voltage in the grid connection mode, and the output current of the inverter (12) is zero. The power conversion system according to item 2, characterized in that it is driven.
According to this, when the system power supply (2) is abnormal, it is possible to switch to the backup power supply instantly.
[Item 4]
A general load (3b) is connected to the path between the bi-directional switch (20) and the system power supply (2),
The power according to item 2 or 3, wherein the load (3a) connected to the path between the power conversion device (10) and the bidirectional switch (20) is a specific load (3a) Conversion system.
According to this, at the time of a power failure of the system power supply (2), the specific load (3a) can be preferentially backed up.
[Item 5]
The power conversion system according to any one of items 1 to 4, wherein the semiconductor switches (S1, S2) are thyristors (S1, S2).
According to this, when the grid voltage deviates from the predetermined voltage range and / or the predetermined frequency range, it is possible to forcibly extinguish the thyristors (S1, S2).
[Item 6]
A power converter (10) connected to a DC power supply (1) and a bi-directional switch (20) inserted between the system power supply (2), and two semiconductor switches (S1) having no self-extinguishing capability , S2) is a method of extinguishing a bidirectional switch (20) configured to be connected in parallel in the reverse direction,
When the detected voltage of the path between the bidirectional switch (20) and the system power supply (2) deviates from a predetermined voltage range and / or a predetermined frequency range, the two semiconductor switches (S1, S2) The gate signal is turned off, and a voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more are alternately output from the power conversion device (10) at least once. Direction switch extinguishing method.
According to this, when the grid voltage deviates from the predetermined voltage range and / or the predetermined frequency range, it is possible to forcibly extinguish the two semiconductor switches (S1, S2) having no self-extinguishing ability.
　１　蓄電部、　２　系統電源、　３　負荷、　３ａ　特定負荷、　３ｂ　一般負荷、　１０　電力変換装置、　１０ａ　ＡＣ－ＤＣコンバータ、　１０ｂ　インバータ、　１０ｃ　ＡＣ－ＤＣコンバータ、　１１　双方向ＤＣ－ＤＣコンバータ、　１２　双方向インバータ、　１３　制御部、　２０　交流スイッチ、　２０ａ　電源切替器、　Ｓ１　第１サイリスタ、　Ｓ２　第２サイリスタ、　３０　電圧検出回路、　１３１　系統電源異常検出部、　１３２　逆電圧指令値発生部、　１３３　加算部、　１３４　出力電圧・電流検出部、　１３５　操作量生成部、　１３６　駆動部。 1 storage unit, 2 power sources, 3 loads, 3a specific load, 3b general load, 10 power converters, 10a AC-DC converter, 10b inverter, 10c AC-DC converter, 11 bidirectional DC-DC converter, 12 bidirectional Inverter, 13 control unit, 20 AC switch, 20a power switch, S1 first thyristor, S2 second thyristor, 30 voltage detection circuit, 131 system power failure detection unit, 132 reverse voltage command value generation unit, 133 addition unit, 134 Output voltage / current detection unit, 135 operation amount generation unit, 136 drive unit.
　本発明は、蓄電システムに利用可能である。 The present invention is applicable to a storage system.

Claims (6)

  1. 　直流電源と系統電源の間に接続される電力変換装置と、
    　前記電力変換装置と前記系統電源の間に挿入される双方向スイッチであり、自己消弧能力を持たない２つの半導体スイッチが逆向きに並列に接続されて構成される双方向スイッチと、を備え、
    　前記双方向スイッチと前記系統電源の間の経路の検出電圧が、所定の電圧範囲、所定の周波数範囲を逸脱したとき、前記２つの半導体スイッチのゲート信号をオフするとともに、前記電力変換装置は、前記検出電圧より所定値以上高い電圧と、前記検出電圧より所定値以上低い電圧を交互に少なくとも１回出力することを特徴とする電力変換システム。     A power converter connected between the DC power supply and the grid power supply;
    A bidirectional switch which is a bidirectional switch inserted between the power conversion device and the system power supply, and configured by connecting two semiconductor switches having no self arc extinguishing ability in parallel in opposite directions ,
    When the detection voltage of the path between the bidirectional switch and the system power supply deviates from a predetermined voltage range and a predetermined frequency range, the power conversion device turns off the gate signals of the two semiconductor switches, A power conversion system characterized by alternately outputting a voltage higher by a predetermined value or more than the detection voltage and a voltage lower by a predetermined value or more than the detection voltage at least once.
  2. 　前記直流電源は蓄電部であり、
    　前記電力変換装置と前記双方向スイッチの間の経路に負荷が接続され、
    　前記電力変換装置は、
    　前記蓄電部から放電される直流電力を交流電力に変換して出力するとともに、前記系統電源から入力される交流電力を直流電力に変換して前記蓄電部を充電するインバータと、
    　前記検出電圧が前記所定の電圧範囲、所定の周波数範囲に収まるとき系統連系モードで前記インバータを駆動し、前記検出電圧が前記所定の電圧範囲、所定の周波数範囲を逸脱するとき自立モードで前記インバータを駆動する制御部と、
    　を含むことを特徴とする請求項１に記載の電力変換システム。     The DC power source is a storage unit,
    A load is connected to a path between the power converter and the bidirectional switch;
    The power converter is
    An inverter that converts DC power discharged from the storage unit into AC power and outputs the AC power, and converts AC power input from the system power supply into DC power to charge the storage unit;
    The inverter is driven in the grid connection mode when the detection voltage falls within the predetermined voltage range and the predetermined frequency range, and when the detection voltage deviates from the predetermined voltage range and the predetermined frequency range A control unit that drives an inverter;
    The power conversion system according to claim 1, comprising:
  3. 　前記制御部は、前記系統連系モードにおいて、前記インバータの出力電圧が系統電圧に対応し、前記インバータの出力電流がゼロになるよう、前記インバータを駆動することを特徴とする請求項２に記載の電力変換システム。 The said control part drives the said inverter so that the output voltage of the said inverter respond | corresponds to a system voltage in the said grid connection mode, and the output current of the said inverter becomes zero. Power conversion system.
  4. 　前記双方向スイッチと前記系統電源の間の経路に一般負荷が接続され、
    　前記電力変換装置と前記双方向スイッチの間の経路に接続される前記負荷は、特定負荷であることを特徴とする請求項２または３に記載の電力変換システム。     A general load is connected to a path between the bidirectional switch and the system power supply,
    The power conversion system according to claim 2 or 3, wherein the load connected to the path between the power conversion device and the bidirectional switch is a specific load.
  5. 　前記半導体スイッチはサイリスタであることを特徴とする請求項１から４のいずれかに記載の電力変換システム。 The power conversion system according to any one of claims 1 to 4, wherein the semiconductor switch is a thyristor.
  6. 　直流電源に接続される電力変換装置と、系統電源の間に挿入される双方向スイッチであり、自己消弧能力を持たない２つの半導体スイッチが逆向きに並列に接続されて構成される双方向スイッチの消弧方法であって、
    　前記双方向スイッチと前記系統電源の間の経路の検出電圧が、所定の電圧範囲、所定の周波数範囲を逸脱したとき、前記２つの半導体スイッチのゲート信号をオフするとともに、前記電力変換装置から、前記検出電圧より所定値以上高い電圧と、前記検出電圧より所定値以上低い電圧を交互に少なくとも１回出力することを特徴とする双方向スイッチの消弧方法。     Bidirectional switch composed of a power converter connected to a DC power supply and a bi-directional switch inserted between the grid power supplies and having two semiconductor switches without self-extinguishing ability connected in reverse in parallel How to extinguish the switch,
    When the detection voltage of the path between the bidirectional switch and the system power supply deviates from a predetermined voltage range and a predetermined frequency range, the gate signals of the two semiconductor switches are turned off, and from the power conversion device, A method for extinguishing a bidirectional switch, comprising alternately outputting a voltage higher than the detection voltage by a predetermined value or more and a voltage lower than the detection voltage by a predetermined value or more at least once.
PCT/JP2017/005928 2016-08-22 2017-02-17 Power conversion system and arc-extinguishing method for bidirectional switch WO2018037591A1 (en)

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JPH11266540A (en) * 1998-03-18 1999-09-28 Nissin Electric Co Ltd System linkage breaking method with inverter equipment for distributed power source
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JP2003087999A (en) * 2001-06-26 2003-03-20 Sanyo Denki Co Ltd Uninterruptible power supply and ac switch interrupting method therefor
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