WO2015098688A1 - Overvoltage protection circuit and power conversion device provided therewith - Google Patents

Overvoltage protection circuit and power conversion device provided therewith Download PDF

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Publication number
WO2015098688A1
WO2015098688A1 PCT/JP2014/083542 JP2014083542W WO2015098688A1 WO 2015098688 A1 WO2015098688 A1 WO 2015098688A1 JP 2014083542 W JP2014083542 W JP 2014083542W WO 2015098688 A1 WO2015098688 A1 WO 2015098688A1
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Prior art keywords
circuit
voltage
switch
overvoltage
power supply
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PCT/JP2014/083542
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French (fr)
Japanese (ja)
Inventor
俊彰 佐藤
矢吹　俊生
田口　泰貴
淳也 三井
康平 森田
敬之 畑山
Original Assignee
ダイキン工業株式会社
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Application filed by ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Priority to CN201480067793.7A priority Critical patent/CN105814762B/en
Publication of WO2015098688A1 publication Critical patent/WO2015098688A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage

Definitions

  • the present invention relates to an overvoltage protection circuit and a power conversion device including the same.
  • an overvoltage protection circuit as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2009-207329) is provided. This overvoltage protection circuit is configured to shut off the power supply with a relay when the voltage is equal to or higher than a predetermined voltage.
  • the time required for the power supply voltage to become excessive is extremely short, and it is difficult to reliably protect with a slow response due to the interruption by the relay.
  • a semiconductor element such as a semiconductor element that has a short time to withstand overvoltage cannot be protected by being interrupted by a relay.
  • increasing the breakdown voltage of a semiconductor element or the like only for an instantaneous excessive voltage leads to an increase in cost and size.
  • an object of the present invention is to provide a small-sized and low-cost overvoltage protection circuit that protects a device from a momentary excessive voltage, and a power conversion device including the same.
  • An overvoltage protection device is an overvoltage protection circuit connected between a power supply and a device to which power is supplied from the power supply, and includes an overvoltage conduction circuit, a first impedance circuit, 2 impedance circuit.
  • the overvoltage conduction circuit is connected in parallel with the device between a pair of power supply lines connecting the power source and the device, and allows current to flow when overvoltage occurs.
  • the first impedance circuit is connected between the pair of power supply lines in parallel with the device and in series with the overvoltage conduction circuit.
  • the second impedance circuit is connected between the power supply in the power supply line and the first impedance circuit.
  • a closed circuit of [power source-overvoltage conduction circuit-first impedance circuit-second impedance circuit-power source] is configured by conducting the overvoltage conduction circuit at the time of overvoltage.
  • An overvoltage protection circuit is the overvoltage protection circuit according to the first aspect, wherein the overvoltage conduction circuit is a transient voltage suppressor, a Zener diode, a surge absorber, and an avalanche as elements that allow a current to flow during overvoltage. Any one of the diodes is included.
  • a transient voltage suppressor, a Zener diode, a surge absorber, and an avalanche diode are all elements that operate with a short response time with respect to voltage transient fluctuations. Therefore, in this overvoltage protection circuit, when the element conducts at the time of overvoltage, only a voltage corresponding to the ratio of the impedances of the two impedance circuits is applied to the device, and thus the device can be protected from the overvoltage.
  • the overvoltage protection circuit according to the third aspect of the present invention is the overvoltage protection circuit according to the first aspect, and further includes a voltage detector for detecting the voltage of the power supply.
  • the overvoltage conduction circuit has a switch that opens and closes between the power supply line and the first impedance circuit. This switch is turned on when the detection value by the voltage detector exceeds a predetermined threshold value, and conducts between the power supply line and the first impedance circuit.
  • the switch causes the power supply line and the first impedance circuit to conduct at the time of overvoltage. Since only a voltage according to the ratio ⁇ Za / (Za + Zb) ⁇ of the two impedances of the power supply voltage is applied, the device can be protected from overvoltage.
  • the overvoltage protection circuit according to the fourth aspect of the present invention is the overvoltage protection circuit according to the first aspect or the second aspect, and further includes a voltage detector and a bypass circuit.
  • the voltage detector detects the voltage of the power supply.
  • the bypass circuit is a circuit that bypasses the second impedance circuit.
  • the bypass circuit has a second switch that opens and closes the bypass circuit. The second switch normally closes the bypass circuit, and shuts off the bypass circuit when the value detected by the voltage detector exceeds a predetermined threshold value.
  • the bypass circuit is normally closed, so that power is not consumed by the impedance Zb. It is also possible to avoid the voltage applied to the device being lowered by the voltage drop at the impedance Zb.
  • the overvoltage protection circuit according to the fifth aspect of the present invention is the overvoltage protection circuit according to the third aspect, and further includes a bypass circuit.
  • the bypass circuit is a circuit that bypasses the second impedance circuit.
  • the bypass circuit has a second switch that opens and closes the bypass circuit. The second switch normally closes the bypass circuit, and shuts off the bypass circuit when the detection value by the voltage detector exceeds a predetermined threshold value.
  • the bypass circuit is normally closed, so that power is not consumed by the impedance Zb. It is also possible to avoid the voltage applied to the device being lowered by the voltage drop at the impedance Zb.
  • the overvoltage protection circuit according to the sixth aspect of the present invention is the overvoltage protection circuit according to the first aspect or the second aspect, and further includes a voltage detector and a third switch.
  • the voltage detection value detects the voltage of the power supply.
  • the third switch opens and closes the power line.
  • the third switch normally turns on the power line, and shuts off the power line after the operation of the second switch when the value detected by the voltage detector exceeds a predetermined threshold.
  • the switch and the second switch operate at the time of overvoltage, so that the device has two impedances of the power supply voltage. Since only a voltage corresponding to the ratio ⁇ Za / (Za + Zb) ⁇ is applied, the device can be protected from overvoltage, and further, the power at the impedances Za and Zb can be obtained by operating the third switch to cut off the power line. Stop consumption. As a result, overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
  • An overvoltage protection circuit is the overvoltage protection circuit according to any one of the third aspect to the fifth aspect, and further includes a third switch.
  • the third switch opens and closes the power line.
  • the third switch normally turns on the power line, and shuts off the power line after the operation of the second switch when the value detected by the voltage detector exceeds a predetermined threshold.
  • the switch and the second switch operate at the time of overvoltage, so that the device has two impedances of the power supply voltage. Since only a voltage corresponding to the ratio ⁇ Za / (Za + Zb) ⁇ is applied, the device can be protected from overvoltage, and further, the power at the impedances Za and Zb can be obtained by operating the third switch to cut off the power line. Stop consumption. As a result, overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
  • the overvoltage protection circuit according to the eighth aspect of the present invention is the overvoltage protection circuit according to any one of the first to seventh aspects, and the power supply is an AC power supply.
  • the overvoltage protection circuit according to the ninth aspect of the present invention is the overvoltage protection circuit according to any one of the first to seventh aspects, and the power source is a DC power source.
  • the switch for turning on and off the alternating current needs bidirectionality, but the switch arranged on the downstream side of the DC power supply may be a one-way switch, so that the cost of the switch can be reduced.
  • a power conversion device includes a converter circuit, an inverter circuit, and an overvoltage protection circuit according to any one of the first to ninth aspects.
  • the converter circuit is connected to an AC power source and converts an AC voltage into a DC voltage.
  • the inverter circuit converts a DC voltage into an AC voltage.
  • the overvoltage protection circuit can protect the converter circuit from excessively applied alternating voltage or the inverter circuit from transiently applied excessive DC voltage.
  • a closed circuit of [power supply-overvoltage conduction circuit-first impedance circuit-second impedance circuit-power supply] is configured by conducting the overvoltage conduction circuit at the time of overvoltage.
  • the overvoltage protection circuit according to the second aspect of the present invention protects the device from overvoltage because the device conducts at the time of overvoltage so that only a voltage corresponding to the impedance ratio of the two impedance circuits is applied to the device. Can do.
  • the switch is connected between the power supply line and the first impedance circuit when overvoltage occurs.
  • a voltage corresponding to the ratio of two impedances of the power supply voltage ⁇ Za / (Za + Zb) ⁇ is applied to the device, so that the device can be protected from overvoltage.
  • the bypass circuit is normally closed. No power is consumed by the impedance Zb, and it can be avoided that the voltage applied to the device is lowered by the voltage drop at the impedance Zb.
  • the switch and the second switch operate at the time of overvoltage.
  • a voltage corresponding to the ratio of the two impedances of the power supply voltage ⁇ Za / (Za + Zb) ⁇ is applied to the device, so that the device can be protected from overvoltage, and the third switch operates to By cutting off, power consumption at the impedances Za and Zb is stopped.
  • overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
  • the overvoltage protection circuit according to the eighth aspect of the present invention even if the supply voltage from the AC power supply is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device. Therefore, it is not necessary to design the equipment with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
  • the switch for turning on and off the alternating current needs bidirectionality, but the switch arranged on the downstream side of the DC power supply may be a one-way switch, so the cost of the switch is low. Can be achieved.
  • the overvoltage protection circuit protects the converter circuit from an excessive AC voltage applied transiently or protects the inverter circuit from an excessive DC voltage applied transiently. be able to.
  • the circuit diagram of the power converter device provided with the overvoltage protection circuit which concerns on 5th Embodiment of this invention.
  • FIG. 1 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the first embodiment of the present invention.
  • the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902.
  • the overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
  • the overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, and a second impedance circuit 22.
  • Overvoltage conduction circuit 10 is composed of an element that allows current to flow when overvoltage occurs.
  • a transient voltage suppressor As an element for passing a current at the time of overvoltage, a transient voltage suppressor, a Zener diode, a surge absorber, or an avalanche diode is employed.
  • the overvoltage conduction circuit 10 is composed of one surge absorber.
  • a surge absorber is a voltage-dependent element and has a high resistance in a normal state. However, when the applied voltage exceeds a predetermined voltage, the voltage is limited by abruptly decreasing the resistance. It can be carried out.
  • Specific elements of the surge absorber include, but are not limited to, arresters and discharge tubes.
  • the overvoltage conduction circuit 10 is connected in parallel with the device 30 between a pair of power supply lines 901 and 902.
  • the overvoltage conduction circuit 10 is connected between the power supply lines for each phase.
  • the first impedance circuit 21 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za.
  • the first impedance circuit 21 is connected between the pair of power supply lines 901 and 902 in parallel with the device 30 and in series with the overvoltage conduction circuit 10.
  • Second impedance circuit 22 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb.
  • the second impedance circuit 22 is connected between the commercial power supply 90 and the first impedance circuit 21 on the power supply line 902.
  • FIG. 2 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the second embodiment of the present invention.
  • the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902.
  • the overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
  • the overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, and a voltage detector 33.
  • Overvoltage conduction circuit 10 employs a switch 11 instead of the surge absorber in the first embodiment.
  • the switch 11 is composed of a phototriac coupler, a light emitting diode 11a is provided on the input side (between A1 and A2), and a phototriac 11b is provided on the output side (between B1 and B2). Yes.
  • the equivalent circuit of the phototriac 11b has a configuration in which two photothyristors 111 and 112 are connected in parallel in opposite directions.
  • the anode A1 of the light emitting diode 11a is connected to the power source Vc via the resistor R1.
  • the cathode A2 of the light emitting diode 11a is connected to the control unit 40 through a signal line.
  • the first anode B1 of the phototriac 11b is connected to the power supply line 901.
  • the second anode B2 of the phototriac 11b is connected to the first impedance circuit 21.
  • the light emitting diode 11a emits light when a current flows.
  • the phototriac 11b receives light from the light emitting diode 11a in a state where the potential of the first anode B1 is higher than the potential of the second anode B2, the photothyristor 111 is turned on.
  • the photothyristor 112 is turned on.
  • the phototriac 11b is a bidirectional element that operates with respect to a bidirectional applied voltage, and also operates at a high speed, so that it is used as a bidirectional high-speed switch.
  • the bidirectional high-speed switch is not limited to the photo triac, but a normal triac or a MOSFET connected so as to conduct in both directions may be adopted.
  • a drive circuit corresponding to the form of the switch is appropriately used.
  • the overvoltage conduction circuit 10 is connected in parallel with the device 30 between a pair of power supply lines 901 and 902. When overvoltage protection between phases is performed when the commercial power supply 90 is a multiphase power supply, the overvoltage conduction circuit 10 is connected between the power supply lines for each phase.
  • control unit 40 performs operation control of the switch 11, that is, energization control to the light emitting diode 11a.
  • the first impedance circuit 21 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za.
  • the first impedance circuit 21 is connected between the pair of power supply lines 901 and 902 in parallel with the device 30 and in series with the overvoltage conduction circuit 10.
  • Second impedance circuit 22 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb.
  • the second impedance circuit 22 is connected between the commercial power supply 90 and the first impedance circuit 21 on the power supply line 902.
  • FIG. 3 is a circuit diagram of a general voltage detector 33.
  • the voltage detector 33 includes a transformer circuit 331 and a converter circuit 332.
  • the transformer circuit 331 is located on the input side and includes a primary winding 331a and a secondary winding 331b.
  • the converter circuit 332 is a circuit in which a rectifying unit 332a composed of a rectifying diode and a smoothing capacitor 332b are connected in parallel.
  • the voltage detector 33 when an AC voltage is applied to the transformer circuit 331, the AC voltage is transformed by the transformer circuit 331. Then, the voltage across the secondary winding 331 b is input to the converter circuit 332.
  • the AC voltage after transformation input to the converter circuit 332 is converted into a DC voltage by the rectifying unit 332a and smoothed by the smoothing capacitor 332b.
  • This smoothed DC voltage is input to the control unit 40. That is, a DC voltage corresponding to the voltage applied to the primary winding 331a is input to the control unit 40.
  • control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 To do. As a result, the photo triac 11b is turned off and returns to normal operation.
  • FIG. 4 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the third embodiment of the present invention.
  • the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902.
  • the overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
  • the overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, a voltage detector 33, and a bypass circuit 35.
  • a bypass circuit 35 is added to the second embodiment, and an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, and The same voltage detector 33 is employed. Therefore, only the bypass circuit 35 will be described here.
  • the bypass circuit 35 is a circuit that is connected in parallel to the second impedance circuit 22 and bypasses the second impedance circuit 22.
  • the bypass circuit 35 includes the second switch 12.
  • the second switch 12 opens and closes the bypass circuit 35.
  • opening and closing the bypass circuit 35 means making the bypass circuit 35 conductive or non-conductive to make it non-conductive.
  • Second switch 12 The second switch 12 normally closes the bypass circuit 35, that is, keeps it in a conductive state. This is because if the bypass circuit 35 is left open (non-conducting state) during normal operation, the second impedance circuit 22 is always connected and power is always consumed, and the voltage applied to the device 30 is second. This is because the voltage is lowered by the voltage drop of the impedance Zb of the impedance circuit 22.
  • the bypass circuit 35 is quickly opened and the second impedance circuit 22 is connected, and the commercial power supply 90—overvoltage conduction circuit 10—first impedance circuit 21—second impedance circuit 22— It is necessary to configure a closed circuit called a commercial power supply 90. For this reason, the second switch 12 is required to operate at high speed.
  • a triac As the second switch 12, a triac, a MOSFET connected so as to conduct in both directions, or the like is employed. In the present embodiment, a phototriac coupler is employed as with the switch 11.
  • the second switch 12 is provided with a light emitting diode 12a on the input side (between C1 and C2) and a phototriac 12b on the output side (between D1 and D2).
  • the equivalent circuit of the phototriac 12b has a configuration in which two photothyristors 121 and 122 are connected in parallel in opposite directions.
  • the anode C1 of the light emitting diode 12a is connected to the power source Vc via the resistor R2.
  • the cathode C2 of the light emitting diode 12a is connected to the control unit 40 via a signal line.
  • the first anode D1 of the phototriac 12b is connected between the second impedance circuit 22 in the power supply line 902 and the device 30.
  • the second anode D2 of the photo triac 12b is connected to the power line 902 between the second impedance circuit 22 and the commercial power source 90.
  • the operating principle of the photothyristors 121 and 122 of the light-emitting diode 12a and the phototriac 12b is the same as the operating principle of the light-emitting diode 11a and the photothyristor 111 and 112 of the phototriac 11b in the switch 11, so that the description of the operation is omitted here. .
  • the control unit 40 When the voltage Vac of the commercial power supply 90 suddenly increases and the control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold, the control unit 40 energizes the light emitting diode 11a of the switch 11 to generate a photo The triac 11b is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 12a of the second switch 12 and turns off the phototriac 12b.
  • control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 Then, the photo triac 11b is turned off. At the same time, the control unit 40 energizes the light emitting diode 12a of the second switch 12 to turn on the phototriac 12b. As a result, the normal operation is restored.
  • FIG. 5 is a circuit diagram of an apparatus including an overvoltage protection circuit 50 according to the fourth embodiment of the present invention.
  • the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902.
  • the overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
  • the overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, a voltage detector 33, a bypass circuit 35, and a third switch 13.
  • a third switch 13 is added to the third embodiment, and an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, The same voltage detector 33 and bypass circuit 35 are employed. Therefore, only the third switch 13 will be described here.
  • (2-1) Third switch 13 The third switch 13 opens and closes the power line 901.
  • opening and closing the power supply line 901 means that the power supply line 901 is turned on or off to make it non-conductive.
  • the third switch 13 normally closes the power supply line 901, that is, keeps it conductive.
  • the switch 11 is turned on, the second switch 12 is turned off, and a closed circuit of the commercial power supply 90-overvoltage conduction circuit 10-first impedance circuit 21-second impedance circuit 22-commercial power supply 90 is formed.
  • the third switch 13 is turned off and the power line 901 is shut off.
  • the purpose of cutting off the power supply line 901 is to stop power consumption in the first impedance circuit 21 and the second impedance circuit 22, and it is possible to suppress overheating of the first impedance circuit 21 and the second impedance circuit 22.
  • the power rating can be reduced, and the cost can be reduced.
  • the third switch 13 is not required to have high speed like the switch 11 and the second switch 12, a relay circuit is employed in this embodiment.
  • the third switch 13 includes a relay contact 13a for opening and closing the power supply line 901, a relay coil 13b for operating the relay contact 13a, and a transistor 13c for energizing and de-energizing the relay coil 13b. Is included. One end of the relay coil 13b is connected to the positive electrode of the power source Vb, and the other end is connected to the collector side of the transistor 13c. The controller 40 switches between the presence and absence of the base current of the transistor 13c, turns on and off the collector and the emitter, and energizes and de-energizes the relay coil 13b.
  • the control unit 40 When the voltage Vac of the commercial power supply 90 suddenly increases and the control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold, the control unit 40 energizes the light emitting diode 11a of the switch 11 to generate a photo The triac 11b is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 12a of the second switch 12 and turns off the phototriac 12b.
  • the third switch 13 cuts off the power supply line 901 and stops the power consumption in the first impedance circuit 21 and the second impedance circuit 22.
  • control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 Then, the photo triac 11b is turned off. At the same time, the control unit 40 energizes the light emitting diode 12a of the second switch 12 to turn on the phototriac 12b. Further, the third switch 13 is turned on and the power supply line 901 is connected to return to the normal operation.
  • the third switch 13 cuts off the power supply line 901 to stop power consumption in the first impedance circuit 21 and the second impedance circuit 22. As a result, overheating of the first impedance circuit 21 and the second impedance circuit 22 can be suppressed, and the power rating can be reduced.
  • FIG. 6 is a circuit diagram of a power converter 200 including an overvoltage protection circuit 100 according to the fifth embodiment of the present invention.
  • the power conversion device 200 includes a DC power supply unit 80, an inverter 95, and an overvoltage protection circuit 100.
  • the inverter 95 is supplied with power from the DC power supply unit 80 via a pair of power supply lines 801 and 802.
  • the overvoltage protection circuit 100 is connected between the DC power supply unit 80 and the inverter 95.
  • the DC power supply unit 80 includes a rectifying unit 81 and a smoothing capacitor 82 connected in parallel with the rectifying unit 81.
  • the rectifying unit 81 is configured in a bridge shape by four diodes D1a, D1b, D2a, and D2b. Specifically, the diodes D1a and D1b and D2a and D2b are respectively connected in series. The cathode terminals of the diodes D1a and D2a are both connected to the plus side terminal of the smoothing capacitor 82 and function as the positive side output terminal of the rectifying unit 81. The anode terminals of the diodes D1b and D2b are both connected to the minus terminal of the smoothing capacitor 82 and function as the negative output terminal of the rectifier 81.
  • connection point of the diode D1a and the diode D1b is connected to one pole of the commercial power supply 90.
  • a connection point between the diode D2a and the diode D2b is connected to the other pole of the commercial power supply 90.
  • the rectifying unit 81 rectifies the AC voltage output from the commercial power supply 90 to generate a DC voltage, and supplies this to the smoothing capacitor 82.
  • the smoothing capacitor 82 smoothes the voltage rectified by the rectifying unit 81.
  • the smoothed voltage Vdc is applied to the inverter 95 connected to the output side of the smoothing capacitor 82.
  • the DC power supply unit 80 can be rephrased as a converter circuit that converts an AC voltage into a DC voltage.
  • the inverter 95 includes a plurality of IGBTs (insulated gate bipolar transistors, hereinafter simply referred to as transistors) and a plurality of free-wheeling diodes.
  • the inverter 95 is applied with the voltage Vdc from the smoothing capacitor 82, and each transistor is turned on and off at the timing instructed by the gate drive circuit 96, thereby generating a drive voltage for driving the motor 150.
  • the motor 150 is, for example, a compressor motor or a fan motor of a heat pump type air conditioner.
  • inverter 95 of this embodiment is a voltage source inverter, it is not limited to it, A current source inverter may be sufficient.
  • Gate drive circuit 96 The gate drive circuit 96 changes the on / off state of each transistor of the inverter 95 based on a command from the control unit 40.
  • the overvoltage protection circuit 100 includes an overvoltage conduction circuit 60, a first impedance circuit 71, a second impedance circuit 72, a voltage detector 83, a bypass circuit 85, and a third switch 63.
  • the fifth embodiment is different from the first to fourth embodiments already described in that the overvoltage protection circuit 100 is provided in the DC section. Therefore, in view of the fact that each component is also replaced from the AC specification to the DC specification, the description will be given again by changing the code even if the names are the same.
  • (2-1) Overvoltage conduction circuit 60 The overvoltage conduction circuit 60 employs a switch 61 instead of the switch 11 in the fourth embodiment.
  • the switch 61 includes a photocoupler 61a, a drive circuit 61b, and a transistor 61c.
  • the photocoupler 61a includes a light emitting diode 611 and a phototransistor 612.
  • the light emitting diode 611 of the photocoupler 61a is connected to the input side (between E1 and E2) of the switch 61.
  • the anode E1 of the light emitting diode 611 is connected to the power source Vc via the resistor R1.
  • the cathode E2 of the light emitting diode 611 is connected to the control unit 40 via a signal line.
  • the phototransistor 612 is connected between the drive circuit 61b and GND.
  • a transistor 61c is provided on the output side (between F1 and F2) of the switch 61.
  • the collector F1 of the transistor 61c is connected to the power supply line 801.
  • the emitter F2 of the transistor 61c is connected to the first impedance circuit 71.
  • the control signal of the control unit 40 is input to the drive circuit 61b via the photocoupler 61a.
  • a driving power supply (not shown) is connected to the driving circuit 61b.
  • the control unit 40 turns on the signal line of the light emitting diode 611, the light emitting diode 611 emits light and the phototransistor 612 becomes conductive. While the phototransistor 612 is conducting, a driving signal is output from the driving circuit 61b to the base of the transistor 61c, and the collector F1-emitter F2 of the transistor 61c is conducted.
  • control unit 40 turns off the signal line of the light emitting diode 611, the light emitting diode 611 does not emit light, and the phototransistor 612 does not conduct. While the phototransistor 612 is not conducting, the collector F1 and the emitter F2 of the transistor 61c are not conducting.
  • a one-way switch may be used, so that bidirectionality is not required when the AC circuit is opened / closed, and there is a cost merit.
  • the configuration of the one-way switch is not limited to this embodiment, but it is desirable that the switch operation can be performed at high speed like a semiconductor switch.
  • the overvoltage conduction circuit 60 is connected in parallel with the device 30 between a pair of power supply lines 801 and 802.
  • the first impedance circuit 71 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za. In general, a resistance element is employed.
  • the first impedance circuit 71 is connected between the pair of power supply lines 801 and 802 in parallel with the inverter 95 and in series with the overvoltage conduction circuit 60.
  • Second impedance circuit 72 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb. In general, a resistance element is employed.
  • the second impedance circuit 72 is connected between the DC power supply unit 80 and the first impedance circuit 71 on the power supply line 802.
  • the voltage detector 83 is connected to the output side of the smoothing capacitor 82, and detects the voltage across the smoothing capacitor 82, that is, the value of the smoothed voltage Vdc.
  • the voltage detector 83 is configured such that two resistors connected in series with each other are connected in parallel to the smoothing capacitor 82 and the voltage Vdc is divided. The voltage value at the connection point between the two resistors is input to the control unit 40.
  • the bypass circuit 85 is a circuit that is connected in parallel to the second impedance circuit 72 and bypasses the second impedance circuit 72.
  • the bypass circuit 85 has a second switch 62.
  • the second switch 62 opens and closes the bypass circuit 85.
  • opening and closing the bypass circuit 85 means that the bypass circuit 35 is turned on or off to make it non-conductive.
  • Second switch 62 The second switch 62 normally closes the bypass circuit 85, that is, keeps it in a conductive state. This is because if the bypass circuit 85 is left open (non-conducting state) during normal operation, power is always consumed by the second impedance circuit 72, and the voltage applied to the inverter 95 is the voltage of the impedance Zb of the second impedance circuit 72. This is because it is lowered by the amount of descent.
  • the bypass circuit 85 is quickly opened, and a closed circuit of DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80. Need to be configured. For this reason, the second switch 62 is required to operate at high speed. In the present embodiment, the same switch as the switch 61 is employed. The switch is not limited to this embodiment.
  • a light emitting diode 621 of a photocoupler 62a is provided on the input side (between G1 and G2), and a transistor 62c is provided on the output side (between H1 and H2).
  • the anode G1 of the light emitting diode 621 is connected to the power source Vc via the resistor R2.
  • the cathode G2 of the light emitting diode 621 is connected to the control unit 40 via a signal line.
  • the collector H1 of the transistor 62c is connected between the second impedance circuit 72 in the power supply line 802 and the inverter 95.
  • the emitter H2 of the transistor 62c is connected to the power supply line 802 between the second impedance circuit 72 and the DC power supply unit 80.
  • the third switch 63 opens and closes the power line 801.
  • opening and closing the power supply line 801 is to turn the power supply line 801 on or off to make it non-conductive.
  • the third switch 63 normally closes the power supply line 801, that is, keeps it conductive.
  • the switch 61 is turned on, the second switch 62 is turned off, and a closed circuit of DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80 is formed.
  • the third switch 63 is turned off and the power line 801 is shut off.
  • the purpose of cutting off the power supply line 801 is to stop power consumption in the first impedance circuit 71 and the second impedance circuit 72, and it is possible to suppress overheating of the first impedance circuit 71 and the second impedance circuit 72.
  • the power rating can be reduced, and the cost can be reduced.
  • the third switch 63 is not required to have high speed like the switch 61 and the second switch 62, a relay circuit is employed in this embodiment.
  • the third switch 63 includes a relay contact 63a for opening and closing the power supply line 801, a relay coil 63b for operating the relay contact 63a, and a transistor 63c for energizing and de-energizing the relay coil 63b. Is included. One end of the relay coil 63b is connected to the positive electrode of the power source Vb, and the other end is connected to the collector side of the transistor 63c. The controller 40 switches between the presence and absence of the base current of the transistor 63c, turns on and off the collector and the emitter, and performs energization and de-energization of the relay coil 63b.
  • the control unit 40 When the voltage Vdc of the DC power supply unit 80 increases rapidly and the control unit 40 determines that the voltage output from the voltage detector 83 exceeds the threshold value, the control unit 40 energizes the light emitting diode 611 of the switch 61, The transistor 61c is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 621 of the second switch 62 and turns off the transistor 62c.
  • the third switch 63 cuts off the power supply line 801 and stops the power consumption in the first impedance circuit 71 and the second impedance circuit 72.
  • the control unit 40 determines that the voltage Vac of the commercial power supply 90 and the voltage Vdc of the DC power supply unit 80 are decreased and the voltage output from the voltage detector 83 is lower than the threshold for recovery, the control unit 40 switches the switch 61.
  • the light-emitting diode 611 is turned off, and the transistor 61c is turned off.
  • the control unit 40 energizes the light emitting diode 621 of the second switch 62 to turn on the transistor 62c. Further, by turning on the third switch 63 and connecting the power supply line 801, the normal operation is restored.
  • the third switch 63 cuts off the power supply line 801 to stop power consumption in the first impedance circuit 71 and the second impedance circuit 72. As a result, overheating of the first impedance circuit 71 and the second impedance circuit 72 can be suppressed, and the power rating can be reduced.
  • the switch 61 and the second switch 62 disposed on the downstream side of the DC power supply unit 80 may be unidirectional switches, the cost of the switches can be reduced.
  • FIG. 7 is a circuit diagram of a power conversion device 200 including the overvoltage protection circuit 100 according to the sixth embodiment of the present invention.
  • the inverter 95 is supplied with power from a DC power supply unit 80 via a pair of power supply lines 801 and 802.
  • a part of the overvoltage protection circuit 100 is connected between the commercial power supply 90 and the DC power supply unit 80, and the other part is connected between the DC power supply unit 80 and the inverter 95.
  • the overvoltage protection circuit 100 includes an overvoltage conduction circuit 60, a first impedance circuit 71, a second impedance circuit 72, a voltage detector 33, a bypass circuit 85, and a third switch 13.
  • a voltage detector and a third switch which are components of the overvoltage protection circuit 100, are provided between the commercial power supply 90 and the DC power supply unit 80. It is that. That is, the arrangement of the voltage detector and the third switch is the same as the arrangement of the voltage detector 33 and the third switch 13 in the fourth embodiment. Therefore, in view of the fact that the voltage detector and the third switch are replaced from the DC specification to the AC specification, the voltage detector 33 and the third switch 13 of the fourth embodiment are employed.
  • each component includes the voltage detector 33 and the third switch 13 of the fourth embodiment, the overvoltage conduction circuit 60 of the fifth embodiment, the first impedance circuit 71, the second impedance circuit 72, and the bypass circuit 85. Therefore, the description is omitted here and only the operation is described.
  • control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold value due to the fluctuation of the voltage Vac of the commercial power supply 90, the control unit 40 energizes the light emitting diode 611 of the switch 61. Then, the transistor 61c is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 621 of the second switch 62 and turns off the transistor 62c.
  • the third switch 13 cuts off the power supply line 901 and stops the power consumption in the first impedance circuit 71 and the second impedance circuit 72.
  • the third switch 13 cuts off the power supply line 901 to stop the power consumption in the first impedance circuit 71 and the second impedance circuit 72. As a result, overheating of the first impedance circuit 71 and the second impedance circuit 72 can be suppressed, and the power rating can be reduced.
  • the switch 61 and the second switch 62 disposed on the downstream side of the DC power supply unit 80 may be unidirectional switches, the cost of the switches can be reduced.
  • the second switch 12 is turned on and the bypass circuit 35 is closed, so that no power is consumed in the second impedance circuit 22, and the voltage applied to the device 30 is equal to the voltage drop in the second impedance circuit 22. Only lowering can be avoided.
  • the third switch 13 stops the power consumption in the first impedance circuit 21 and the second impedance circuit 22 by cutting off the power supply line 901, the power rating of the first impedance circuit 21 and the second impedance circuit 22 is reduced. Can do.
  • the overvoltage protection circuit 50 according to the first embodiment shown in FIG. 1, the second embodiment shown in FIG. 2, and the third embodiment shown in FIG. 4 is an overvoltage protection circuit for an AC voltage.
  • the power source is a DC power source or when a DC power source unit that rectifies an AC power source is provided in the device, each component may be replaced with the DC specification and provided downstream of the DC power source unit.
  • the sixth embodiment is different from the fifth embodiment in that the voltage detector and the third switch are provided between the commercial power supply 90 and the DC power supply unit 80, but only the voltage detector is commercialized. You may make it provide between the power supply 90 and the DC power supply part 80.
  • the third switch is turned off after the protection operation of the device 30 is performed.
  • the third switch may be turned off after a predetermined time has elapsed since the protection operation was performed.
  • the third switch is turned off after the protection operation of the device 30 is performed.
  • the device further includes a device voltage detector that detects the device voltage V, and the device voltage exceeds a predetermined value. Sometimes the third switch may be turned off.
  • a surge absorber has been described as an example of an element that allows a current to flow during overvoltage.
  • the power supply voltage is divided by the impedance ratio and applied to the device 30.
  • an overvoltage circuit such as a varistor or Zener diode that maintains a predetermined voltage when the element itself is on, the voltage obtained by removing the retained voltage from the power supply voltage. Is divided by the impedance ratio.
  • the applied voltage to the device is limited, and the device can be protected from overvoltage.
  • the present invention is useful for equipment used in an area where power supply voltage is likely to fluctuate, such as a refrigeration apparatus.

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Abstract

This invention addresses the problem of providing a small-form-factor, low-cost overvoltage protection circuit that protects equipment from momentary excessive voltages and a power conversion device provided with said overvoltage protection circuit. In said overvoltage protection circuit (50), normally, a second switch (12) is on, closing a bypass circuit (35), so no power is consumed in a second impedance circuit (22), preventing a voltage being applied to equipment (30) from decreasing by an amount equal to the voltage drop across said second impedance circuit (22). When an overvoltage occurs, a switch (11) in an overvoltage-conducting circuit (10) turns on and the aforementioned second switch (12) turns off such that only a voltage corresponding to the ratio between the impedances of a first impedance circuit (21) and the abovementioned second impedance circuit (22) is applied to the abovementioned equipment (30), thus protecting said equipment (30) from the overvoltage.

Description

過電圧保護回路、及びそれを備えた電力変換装置Overvoltage protection circuit and power conversion device including the same
　本発明は、過電圧保護回路、及びそれを備えた電力変換装置に関する。 The present invention relates to an overvoltage protection circuit and a power conversion device including the same.
　電源電圧の変動が起こり易い地域で使用される機器は、電圧上昇時の対策如何によっては、機器の故障を招く虞がある。それゆえ、特許文献１（特開２００９－２０７３２９号公報）に開示されているような過電圧保護回路が設けられる。この過電圧保護回路は、所定電圧以上のときにリレーで電源を遮断する構成である。 ∙ Equipment used in areas where power supply voltage is likely to fluctuate may cause equipment failure depending on the measures taken when the voltage rises. Therefore, an overvoltage protection circuit as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2009-207329) is provided. This overvoltage protection circuit is configured to shut off the power supply with a relay when the voltage is equal to or higher than a predetermined voltage.
　しかしながら、電源電圧が過大となるのに要する時間は極めて短く、上記リレーによる遮断では反応が遅く確実に保護することは困難である。特に半導体素子のような、過電圧に耐えうる時間が短いものについては、リレーによる遮断では保護ができない。また、瞬間的な過大電圧のためだけに半導体素子などの耐圧を高くすることは高コスト化、大型化を招来する。 However, the time required for the power supply voltage to become excessive is extremely short, and it is difficult to reliably protect with a slow response due to the interruption by the relay. In particular, a semiconductor element such as a semiconductor element that has a short time to withstand overvoltage cannot be protected by being interrupted by a relay. Further, increasing the breakdown voltage of a semiconductor element or the like only for an instantaneous excessive voltage leads to an increase in cost and size.
　そこで、本発明の課題は、瞬間的な過大電圧から機器を保護する小型・低コストの過電圧保護回路、及びそれを備えた電力変換装置を提供することにある。 Therefore, an object of the present invention is to provide a small-sized and low-cost overvoltage protection circuit that protects a device from a momentary excessive voltage, and a power conversion device including the same.
　本発明の第１観点に係る過電圧保護装置は、電源とその電源から電力を供給される機器との間に接続される過電圧保護回路であって、過電圧導通回路と、第１インピーダンス回路と、第２インピーダンス回路とを備えている。過電圧導通回路は、電源と機器とを結ぶ一対の電源ライン間にその機器と並列に接続され、過電圧時に電流を流す。第１インピーダンス回路は、一対の電源ライン間に機器と並列に、且つ過電圧導通回路と直列に接続されている。第２インピーダンス回路は、電源ラインのうちの電源と第１インピーダンス回路との間に接続されている。 An overvoltage protection device according to a first aspect of the present invention is an overvoltage protection circuit connected between a power supply and a device to which power is supplied from the power supply, and includes an overvoltage conduction circuit, a first impedance circuit, 2 impedance circuit. The overvoltage conduction circuit is connected in parallel with the device between a pair of power supply lines connecting the power source and the device, and allows current to flow when overvoltage occurs. The first impedance circuit is connected between the pair of power supply lines in parallel with the device and in series with the overvoltage conduction circuit. The second impedance circuit is connected between the power supply in the power supply line and the first impedance circuit.
　この過電圧保護回路では、過電圧時に、過電圧導通回路が導通することによって、［電源―過電圧導通回路―第１インピーダンス回路―第２インピーダンス回路―電源］の閉回路が構成される。その結果、機器には、２つのインピーダンス回路のインピーダンスの比に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 In this overvoltage protection circuit, a closed circuit of [power source-overvoltage conduction circuit-first impedance circuit-second impedance circuit-power source] is configured by conducting the overvoltage conduction circuit at the time of overvoltage. As a result, since only a voltage corresponding to the ratio of the impedances of the two impedance circuits is applied to the device, the device can be protected from overvoltage.
　本発明の第２観点に係る過電圧保護回路は、第１観点に係る過電圧保護回路であって、過電圧導通回路が、過電圧時に電流を流す素子として、過渡電圧サプレッサ、ツェナダイオード、サージアブソーバ、及びアバランシェダイオードのいずれか１つを含んでいる。 An overvoltage protection circuit according to a second aspect of the present invention is the overvoltage protection circuit according to the first aspect, wherein the overvoltage conduction circuit is a transient voltage suppressor, a Zener diode, a surge absorber, and an avalanche as elements that allow a current to flow during overvoltage. Any one of the diodes is included.
　過渡電圧サプレッサ、ツェナダイオード、サージアブソーバ、及びアバランシェダイオードは、いずれも電圧の過渡変動に対して、短い応答時間で動作する素子である。それゆえ、この過電圧保護回路では、過電圧時に当該素子が導通することによって、機器には、２つのインピーダンス回路のインピーダンスの比に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 A transient voltage suppressor, a Zener diode, a surge absorber, and an avalanche diode are all elements that operate with a short response time with respect to voltage transient fluctuations. Therefore, in this overvoltage protection circuit, when the element conducts at the time of overvoltage, only a voltage corresponding to the ratio of the impedances of the two impedance circuits is applied to the device, and thus the device can be protected from the overvoltage.
　本発明の第３観点に係る過電圧保護回路は、第１観点に係る過電圧保護回路であって、電源の電圧を検出する電圧検出器をさらに備えている。過電圧導通回路は、電源ラインと第１インピーダンス回路との間を開閉するスイッチを有している。このスイッチは、電圧検出器による検出値が所定の閾値を超えたときにオンして電源ラインと第１インピーダンス回路との間を導通させる。 The overvoltage protection circuit according to the third aspect of the present invention is the overvoltage protection circuit according to the first aspect, and further includes a voltage detector for detecting the voltage of the power supply. The overvoltage conduction circuit has a switch that opens and closes between the power supply line and the first impedance circuit. This switch is turned on when the detection value by the voltage detector exceeds a predetermined threshold value, and conducts between the power supply line and the first impedance circuit.
　この過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、過電圧時にスイッチが電源ラインと第１インピーダンス回路との間を導通させることによって、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 In this overvoltage protection circuit, for example, when the impedance of each of the first impedance circuit and the second impedance circuit is Za and Zb, the switch causes the power supply line and the first impedance circuit to conduct at the time of overvoltage. Since only a voltage according to the ratio {Za / (Za + Zb)} of the two impedances of the power supply voltage is applied, the device can be protected from overvoltage.
　本発明の第４観点に係る過電圧保護回路は、第１観点又は第２観点に係る過電圧保護回路であって、電圧検出器と、バイパス回路とをさらに備えている。電圧検出器は、電源の電圧を検出する。バイパス回路は、第２インピーダンス回路を迂回する回路である。また、バイパス回路は、バイパス回路を開閉する第２スイッチを有する。この第２スイッチは、通常時はバイパス回路を閉じ、電圧検出器による検出値が所定の閾値を超えたときにバイパス回路を遮断する。 The overvoltage protection circuit according to the fourth aspect of the present invention is the overvoltage protection circuit according to the first aspect or the second aspect, and further includes a voltage detector and a bypass circuit. The voltage detector detects the voltage of the power supply. The bypass circuit is a circuit that bypasses the second impedance circuit. The bypass circuit has a second switch that opens and closes the bypass circuit. The second switch normally closes the bypass circuit, and shuts off the bypass circuit when the value detected by the voltage detector exceeds a predetermined threshold value.
　この過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、通常時はバイパス回路を閉じているので、インピーダンスＺｂで電力が消費されることはなく、機器への印加電圧がインピーダンスＺｂでの電圧降下分だけ低くなることも回避することができる。 In this overvoltage protection circuit, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the bypass circuit is normally closed, so that power is not consumed by the impedance Zb. It is also possible to avoid the voltage applied to the device being lowered by the voltage drop at the impedance Zb.
　他方、過電圧時に第２スイッチがバイパス回路を遮断することにより、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 On the other hand, since the second switch cuts off the bypass circuit at the time of overvoltage, only the voltage according to the ratio of two impedances of power supply voltage {Za / (Za + Zb)} is applied to the device, so that the device is protected from overvoltage. Can do.
　本発明の第５観点に係る過電圧保護回路は、第３観点に係る過電圧保護回路であって、バイパス回路をさらに備えている。バイパス回路は、第２インピーダンス回路を迂回する回路である。また、バイパス回路は、バイパス回路を開閉する第２スイッチを有している。第２スイッチは、通常時はバイパス回路を閉じ、電圧検出器による検出値が所定の閾値を超えたときにバイパス回路を遮断する。 The overvoltage protection circuit according to the fifth aspect of the present invention is the overvoltage protection circuit according to the third aspect, and further includes a bypass circuit. The bypass circuit is a circuit that bypasses the second impedance circuit. The bypass circuit has a second switch that opens and closes the bypass circuit. The second switch normally closes the bypass circuit, and shuts off the bypass circuit when the detection value by the voltage detector exceeds a predetermined threshold value.
　この過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、通常時はバイパス回路を閉じているので、インピーダンスＺｂで電力が消費されることはなく、機器への印加電圧がインピーダンスＺｂでの電圧降下分だけ低くなることも回避することができる。 In this overvoltage protection circuit, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the bypass circuit is normally closed, so that power is not consumed by the impedance Zb. It is also possible to avoid the voltage applied to the device being lowered by the voltage drop at the impedance Zb.
　他方、過電圧時に第２スイッチがバイパス回路を遮断することにより、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 On the other hand, since the second switch cuts off the bypass circuit at the time of overvoltage, only the voltage according to the ratio of two impedances of power supply voltage {Za / (Za + Zb)} is applied to the device, so that the device is protected from overvoltage. Can do.
　本発明の第６観点に係る過電圧保護回路は、第１観点又は第２観点に係る過電圧保護回路であって、電圧検出器と、第３スイッチとをさらに備えている。電圧検出値は、電源の電圧を検出する。第３スイッチは、電源ラインを開閉する。第３スイッチは、通常時は電源ラインを導通状態にし、電圧検出器による検出値が所定の閾値を超えたとき、第２スイッチの動作後に電源ラインを遮断する。 The overvoltage protection circuit according to the sixth aspect of the present invention is the overvoltage protection circuit according to the first aspect or the second aspect, and further includes a voltage detector and a third switch. The voltage detection value detects the voltage of the power supply. The third switch opens and closes the power line. The third switch normally turns on the power line, and shuts off the power line after the operation of the second switch when the value detected by the voltage detector exceeds a predetermined threshold.
　この過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、過電圧時にスイッチ及び第２スイッチが動作することによって、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので機器を過電圧から保護することができ、さらに、第３スイッチが動作して電源ラインを遮断することによってインピーダンスＺａ及びＺｂでの電力消費を止める。この結果、インピーダンスＺａ及びＺｂの過熱を抑制し、電力定格を小さくすることができる。 In this overvoltage protection circuit, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the switch and the second switch operate at the time of overvoltage, so that the device has two impedances of the power supply voltage. Since only a voltage corresponding to the ratio {Za / (Za + Zb)} is applied, the device can be protected from overvoltage, and further, the power at the impedances Za and Zb can be obtained by operating the third switch to cut off the power line. Stop consumption. As a result, overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
　本発明の第７観点に係る過電圧保護回路は、第３観点から第５観点のいずれか１つに係る過電圧保護回路であって、第３スイッチをさらに備えている。第３スイッチは、電源ラインを開閉する。第３スイッチは、通常時は電源ラインを導通状態にし、電圧検出器による検出値が所定の閾値を超えたとき、第２スイッチの動作後に電源ラインを遮断する。 An overvoltage protection circuit according to a seventh aspect of the present invention is the overvoltage protection circuit according to any one of the third aspect to the fifth aspect, and further includes a third switch. The third switch opens and closes the power line. The third switch normally turns on the power line, and shuts off the power line after the operation of the second switch when the value detected by the voltage detector exceeds a predetermined threshold.
　この過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、過電圧時にスイッチ及び第２スイッチが動作することによって、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので機器を過電圧から保護することができ、さらに、第３スイッチが動作して電源ラインを遮断することによってインピーダンスＺａ及びＺｂでの電力消費を止める。この結果、インピーダンスＺａ及びＺｂの過熱を抑制し、電力定格を小さくすることができる。 In this overvoltage protection circuit, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the switch and the second switch operate at the time of overvoltage, so that the device has two impedances of the power supply voltage. Since only a voltage corresponding to the ratio {Za / (Za + Zb)} is applied, the device can be protected from overvoltage, and further, the power at the impedances Za and Zb can be obtained by operating the third switch to cut off the power line. Stop consumption. As a result, overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
　本発明の第８観点に係る過電圧保護回路は、第１観点から第７観点のいずれか一つに係る過電圧保護回路であって、電源がＡＣ電源である。 The overvoltage protection circuit according to the eighth aspect of the present invention is the overvoltage protection circuit according to any one of the first to seventh aspects, and the power supply is an AC power supply.
　この過電圧保護回路では、ＡＣ電源からの供給電圧が過大電圧であっても、機器には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器の電圧定格を高く設計する必要がなく、合理的である。 In this overvoltage protection circuit, even if the supply voltage from the AC power supply is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device. Therefore, it is not necessary to design the equipment with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　本発明の第９観点に係る過電圧保護回路は、第１観点から第７観点のいずれか一つに係る過電圧保護回路であって、電源がＤＣ電源である。 The overvoltage protection circuit according to the ninth aspect of the present invention is the overvoltage protection circuit according to any one of the first to seventh aspects, and the power source is a DC power source.
　この過電圧保護回路では、交流を入り切りするスイッチは双方向性を必要とするが、ＤＣ電源の下流側に配置されるスイッチは片方向スイッチでよいので、スイッチの低コスト化を図ることができる。 In this overvoltage protection circuit, the switch for turning on and off the alternating current needs bidirectionality, but the switch arranged on the downstream side of the DC power supply may be a one-way switch, so that the cost of the switch can be reduced.
　本発明の第１０観点に係る電力変換装置は、コンバータ回路と、インバータ回路と、第１観点から第９観点のいずれか一つに係る過電圧保護回路とを備えている。コンバータ回路は、交流電源に接続され、交流電圧を直流電圧に変換する。インバータ回路は、直流電圧を交流電圧に変換する。 A power conversion device according to a tenth aspect of the present invention includes a converter circuit, an inverter circuit, and an overvoltage protection circuit according to any one of the first to ninth aspects. The converter circuit is connected to an AC power source and converts an AC voltage into a DC voltage. The inverter circuit converts a DC voltage into an AC voltage.
　この電力変換装置では、過電圧保護回路が、コンバータ回路を過渡的に印加される過大交流電圧から保護し、又はインバータ回路を過渡的に印加される過大直流電圧から保護することができる。 In this power converter, the overvoltage protection circuit can protect the converter circuit from excessively applied alternating voltage or the inverter circuit from transiently applied excessive DC voltage.
　本発明の第１観点に係る過電圧保護装置では、過電圧時に、過電圧導通回路が導通することによって、［電源―過電圧導通回路―第１インピーダンス回路―第２インピーダンス回路―電源］の閉回路が構成される。その結果、機器には、２つのインピーダンス回路のインピーダンスの比に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 In the overvoltage protection device according to the first aspect of the present invention, a closed circuit of [power supply-overvoltage conduction circuit-first impedance circuit-second impedance circuit-power supply] is configured by conducting the overvoltage conduction circuit at the time of overvoltage. The As a result, since only a voltage corresponding to the ratio of the impedances of the two impedance circuits is applied to the device, the device can be protected from overvoltage.
　本発明の第２観点に係る過電圧保護回路では、過電圧時に素子が導通することによって、機器には、２つのインピーダンス回路のインピーダンスの比に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 The overvoltage protection circuit according to the second aspect of the present invention protects the device from overvoltage because the device conducts at the time of overvoltage so that only a voltage corresponding to the impedance ratio of the two impedance circuits is applied to the device. Can do.
　本発明の第３観点に係る過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、過電圧時にスイッチが電源ラインと第１インピーダンス回路との間を導通させることによって、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 In the overvoltage protection circuit according to the third aspect of the present invention, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the switch is connected between the power supply line and the first impedance circuit when overvoltage occurs. By conducting the current, only a voltage corresponding to the ratio of two impedances of the power supply voltage {Za / (Za + Zb)} is applied to the device, so that the device can be protected from overvoltage.
　本発明の第４観点又は第５観点に係る過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、通常時はバイパス回路を閉じているので、インピーダンスＺｂで電力が消費されることはなく、機器への印加電圧がインピーダンスＺｂでの電圧降下分だけ低くなることも回避することができる。 In the overvoltage protection circuit according to the fourth aspect or the fifth aspect of the present invention, for example, when the impedance of each of the first impedance circuit and the second impedance circuit is Za and Zb, the bypass circuit is normally closed. No power is consumed by the impedance Zb, and it can be avoided that the voltage applied to the device is lowered by the voltage drop at the impedance Zb.
　他方、過電圧時に第２スイッチがバイパス回路を遮断することにより、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので、機器を過電圧から保護することができる。 On the other hand, since the second switch cuts off the bypass circuit at the time of overvoltage, only the voltage according to the ratio of two impedances of power supply voltage {Za / (Za + Zb)} is applied to the device, so that the device is protected from overvoltage. Can do.
　本発明の第６観点又は第７観点に係る過電圧保護回路では、例えば、第１インピーダンス回路及び第２インピーダンス回路それぞれのインピーダンスをＺａ及びＺｂとしたとき、過電圧時にスイッチ及び第２スイッチが動作することによって、機器には電源電圧の２つのインピーダンスの比｛Ｚａ／（Ｚａ＋Ｚｂ）｝に応じた電圧しか印加されないので機器を過電圧から保護することができ、さらに、第３スイッチが動作して電源ラインを遮断することによってインピーダンスＺａ及びＺｂでの電力消費を止める。この結果、インピーダンスＺａ及びＺｂの過熱を抑制し、電力定格を小さくすることができる。 In the overvoltage protection circuit according to the sixth aspect or the seventh aspect of the present invention, for example, when the impedances of the first impedance circuit and the second impedance circuit are Za and Zb, the switch and the second switch operate at the time of overvoltage. Thus, only a voltage corresponding to the ratio of the two impedances of the power supply voltage {Za / (Za + Zb)} is applied to the device, so that the device can be protected from overvoltage, and the third switch operates to By cutting off, power consumption at the impedances Za and Zb is stopped. As a result, overheating of the impedances Za and Zb can be suppressed and the power rating can be reduced.
　本発明の第８観点に係る過電圧保護回路では、ＡＣ電源からの供給電圧が過大電圧であっても、機器には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器の電圧定格を高く設計する必要がなく、合理的である。 In the overvoltage protection circuit according to the eighth aspect of the present invention, even if the supply voltage from the AC power supply is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device. Therefore, it is not necessary to design the equipment with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　本発明の第９観点に係る過電圧保護回路では、交流を入り切りするスイッチは双方向性を必要とするが、ＤＣ電源の下流側に配置されるスイッチは片方向スイッチでよいので、スイッチの低コスト化を図ることができる。 In the overvoltage protection circuit according to the ninth aspect of the present invention, the switch for turning on and off the alternating current needs bidirectionality, but the switch arranged on the downstream side of the DC power supply may be a one-way switch, so the cost of the switch is low. Can be achieved.
　本発明の第１０観点に係る電力変換装置では、過電圧保護回路が、コンバータ回路を過渡的に印加される過大交流電圧から保護し、又はインバータ回路を過渡的に印加される過大直流電圧から保護することができる。 In the power conversion device according to the tenth aspect of the present invention, the overvoltage protection circuit protects the converter circuit from an excessive AC voltage applied transiently or protects the inverter circuit from an excessive DC voltage applied transiently. be able to.
本発明の第１実施形態に係る過電圧保護回路を備えた装置の回路図。The circuit diagram of the apparatus provided with the overvoltage protection circuit which concerns on 1st Embodiment of this invention. 本発明の第２実施形態に係る過電圧保護回路を備えた装置の回路図。The circuit diagram of the apparatus provided with the overvoltage protection circuit which concerns on 2nd Embodiment of this invention. 電圧検出器の回路図。The circuit diagram of a voltage detector. 本発明の第３実施形態に係る過電圧保護回路を備えた装置の回路図。The circuit diagram of the apparatus provided with the overvoltage protection circuit which concerns on 3rd Embodiment of this invention. 本発明の第４実施形態に係る過電圧保護回路を備えた装置の回路図。The circuit diagram of the apparatus provided with the overvoltage protection circuit which concerns on 4th Embodiment of this invention. 本発明の第５実施形態に係る過電圧保護回路を備えた電力変換装置の回路図。The circuit diagram of the power converter device provided with the overvoltage protection circuit which concerns on 5th Embodiment of this invention. 本発明の第６実施形態に係る過電圧保護回路を備えた電力変換装置の回路図。The circuit diagram of the power converter device provided with the overvoltage protection circuit which concerns on 6th Embodiment of this invention.
　以下、図面を参照しながら、本発明の実施形態について説明する。なお、以下の実施形態は、本発明の具体例であって、本発明の技術的範囲を限定するものではない。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.
　＜第１実施形態＞
　（１）過電圧保護回路５０の構成
　図１は、本発明の第１実施形態に係る過電圧保護回路５０を備えた装置の回路図である。図１において、機器３０は、商用電源９０から一対の電源ライン９０１，９０２を介して電力供給されている。過電圧保護回路５０は、商用電源９０と機器３０との間に接続されている。 <First Embodiment>
(1) Configuration of Overvoltage Protection Circuit 50 FIG. 1 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the first embodiment of the present invention. In FIG. 1, the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902. The overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
　過電圧保護回路５０は、過電圧導通回路１０と、第１インピーダンス回路２１と、第２インピーダンス回路２２とを含んでいる。 The overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, and a second impedance circuit 22.
　（２）過電圧保護回路５０の詳細構成
　（２－１）過電圧導通回路１０
　過電圧導通回路１０は、過電圧時に電流を流す素子で構成されている。過電圧時に電流を流す素子としては、過渡電圧サプレッサ、ツェナダイオード、サージアブソーバ、及びアバランシェダイオードのいずれかが採用される。 (2) Detailed configuration of overvoltage protection circuit 50 (2-1) Overvoltage conduction circuit 10
The overvoltage conduction circuit 10 is composed of an element that allows current to flow when overvoltage occurs. As an element for passing a current at the time of overvoltage, a transient voltage suppressor, a Zener diode, a surge absorber, or an avalanche diode is employed.
　本実施形態では、過電圧導通回路１０は、一つのサージアブソーバで構成されている。サージアブソーバは、電圧依存性を持つ素子であり、通常の状態では高い抵抗を有しているが、印加される電圧が所定電圧を越えたときに抵抗を急激に低下させることによって電圧の制限を行うことができる。サージアブソーバの具体的な素子としては、アレスタや放電管などがあげられるが、これらに限定するものではない。 In the present embodiment, the overvoltage conduction circuit 10 is composed of one surge absorber. A surge absorber is a voltage-dependent element and has a high resistance in a normal state. However, when the applied voltage exceeds a predetermined voltage, the voltage is limited by abruptly decreasing the resistance. It can be carried out. Specific elements of the surge absorber include, but are not limited to, arresters and discharge tubes.
　過電圧導通回路１０は、一対の電源ライン９０１，９０２間に機器３０と並列に接続されている。なお、商用電源９０が多相電源のときに各相間の過電圧保護を行う場合は各相分の電源ライン間に、過電圧導通回路１０が接続される。 The overvoltage conduction circuit 10 is connected in parallel with the device 30 between a pair of power supply lines 901 and 902. When the commercial power supply 90 is a multiphase power supply and overvoltage protection between phases is performed, the overvoltage conduction circuit 10 is connected between the power supply lines for each phase.
　（２－２）第１インピーダンス回路２１
　第１インピーダンス回路２１は、当該回路における電圧と電流との比であるインピーダンスがＺａとなるように構成された回路である。 (2-2) First impedance circuit 21
The first impedance circuit 21 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za.
　第１インピーダンス回路２１は、一対の電源ライン９０１，９０２間に機器３０と並列に、且つ過電圧導通回路１０と直列に接続されている。 The first impedance circuit 21 is connected between the pair of power supply lines 901 and 902 in parallel with the device 30 and in series with the overvoltage conduction circuit 10.
　（２－３）第２インピーダンス回路２２
　第２インピーダンス回路２２は、当該回路における電圧と電流との比であるインピーダンスがＺｂとなるように構成された回路である。 (2-3) Second impedance circuit 22
The second impedance circuit 22 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb.
　第２インピーダンス回路２２は、電源ライン９０２上で、商用電源９０と第１インピーダンス回路２１との間に接続されている。 The second impedance circuit 22 is connected between the commercial power supply 90 and the first impedance circuit 21 on the power supply line 902.
　（３）過電圧保護回路５０の動作
　説明の便宜上、商用電源９０の電圧をＶａｃ、機器３０に印加される電圧をＶａ、第２インピーダンス回路２２の両端にかかる電圧をＶｂとする。 (3) Operation of Overvoltage Protection Circuit 50 For convenience of explanation, the voltage of the commercial power supply 90 is Vac, the voltage applied to the device 30 is Va, and the voltage applied to both ends of the second impedance circuit 22 is Vb.
　図１において、通常時、過電圧導通回路１０のサージアブソーバは導通していないので、機器３０には電圧Ｖａ＝Ｖａｃ－Ｖｂが印加されている。 In FIG. 1, since the surge absorber of the overvoltage conduction circuit 10 is not normally conducted, the voltage Va = Vac−Vb is applied to the device 30.
　商用電源９０の電圧Ｖａｃが急激に変動して過電圧となり、電圧Ｖａがサージアブソーバの動作開始電圧を超えると、過電圧導通回路１０のサージアブソーバが導通して、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路が構成される。このとき、機器３０には電圧Ｖａｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖａｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、機器３０が過電圧から保護される。 When the voltage Vac of the commercial power supply 90 suddenly fluctuates and becomes overvoltage, and the voltage Va exceeds the operation start voltage of the surge absorber, the surge absorber of the overvoltage conduction circuit 10 becomes conductive, and the commercial power supply 90-overvoltage conduction circuit 10-first A closed circuit of 1 impedance circuit 21 -second impedance circuit 22 -commercial power supply 90 is formed. At this time, only the voltage Va = Vac × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vac is applied to the device 30. As a result, the device 30 is protected from overvoltage.
　（４）第１実施形態の特徴
　（４－１）
　過電圧保護回路５０では、過電圧時に過電圧導通回路１０のサージアブソーバが導通することによって、機器３０には第１インピーダンス回路２１と第２インピーダンス回路２２のインピーダンスの比に応じた電圧しか印加されないので、機器３０が過電圧から保護される。 (4) Features of the first embodiment (4-1)
In the overvoltage protection circuit 50, when the surge absorber of the overvoltage conduction circuit 10 conducts at the time of overvoltage, only a voltage corresponding to the impedance ratio of the first impedance circuit 21 and the second impedance circuit 22 is applied to the device 30. 30 is protected from overvoltage.
　（４－２）
　商用電源９０からの供給電圧が過大電圧であっても、機器３０には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器３０の電圧定格を高く設計する必要がなく、合理的である。 (4-2)
Even if the supply voltage from the commercial power supply 90 is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device 30. Therefore, it is not necessary to design the device 30 with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　＜第２実施形態＞
　（１）過電圧保護回路５０の構成
　図２は、本発明の第２実施形態に係る過電圧保護回路５０を備えた装置の回路図である。図２において、機器３０は、商用電源９０から一対の電源ライン９０１，９０２を介して電力供給されている。過電圧保護回路５０は、商用電源９０と機器３０との間に接続されている。 Second Embodiment
(1) Configuration of Overvoltage Protection Circuit 50 FIG. 2 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the second embodiment of the present invention. In FIG. 2, the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902. The overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
　過電圧保護回路５０は、過電圧導通回路１０と、第１インピーダンス回路２１と、第２インピーダンス回路２２と、電圧検出器３３とを含んでいる。 The overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, and a voltage detector 33.
　（２）過電圧保護回路５０の詳細構成
　（２－１）過電圧導通回路１０
　過電圧導通回路１０は、第１実施形態におけるサージアブソーバに替わってスイッチ１１が採用されている。図２に示すように、スイッチ１１は、フォトトライアックカプラで構成され、入力側（Ａ１－Ａ２間）に発光ダイオード１１ａが設けられ、出力側（Ｂ１－Ｂ２間）にフォトトライアック１１ｂが設けられている。フォトトライアック１１ｂの等価回路は、２つのフォトサイリスタ１１１，１１２を互いに逆方向に並列接続した構成である。 (2) Detailed configuration of overvoltage protection circuit 50 (2-1) Overvoltage conduction circuit 10
The overvoltage conduction circuit 10 employs a switch 11 instead of the surge absorber in the first embodiment. As shown in FIG. 2, the switch 11 is composed of a phototriac coupler, a light emitting diode 11a is provided on the input side (between A1 and A2), and a phototriac 11b is provided on the output side (between B1 and B2). Yes. The equivalent circuit of the phototriac 11b has a configuration in which two photothyristors 111 and 112 are connected in parallel in opposite directions.
　発光ダイオード１１ａのアノードＡ１は抵抗Ｒ１を介して電源Ｖｃに接続されている。また、発光ダイオード１１ａのカソードＡ２は信号線を介して制御部４０に接続されている。 The anode A1 of the light emitting diode 11a is connected to the power source Vc via the resistor R1. The cathode A2 of the light emitting diode 11a is connected to the control unit 40 through a signal line.
　フォトトライアック１１ｂの第１アノードＢ１は電源ライン９０１に接続されている。また、フォトトライアック１１ｂの第２アノードＢ２は第１インピーダンス回路２１に接続されている。 The first anode B1 of the phototriac 11b is connected to the power supply line 901. The second anode B2 of the phototriac 11b is connected to the first impedance circuit 21.
　発光ダイオード１１ａは電流が流れると発光する。フォトトライアック１１ｂは、第１アノードＢ１の電位が第２アノードＢ２の電位より大きい状態で発光ダイオード１１ａからの光を受けるとフォトサイリスタ１１１がオン状態になる。他方、第１アノードＢ１の電位が第２アノードＢ２の電位より小さい状態で発光ダイオード１１ａからの光を受けるとフォトサイリスタ１１２がオン状態になる。 The light emitting diode 11a emits light when a current flows. When the phototriac 11b receives light from the light emitting diode 11a in a state where the potential of the first anode B1 is higher than the potential of the second anode B2, the photothyristor 111 is turned on. On the other hand, when light from the light emitting diode 11a is received in a state where the potential of the first anode B1 is smaller than the potential of the second anode B2, the photothyristor 112 is turned on.
　このように、フォトトライアック１１ｂは双方向の印加電圧に対して動作する双方向素子であり、しかも高速で動作するので、双方向の高速スイッチとして利用される。 Thus, the phototriac 11b is a bidirectional element that operates with respect to a bidirectional applied voltage, and also operates at a high speed, so that it is used as a bidirectional high-speed switch.
　なお、双方向の高速スイッチとしては、フォトトライアックだけに限定されるものではなく、通常のトライアックや双方向に導通させるように接続したＭＯＳＦＥＴなどを採用してもよい。別の形態の高速スイッチを用いる場合には、そのスイッチの形態に応じた駆動回路が適宜使用される。 Note that the bidirectional high-speed switch is not limited to the photo triac, but a normal triac or a MOSFET connected so as to conduct in both directions may be adopted. When another form of high-speed switch is used, a drive circuit corresponding to the form of the switch is appropriately used.
　過電圧導通回路１０は、一対の電源ライン９０１，９０２間に機器３０と並列に接続されている。なお、商用電源９０が多相電源のときに各相間の過電圧保護を行う場合は、各相分の電源ライン間に過電圧導通回路１０が接続される。 The overvoltage conduction circuit 10 is connected in parallel with the device 30 between a pair of power supply lines 901 and 902. When overvoltage protection between phases is performed when the commercial power supply 90 is a multiphase power supply, the overvoltage conduction circuit 10 is connected between the power supply lines for each phase.
　また、スイッチ１１の動作制御、つまり発光ダイオード１１ａへの通電制御は制御部４０が行う。 Further, the control unit 40 performs operation control of the switch 11, that is, energization control to the light emitting diode 11a.
　（２－２）第１インピーダンス回路２１
　第１インピーダンス回路２１は、当該回路における電圧と電流との比であるインピーダンスがＺａとなるように構成された回路である。 (2-2) First impedance circuit 21
The first impedance circuit 21 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za.
　第１インピーダンス回路２１は、一対の電源ライン９０１，９０２間に機器３０と並列に、且つ過電圧導通回路１０と直列に接続されている。 The first impedance circuit 21 is connected between the pair of power supply lines 901 and 902 in parallel with the device 30 and in series with the overvoltage conduction circuit 10.
　（２－３）第２インピーダンス回路２２
　第２インピーダンス回路２２は、当該回路における電圧と電流との比であるインピーダンスがＺｂとなるように構成された回路である。 (2-3) Second impedance circuit 22
The second impedance circuit 22 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb.
　第２インピーダンス回路２２は、電源ライン９０２上で、商用電源９０と第１インピーダンス回路２１との間に接続されている。 The second impedance circuit 22 is connected between the commercial power supply 90 and the first impedance circuit 21 on the power supply line 902.
　（２－４）電圧検出器３３
　電圧検出器３３は、交流電圧検出回路によって構成されている。交流電圧検出回路は、多様であり、使用条件によって適宜採用される。例えば、図３は一般的な電圧検出器３３の回路図である。図３において、電圧検出器３３は、変圧回路３３１、コンバータ回路３３２とで構成されている。 (2-4) Voltage detector 33
The voltage detector 33 is configured by an AC voltage detection circuit. There are various AC voltage detection circuits, and they are appropriately adopted depending on use conditions. For example, FIG. 3 is a circuit diagram of a general voltage detector 33. In FIG. 3, the voltage detector 33 includes a transformer circuit 331 and a converter circuit 332.
　変圧回路３３１は、入力側に位置し、一次側巻線３３１ａと二次側巻線３３１ｂとからなる。 The transformer circuit 331 is located on the input side and includes a primary winding 331a and a secondary winding 331b.
　コンバータ回路３３２は、整流ダイオードで構成される整流部３３２ａと、平滑コンデンサ３３２ｂとが並列接続された回路である。 The converter circuit 332 is a circuit in which a rectifying unit 332a composed of a rectifying diode and a smoothing capacitor 332b are connected in parallel.
　電圧検出器３３では、変圧回路３３１に交流電圧が印加されると、交流電圧は変圧回路３３１によって変圧される。そして、二次側巻線３３１ｂの両端電圧がコンバータ回路３３２に入力される。 In the voltage detector 33, when an AC voltage is applied to the transformer circuit 331, the AC voltage is transformed by the transformer circuit 331. Then, the voltage across the secondary winding 331 b is input to the converter circuit 332.
　コンバータ回路３３２に入力された変圧後の交流電圧は、整流部３３２ａで直流電圧に変換され、平滑コンデンサ３３２ｂで平滑化される。この平滑化された直流電圧が制御部４０に入力される。すなわち、一次側巻線３３１ａに印加される電圧に応じた直流電圧が、制御部４０に入力されることになる。 The AC voltage after transformation input to the converter circuit 332 is converted into a DC voltage by the rectifying unit 332a and smoothed by the smoothing capacitor 332b. This smoothed DC voltage is input to the control unit 40. That is, a DC voltage corresponding to the voltage applied to the primary winding 331a is input to the control unit 40.
　（３）過電圧保護回路５０の動作
　説明の便宜上、商用電源９０の電圧をＶａｃ、機器３０に印加される電圧をＶａ、第２インピーダンス回路２２の両端にかかる電圧をＶｂとする。 (3) Operation of Overvoltage Protection Circuit 50 For convenience of explanation, the voltage of the commercial power supply 90 is Vac, the voltage applied to the device 30 is Va, and the voltage applied to both ends of the second impedance circuit 22 is Vb.
　図２において、通常時、過電圧導通回路１０のスイッチ１１はオフしているので、機器３０には電圧Ｖａ＝Ｖａｃ－Ｖｂが印加されている。 In FIG. 2, since the switch 11 of the overvoltage conduction circuit 10 is normally turned off, the voltage Va = Vac−Vb is applied to the device 30.
　商用電源９０の電圧Ｖａｃが急激に増加し、制御部４０が電圧検出器３３から出力される電圧が閾値を超えたと判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａに通電する。これによって、フォトトライアック１１ｂがオンし、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路が構成される。このとき、機器３０には電圧Ｖａｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖａｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、機器３０が過電圧から保護される。なお、機器３０を保護するため、スイッチ１１には高速動作が求められる。 When the voltage Vac of the commercial power supply 90 suddenly increases and the control unit 40 determines that the voltage output from the voltage detector 33 exceeds the threshold, the control unit 40 energizes the light emitting diode 11a of the switch 11. As a result, the phototriac 11b is turned on, and a closed circuit of commercial power supply 90-overvoltage conduction circuit 10-first impedance circuit 21-second impedance circuit 22-commercial power supply 90 is formed. At this time, only the voltage Va = Vac × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vac is applied to the device 30. As a result, the device 30 is protected from overvoltage. In order to protect the device 30, the switch 11 is required to operate at high speed.
　商用電源９０の電圧Ｖａｃが下がり、電圧検出器３３から出力される電圧が復帰のための閾値よりも下がったと制御部４０が判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａの通電をオフする。これによって、フォトトライアック１１ｂはオフし、通常の動作に復帰する。 When the control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 To do. As a result, the photo triac 11b is turned off and returns to normal operation.
　（４）第２実施形態の特徴
　（４－１）
　過電圧保護回路５０では、過電圧時に過電圧導通回路１０のスイッチ１１がオンすることによって、機器３０には第１インピーダンス回路２１と第２インピーダンス回路２２のインピーダンスの比に応じた電圧しか印加されないので、機器３０が過電圧から保護される。 (4) Features of the second embodiment (4-1)
In the overvoltage protection circuit 50, since the switch 11 of the overvoltage conduction circuit 10 is turned on at the time of overvoltage, only a voltage corresponding to the impedance ratio of the first impedance circuit 21 and the second impedance circuit 22 is applied to the device 30. 30 is protected from overvoltage.
　（４－２）
　商用電源９０からの供給電圧が過大電圧であっても、機器３０には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器３０の電圧定格を高く設計する必要がなく、合理的である。 (4-2)
Even if the supply voltage from the commercial power supply 90 is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device 30. Therefore, it is not necessary to design the device 30 with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　＜第３実施形態＞
　（１）過電圧保護回路５０の構成
　図４は、本発明の第３実施形態に係る過電圧保護回路５０を備えた装置の回路図である。図４において、機器３０は、商用電源９０から一対の電源ライン９０１，９０２を介して電力供給されている。過電圧保護回路５０は、商用電源９０と機器３０との間に接続されている。 <Third Embodiment>
(1) Configuration of Overvoltage Protection Circuit 50 FIG. 4 is a circuit diagram of a device including an overvoltage protection circuit 50 according to the third embodiment of the present invention. In FIG. 4, the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902. The overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
　過電圧保護回路５０は、過電圧導通回路１０と、第１インピーダンス回路２１と、第２インピーダンス回路２２と、電圧検出器３３、バイパス回路３５とを含んでいる。 The overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, a voltage detector 33, and a bypass circuit 35.
　（２）過電圧保護回路５０の詳細構成
　第３実施形態は、第２実施形態にバイパス回路３５が追加された形態であり、過電圧導通回路１０、第１インピーダンス回路２１、第２インピーダンス回路２２、及び電圧検出器３３については同様のものを採用している。したがって、ここではバイパス回路３５についてのみを説明する。 (2) Detailed Configuration of Overvoltage Protection Circuit 50 In the third embodiment, a bypass circuit 35 is added to the second embodiment, and an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, and The same voltage detector 33 is employed. Therefore, only the bypass circuit 35 will be described here.
　（２－１）バイパス回路３５
　バイパス回路３５は、第２インピーダンス回路２２に並列接続されており、第２インピーダンス回路２２を迂回する回路である。バイパス回路３５は、第２スイッチ１２を有している。第２スイッチ１２は、バイパス回路３５を開閉する。ここで、バイパス回路３５を開閉するとは、バイパス回路３５を導通又は遮断して非導通にすることである。 (2-1) Bypass circuit 35
The bypass circuit 35 is a circuit that is connected in parallel to the second impedance circuit 22 and bypasses the second impedance circuit 22. The bypass circuit 35 includes the second switch 12. The second switch 12 opens and closes the bypass circuit 35. Here, opening and closing the bypass circuit 35 means making the bypass circuit 35 conductive or non-conductive to make it non-conductive.
　（２－２）第２スイッチ１２
　第２スイッチ１２は、通常時はバイパス回路３５を閉、つまり導通状態にしておく。なぜなら、通常時にバイパス回路３５を開（非導通状態）にしておくと、第２インピーダンス回路２２が常に接続された状態となって常に電力消費される上に、機器３０への印加電圧が第２インピーダンス回路２２のインピーダンスＺｂの電圧降下分だけ低くなるからである。 (2-2) Second switch 12
The second switch 12 normally closes the bypass circuit 35, that is, keeps it in a conductive state. This is because if the bypass circuit 35 is left open (non-conducting state) during normal operation, the second impedance circuit 22 is always connected and power is always consumed, and the voltage applied to the device 30 is second. This is because the voltage is lowered by the voltage drop of the impedance Zb of the impedance circuit 22.
　他方、過電圧時は機器３０を保護するためにバイパス回路３５を素早く開にして第２インピーダンス回路２２を接続し、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路を構成する必要がある。そのため、第２スイッチ１２には、高速動作が求められる。 On the other hand, in order to protect the device 30 during overvoltage, the bypass circuit 35 is quickly opened and the second impedance circuit 22 is connected, and the commercial power supply 90—overvoltage conduction circuit 10—first impedance circuit 21—second impedance circuit 22— It is necessary to configure a closed circuit called a commercial power supply 90. For this reason, the second switch 12 is required to operate at high speed.
　第２スイッチ１２としては、トライアック、双方向に導通させるように接続したＭＯＳＦＥＴなどが採用される。本実施形態では、スイッチ１１と同じくフォトトライアックカプラが採用されている。 As the second switch 12, a triac, a MOSFET connected so as to conduct in both directions, or the like is employed. In the present embodiment, a phototriac coupler is employed as with the switch 11.
　図４に示すように、第２スイッチ１２は、入力側（Ｃ１－Ｃ２間）に発光ダイオード１２ａが設けられ、出力側（Ｄ１－Ｄ２間）にフォトトライアック１２ｂが設けられている。フォトトライアック１２ｂの等価回路は、２つのフォトサイリスタ１２１，１２２を互いに逆方向に並列接続した構成である。 As shown in FIG. 4, the second switch 12 is provided with a light emitting diode 12a on the input side (between C1 and C2) and a phototriac 12b on the output side (between D1 and D2). The equivalent circuit of the phototriac 12b has a configuration in which two photothyristors 121 and 122 are connected in parallel in opposite directions.
　発光ダイオード１２ａのアノードＣ１は抵抗Ｒ２を介して電源Ｖｃに接続されている。また、発光ダイオード１２ａのカソードＣ２は信号線を介して制御部４０に接続されている。 The anode C1 of the light emitting diode 12a is connected to the power source Vc via the resistor R2. The cathode C2 of the light emitting diode 12a is connected to the control unit 40 via a signal line.
　フォトトライアック１２ｂの第１アノードＤ１は、電源ライン９０２のうちの第２インピーダンス回路２２と機器３０との間に接続されている。また、フォトトライアック１２ｂの第２アノードＤ２は電源ライン９０２にうちの第２インピーダンス回路２２と商用電源９０との間に接続されている。 The first anode D1 of the phototriac 12b is connected between the second impedance circuit 22 in the power supply line 902 and the device 30. The second anode D2 of the photo triac 12b is connected to the power line 902 between the second impedance circuit 22 and the commercial power source 90.
　発光ダイオード１２ａ及びフォトトライアック１２ｂのフォトサイリスタ１２１，１２２の動作原理は、スイッチ１１における発光ダイオード１１ａ及びフォトトライアック１１ｂのフォトサイリスタ１１１，１１２の動作原理と同じであるので、ここでは動作説明を省略する。 The operating principle of the photothyristors 121 and 122 of the light-emitting diode 12a and the phototriac 12b is the same as the operating principle of the light-emitting diode 11a and the photothyristor 111 and 112 of the phototriac 11b in the switch 11, so that the description of the operation is omitted here. .
　（３）過電圧保護回路５０の動作
　図４において、通常時、過電圧導通回路１０のスイッチ１１はオフし、バイパス回路３５は第２スイッチ１２が閉じて導通状態であるので、機器３０には電圧Ｖａ＝Ｖａｃが印加されている。 (3) Operation of Overvoltage Protection Circuit 50 In FIG. 4, the switch 11 of the overvoltage conduction circuit 10 is normally turned off and the bypass circuit 35 is in the conduction state with the second switch 12 closed, so that the voltage Va is applied to the device 30. = Vac is applied.
　商用電源９０の電圧Ｖａｃが急激に増加し、制御部４０が電圧検出器３３から出力される電圧が閾値を超えたと判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａに通電して、フォトトライアック１１ｂをオンさせる。同時に制御部４０は、第２スイッチ１２の発光ダイオード１２ａへの通電を停止し、フォトトライアック１２ｂをオフさせる。 When the voltage Vac of the commercial power supply 90 suddenly increases and the control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold, the control unit 40 energizes the light emitting diode 11a of the switch 11 to generate a photo The triac 11b is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 12a of the second switch 12 and turns off the phototriac 12b.
　その結果、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路が構成される。このとき、機器３０には電圧Ｖａｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖａｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、機器３０が過電圧から保護される。 As a result, a closed circuit of commercial power supply 90-overvoltage conduction circuit 10-first impedance circuit 21-second impedance circuit 22-commercial power supply 90 is formed. At this time, only the voltage Va = Vac × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vac is applied to the device 30. As a result, the device 30 is protected from overvoltage.
　商用電源９０の電圧Ｖａｃが下がり、電圧検出器３３から出力される電圧が復帰のための閾値よりも下がったと制御部４０が判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａの通電をオフし、フォトトライアック１１ｂをオフさせる。同時に制御部４０は、第２スイッチ１２の発光ダイオード１２ａへ通電し、フォトトライアック１２ｂをオンさせる。これにより、通常の動作に復帰する。 When the control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 Then, the photo triac 11b is turned off. At the same time, the control unit 40 energizes the light emitting diode 12a of the second switch 12 to turn on the phototriac 12b. As a result, the normal operation is restored.
　（４）第３実施形態の特徴
　（４－１）
　過電圧保護回路５０では、通常時は第２スイッチ１２をオンにしてバイパス回路３５を閉じているので、第２インピーダンス回路２２で電力が消費されることはなく、機器３０への印加電圧が第２インピーダンス回路２２での電圧降下分だけ低くなることも回避することができる。 (4) Features of the third embodiment (4-1)
In the overvoltage protection circuit 50, since the second switch 12 is normally turned on and the bypass circuit 35 is closed, power is not consumed by the second impedance circuit 22, and the voltage applied to the device 30 is the second voltage. It can also be avoided that the voltage drop in the impedance circuit 22 is lowered.
　（４－２）
　また、過電圧時には、過電圧導通回路１０のスイッチ１１がオンし、第２スイッチ１２がオフすることによって、機器３０には第１インピーダンス回路２１と第２インピーダンス回路２２のインピーダンスの比に応じた電圧しか印加されないので、機器３０が過電圧から保護される。 (4-2)
In addition, when overvoltage occurs, the switch 11 of the overvoltage conduction circuit 10 is turned on and the second switch 12 is turned off, so that the device 30 has only a voltage corresponding to the impedance ratio of the first impedance circuit 21 and the second impedance circuit 22. Since it is not applied, the device 30 is protected from overvoltage.
　（４－３）
　商用電源９０からの供給電圧が過大電圧であっても、機器３０には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器３０の電圧定格を高く設計する必要がなく、合理的である。 (4-3)
Even if the supply voltage from the commercial power supply 90 is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device 30. Therefore, it is not necessary to design the device 30 with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　＜第４実施形態＞
　（１）過電圧保護回路５０の構成
　図５は、本発明の第４実施形態に係る過電圧保護回路５０を備えた装置の回路図である。図５において、機器３０は、商用電源９０から一対の電源ライン９０１，９０２を介して電力供給されている。過電圧保護回路５０は、商用電源９０と機器３０との間に接続されている。 <Fourth embodiment>
(1) Configuration of Overvoltage Protection Circuit 50 FIG. 5 is a circuit diagram of an apparatus including an overvoltage protection circuit 50 according to the fourth embodiment of the present invention. In FIG. 5, the device 30 is supplied with power from a commercial power supply 90 via a pair of power supply lines 901 and 902. The overvoltage protection circuit 50 is connected between the commercial power supply 90 and the device 30.
　過電圧保護回路５０は、過電圧導通回路１０と、第１インピーダンス回路２１と、第２インピーダンス回路２２と、電圧検出器３３、バイパス回路３５と、第３スイッチ１３とを含んでいる。 The overvoltage protection circuit 50 includes an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, a voltage detector 33, a bypass circuit 35, and a third switch 13.
　（２）過電圧保護回路５０の詳細構成
　第４実施形態は、第３実施形態に第３スイッチ１３が追加された形態であり、過電圧導通回路１０、第１インピーダンス回路２１、第２インピーダンス回路２２、電圧検出器３３、及びバイパス回路３５については同様のものを採用している。したがって、ここでは第３スイッチ１３についてのみを説明する。 (2) Detailed Configuration of Overvoltage Protection Circuit 50 In the fourth embodiment, a third switch 13 is added to the third embodiment, and an overvoltage conduction circuit 10, a first impedance circuit 21, a second impedance circuit 22, The same voltage detector 33 and bypass circuit 35 are employed. Therefore, only the third switch 13 will be described here.
　（２－１）第３スイッチ１３
　第３スイッチ１３は、電源ライン９０１を開閉する。ここで、電源ライン９０１を開閉するとは、電源ライン９０１を導通又は遮断して非導通にすることである。 (2-1) Third switch 13
The third switch 13 opens and closes the power line 901. Here, opening and closing the power supply line 901 means that the power supply line 901 is turned on or off to make it non-conductive.
　第３スイッチ１３は、通常時は電源ライン９０１を閉、つまり導通状態にしておく。他方、過電圧時には、スイッチ１１がオンし、第２スイッチ１２がオフして、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路が構成され、機器３０の保護動作が行われた後に、第３スイッチ１３がオフして電源ライン９０１を遮断する。 The third switch 13 normally closes the power supply line 901, that is, keeps it conductive. On the other hand, at the time of overvoltage, the switch 11 is turned on, the second switch 12 is turned off, and a closed circuit of the commercial power supply 90-overvoltage conduction circuit 10-first impedance circuit 21-second impedance circuit 22-commercial power supply 90 is formed. After the protection operation of the device 30 is performed, the third switch 13 is turned off and the power line 901 is shut off.
　電源ライン９０１を遮断する目的は、第１インピーダンス回路２１及び第２インピーダンス回路２２での電力消費を止めるためであり、第１インピーダンス回路２１及び第２インピーダンス回路２２の過熱を抑制することができるので、電力定格を小さくすることができ、低コスト化を図ることができる。 The purpose of cutting off the power supply line 901 is to stop power consumption in the first impedance circuit 21 and the second impedance circuit 22, and it is possible to suppress overheating of the first impedance circuit 21 and the second impedance circuit 22. The power rating can be reduced, and the cost can be reduced.
　第３スイッチ１３は、スイッチ１１及び第２スイッチ１２のような高速性は求められないので、本実施形態ではリレー回路が採用されている。 Since the third switch 13 is not required to have high speed like the switch 11 and the second switch 12, a relay circuit is employed in this embodiment.
　図５に示すように、第３スイッチ１３は、電源ライン９０１を開閉するリレー接点１３ａと、リレー接点１３ａを動作させるリレーコイル１３ｂと、リレーコイル１３ｂへの通電と非通電とを行うトランジスタ１３ｃとを含んでいる。リレーコイル１３ｂの一端は、電源Ｖｂの正極に接続され、他端はトランジスタ１３ｃのコレクタ側に接続されている。制御部４０は、トランジスタ１３ｃのベース電流の有無を切り換えて、コレクタとエミッタ間をオンオフし、リレーコイル１３ｂへの通電と非通電を行う。 As shown in FIG. 5, the third switch 13 includes a relay contact 13a for opening and closing the power supply line 901, a relay coil 13b for operating the relay contact 13a, and a transistor 13c for energizing and de-energizing the relay coil 13b. Is included. One end of the relay coil 13b is connected to the positive electrode of the power source Vb, and the other end is connected to the collector side of the transistor 13c. The controller 40 switches between the presence and absence of the base current of the transistor 13c, turns on and off the collector and the emitter, and energizes and de-energizes the relay coil 13b.
　（３）過電圧保護回路５０の動作
　図５において、通常時、過電圧導通回路１０のスイッチ１１はオフし、バイパス回路３５は第２スイッチ１２が閉じて導通状態であり、且つ第３スイッチ１３は電源ライン９０１を導通状態にしているので、機器３０には電圧Ｖａ＝Ｖａｃが印加されている。 (3) Operation of Overvoltage Protection Circuit 50 In FIG. 5, normally, the switch 11 of the overvoltage conduction circuit 10 is turned off, the bypass circuit 35 is in the conduction state with the second switch 12 closed, and the third switch 13 is a power source. Since the line 901 is in a conducting state, the voltage Va = Vac is applied to the device 30.
　商用電源９０の電圧Ｖａｃが急激に増加し、制御部４０が電圧検出器３３から出力される電圧が閾値を超えたと判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａに通電して、フォトトライアック１１ｂをオンさせる。同時に制御部４０は、第２スイッチ１２の発光ダイオード１２ａへの通電を停止し、フォトトライアック１２ｂをオフさせる。 When the voltage Vac of the commercial power supply 90 suddenly increases and the control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold, the control unit 40 energizes the light emitting diode 11a of the switch 11 to generate a photo The triac 11b is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 12a of the second switch 12 and turns off the phototriac 12b.
　その結果、商用電源９０―過電圧導通回路１０―第１インピーダンス回路２１―第２インピーダンス回路２２―商用電源９０という閉回路が構成される。このとき、機器３０には電圧Ｖａｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖａｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、機器３０が過電圧から保護される。 As a result, a closed circuit of commercial power supply 90-overvoltage conduction circuit 10-first impedance circuit 21-second impedance circuit 22-commercial power supply 90 is formed. At this time, only the voltage Va = Vac × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vac is applied to the device 30. As a result, the device 30 is protected from overvoltage.
　その後、過電圧状態が続いている場合には、第３スイッチ１３が電源ライン９０１を遮断して、第１インピーダンス回路２１及び第２インピーダンス回路２２での電力消費を止める。 Thereafter, when the overvoltage state continues, the third switch 13 cuts off the power supply line 901 and stops the power consumption in the first impedance circuit 21 and the second impedance circuit 22.
　商用電源９０の電圧Ｖａｃが下がり、電圧検出器３３から出力される電圧が復帰のための閾値よりも下がったと制御部４０が判定したとき、制御部４０はスイッチ１１の発光ダイオード１１ａの通電をオフし、フォトトライアック１１ｂをオフさせる。同時に制御部４０は、第２スイッチ１２の発光ダイオード１２ａへ通電し、フォトトライアック１２ｂをオンさせる。さらに、第３スイッチ１３をオンさせて電源ライン９０１を接続することで、通常の動作に復帰する。 When the control unit 40 determines that the voltage Vac of the commercial power supply 90 has dropped and the voltage output from the voltage detector 33 has fallen below the threshold for recovery, the control unit 40 turns off the light-emitting diode 11a of the switch 11 Then, the photo triac 11b is turned off. At the same time, the control unit 40 energizes the light emitting diode 12a of the second switch 12 to turn on the phototriac 12b. Further, the third switch 13 is turned on and the power supply line 901 is connected to return to the normal operation.
　（４）第４実施形態の特徴
　（４－１）
　過電圧保護回路５０では、通常時は第２スイッチ１２をオンにしてバイパス回路３５を閉じているので、第２インピーダンス回路２２で電力が消費されることはなく、機器３０への印加電圧が第２インピーダンス回路２２での電圧降下分だけ低くなることも回避することができる。 (4) Features of the fourth embodiment (4-1)
In the overvoltage protection circuit 50, since the second switch 12 is normally turned on and the bypass circuit 35 is closed, power is not consumed by the second impedance circuit 22, and the voltage applied to the device 30 is the second voltage. It can also be avoided that the voltage drop in the impedance circuit 22 is lowered.
　（４－２）
　また、過電圧時には、過電圧導通回路１０のスイッチ１１がオンし、第２スイッチ１２がオフすることによって、機器３０には第１インピーダンス回路２１と第２インピーダンス回路２２のインピーダンスの比に応じた電圧しか印加されないので、機器３０が過電圧から保護される。 (4-2)
In addition, when overvoltage occurs, the switch 11 of the overvoltage conduction circuit 10 is turned on and the second switch 12 is turned off, so that the device 30 has only a voltage corresponding to the impedance ratio of the first impedance circuit 21 and the second impedance circuit 22. Since it is not applied, the device 30 is protected from overvoltage.
　（４－３）
　さらに、第３スイッチ１３が電源ライン９０１を遮断することによって第１インピーダンス回路２１及び第２インピーダンス回路２２での電力消費を止める。この結果、第１インピーダンス回路２１及び第２インピーダンス回路２２の過熱を抑制し、電力定格を小さくすることができる。 (4-3)
Further, the third switch 13 cuts off the power supply line 901 to stop power consumption in the first impedance circuit 21 and the second impedance circuit 22. As a result, overheating of the first impedance circuit 21 and the second impedance circuit 22 can be suppressed, and the power rating can be reduced.
　（４－４）
　商用電源９０からの供給電圧が過大電圧であっても、機器３０には２つのインピーダンスの比に応じた電圧しか印加されない。それゆえ、短時間の過大電圧からの保護だけのために機器３０の電圧定格を高く設計する必要がなく、合理的である。 (4-4)
Even if the supply voltage from the commercial power supply 90 is an excessive voltage, only a voltage corresponding to the ratio of the two impedances is applied to the device 30. Therefore, it is not necessary to design the device 30 with a high voltage rating only for protection from an excessive voltage for a short time, which is reasonable.
　＜第５実施形態＞
　（１）電力変換装置２００の構成
　図６は、本発明の第５実施形態に係る過電圧保護回路１００を備えた電力変換装置２００の回路図である。図６において、電力変換装置２００は、直流電源部８０、インバータ９５、過電圧保護回路１００で構成されている。 <Fifth Embodiment>
(1) Configuration of Power Converter 200 FIG. 6 is a circuit diagram of a power converter 200 including an overvoltage protection circuit 100 according to the fifth embodiment of the present invention. In FIG. 6, the power conversion device 200 includes a DC power supply unit 80, an inverter 95, and an overvoltage protection circuit 100.
　インバータ９５は、直流電源部８０から一対の電源ライン８０１，８０２を介して電力供給されている。過電圧保護回路１００は、直流電源部８０とインバータ９５との間に接続されている。 The inverter 95 is supplied with power from the DC power supply unit 80 via a pair of power supply lines 801 and 802. The overvoltage protection circuit 100 is connected between the DC power supply unit 80 and the inverter 95.
　（１－１）直流電源部８０
　直流電源部８０は、整流部８１と、整流部８１と並列接続される平滑コンデンサ８２とで構成されている。 (1-1) DC power supply unit 80
The DC power supply unit 80 includes a rectifying unit 81 and a smoothing capacitor 82 connected in parallel with the rectifying unit 81.
　整流部８１は、４つのダイオードＤ１ａ，Ｄ１ｂ，Ｄ２ａ，Ｄ２ｂによってブリッジ状に構成されている。具体的には、ダイオードＤ１ａとＤ１ｂ、Ｄ２ａとＤ２ｂは、それぞれ互いに直列に接続されている。ダイオードＤ１ａ，Ｄ２ａの各カソード端子は、共に平滑コンデンサ８２のプラス側端子に接続されており、整流部８１の正側出力端子として機能する。ダイオードＤ１ｂ，Ｄ２ｂの各ダイオードの各アノード端子は、共に平滑コンデンサ８２のマイナス側端子に接続されており、整流部８１の負側出力端子として機能する。 The rectifying unit 81 is configured in a bridge shape by four diodes D1a, D1b, D2a, and D2b. Specifically, the diodes D1a and D1b and D2a and D2b are respectively connected in series. The cathode terminals of the diodes D1a and D2a are both connected to the plus side terminal of the smoothing capacitor 82 and function as the positive side output terminal of the rectifying unit 81. The anode terminals of the diodes D1b and D2b are both connected to the minus terminal of the smoothing capacitor 82 and function as the negative output terminal of the rectifier 81.
　ダイオードＤ１ａ及びダイオードＤ１ｂの接続点は、商用電源９０の一方の極に接続されている。ダイオードＤ２ａ及びダイオードＤ２ｂの接続点は、商用電源９０の他方の極に接続されている。整流部８１は、商用電源９０から出力される交流電圧を整流して直流電圧を生成し、これを平滑コンデンサ８２へ供給する。 The connection point of the diode D1a and the diode D1b is connected to one pole of the commercial power supply 90. A connection point between the diode D2a and the diode D2b is connected to the other pole of the commercial power supply 90. The rectifying unit 81 rectifies the AC voltage output from the commercial power supply 90 to generate a DC voltage, and supplies this to the smoothing capacitor 82.
　平滑コンデンサ８２は、整流部８１によって整流された電圧を平滑する。平滑後の電圧Ｖｄｃは、平滑コンデンサ８２の出力側に接続されるインバータ９５へ印加される。 The smoothing capacitor 82 smoothes the voltage rectified by the rectifying unit 81. The smoothed voltage Vdc is applied to the inverter 95 connected to the output side of the smoothing capacitor 82.
　なお、コンデンサの種類としては、電解コンデンサやフィルムコンデンサ、タンタルコンデンサ等が挙げられるが、本実施形態においては、平滑コンデンサ８２として電解コンデンサが採用される。 In addition, as a kind of capacitor | condenser, although an electrolytic capacitor, a film capacitor, a tantalum capacitor etc. are mentioned, an electrolytic capacitor is employ | adopted as the smoothing capacitor 82 in this embodiment.
　この直流電源部８０は、交流電圧を直流電圧に変換するコンバータ回路と言い換えることもできる。 The DC power supply unit 80 can be rephrased as a converter circuit that converts an AC voltage into a DC voltage.
　（１－２）インバータ９５
　インバータ９５は、複数のＩＧＢＴ（絶縁ゲート型バイポーラトランジスタ、以下、単にトランジスタという）及び複数の還流用ダイオードを含んでいる。インバータ９５は、平滑コンデンサ８２からの電圧Ｖｄｃが印加され、かつゲート駆動回路９６により指示されたタイミングで各トランジスタがオン及びオフを行うことによって、モータ１５０を駆動する駆動電圧を生成する。モータ１５０は、例えばヒートポンプ式空気調和機の圧縮機モータ、ファンモータである。 (1-2) Inverter 95
The inverter 95 includes a plurality of IGBTs (insulated gate bipolar transistors, hereinafter simply referred to as transistors) and a plurality of free-wheeling diodes. The inverter 95 is applied with the voltage Vdc from the smoothing capacitor 82, and each transistor is turned on and off at the timing instructed by the gate drive circuit 96, thereby generating a drive voltage for driving the motor 150. The motor 150 is, for example, a compressor motor or a fan motor of a heat pump type air conditioner.
　なお、本実施形態のインバータ９５は、電圧形インバータであるが、それに限定されるものではなく、電流形インバータでもよい。 In addition, although the inverter 95 of this embodiment is a voltage source inverter, it is not limited to it, A current source inverter may be sufficient.
　（１－３）ゲート駆動回路９６
　ゲート駆動回路９６は、制御部４０からの指令に基づき、インバータ９５の各トランジスタのオン及びオフの状態を変化させる。 (1-3) Gate drive circuit 96
The gate drive circuit 96 changes the on / off state of each transistor of the inverter 95 based on a command from the control unit 40.
　（１－４）過電圧保護回路１００
　過電圧保護回路１００は、過電圧導通回路６０と、第１インピーダンス回路７１と、第２インピーダンス回路７２と、電圧検出器８３、バイパス回路８５と、第３スイッチ６３とを含んでいる。 (1-4) Overvoltage protection circuit 100
The overvoltage protection circuit 100 includes an overvoltage conduction circuit 60, a first impedance circuit 71, a second impedance circuit 72, a voltage detector 83, a bypass circuit 85, and a third switch 63.
　（２）過電圧保護回路１００の詳細構成
　第５実施形態と、既に説明した第１から第４までの実施形態と大きく異なる点は、過電圧保護回路１００が直流部に設けられていることである。したがって、各構成要素も交流仕様から直流仕様に置き換えられることに鑑みて、同一名称であっても符号を換えて、再度説明する。 (2) Detailed Configuration of Overvoltage Protection Circuit 100 The fifth embodiment is different from the first to fourth embodiments already described in that the overvoltage protection circuit 100 is provided in the DC section. Therefore, in view of the fact that each component is also replaced from the AC specification to the DC specification, the description will be given again by changing the code even if the names are the same.
　（２－１）過電圧導通回路６０
　過電圧導通回路６０は、第４実施形態におけるスイッチ１１に替わってスイッチ６１が採用されている。 (2-1) Overvoltage conduction circuit 60
The overvoltage conduction circuit 60 employs a switch 61 instead of the switch 11 in the fourth embodiment.
　図６に示すように、スイッチ６１は、フォトカプラ６１ａと、駆動回路６１ｂと、トランジスタ６１ｃとで構成されている。フォトカプラ６１ａは、発光ダイオード６１１とフォトトランジスタ６１２を内蔵している。 As shown in FIG. 6, the switch 61 includes a photocoupler 61a, a drive circuit 61b, and a transistor 61c. The photocoupler 61a includes a light emitting diode 611 and a phototransistor 612.
　スイッチ６１の入力側（Ｅ１－Ｅ２間）にはフォトカプラ６１ａの発光ダイオード６１１が接続されている。発光ダイオード６１１のアノードＥ１は抵抗Ｒ１を介して電源Ｖｃに接続されている。発光ダイオード６１１のカソードＥ２は信号線を介して制御部４０に接続されている。また、フォトトランジスタ６１２は駆動回路６１ｂとＧＮＤとの間に接続されている。 The light emitting diode 611 of the photocoupler 61a is connected to the input side (between E1 and E2) of the switch 61. The anode E1 of the light emitting diode 611 is connected to the power source Vc via the resistor R1. The cathode E2 of the light emitting diode 611 is connected to the control unit 40 via a signal line. The phototransistor 612 is connected between the drive circuit 61b and GND.
　スイッチ６１の出力側（Ｆ１－Ｆ２間）にトランジスタ６１ｃが設けられている。トランジスタ６１ｃのコレクタＦ１は電源ライン８０１に接続されている。また、トランジスタ６１ｃのエミッタＦ２は第１インピーダンス回路７１に接続されている。 A transistor 61c is provided on the output side (between F1 and F2) of the switch 61. The collector F1 of the transistor 61c is connected to the power supply line 801. The emitter F2 of the transistor 61c is connected to the first impedance circuit 71.
　制御部４０の制御信号は、フォトカプラ６１ａを介して駆動回路６１ｂに入力される。駆動回路６１ｂには、駆動用電源（図示せず）が接続されており、制御部４０が発光ダイオード６１１の信号ラインをオンさせると、発光ダイオード６１１が発光しフォトトランジスタ６１２が導通する。このフォトトランジスタ６１２が導通している間、駆動回路６１ｂからトランジスタ６１ｃのベースに駆動信号が出力され、トランジスタ６１ｃのコレクタＦ１－エミッタＦ２間が導通する。 The control signal of the control unit 40 is input to the drive circuit 61b via the photocoupler 61a. A driving power supply (not shown) is connected to the driving circuit 61b. When the control unit 40 turns on the signal line of the light emitting diode 611, the light emitting diode 611 emits light and the phototransistor 612 becomes conductive. While the phototransistor 612 is conducting, a driving signal is output from the driving circuit 61b to the base of the transistor 61c, and the collector F1-emitter F2 of the transistor 61c is conducted.
　逆に、制御部４０が発光ダイオード６１１の信号ラインをオフさせると、発光ダイオード６１１が発光しないので、フォトトランジスタ６１２は導通しない。このフォトトランジスタ６１２が導通していない間、トランジスタ６１ｃのコレクタＦ１－エミッタＦ２間も導通しない。 Conversely, when the control unit 40 turns off the signal line of the light emitting diode 611, the light emitting diode 611 does not emit light, and the phototransistor 612 does not conduct. While the phototransistor 612 is not conducting, the collector F1 and the emitter F2 of the transistor 61c are not conducting.
　このように、直流回路を開閉するときは片方向スイッチでよいので、交流回路を開閉する場合の双方向性は必要とせず、コストメリットがある。なお片方向スイッチの構成は本実施形態に限定するものではないが、半導体スイッチのように高速にスイッチ動作を行なうことができるのが望ましい。 Thus, when the DC circuit is opened / closed, a one-way switch may be used, so that bidirectionality is not required when the AC circuit is opened / closed, and there is a cost merit. The configuration of the one-way switch is not limited to this embodiment, but it is desirable that the switch operation can be performed at high speed like a semiconductor switch.
　過電圧導通回路６０は、一対の電源ライン８０１，８０２間に機器３０と並列に接続されている。 The overvoltage conduction circuit 60 is connected in parallel with the device 30 between a pair of power supply lines 801 and 802.
　（２－２）第１インピーダンス回路７１
　第１インピーダンス回路７１は、当該回路における電圧と電流との比であるインピーダンスがＺａとなるように構成された回路である。一般に抵抗素子が採用される。 (2-2) First impedance circuit 71
The first impedance circuit 71 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Za. In general, a resistance element is employed.
　第１インピーダンス回路７１は、一対の電源ライン８０１，８０２間にインバータ９５と並列に、且つ過電圧導通回路６０と直列に接続されている。 The first impedance circuit 71 is connected between the pair of power supply lines 801 and 802 in parallel with the inverter 95 and in series with the overvoltage conduction circuit 60.
　（２－３）第２インピーダンス回路７２
　第２インピーダンス回路７２は、当該回路における電圧と電流との比であるインピーダンスがＺｂとなるように構成された回路である。一般に抵抗素子が採用される。 (2-3) Second impedance circuit 72
The second impedance circuit 72 is a circuit configured such that an impedance that is a ratio of a voltage and a current in the circuit is Zb. In general, a resistance element is employed.
　第２インピーダンス回路７２は、電源ライン８０２上で、直流電源部８０と第１インピーダンス回路７１との間に接続されている。 The second impedance circuit 72 is connected between the DC power supply unit 80 and the first impedance circuit 71 on the power supply line 802.
　（２－４）電圧検出器８３
　電圧検出器８３は、平滑コンデンサ８２の出力側に接続されており、平滑コンデンサ８２の両端電圧、即ち平滑後の電圧Ｖｄｃの値を検出する。電圧検出器８３は、例えば、互いに直列に接続された２つの抵抗が平滑コンデンサ８２に並列接続され、電圧Ｖｄｃが分圧されるように構成される。それら２つの抵抗同士の接続点の電圧値は、制御部４０に入力される。 (2-4) Voltage detector 83
The voltage detector 83 is connected to the output side of the smoothing capacitor 82, and detects the voltage across the smoothing capacitor 82, that is, the value of the smoothed voltage Vdc. For example, the voltage detector 83 is configured such that two resistors connected in series with each other are connected in parallel to the smoothing capacitor 82 and the voltage Vdc is divided. The voltage value at the connection point between the two resistors is input to the control unit 40.
　（２－５）バイパス回路８５
　バイパス回路８５は、第２インピーダンス回路７２に並列接続されており、第２インピーダンス回路７２を迂回する回路である。バイパス回路８５は、第２スイッチ６２を有している。第２スイッチ６２は、バイパス回路８５を開閉する。ここで、バイパス回路８５を開閉するとは、バイパス回路３５を導通又は遮断して非導通にすることである。 (2-5) Bypass circuit 85
The bypass circuit 85 is a circuit that is connected in parallel to the second impedance circuit 72 and bypasses the second impedance circuit 72. The bypass circuit 85 has a second switch 62. The second switch 62 opens and closes the bypass circuit 85. Here, opening and closing the bypass circuit 85 means that the bypass circuit 35 is turned on or off to make it non-conductive.
　（２－６）第２スイッチ６２
　第２スイッチ６２は、通常時はバイパス回路８５を閉、つまり導通状態にしておく。なぜなら、通常時にバイパス回路８５を開（非導通状態）にしておくと、第２インピーダンス回路７２で常に電力消費される上に、インバータ９５への印加電圧が第２インピーダンス回路７２のインピーダンスＺｂの電圧降下分だけ低くなるからである。 (2-6) Second switch 62
The second switch 62 normally closes the bypass circuit 85, that is, keeps it in a conductive state. This is because if the bypass circuit 85 is left open (non-conducting state) during normal operation, power is always consumed by the second impedance circuit 72, and the voltage applied to the inverter 95 is the voltage of the impedance Zb of the second impedance circuit 72. This is because it is lowered by the amount of descent.
　他方、過電圧時はインバータ９５を保護するためにバイパス回路８５を素早く開にして、直流電源部８０―過電圧導通回路６０―第１インピーダンス回路７１―第２インピーダンス回路７２―直流電源部８０という閉回路を構成する必要がある。そのため、第２スイッチ６２には、高速動作が求められる。本実施形態では、スイッチ６１と同じスイッチが採用されている。なお、スイッチは本実施形態に限定されない。 On the other hand, in order to protect the inverter 95 at the time of overvoltage, the bypass circuit 85 is quickly opened, and a closed circuit of DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80. Need to be configured. For this reason, the second switch 62 is required to operate at high speed. In the present embodiment, the same switch as the switch 61 is employed. The switch is not limited to this embodiment.
　図６に示すように、第２スイッチ６２は、入力側（Ｇ１－Ｇ２間）にフォトカプラ６２ａの発光ダイオード６２１が設けられ、出力側（Ｈ１－Ｈ２間）にトランジスタ６２ｃが設けられている。発光ダイオード６２１のアノードＧ１は抵抗Ｒ２を介して電源Ｖｃに接続されている。また、発光ダイオード６２１のカソードＧ２は信号線を介して制御部４０に接続されている。 As shown in FIG. 6, in the second switch 62, a light emitting diode 621 of a photocoupler 62a is provided on the input side (between G1 and G2), and a transistor 62c is provided on the output side (between H1 and H2). The anode G1 of the light emitting diode 621 is connected to the power source Vc via the resistor R2. The cathode G2 of the light emitting diode 621 is connected to the control unit 40 via a signal line.
　トランジスタ６２ｃのコレクタＨ１は、電源ライン８０２のうちの第２インピーダンス回路７２とインバータ９５との間に接続されている。また、トランジスタ６２ｃのエミッタＨ２は電源ライン８０２にうちの第２インピーダンス回路７２と直流電源部８０との間に接続されている。 The collector H1 of the transistor 62c is connected between the second impedance circuit 72 in the power supply line 802 and the inverter 95. The emitter H2 of the transistor 62c is connected to the power supply line 802 between the second impedance circuit 72 and the DC power supply unit 80.
　第２スイッチ６２の動作原理は、スイッチ６１の動作原理と同じであるので、ここでは動作説明を省略する。 Since the operation principle of the second switch 62 is the same as that of the switch 61, the description of the operation is omitted here.
　（２－７）第３スイッチ６３
　第３スイッチ６３は、電源ライン８０１を開閉する。ここで、電源ライン８０１を開閉するとは、電源ライン８０１を導通又は遮断して非導通にすることである。 (2-7) Third switch 63
The third switch 63 opens and closes the power line 801. Here, opening and closing the power supply line 801 is to turn the power supply line 801 on or off to make it non-conductive.
　第３スイッチ６３は、通常時は電源ライン８０１を閉、つまり導通状態にしておく。他方、過電圧時には、スイッチ６１がオンし、第２スイッチ６２がオフして、直流電源部８０―過電圧導通回路６０―第１インピーダンス回路７１―第２インピーダンス回路７２―直流電源部８０という閉回路が構成され、インバータ９５の保護動作が行われた後に、第３スイッチ６３がオフして電源ライン８０１を遮断する。 The third switch 63 normally closes the power supply line 801, that is, keeps it conductive. On the other hand, at the time of overvoltage, the switch 61 is turned on, the second switch 62 is turned off, and a closed circuit of DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80 is formed. After the configuration and the protective operation of the inverter 95 is performed, the third switch 63 is turned off and the power line 801 is shut off.
　電源ライン８０１を遮断する目的は、第１インピーダンス回路７１及び第２インピーダンス回路７２での電力消費を止めるためであり、第１インピーダンス回路７１及び第２インピーダンス回路７２の過熱を抑制することができるので、電力定格を小さくすることができ、低コスト化を図ることができる。 The purpose of cutting off the power supply line 801 is to stop power consumption in the first impedance circuit 71 and the second impedance circuit 72, and it is possible to suppress overheating of the first impedance circuit 71 and the second impedance circuit 72. The power rating can be reduced, and the cost can be reduced.
　第３スイッチ６３は、スイッチ６１及び第２スイッチ６２のような高速性は求められないので、本実施形態ではリレー回路が採用されている。 Since the third switch 63 is not required to have high speed like the switch 61 and the second switch 62, a relay circuit is employed in this embodiment.
　図６に示すように、第３スイッチ６３は、電源ライン８０１を開閉するリレー接点６３ａと、リレー接点６３ａを動作させるリレーコイル６３ｂと、リレーコイル６３ｂへの通電と非通電とを行うトランジスタ６３ｃとを含んでいる。リレーコイル６３ｂの一端は、電源Ｖｂの正極に接続され、他端はトランジスタ６３ｃのコレクタ側に接続されている。制御部４０は、トランジスタ６３ｃのベース電流の有無を切り換えて、コレクタとエミッタ間をオンオフし、リレーコイル６３ｂへの通電と非通電を行う。 As shown in FIG. 6, the third switch 63 includes a relay contact 63a for opening and closing the power supply line 801, a relay coil 63b for operating the relay contact 63a, and a transistor 63c for energizing and de-energizing the relay coil 63b. Is included. One end of the relay coil 63b is connected to the positive electrode of the power source Vb, and the other end is connected to the collector side of the transistor 63c. The controller 40 switches between the presence and absence of the base current of the transistor 63c, turns on and off the collector and the emitter, and performs energization and de-energization of the relay coil 63b.
　（３）過電圧保護回路５０の動作
　図６において、通常時、過電圧導通回路６０のスイッチ６１はオフし、バイパス回路８５は第２スイッチ６２が閉じて導通状態であり、且つ第３スイッチ６３は電源ライン８０１を導通状態にしているので、インバータ９５には電圧Ｖａ＝Ｖｄｃが印加されている。 (3) Operation of Overvoltage Protection Circuit 50 In FIG. 6, normally, the switch 61 of the overvoltage conduction circuit 60 is turned off, the bypass circuit 85 is in the conduction state with the second switch 62 closed, and the third switch 63 is a power source. Since the line 801 is in a conductive state, the voltage Va = Vdc is applied to the inverter 95.
　直流電源部８０の電圧Ｖｄｃが急激に増加し、制御部４０が電圧検出器８３から出力される電圧が閾値を超えたと判定したとき、制御部４０はスイッチ６１の発光ダイオード６１１に通電して、トランジスタ６１ｃをオンさせる。同時に制御部４０は、第２スイッチ６２の発光ダイオード６２１への通電を停止し、トランジスタ６２ｃをオフさせる。 When the voltage Vdc of the DC power supply unit 80 increases rapidly and the control unit 40 determines that the voltage output from the voltage detector 83 exceeds the threshold value, the control unit 40 energizes the light emitting diode 611 of the switch 61, The transistor 61c is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 621 of the second switch 62 and turns off the transistor 62c.
　その結果、直流電源部８０―過電圧導通回路６０―第１インピーダンス回路７１―第２インピーダンス回路７２―直流電源部８０という閉回路が構成される。このとき、インバータ９５には電圧Ｖｄｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖｄｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、インバータ９５が過電圧から保護される。 As a result, a closed circuit of the DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80 is formed. At this time, only the voltage Va = Vdc × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vdc is applied to the inverter 95. As a result, the inverter 95 is protected from overvoltage.
　その後、過電圧状態が続いている場合には、第３スイッチ６３が電源ライン８０１を遮断して、第１インピーダンス回路７１及び第２インピーダンス回路７２での電力消費を止める。 Thereafter, when the overvoltage state continues, the third switch 63 cuts off the power supply line 801 and stops the power consumption in the first impedance circuit 71 and the second impedance circuit 72.
　商用電源９０の電圧Ｖａｃ及び直流電源部８０の電圧Ｖｄｃが下がり、電圧検出器８３から出力される電圧が復帰のための閾値よりも下がったと制御部４０が判定したとき、制御部４０はスイッチ６１の発光ダイオード６１１の通電をオフし、トランジスタ６１ｃをオフさせる。同時に制御部４０は、第２スイッチ６２の発光ダイオード６２１へ通電し、トランジスタ６２ｃをオンさせる。さらに、第３スイッチ６３をオンさせて電源ライン８０１を接続することで、通常の動作に復帰する。 When the control unit 40 determines that the voltage Vac of the commercial power supply 90 and the voltage Vdc of the DC power supply unit 80 are decreased and the voltage output from the voltage detector 83 is lower than the threshold for recovery, the control unit 40 switches the switch 61. The light-emitting diode 611 is turned off, and the transistor 61c is turned off. At the same time, the control unit 40 energizes the light emitting diode 621 of the second switch 62 to turn on the transistor 62c. Further, by turning on the third switch 63 and connecting the power supply line 801, the normal operation is restored.
　（４）第５実施形態の特徴
　（４－１）
　過電圧保護回路１００では、通常時は第２スイッチ６２をオンにしてバイパス回路８５を閉じているので、第２インピーダンス回路７２で電力が消費されることはなく、インバータ９５への印加電圧が第２インピーダンス回路７２での電圧降下分だけ低くなることも回避することができる。 (4) Features of the fifth embodiment (4-1)
In the overvoltage protection circuit 100, since the second switch 62 is normally turned on and the bypass circuit 85 is closed, power is not consumed by the second impedance circuit 72, and the voltage applied to the inverter 95 is the second voltage. It can also be avoided that the voltage drops by the voltage drop in the impedance circuit 72.
　（４－２）
　また、過電圧時には、過電圧導通回路６０のスイッチ６１がオンし、第２スイッチ６２がオフすることによって、インバータ９５には第１インピーダンス回路７１と第２インピーダンス回路７２のインピーダンスの比に応じた電圧しか印加されないので、インバータ９５が過電圧から保護される。 (4-2)
In addition, when overvoltage occurs, the switch 61 of the overvoltage conduction circuit 60 is turned on and the second switch 62 is turned off, so that the inverter 95 has only a voltage corresponding to the impedance ratio of the first impedance circuit 71 and the second impedance circuit 72. Since it is not applied, the inverter 95 is protected from overvoltage.
　（４－３）
　また、第３スイッチ６３が電源ライン８０１を遮断することによって第１インピーダンス回路７１及び第２インピーダンス回路７２での電力消費を止める。この結果、第１インピーダンス回路７１及び第２インピーダンス回路７２の過熱を抑制し、電力定格を小さくすることができる。 (4-3)
Further, the third switch 63 cuts off the power supply line 801 to stop power consumption in the first impedance circuit 71 and the second impedance circuit 72. As a result, overheating of the first impedance circuit 71 and the second impedance circuit 72 can be suppressed, and the power rating can be reduced.
　（４－４）
　さらに、直流電源部８０の下流側に配置されるスイッチ６１、第２スイッチ６２は片方向スイッチでよいので、スイッチの低コスト化を図ることができる。 (4-4)
Furthermore, since the switch 61 and the second switch 62 disposed on the downstream side of the DC power supply unit 80 may be unidirectional switches, the cost of the switches can be reduced.
　＜第６実施形態＞
　（１）過電圧保護回路１００の構成
　図７は、本発明の第６実施形態に係る過電圧保護回路１００を備えた電力変換装置２００の回路図である。図７において、インバータ９５は、直流電源部８０から一対の電源ライン８０１，８０２を介して電力供給されている。過電圧保護回路１００の一部は商用電源９０と直流電源部８０との間に接続され、他の部分は直流電源部８０とインバータ９５との間に接続されている。 <Sixth Embodiment>
(1) Configuration of Overvoltage Protection Circuit 100 FIG. 7 is a circuit diagram of a power conversion device 200 including the overvoltage protection circuit 100 according to the sixth embodiment of the present invention. In FIG. 7, the inverter 95 is supplied with power from a DC power supply unit 80 via a pair of power supply lines 801 and 802. A part of the overvoltage protection circuit 100 is connected between the commercial power supply 90 and the DC power supply unit 80, and the other part is connected between the DC power supply unit 80 and the inverter 95.
　過電圧保護回路１００は、過電圧導通回路６０と、第１インピーダンス回路７１と、第２インピーダンス回路７２と、電圧検出器３３、バイパス回路８５と、第３スイッチ１３とを含んでいる。 The overvoltage protection circuit 100 includes an overvoltage conduction circuit 60, a first impedance circuit 71, a second impedance circuit 72, a voltage detector 33, a bypass circuit 85, and a third switch 13.
　第６実施形態と、既に説明した第５実施形態と異なる点は、過電圧保護回路１００の構成要素である電圧検出器と第３スイッチとが商用電源９０と直流電源部８０との間に設けられていることである。つまり、電圧検出器及び第３スイッチの配置が、第４実施形態における電圧検出器３３及び第３スイッチ１３の配置と同じである。したがって、電圧検出器及び第３スイッチが直流仕様から交流仕様に置き換えられることに鑑みて、第４実施形態の電圧検出器３３及び第３スイッチ１３が採用されている。 The difference between the sixth embodiment and the fifth embodiment already described is that a voltage detector and a third switch, which are components of the overvoltage protection circuit 100, are provided between the commercial power supply 90 and the DC power supply unit 80. It is that. That is, the arrangement of the voltage detector and the third switch is the same as the arrangement of the voltage detector 33 and the third switch 13 in the fourth embodiment. Therefore, in view of the fact that the voltage detector and the third switch are replaced from the DC specification to the AC specification, the voltage detector 33 and the third switch 13 of the fourth embodiment are employed.
　したがって、各構成要素の内容は、第４実施形態の電圧検出器３３及び第３スイッチ１３、第５実施形態の過電圧導通回路６０、第１インピーダンス回路７１、第２インピーダンス回路７２、及びバイパス回路８５と同様であるので、ここでは説明を省略し、動作説明のみ行う。 Therefore, the content of each component includes the voltage detector 33 and the third switch 13 of the fourth embodiment, the overvoltage conduction circuit 60 of the fifth embodiment, the first impedance circuit 71, the second impedance circuit 72, and the bypass circuit 85. Therefore, the description is omitted here and only the operation is described.
　（２）過電圧保護回路５０の動作
　図７において、通常時、過電圧導通回路６０のスイッチ６１はオフし、バイパス回路８５は第２スイッチ６２が閉じて導通状態であり、且つ第３スイッチ６３は電源ライン９０１を導通状態にしているので、インバータ９５には電圧Ｖａ＝Ｖｄｃが印加されている。 (2) Operation of Overvoltage Protection Circuit 50 In FIG. 7, normally, the switch 61 of the overvoltage conduction circuit 60 is turned off, the bypass circuit 85 is in the conduction state with the second switch 62 closed, and the third switch 63 is a power source. Since the line 901 is in a conducting state, the voltage Va = Vdc is applied to the inverter 95.
　商用電源９０の電圧Ｖａｃの変動によってＶａｃが急激に増加し、制御部４０が電圧検出器３３から出力される電圧が閾値を超えたと判定したとき、制御部４０はスイッチ６１の発光ダイオード６１１に通電して、トランジスタ６１ｃをオンさせる。同時に制御部４０は、第２スイッチ６２の発光ダイオード６２１への通電を停止し、トランジスタ６２ｃをオフさせる。 When the control unit 40 determines that the voltage output from the voltage detector 33 has exceeded the threshold value due to the fluctuation of the voltage Vac of the commercial power supply 90, the control unit 40 energizes the light emitting diode 611 of the switch 61. Then, the transistor 61c is turned on. At the same time, the control unit 40 stops energization of the light emitting diode 621 of the second switch 62 and turns off the transistor 62c.
　その結果、直流電源部８０―過電圧導通回路６０―第１インピーダンス回路７１―第２インピーダンス回路７２―直流電源部８０という閉回路が構成される。このとき、インバータ９５には電圧Ｖｄｃの２つのインピーダンスの比に応じた電圧Ｖａ＝Ｖｄｃ×Ｚａ／（Ｚａ＋Ｚｂ）しか印加されない。その結果、インバータ９５が過電圧から保護される。 As a result, a closed circuit of the DC power supply unit 80-overvoltage conduction circuit 60-first impedance circuit 71-second impedance circuit 72-DC power supply unit 80 is formed. At this time, only the voltage Va = Vdc × Za / (Za + Zb) corresponding to the ratio of the two impedances of the voltage Vdc is applied to the inverter 95. As a result, the inverter 95 is protected from overvoltage.
　その後、第３スイッチ１３が電源ライン９０１を遮断して、第１インピーダンス回路７１及び第２インピーダンス回路７２での電力消費を止める。 Thereafter, the third switch 13 cuts off the power supply line 901 and stops the power consumption in the first impedance circuit 71 and the second impedance circuit 72.
　（３）第６実施形態の特徴
　（３－１）
　過電圧保護回路１００では、通常時は第２スイッチ６２をオンにしてバイパス回路８５を閉じているので、第２インピーダンス回路７２で電力が消費されることはなく、インバータ９５への印加電圧が第２インピーダンス回路７２での電圧降下分だけ低くなることも回避することができる。 (3) Features of the sixth embodiment (3-1)
In the overvoltage protection circuit 100, since the second switch 62 is normally turned on and the bypass circuit 85 is closed, power is not consumed by the second impedance circuit 72, and the voltage applied to the inverter 95 is the second voltage. It can also be avoided that the voltage drops by the voltage drop in the impedance circuit 72.
　（３－２）
　また、過電圧時には、過電圧導通回路６０のスイッチ６１がオンし、第２スイッチ６２がオフすることによって、インバータ９５には第１インピーダンス回路７１と第２インピーダンス回路７２のインピーダンスの比に応じた電圧しか印加されないので、インバータ９５が過電圧から保護される。 (3-2)
In addition, when overvoltage occurs, the switch 61 of the overvoltage conduction circuit 60 is turned on and the second switch 62 is turned off, so that the inverter 95 has only a voltage corresponding to the impedance ratio of the first impedance circuit 71 and the second impedance circuit 72. Since it is not applied, the inverter 95 is protected from overvoltage.
　（３－３）
　また、第３スイッチ１３が電源ライン９０１を遮断することによって第１インピーダンス回路７１及び第２インピーダンス回路７２での電力消費を止める。この結果、第１インピーダンス回路７１及び第２インピーダンス回路７２の過熱を抑制し、電力定格を小さくすることができる。 (3-3)
Further, the third switch 13 cuts off the power supply line 901 to stop the power consumption in the first impedance circuit 71 and the second impedance circuit 72. As a result, overheating of the first impedance circuit 71 and the second impedance circuit 72 can be suppressed, and the power rating can be reduced.
　（３－４）
　さらに、直流電源部８０の下流側に配置されるスイッチ６１、第２スイッチ６２は片方向スイッチでよいので、スイッチの低コスト化を図ることができる。 (3-4)
Furthermore, since the switch 61 and the second switch 62 disposed on the downstream side of the DC power supply unit 80 may be unidirectional switches, the cost of the switches can be reduced.
　＜その他実施形態＞
　（Ａ）
　図１で示す第１実施形態における第２インピーダンス回路２２に、図４で示す第３実施形態におけるバイパス回路３５を並列接続した実施形態も有効である。 <Other embodiments>
(A)
The embodiment in which the bypass circuit 35 in the third embodiment shown in FIG. 4 is connected in parallel to the second impedance circuit 22 in the first embodiment shown in FIG. 1 is also effective.
　通常時は第２スイッチ１２をオンにしてバイパス回路３５を閉じるので、第２インピーダンス回路２２で電力が消費されることはなく、機器３０への印加電圧が第２インピーダンス回路２２での電圧降下分だけ低くなることを回避することができる。 Normally, the second switch 12 is turned on and the bypass circuit 35 is closed, so that no power is consumed in the second impedance circuit 22, and the voltage applied to the device 30 is equal to the voltage drop in the second impedance circuit 22. Only lowering can be avoided.
　（Ｂ）
　図１に示す第１実施形態及び図２示す第２実施形態における電源ライン９０１を、図５で示す第４実施形態における第３スイッチ１３で開閉する実施形態も有効である。 (B)
An embodiment in which the power supply line 901 in the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 2 is opened and closed by the third switch 13 in the fourth embodiment shown in FIG. 5 is also effective.
　第３スイッチ１３が電源ライン９０１を遮断することによって第１インピーダンス回路２１及び第２インピーダンス回路２２での電力消費を止めるので、第１インピーダンス回路２１及び第２インピーダンス回路２２の電力定格を小さくすることができる。 Since the third switch 13 stops the power consumption in the first impedance circuit 21 and the second impedance circuit 22 by cutting off the power supply line 901, the power rating of the first impedance circuit 21 and the second impedance circuit 22 is reduced. Can do.
　（Ｃ）
　図１に示す第１実施形態、図２に示す第２実施形態、及び図４に示す第３実施形態に係る過電圧保護回路５０は、いずれも交流電圧に対する過電圧保護回路を実施形態としているが、電源が直流電源である場合、あるいは機器内に交流電源を整流する直流電源部を持つ場合には、各構成要素を交流仕様から直流仕様へ置き換えて直流電源部の下流側に設けてもよい。 (C)
The overvoltage protection circuit 50 according to the first embodiment shown in FIG. 1, the second embodiment shown in FIG. 2, and the third embodiment shown in FIG. 4 is an overvoltage protection circuit for an AC voltage. When the power source is a DC power source or when a DC power source unit that rectifies an AC power source is provided in the device, each component may be replaced with the DC specification and provided downstream of the DC power source unit.
　（Ｄ）
　第６実施形態は、第５実施形態から、電圧検出器と第３スイッチとを、商用電源９０と直流電源部８０との間に設けるように変更したものであるが、電圧検出器のみを商用電源９０と直流電源部８０との間に設けるようにしてもよい。 (D)
The sixth embodiment is different from the fifth embodiment in that the voltage detector and the third switch are provided between the commercial power supply 90 and the DC power supply unit 80, but only the voltage detector is commercialized. You may make it provide between the power supply 90 and the DC power supply part 80. FIG.
　（Ｅ）
　第５実施形態、第６実施形態では、機器の内部に過電圧保護回路を持つ例を示したが、機器はコンバータ回路とインバータ回路を持つものに限定されない。 (E)
In the fifth embodiment and the sixth embodiment, the example in which the overvoltage protection circuit is provided inside the device has been described, but the device is not limited to the one having the converter circuit and the inverter circuit.
　（Ｆ）
　第３実施形態では、機器３０の保護動作が行なわれた後に第３スイッチがオフされるものとしたが、保護動作が行なわれてから所定時間経過後に第３スイッチをオフしてもよい。 (F)
In the third embodiment, the third switch is turned off after the protection operation of the device 30 is performed. However, the third switch may be turned off after a predetermined time has elapsed since the protection operation was performed.
　（Ｇ）
　第３実施形態では、機器３０の保護動作が行なわれた後に第３スイッチがオフされるものとしたが、機器電圧Ｖを検出する機器電圧検出器を更に備え、機器電圧が所定値を超えたときに第３スイッチをオフしてもよい。 (G)
In the third embodiment, the third switch is turned off after the protection operation of the device 30 is performed. However, the device further includes a device voltage detector that detects the device voltage V, and the device voltage exceeds a predetermined value. Sometimes the third switch may be turned off.
　（Ｈ）
　第１実施形態では、過電圧時に電流を流す素子としてサージアブソーバを例にとって説明した。この場合には第１実施形態で説明したように、導通時に素子自体で電圧は保持しないため、電源電圧はインピーダンスの比によって分圧されて機器３０に印加される。しかし、過電圧導通回路の素子として、バリスタやツェナダイオードなどの導通時に素子自体で所定の電圧を保持するような素子を過電圧回路に適用した場合には、電源電圧からその保持電圧分を除いた電圧がインピーダンスの比によって分圧されることなる。この場合には、素子の保持電圧とインピーダンスで分圧された電圧を加算した電圧しか機器に印加されないので、機器への引加電圧が制限されて、機器を過電圧から保護することができる。 (H)
In the first embodiment, a surge absorber has been described as an example of an element that allows a current to flow during overvoltage. In this case, as described in the first embodiment, since the voltage is not held by the element itself when conducting, the power supply voltage is divided by the impedance ratio and applied to the device 30. However, when an overvoltage circuit is applied to an overvoltage circuit, such as a varistor or Zener diode that maintains a predetermined voltage when the element itself is on, the voltage obtained by removing the retained voltage from the power supply voltage. Is divided by the impedance ratio. In this case, since only the voltage obtained by adding the holding voltage of the element and the voltage divided by the impedance is applied to the device, the applied voltage to the device is limited, and the device can be protected from overvoltage.
　本発明は、電源電圧の変動が起こり易い地域で使用される機器、例えば、冷凍装置に有用である。 The present invention is useful for equipment used in an area where power supply voltage is likely to fluctuate, such as a refrigeration apparatus.
１０，６０　　　過電圧導通回路
１１，６１　　　スイッチ
１２，６２　　　第２スイッチ
１３，６３　　　第３スイッチ
２１，７１　　　第１インピーダンス回路
２２，７２　　　第２インピーダンス回路
３３，８３　　　電圧検出器
３５，８５　　　バイパス回路
５０，１００　　過電圧保護回路
８０　　　　　　直流電源部（ＤＣ電源、コンバータ回路）
９０　　　　　　商用電源（ＡＣ電源）
９５　　　　　　インバータ（インバータ回路） 10, 60 Overvoltage conduction circuit 11, 61 Switch 12, 62 Second switch 13, 63 Third switch 21, 71 First impedance circuit 22, 72 Second impedance circuit 33, 83 Voltage detector 35, 85 Bypass circuit 50, 100 Overvoltage protection circuit 80 DC power supply (DC power supply, converter circuit)
90 Commercial power (AC power)
95 Inverter (Inverter circuit)
特開２００９－２０７３２９号公報JP 2009-207329 A

Claims (10)

  1. 　電源と前記電源から電力を供給される機器との間に接続される過電圧保護回路であって、
    　前記電源と前記機器とを結ぶ一対の電源ライン間に前記機器と並列に接続され、過電圧時に電流を流す過電圧導通回路（１０，６０）と、
    　一対の前記電源ライン間に前記機器と並列に、且つ前記過電圧導通回路（１０，６０）と直列に接続される第１インピーダンス回路（２１，７１）と、
    　前記電源ラインのうちの前記電源と前記第１インピーダンス回路（２１，７１）との間に接続される第２インピーダンス回路（２２，７２）と、
    を備える、
    過電圧保護回路（５０，１００）。     An overvoltage protection circuit connected between a power source and a device supplied with power from the power source,
    An overvoltage conduction circuit (10, 60) that is connected in parallel with the device between a pair of power supply lines connecting the power source and the device, and causes a current to flow in the event of an overvoltage,
    A first impedance circuit (21, 71) connected in parallel with the device between a pair of power supply lines and in series with the overvoltage conduction circuit (10, 60);
    A second impedance circuit (22, 72) connected between the power supply of the power supply line and the first impedance circuit (21, 71);
    Comprising
    Overvoltage protection circuit (50, 100).
  2. 　前記過電圧導通回路（１０，６０）は、過電圧時に電流を流す素子として、過渡電圧サプレッサ、ツェナダイオード、サージアブソーバ、及びアバランシェダイオードのいずれか１つを含む、
    請求項１に記載の過電圧保護回路（５０，１００）。     The overvoltage conduction circuit (10, 60) includes any one of a transient voltage suppressor, a Zener diode, a surge absorber, and an avalanche diode as an element that allows a current to flow when overvoltage occurs.
    The overvoltage protection circuit (50, 100) according to claim 1.
  3. 　前記電源の電圧を検出する電圧検出器（３３，８３）をさらに備え、
    　前記過電圧導通回路（１０，６０）は、前記電源ラインと前記第１インピーダンス回路（２１，７１）との間を開閉するスイッチ（１１，６１）を有し、
    　前記スイッチ（１１，６１）は、前記電圧検出器（３３，８３）による検出値が所定の閾値を超えたときにオンして前記電源ラインと前記第１インピーダンス回路（２１，７１）との間を導通させる、
    請求項１に記載の過電圧保護回路（５０，１００）。     A voltage detector (33, 83) for detecting the voltage of the power source;
    The overvoltage conduction circuit (10, 60) has a switch (11, 61) for opening and closing between the power supply line and the first impedance circuit (21, 71),
    The switch (11, 61) is turned on when a value detected by the voltage detector (33, 83) exceeds a predetermined threshold, and between the power supply line and the first impedance circuit (21, 71). Continuity,
    The overvoltage protection circuit (50, 100) according to claim 1.
  4. 　前記電源の電圧を検出する電圧検出器（３３，８３）と、
    　前記第２インピーダンス回路（２２，７２）を迂回するバイパス回路（３５，８５）と、
    をさらに備え、
    　前記バイパス回路（３５，８５）は、前記バイパス回路（３５，８５）を開閉する第２スイッチ（１２，６２）を有し、
    　前記第２スイッチ（１２，６２）は、通常時は前記バイパス回路（３５，８５）を閉じ、前記電圧検出器（３３，８３）による検出値が所定の閾値を超えたときに前記バイパス回路（３５，８５）を遮断する、
    請求項１又は請求項２に記載の過電圧保護回路（５０，１００）。     A voltage detector (33, 83) for detecting the voltage of the power source;
    A bypass circuit (35, 85) bypassing the second impedance circuit (22, 72);
    Further comprising
    The bypass circuit (35, 85) has a second switch (12, 62) for opening and closing the bypass circuit (35, 85),
    The second switch (12, 62) normally closes the bypass circuit (35, 85), and when the detected value by the voltage detector (33, 83) exceeds a predetermined threshold, 35, 85),
    The overvoltage protection circuit (50, 100) according to claim 1 or 2.
  5. 　前記第２インピーダンス回路（２２，７２）を迂回するバイパス回路（３５，８５）をさらに備え、
    　前記バイパス回路（３５，８５）は、前記バイパス回路（３５，８５）を開閉する第２スイッチ（１２，６２）を有し、
    　前記第２スイッチ（１２，６２）は、通常時は前記バイパス回路（３５，８５）を閉じ、前記電圧検出器（３３，８３）による検出値が所定の閾値を超えたときに前記バイパス回路（３５，８５）を遮断する、
    請求項３に記載の過電圧保護回路（５０，１００）。     A bypass circuit (35, 85) for bypassing the second impedance circuit (22, 72);
    The bypass circuit (35, 85) has a second switch (12, 62) for opening and closing the bypass circuit (35, 85),
    The second switch (12, 62) normally closes the bypass circuit (35, 85), and when the detected value by the voltage detector (33, 83) exceeds a predetermined threshold, 35, 85),
    The overvoltage protection circuit (50, 100) according to claim 3.
  6. 　前記電源の電圧を検出する電圧検出器（３３，８３）と、
    　前記電源ラインを開閉する第３スイッチ（１３，６３）と、
    をさらに備え、
    　前記第３スイッチ（１３，６３）は、通常時は前記電源ラインを導通状態にし、前記電圧検出器（３３，８３）による検出値が所定の閾値を超えたとき、前記過電圧導通回路（１０，６０）の導通後に前記電源ラインを遮断する、
    請求項１又は請求項２に記載の過電圧保護回路（５０，１００）。     A voltage detector (33, 83) for detecting the voltage of the power source;
    A third switch (13, 63) for opening and closing the power line;
    Further comprising
    The third switch (13, 63) normally turns on the power supply line, and when the detection value by the voltage detector (33, 83) exceeds a predetermined threshold, the overvoltage conduction circuit (10, 60) shuts off the power line after continuity;
    The overvoltage protection circuit (50, 100) according to claim 1 or 2.
  7. 　前記電源ラインを開閉する第３スイッチ（１３，６３）をさらに備え、
    　前記第３スイッチ（１３，６３）は、通常時は前記電源ラインを導通状態にし、前記電圧検出器（３３，８３）による検出値が所定の閾値を超えたとき、前記過電圧導通回路（１０，６０）の導通後に前記電源ラインを遮断する、
    請求項３から請求項５のいずれか１項に記載の過電圧保護回路（５０，１００）。     A third switch (13, 63) for opening and closing the power line;
    The third switch (13, 63) normally turns on the power supply line, and when the detection value by the voltage detector (33, 83) exceeds a predetermined threshold, the overvoltage conduction circuit (10, 60) shuts off the power line after continuity;
    The overvoltage protection circuit (50, 100) according to any one of claims 3 to 5.
  8. 　前記電源は、ＡＣ電源である、
    請求項１から請求項７のいずれか１項に記載の過電圧保護回路（５０）。     The power source is an AC power source;
    The overvoltage protection circuit (50) according to any one of claims 1 to 7.
  9. 　前記電源は、ＤＣ電源である、
    請求項１から請求項７のいずれか１項に記載の過電圧保護回路（１００）。     The power source is a DC power source;
    The overvoltage protection circuit (100) according to any one of claims 1 to 7.
  10. 　交流電源に接続され、交流電圧を直流電圧に変換するコンバータ回路（８０）と、
    　前記直流電圧を交流電圧に変換するインバータ回路（９５）と、
    　請求項１から請求項９のいずれか１項に記載の過電圧保護回路（１００）と、
    を備える、
    電力変換装置。     A converter circuit (80) connected to an AC power source and converting AC voltage to DC voltage;
    An inverter circuit (95) for converting the DC voltage into an AC voltage;
    Overvoltage protection circuit (100) according to any one of claims 1 to 9,
    Comprising
    Power conversion device.
PCT/JP2014/083542 2013-12-27 2014-12-18 Overvoltage protection circuit and power conversion device provided therewith WO2015098688A1 (en)

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