JP2008072865A - Power supply circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply circuit which reduces a surge voltage and intercepts an ac power line by a semiconductor switch. <P>SOLUTION: At least one semiconductor switch arranged on the ac power line is turned off in timing when an ac current becomes almost zero, based on a monitor output of a current monitor. Moreover, a first semiconductor switch which flows a current of first polarity and a second semiconductor switch which flows a current of second polarity are included. While the current flows through one of the first and the second semiconductor switches, the other is turned off, based on the monitor output of the current monitor or a voltage monitor. Once the other is turned off, another semiconductor switch is turned off after the current flowing through one semiconductor switch disappears. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply circuit used in, for example, an electrically driven automobile, and more particularly to a power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line. Is.

  In recent years, development of electric drive vehicles using electric power as at least a part of a drive source, for example, hybrid vehicles and electric vehicles has been progressing. A hybrid vehicle uses a motor driven by electric power and an internal combustion engine in combination to drive the vehicle. An electric vehicle drives an automobile only by a motor driven by electric power. These hybrid vehicles and electric vehicles are collectively referred to as electric drive vehicles. This electric drive vehicle uses a power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load, for example, a motor is connected to the power converter through an AC power line.

  As this type of power supply circuit, Japanese Patent Laying-Open No. 2005-260613 (Patent Document 1) discloses a circuit breaker provided in a power circuit between a power source such as a battery of a hybrid vehicle or an electric vehicle and a load. What to do is disclosed. In this circuit breaker, a nitride semiconductor device that directly cuts off the power circuit is used.

  Japanese Patent Application Laid-Open No. 8-182105 (Patent Document 2) discloses an electric vehicle control device using a power conversion device constituted by a plurality of semiconductor switches. In this electric vehicle control device, a DC current line between the pantograph and the power converter is provided with a current breaker that turns on and off the current. In addition, in order to prevent a voltage generated by a power generation operation of the motor from causing a short circuit between phases through a semiconductor switch in which a conduction failure occurs when one semiconductor device constituting the power conversion device has a conduction failure, An opening means for opening the AC power line between the electric motor as a load is provided. As the opening means, a contactor, an overcurrent fuse, or a contactless circuit breaker using a semiconductor element is used.

JP-A-2005-260613 JP-A-8-182105

  In Patent Document 1, by using a nitride semiconductor switch composed of a nitride semiconductor, the breakdown voltage can be increased, and the nitride semiconductor switch is connected to the power line of the power supply circuit. Although the power line can be cut off directly by the switch, in the power supply circuit of Patent Document 1, no consideration is given to the surge voltage caused by the current, load, and wiring inductance when the power line is cut off. For this reason, if the power supply circuit of Patent Document 1 is used as it is, it cannot withstand a surge voltage generated by the inductance of the load and wiring, and there is a disadvantage that the nitride semiconductor device is destroyed. In particular, when power is supplied to a load with a large inductance such as a motor or transformer, or when power from a power source with a large inductance such as a generator or transformer is shut off, the generated surge voltage increases, so the semiconductor switch is overvoltaged. There is a high possibility of destruction.

  In Patent Document 2, the AC power line between the power converter and the load can be cut off together with the DC power line for the power converter, but the contactor used for the opening means provided in the AC power line is a contact point. Since an arc is generated when the circuit is opened, the structure for ensuring safety is complicated, and a relatively large coil is required to operate the contact. For this reason, it is difficult to reduce the cost, size, and weight. . Also, the overcurrent fuse used for the opening means does not operate when the current below the fusing current continues to flow when the semiconductor switch that constitutes the power conversion device is in a conduction failure, so the conduction failure of the semiconductor device of the power conversion device Sometimes unsuitable for applications that reliably shut off power lines. Further, there is no detailed description of a contactless circuit breaker using a semiconductor element used as an opening means.

  The present invention proposes a power supply circuit capable of reliably interrupting an AC power line by a semiconductor switch while suppressing generation of a surge voltage when an abnormality such as a continuity failure occurs in a semiconductor switch of a power converter, for example. To do.

  A power supply circuit according to a first aspect of the present invention is a power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line. A circuit interruption device for interrupting a power line, and a current monitor for monitoring an alternating current flowing in the AC power line, wherein the circuit interruption device includes at least one semiconductor switch disposed on the power line, and the current monitor. And a control unit that shuts off the semiconductor switch based on the monitor output, and the semiconductor switch is turned off at a timing when the alternating current becomes substantially zero.

  A power supply circuit according to a second aspect of the present invention is a power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line. A circuit interruption device for interrupting a power line, and a current monitor for monitoring an alternating current flowing in the AC power line, the circuit interruption device comprising: a first semiconductor switch for causing a first polarity current to flow in the AC power line; A second semiconductor switch for causing a current of a second polarity opposite to the first polarity to flow through the AC power line; and a control unit for shutting off the first and second semiconductor switches based on a monitor output of the current monitor. And the other is in an off state and the other is in an off state, with current flowing through the AC power line through one of the first and second semiconductor switches. After being, in a state in which the current AC has been flowing to the power line is extinguished through the one, characterized in that one of which is turned off.

  A power supply circuit according to a third aspect of the present invention is a power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line. A circuit interrupting device for interrupting the power line, the circuit interrupting device comprising: a first semiconductor switch for supplying a first polarity current to the AC power line; and a second polarity opposite to the first polarity for the AC power line. A second semiconductor switch for passing a current of polarity; a voltage monitoring unit for monitoring a voltage of the first and second semiconductor switches; and the first and second semiconductor switches are cut off based on a monitor output of the voltage monitoring unit. And the other is in the off state and the other is in the off state, with a current flowing through the AC power line through one of the first and second semiconductor switches. After being in a state in which current flowing through the one disappears, characterized in that one of which is turned off.

  In the power conversion circuit according to the first aspect of the present invention, the circuit breaker includes at least one semiconductor switch disposed on the AC power line, and a control unit that shuts off the semiconductor switch based on the monitor output of the current monitor. In addition, since the semiconductor switch is turned off at the timing when the alternating current becomes almost zero, the semiconductor switch reduces the surge voltage when the semiconductor switch is turned off and prevents destruction of the semiconductor switch. The AC power line can be cut off reliably.

  In the power supply circuit according to the second aspect of the present invention, the circuit breaker includes a first semiconductor switch for passing a first polarity current through the AC power line, and a second polarity opposite to the first polarity in the AC power line. A second semiconductor switch for flowing a current of the first and second semiconductor switches based on a monitor output of the current monitor, and the AC power line through one of the first and second semiconductor switches. When the current is flowing, the other is turned off, and after the other is turned off, the current flowing through the AC power line disappears through the other, and one of them is turned off. Therefore, the first and second semiconductor switches are surely eliminated while eliminating the surge voltage when the first and second semiconductor switches are turned off, and preventing the destruction of the first and second semiconductor switches. It is possible to cut off the AC power line.

  In the power supply circuit according to the third aspect of the present invention, the circuit breaker includes a first semiconductor switch for causing a first polarity current to flow in the AC power line, and a second polarity having a polarity opposite to the first polarity in the AC power line. A second semiconductor switch for passing current; a voltage monitor for monitoring the voltage of the first and second semiconductor switches; and a control unit for cutting off the first and second semiconductor switches based on the monitor output of the voltage monitor; In a state where current flows through the AC power line through one of the first and second semiconductor switches, the other is turned off, and after the other is turned off, the current is flowing through the other. Since one of the switches is turned off, the surge voltage when the first and second semiconductor switches are turned off is eliminated, and the destruction of the first and second semiconductor switches is prevented. But , It can be cut off reliably AC power line by the first, second semiconductor switch.

  Several embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is an electric circuit diagram showing an entire power supply circuit according to the present invention, and FIG. 2 is an electric circuit diagram showing a circuit breaker used in the power supply circuit of the first embodiment.

  First, an overall configuration of a power supply circuit 10 according to the present invention will be described with reference to FIG. The power supply circuit 10 of FIG. 1 is the power supply circuit of the first embodiment, but is not limited to the first embodiment, and the power supply circuits of the other second to fifteenth embodiments are configured similarly.

  A power supply circuit 10 shown in FIG. 1 is a power supply circuit used to supply power to a drive motor of an electric drive vehicle. The power supply circuit 10 includes a DC power supply 11, an AC load 13, a power converter 20, a DC breaker 25, and two circuit breakers 30. The DC power supply 11 is an in-vehicle battery, for example. The AC load 13 is, for example, a drive motor of an electrically driven automobile. The power converter 20 is connected to the DC power source 11 through the DC power line 15 and is connected to the AC load 13 through the AC power line 17. The power converter 20 converts the DC voltage from the DC power source 11 into an AC voltage and supplies the AC load 13 to drive the AC load 13, but also converts the AC voltage generated by the AC load 13 into a DC voltage. And is supplied to the DC power supply 11 to charge the in-vehicle battery of the DC power supply 11.

  The AC load 13 is, for example, a three-phase AC drive motor. When power is supplied from the DC power supply 11 to the AC load 13, the power conversion device 20 converts the DC voltage of the DC power supply 11 into a three-phase AC voltage and supplies the AC load 13 with power. When power is supplied from the AC load 13 to the DC power supply 11, the power conversion device 20 converts the three-phase AC voltage generated in the AC load 13 into a DC voltage and supplies the DC power supply 11 with power. The DC power line 15 includes two DC lines 15P and 15N, and the AC power line 17 includes three AC lines 17U, 17V, and 17W. One DC line 15 </ b> P of the DC power line 15 is provided with a DC circuit breaker 25. At least two AC lines 17U and 17W of the AC power line 17 are provided with circuit breakers 30 respectively. The circuit breaker 30 has a pair of main terminals 301 and 302, and the main terminal 301 is connected to the power converter 20 and the main terminal 302 is connected to the AC load 13.

  The power conversion device 20 includes switch circuits 21U, 21V, 21W connected between the DC lines 15P, 15N, and a power capacitor 23. The switch circuits 21U, 21V, and 21W are each configured by connecting a positive-side semiconductor switch 211 and a negative-side semiconductor switch 212 in series. A diode 213 that bypasses the reverse current is connected to each of the semiconductor switches 211 and 212. The AC line 17U is connected between the semiconductor switches 211 and 212 of the switch circuit 21U, the AC line 17U between the semiconductor switches 211 and 212 of the switch circuit 21V is connected, and between the semiconductor switches 211 and 212 of the switch circuit 21W. The AC line 17W is connected to. The power capacitor 23 smoothes the DC output voltage of the power converter 20 when power is supplied from the AC load 13 to the DC power supply 11.

  The circuit breaker 30 is disposed in each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 in the power converter 20, the AC line 17U, Shut off 17W. For example, when a continuity failure occurs in the semiconductor switch 211 of the switch circuit 21U, an abnormal alternating current such as an interphase short circuit flows through the semiconductor switch 211 of the switch circuit 21U, the diode 213 of the switch circuits 21U and 21W, and the alternating current load 13. Similarly, when a continuity failure occurs in the semiconductor switch 212 of the switch circuit 21U and also when a continuity failure occurs in the semiconductor switches 211 and 212 of the other switch circuits 21V and 21W, the diode 231 and the AC load 13 are used similarly. Abnormal AC current flows. The circuit breaker 30 interrupts the AC lines 17U and 17W and interrupts this abnormal alternating current. In the present invention, the circuit breaker 30 is improved so that the AC lines 17U and 17W are reliably blocked by the semiconductor switch without generating a surge voltage. Note that the DC circuit breaker 25 interrupts the DC power line 15 when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power conversion device 20.

  In the first embodiment, the circuit breaker 30 </ b> A shown in FIG. 2 is used as the circuit breaker 30. With reference to FIG. 2, the circuit breaker 30A will be described. As illustrated in FIG. 2, the circuit breaker 30 </ b> A includes a circuit breaker 31, a current monitor 37, and a controller 39. The circuit interrupting unit 31 has one semiconductor switch 32, which is disposed on the AC lines 17U and 17W of the AC power line 17, and directly interrupts the AC lines 17U and 17W. The circuit breaker 31 and the current monitor 37 are connected between the main terminals 301 and 302.

  In the first embodiment, the semiconductor switch 32 is configured by a JFET, that is, a junction field effect transistor. The semiconductor switch 32 composed of this junction field effect transistor has a source S, a drain D and a gate G connected to the AC lines 17U and 17W, and by controlling the potential of the gate G, the source S and drain Controls conduction and disconnection with D. The semiconductor switch 32 composed of a junction field effect transformer can control the conduction and interruption of the bidirectional alternating current i, and can control the conduction and interruption of the alternating current i. The alternating current i flowing through the alternating current lines 17U and 17W includes a first polarity current i1 and a second polarity current i2 having a polarity opposite to the first polarity. The first polarity current i1 flows from the drain D to the source S of the semiconductor switch 32, and the second polarity current i2 flows from the source S to the drain D.

  The current monitor 37 includes a current sensor 371 and a monitor circuit 372. The current sensor 371 is coupled to the AC lines 17U and 17W, detects the AC current i flowing through the AC lines 17U and 17W, and generates a sense output. The monitor circuit 372 receives the sense output from the current sensor 371, amplifies it, and generates a monitor output Smi. The monitor output Smi is a signal obtained by monitoring the change of the alternating current i.

  The control unit 39 supplies a gate control signal SG to the gate G of the semiconductor switch 32 to control energization and interruption of the semiconductor switch 32. The control unit 39 receives an abnormality detection output Sf such as a continuity failure from the power conversion device 20 and a monitor output Smi from the current monitor 37. When the circuit interrupting unit 31 interrupts the AC lines 17U and 17W, the surge voltage Vs may be generated due to the inductance L of the AC load 13 and the AC lines 17U and 17W. This surge voltage Vs is expressed by Vs = L × di / dt. di / dt is the rate of change of the alternating current i at the time of interruption.

  When the control unit 39 receives the abnormality detection output Sf, the control unit 39 refers to the monitor output Smi in real time, and turns off the semiconductor switch 32 at a timing when the AC current i flowing through the AC lines 17U and 17W first becomes substantially zero. The AC lines 17U and 17W are shut off. Specifically, when the abnormality detection output Sf is received at the timing t1 in the state where the current i1 of the first polarity flows in the semiconductor switch 32, the monitor output Smi is referred to in real time, and first after the timing t1. At the timing t2 when the current i1 becomes almost zero, the semiconductor switch 32 is turned off, and the AC lines 17U and 17W are cut off. When the abnormality detection output Sf is received at the timing t1 in the state where the current i2 having the second polarity flows in the semiconductor switch 32, the monitor output Smi is referred to in real time, and after the timing t1, the current i2 is first generated. The semiconductor switch 32 is turned off and the AC lines 17U and 17W are shut off at the timing t2 when the time becomes almost zero. The timing at which the currents i1 and i2 become almost zero is the timing at which the currents i1 and i2 become 1% or less of the rated value of the alternating current i.

  FIG. 3 is a waveform diagram for explaining the operation of the circuit breaker 30. 3A shows the alternating current i, FIG. 3B shows the abnormality detection output Sf, and FIG. 3C shows the gate control signal SG. For example, as shown in FIG. 3A, the abnormality detection output Sf shown in FIG. 3B changes from the high level to the low level at the timing t1 in the state where the current i2 of the second polarity flows in the semiconductor switch 32. When the cutoff instruction Ioff is issued, the control unit 39 gives the cutoff standby Woff, and as shown in FIG. 3 (c), the current i2 of the second polarity is initially substantially after the cutoff instruction Ioff. At the timing t2 when it becomes zero, the semiconductor switch 32 is turned off, and the AC lines 17U and 17W are cut off.

  As described above, in the circuit breaker 30 according to the first embodiment, the semiconductor switch 32 is turned off at the timing when the alternating current i becomes almost zero, so di / dt when the semiconductor switch 32 is turned off is reduced. The surge voltage Vs can be reduced. Therefore, it is possible to prevent the semiconductor switch 32 from being destroyed by the surge voltage Vs, and even if the AC load 13 is a drive motor having a large inductance in an electrically driven vehicle, the conduction of the semiconductor switches 211 and 212 of the power conversion device. An abnormal alternating current that flows in the event of a failure or the like can be reliably interrupted by the semiconductor switch 32.

Embodiment 2. FIG.
FIG. 4 is an electric circuit diagram showing a circuit breaker 30B used in Embodiment 2 of the power supply circuit according to the present invention. The circuit breaker 30B shown in FIG. 4 is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30B is also arranged on each of the AC lines 17U and 17W of the AC power line 17, and cuts off the AC lines 17U and 17W when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20. To do.

  In the circuit breaker 30B shown in FIG. 4, the circuit breaker 31 uses first and second semiconductor switches 331 and 332 made up of IGBTs, that is, insulated gate bipolar transistors. These semiconductor switches 331 and 332 each composed of an IGBT have a collector C, an emitter E, and a gate G, respectively, and by controlling the potential of the gate G, energization between the collector C and the emitter E, Control shut-off. The first and second semiconductor switches 331 and 332 are connected in series to the AC lines 17U and 17W, and the respective emitters E are directly connected to each other. Unlike the junction field effect transistors, the semiconductor switches 331 and 332 made of IGBT can be energized only in a single direction, that is, in the direction from the collector C to the emitter E, and cut off the current in this energization direction. In this case, the withstand voltage is high, but the reverse withstand voltage is low.

  In relation to the characteristics of the first and second semiconductor switches 331 and 332 configured by this IGBT, the current direction setting element 333 is connected in parallel to the first semiconductor switch 331, and the second semiconductor switch 332 includes The current direction setting element 334 is connected in parallel. The current direction setting elements 333 and 334 are diodes, each having an anode A and a cathode K. The anode A of the current direction setting element 333 is the emitter E of the first semiconductor switch 331 and the cathode of the current direction setting element 333. K is directly connected to the collector C of the first semiconductor switch 331. The anode A of the current direction setting element 334 is directly connected to the emitter E of the second semiconductor switch 332, and the cathode K of the current direction setting element 334 is directly connected to the collector C of the second semiconductor switch 332.

  The alternating current i flowing through the alternating current lines 17U and 17W includes a first polarity current i1 and a second polarity current i2 having a polarity opposite to the first polarity. The first polarity current i1 flows through the collector C of the first semiconductor switch 331, its emitter E, the anode A of the current direction setting element 334, and its cathode K. The current i2 of the second polarity flows through the collector C of the second semiconductor switch 332, its emitter E, the anode A of the current direction setting element 333, and its cathode K. In this way, the first and second semiconductor switches 331 and 332 formed of IGBTs are connected in series with each other, and the current direction setting elements 333 and 334 are connected in parallel to the semiconductor switches 331 and 332, thereby providing a circuit breaker. 31 allows alternating current i to flow in both directions. The current direction setting elements 333 and 334 protect the semiconductor switches 331 and 332 against a voltage applied to the semiconductor switches 331 and 332 in the direction opposite to the energization direction.

  In the circuit interruption device 30B shown in FIG. 4, the current monitor 37 is configured in the same manner as the current monitor 37 shown in FIG. 2, and generates a monitor output Smi. The control unit 39 supplies the same gate control signal SG to the gates G of the first and second semiconductor switches 331 and 332 to control the first and second semiconductor switches 331 and 332. The control unit 39 blocks the AC lines 17U and 17W based on the abnormality detection output Sf from the power conversion device 20 and the monitor output Smi from the current monitor 37, similarly to the control unit 39 shown in FIG.

  The control unit 39 controls the first and second semiconductor switches 331 and 332 to be in the off state in the same manner as in the first embodiment. Specifically, when the first semiconductor switch 331 is turned on and the current i1 of the first polarity is flowing, when the cutoff command Ioff is received at timing t1, the monitor output Smi is referred to in real time, and the cutoff standby Woff is set. Then, after the timing t1, at the timing t2 when the current i1 first becomes substantially zero, the first and second semiconductor switches 331 and 332 are turned off, and the AC lines 17U and 17W are cut off. In addition, when the second semiconductor switch 332 is turned on and the second polarity current i2 flows, when the cutoff command Ioff is received at the timing t1, the monitor output Smi is referred to in real time, and the cutoff standby Woff is given. 3, after the timing t1, the first and second semiconductor switches 331 and 332 are turned off and the AC lines 17U and 17W are cut off at the timing t2 when the current i2 first becomes substantially zero. . The timing at which the currents i1 and i2 become substantially zero is the timing at which the currents i1 and i2 become 1% or less of the rated value of the alternating current i.

  As described above, in the circuit breaker 30B according to the second embodiment, the first and second semiconductor switches 331 and 332 are turned off at the timing when the currents i1 and i2 flowing through the AC lines 17U and 17W become almost zero. 1. The di / dt when the second semiconductor switches 331 and 332 are turned off can be reduced, and the surge voltage Vs can be reduced. Therefore, the first and second semiconductor switches 331 and 332 can be prevented from being destroyed by the surge voltage Vs, and even if the AC load 13 is a drive motor having a large inductance in an electric drive vehicle, An abnormal alternating current that flows when the semiconductor switches 211 and 212 are in a continuity failure can be reliably blocked by the semiconductor switches 331 and 332.

Embodiment 3 FIG.
FIG. 5 is an electric circuit diagram showing a circuit breaker 30C used in the third embodiment of the power supply circuit according to the present invention. The circuit breaker 30C shown in FIG. 5 is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30C is also arranged on each of the AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W are cut off. To do.

  In the circuit breaker 30C shown in FIG. 5, the circuit breaker 31 uses first and second semiconductor switches 341 and 342 made up of MOSFETs, that is, MOS field effect transistors. These semiconductor switches 341 and 342 formed of MOSFETs have a source S, a drain D, and a gate G, respectively, and by controlling the potential of the gate G, the energization between the source S and the drain D, Control shut-off. The first and second semiconductor switches 341 and 342 are connected in series to each of the AC lines 17U and 17W, and the respective sources S are directly connected to each other. For example, an N-channel MOSFET is used as the MOSFET constituting the semiconductor switches 341 and 342. The semiconductor switches 341 and 342 formed of MOSFETs can be energized only in a single direction, that is, in a direction from the drain D to the source S because a parasitic diode is formed due to the configuration.

  In relation to the characteristics of the first and second semiconductor switches 341 and 342 formed of the MOSFET, a parasitic diode 343 is connected in parallel to the first semiconductor switch 341, and a parasitic diode is connected to the second semiconductor switch 342. The diodes 344 are connected in parallel, and these parasitic diodes 343 and 344 function as current direction setting elements. The current direction setting elements (parasitic diodes) 343 and 344 each have an anode A and a cathode K, and the anode A of the current direction setting element (parasitic diode) 343 is set to the source S of the first semiconductor switch 341. The cathode K of the element (parasitic diode) 343 is directly connected to the drain D of the first semiconductor switch 341, and the anode A of the current direction setting element (parasitic diode) 344 is connected to the source S of the second semiconductor switch 342 and also in the current direction. The cathode K of the setting element (parasitic diode) 344 is directly connected to the drain D of the second semiconductor switch 342, and functions as a current direction setting element. In order to assist the parasitic diodes 343 and 344 of the MOSFET, a separate diode may be connected in parallel with each of the current direction setting elements (parasitic diodes) 343 and 344 and with the same polarity. These diodes also function as current direction setting elements.

  The alternating current i flowing through the alternating current lines 17U and 17W includes a first polarity current i1 and a second polarity current i2 having a polarity opposite to the first polarity. The first polarity current i1 flows via the drain D of the first semiconductor switch 341, its source S, the anode A of the current direction setting element 344, and its cathode K. The current i2 of the second polarity flows through the drain D of the second semiconductor switch 342, its source S, the anode A of the current direction setting element 343, and its cathode K. The first and second semiconductor switches 341 and 342 formed of MOSFETs are connected in series to each other, and the current direction setting elements 343 and 344 are connected in parallel to the respective semiconductor switches 341 and 342, so that a circuit breaker is provided. 31 allows alternating current i to flow in both directions. The current direction setting elements 343 and 344 protect the semiconductor switches 341 and 342 against a voltage applied to the semiconductor switches 341 and 342 in the direction opposite to the energization direction.

  In the circuit interruption device 30C shown in FIG. 5, the current monitor 37 is configured in the same manner as the current monitor 37 shown in FIG. 2, and generates a monitor output Smi. The control unit 39 is configured to supply the same gate control signal SG to the gates G of the first and second semiconductor switches 341 and 342, and to control the first and second semiconductor switches 341 and 342. Based on the abnormality detection output Sf from 20 and the monitor output Smi from the current monitor 37, the AC lines 17U and 17W are cut off.

  The control unit 39 controls the first and second semiconductor switches 341 and 342 in the same manner as in the first embodiment. Specifically, when the first semiconductor switch 341 is turned on and the current i1 having the first polarity flows, when the cutoff command Ioff is received at the timing t1, the monitor output Smi is referred to in real time, and the cutoff standby Woff is set. The first semiconductor switches 341 and 342 are turned off and the AC lines 17U and 17W are cut off at the timing t2 when the current i1 becomes substantially zero first after the timing t1. Further, when the second semiconductor switch 342 is turned on and the current i2 of the second polarity is flowing, when the cutoff command Ioff is received at the timing t1, the monitor output Smi is referred to in real time as shown in FIG. Then, at the timing t2 when the current i2 first becomes substantially zero after the timing t1, the second semiconductor switches 341 and 342 are turned off to cut off the AC lines 17U and 17W. The timing at which the currents i1 and i2 become substantially zero is the timing at which the currents i1 and i2 become 1% or less of the rated value of the alternating current i.

  As described above, in the circuit breaker 30C according to the third embodiment, the first and second semiconductor switches 341 and 342 are turned off at the timing when the currents i1 and i2 become substantially zero. , 342 can be reduced when the 342 is turned off, and the surge voltage Vs can be reduced. Therefore, it is possible to prevent the semiconductor switches 341 and 342 from being destroyed by the surge voltage Vs, and even if the AC load 13 is a drive motor having a large inductance in an electrically driven vehicle, the semiconductor switches 211 and 212 of the power conversion device. The abnormal alternating current that flows when the continuity failure occurs can be reliably interrupted by the semiconductor switches 341 and 342.

  In the first to third embodiments described above, the semiconductor switches 32, 331, 332, 341, and 342 are turned off at the timing when the currents i1 and i2 become almost zero, and each semiconductor switch is turned off. Di / dt can be reduced and the surge voltage Vs can be reduced.

  The semiconductor switches 32, 331, 332, 341, and 342 in the first to third embodiments are configured using various semiconductor materials. These semiconductor switches can be configured using nitride semiconductors such as general silicon Si, gallium nitride GaN, aluminum nitride AlN, aluminum gallium nitride AlGaN, or silicon carbide SiC semiconductors, for example. A semiconductor material constituting the semiconductor switch is selected in consideration of the characteristics. Nitride semiconductors or silicon carbide SiC generally have a large band gap energy, and semiconductor switches composed of these semiconductor materials generally have a high breakdown voltage of several hundred volts and operate stably even in a high temperature atmosphere of about 200 ° C. Therefore, the heat dissipation structure of the semiconductor switch can be simplified or omitted, and the circuit breaker 31 can be reduced in size and weight. Further, a semiconductor switch made of silicon Si is easy to manufacture and very inexpensive as compared with a semiconductor switch made of nitride semiconductor or silicon carbide SiC, and the low cost of the circuit breakers 30A, 30B, 30C. Can be easily realized.

  In the first to third embodiments, the current monitor 37 may be built in the power conversion device 20. In this case, the current monitor 37 built in the power converter 20 is used in the circuit breakers 30A, 30B, and 30C without arranging the current monitor 37.

Embodiment 4 FIG.
FIG. 6 is an electric circuit diagram showing a circuit interruption device 30D used in the fourth embodiment of the power supply circuit according to the present invention. This circuit breaker 30D is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30D is arranged on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  In the circuit interruption device 30D shown in FIG. 6, the circuit interruption unit 31 uses first and second semiconductor switches 321 and 322 configured by JFETs, that is, junction field effect transistors. These semiconductor switches 321 and 322 formed of JFETs have a source S, a drain D, and a gate G, respectively, and by controlling the potential of the gate G, energization between the source S and the drain D, Control shut-off. The first and second semiconductor switches 321 and 322 are connected in series to each of the AC lines 17U and 17W, and the respective sources S are directly connected to each other.

  The first and second semiconductor switches 321 and 322 formed of JFETs can be energized in both directions, similarly to the semiconductor switch 32 in the first embodiment, but in the fourth embodiment, in the circuit cutoff unit 31, The first and second semiconductor switches 321 and 322 are connected in series with each other, and the current direction setting elements 323 and 324 are connected in parallel with the semiconductor switches 321 and 322, respectively. The current direction setting elements 323 and 324 are diodes. The current direction setting elements 323 and 324 have an anode A and a cathode K, respectively. The anode A of the current direction setting element 323 is connected to the source S of the first semiconductor switch 321. The cathode K of the current direction setting element 323 is directly connected to the drain D of the first semiconductor switch 321. The anode A of the current direction setting element 324 is directly connected to the source S of the second semiconductor switch 322, and the cathode K of the current direction setting element 324 is directly connected to the drain D of the second semiconductor switch 322.

  Similar to the semiconductor switch 32, the semiconductor switches 321 and 322 are configured using various semiconductor materials. The semiconductor switches 321 and 322 can be configured using, for example, a nitride semiconductor such as general silicon Si, gallium nitride GaN, aluminum nitride AlN, aluminum gallium nitride AlGaN, or a silicon carbide SiC semiconductor. A semiconductor material constituting the semiconductor switches 321 and 322 is selected in consideration of the characteristics of the material. Nitride semiconductors or silicon carbide SiC generally have large band gap energy, and semiconductor switches 321 and 322 made of these semiconductor materials generally have a high breakdown voltage of several hundred volts and are stable even in a high temperature atmosphere of about 200 ° C. Therefore, the heat dissipation structure of the semiconductor switches 321 and 322 can be simplified or omitted, and the circuit interrupter 31 can be reduced in size and weight. Further, the semiconductor switches 321 and 322 made of silicon Si are easy to manufacture and very inexpensive as compared with the semiconductor switches 321 and 322 made of nitride semiconductor or silicon carbide SiC, and the circuit breaker 30C is low in cost. Cost can be easily realized.

  The alternating current i flowing through the alternating current lines 17U and 17W includes a first polarity current i1 and a second polarity current i2 having a polarity opposite to the first polarity. The first polarity current i1 flows through the drain D of the first semiconductor switch 321, its source S, the anode A of the current direction setting element 324, and its cathode K. The second polarity current i2 flows through the drain D of the second semiconductor switch 322, the source thereof, the anode A of the current direction setting element 323, and the cathode K thereof.

  In the circuit interruption device 30D shown in FIG. 6, the current monitor 37 is configured in the same manner as the current monitor 37 shown in FIG. 2, and generates a monitor signal Smi. The control unit 39A is configured to control the first and second semiconductor switches 321 and 322 by supplying gate control signals SG1 and SG2 to the gates G of the first and second semiconductor switches 321 and 322, respectively. On the basis of the abnormality detection output Sf from the power converter 20 and the monitor output Smi from the current monitor 37, the AC lines 17U and 17W are cut off.

  7A and 7B are waveform diagrams for explaining the operation of the circuit breaker 30D. FIG. 7A shows the AC current i flowing through the AC lines 17U and 17W, FIG. 7B shows the abnormality detection signal Sf, and FIG. 7 (c) shows a gate control signal SG1 supplied to the gate G of the semiconductor switch 321, and FIG. 7 (d) shows a gate control signal SG2 supplied to the gate G of the semiconductor switch 322.

  As shown in FIG. 7A, the abnormality detection output Sf changes from the high level to the low level at the timing t1 shown in FIG. 7B when the current i2 having the second polarity flows through the second semiconductor switch 322. When the current interruption command Ioff is generated, the control unit 39A refers to the monitor output Smi and confirms that the current i2 of the second polarity is flowing at the timing t1, and then shown in FIG. As described above, the gate control signal SG1 is changed from the high level to the low level, and the first semiconductor switch 321 is immediately turned off. At timing t1, the second polarity current i2 flows through the drain D and source S of the second semiconductor switch 322 and the current direction setting element 323, and the first polarity current i1 flows through the first semiconductor switch 321. I1 = 0. Since the first semiconductor switch 321 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 321 is turned off.

  Even after the first semiconductor switch 321 is immediately turned off at the timing t1, the control unit 39A applies the gate control signal SG2 supplied to the gate G of the second semiconductor switch 322 as shown in FIG. A cutoff standby Woff is applied, and the gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the drain D and source S of the second semiconductor switch 322 and the current direction setting element 323. The control unit 39A refers to the monitor output Smi, changes the gate control signal SG2 from the high level to the low level at the timing t3 after the current i2 of the second polarity disappears, and at the timing t3, the second semiconductor switch 322. To turn off. At this timing t3, the current i2 having the second polarity flowing through the second semiconductor switch 322 disappears, and I2 = 0. Even when the second semiconductor switch 322 is controlled to be in the OFF state, the surge voltage Vs is Does not occur. At the timing t3, the first semiconductor switch 321 has already been turned off, so that the current i1 having the first polarity does not flow.

  In the state where the current i1 of the first polarity flows through the first semiconductor switch 321, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor switch 322 is immediately turned off at the timing t1, The first semiconductor switch 321 is turned off at the timing t3 after the current i1 having the first polarity flowing through the first semiconductor switch 321 disappears after the timing t1.

  As described above, in the circuit breaker 30D according to the fourth embodiment, when the current flows through one of the first and second semiconductor switches 321, 322, the other is turned off and the other is turned off. After that, when the current flowing through one of the semiconductor switches is turned off, one of the semiconductor switches is turned off. Therefore, when the semiconductor switches 321 and 322 are turned off, the surge voltage Vs does not occur, and the semiconductor switch The AC lines 17U and 17W can be blocked while preventing the destruction of the 321 and 322. Therefore, even if the AC load 13 is a drive motor having a large inductance in a voltage-electrically driven vehicle, the semiconductor switches 321 and 322 reliably cut off the abnormal AC current that flows when the semiconductor switches 211 and 212 of the power conversion device are faulty. can do.

  In the fourth embodiment, the current monitor 37 may be built in the power conversion device 20. In this case, the current monitor 37 built in the power converter 20 is used in the circuit breaker 30A without arranging the current monitor 37.

Embodiment 5. FIG.
FIG. 8 is an electric circuit diagram showing a circuit interruption device E used in Embodiment 5 of the power supply circuit according to the present invention. This circuit breaker 30E is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30E is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30E shown in FIG. 8 is different from the circuit breaker 30B used in the second embodiment shown in FIG. 4 in that the control unit 39 is replaced with the control unit 39A, and the first and second semiconductor switches 331 and 332 are respectively provided. The first and second semiconductor switches 331 and 332 are controlled in the same manner as in FIG. 7 by changing the gate control signals SG1 and SG2. The other configuration is the same as that of the circuit breaker 30B used in the second embodiment.

  Also in the fifth embodiment, the semiconductor switches 331 and 332 are controlled in the same manner as in FIG. Specifically, as shown in FIG. 7A, in the state where the current i2 of the second polarity flows through the semiconductor switch 332, the abnormality detection output Sf is changed from the high level at the timing t1 shown in FIG. 7B. When the level is changed to a low level and the current cut-off command Ioff is generated, the control unit 39A refers to the monitor output Smi and confirms that the current i2 of the second polarity flows at the timing t1, and then FIG. ), The gate control signal SG1 is changed from the high level to the low level, and the semiconductor switch 331 is immediately turned off. At the timing t1, the current i2 of the second polarity flows through the drain D and source S of the semiconductor switch 332 and the current direction setting element 333, and the current i1 of the first polarity does not flow through the semiconductor switch 331, i1 = 0. Since the semiconductor switch 331 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 331 is turned off.

  Even after the semiconductor switch 331 is immediately turned off at the timing t1, the control unit 39A sets the cutoff standby Woff to the gate control signal SG2 supplied to the gate G of the semiconductor switch 332 as shown in FIG. The gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the drain D and source S of the semiconductor switch 332 and the current direction setting element 323. The control unit 39A refers to the monitor output Smi, changes the gate control signal SG2 from the high level to the low level at the timing t3 after the current i2 of the second polarity disappears, and turns off the semiconductor switch 332 at the timing t3. Control to the state. At this timing t3, the current i2 having the second polarity flowing through the semiconductor switch 332 disappears, i2 = 0, and even if the semiconductor switch 332 is controlled to be in the OFF state, the surge voltage Vs is not generated. Further, at the timing t3, since the semiconductor switch 331 has already been turned off, the current i1 having the first polarity does not flow.

  In the state where the current i1 of the first polarity flows through the first semiconductor switch 331, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor switch 332 is immediately turned off at the timing t1, The first semiconductor switch 331 is turned off at a timing t3 after the current i1 having the first polarity flowing through the first semiconductor switch 331 disappears after the timing t1.

  As described above, also in the fifth embodiment, when the current flows through one of the first and second semiconductor switches 331 and 332, the other is turned off and the other is turned off. Since one of the semiconductor switches is turned off in a state where the current flowing through the current flows, the surge voltage Vs is not generated when the semiconductor switches 331 and 332 are turned off, and the semiconductor switches 331 and 332 are destroyed. AC line 17U, 17W can be interrupted | blocking, preventing. Therefore, even if the AC load 13 is a drive motor having a large inductance in a surge voltage electric drive vehicle, the semiconductor switch 331, 332 reliably ensures that an abnormal AC current that flows when the semiconductor switches 211, 212 of the power conversion device are continually faulty. Can be blocked.

Embodiment 6 FIG.
FIG. 9 is an electric circuit diagram showing a circuit breaker F used in Embodiment 5 of the power supply circuit according to the present invention. This circuit breaker 30F is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30F is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and cuts off the AC lines 17U and 17W when a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20. To do.

  The circuit breaker 30F shown in FIG. 9 is different from the circuit breaker 30C used in the third embodiment shown in FIG. 5 in that the control unit 39 is replaced with the control unit 39A, and the first and second semiconductor switches 341 and 342 are respectively provided. In addition, the first and second semiconductor switches 341 and 342 are controlled in the same manner as in FIG. Others are the same as the circuit breaker 30C used in the third embodiment.

  Also in the sixth embodiment, the semiconductor switches 341 and 342 are controlled in the same manner as in FIG. Specifically, as shown in FIG. 7A, in the state where the current i2 of the second polarity flows through the semiconductor switch 342, the abnormality detection output Sf is changed from the high level at the timing t1 shown in FIG. 7B. When the level is changed to a low level and the current cut-off command Ioff is generated, the control unit 39A refers to the monitor output Sm and confirms that the current i2 of the second polarity flows at the timing t1, and then FIG. As shown in c), the gate control signal SG1 is changed from the high level to the low level, and the semiconductor switch 341 is immediately turned off. At the timing t1, the current i2 of the second polarity flows through the drain D and source S of the semiconductor switch 342 and the current direction setting element 343, and the current i1 of the first polarity does not flow through the semiconductor switch 341. = 0. Since the semiconductor switch 341 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 341 is turned off.

  Even after the semiconductor switch 341 is immediately turned off at the timing t1, as shown in FIG. 7D, the control unit 39A sets the cutoff standby Woff to the gate control signal SG2 supplied to the gate G of the semiconductor switch 342. The gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the drain D and source S of the semiconductor switch 342 and the current direction setting element 343. The control unit 39A refers to the monitor output Smi, changes the gate control signal SG2 from the high level to the low level at the timing t3 after the current i2 of the second polarity disappears, and turns off the semiconductor switch 342 at the timing t3. Control to the state. At this timing t3, the current i2 having the second polarity flowing through the semiconductor switch 342 disappears, i2 = 0, and the surge voltage Vs is not generated even when the semiconductor switch 342 is controlled to be turned off. Further, at the timing t3, since the semiconductor switch 341 has already been turned off, the current i1 having the first polarity does not flow.

  In the state where the current i1 of the first polarity flows through the first semiconductor switch 341, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor switch 342 is immediately turned off at the timing t1, The first semiconductor switch 341 is turned off at a timing t3 after the current i1 having the first polarity flowing through the first semiconductor switch 341 disappears after the timing t1.

  As described above, also in the sixth embodiment, in the state where the current flows through one of the first and second semiconductor switches 341 and 342, the other is turned off and the other is turned off. Since one of the semiconductor switches is turned off in the state where the current that has flown through is lost, the surge voltage Vs is not generated when the semiconductor switches 341 and 342 are turned off, and the semiconductor switches 341 and 342 are destroyed. AC line 17U, 17W can be interrupted | blocking, preventing. Therefore, even if the AC load 13 is a drive motor having a large inductance in a surge voltage electric drive vehicle, the semiconductor switch 341 and 342 reliably prevents abnormal AC current that flows when the semiconductor switches 211 and 212 of the power conversion device are in conduction failure. Can be blocked.

Embodiment 7 FIG.
FIG. 10 is an electric circuit diagram showing a circuit interruption device 30G used in the seventh embodiment of the power supply circuit according to the present invention. This circuit breaker 30G is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30G is arranged on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30G shown in FIG. 10 changes the circuit breaker 30D shown in FIG. 6 so that the first and second semiconductor switches 321 and 322 connected in series with each other are connected in parallel to each other, and the current direction The setting elements 323 and 324 are connected in series with the first and second semiconductor switches 321 and 322, respectively. The drain D of the first semiconductor switch 321 is connected to the current sensor 371 of the current monitor 37 through the current direction setting element 323, and its source S is connected to the main terminal 302. The drain D of the second semiconductor switch 322 is connected to the main terminal 302 through the current direction setting element 324, and its source S is connected to the current sensor 371.

  The current direction setting element 323 is connected to the drain D side of the first semiconductor switch 321, and its anode A is connected to the current sensor 371 and also to the source S of the second semiconductor switch 322. The cathode K of the current direction setting element 323 is connected to the drain D of the first semiconductor switch 321. The current direction setting element 324 is connected to the drain D side of the second semiconductor switch 322, and its anode A is connected to the main terminal 302 and to the source S of the first semiconductor switch 321. The cathode K of the current direction setting element 324 is connected to the drain D of the second semiconductor switch 322.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 323, the cathode K thereof, the drain D of the first semiconductor switch 321 and the source S thereof. The second polarity current i2 of the alternating current i flows through the anode A of the current direction setting element 324, the cathode K thereof, the drain D of the second semiconductor switch 322, and the source S thereof. Others are the same as the circuit breaker 30D shown in FIG.

  Also in the seventh embodiment, in the same manner as the circuit interrupt device 30D shown in FIG. 6, in the state where the current flows through one of the first and second semiconductor switches 321, 322, the other is turned off. Since the semiconductor switch 321 and 322 is turned off when one of the semiconductor switches 321 and 322 is turned off after the other is turned off, one of the semiconductor switches is turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 321 and 322 from being destroyed without being generated.

Embodiment 8 FIG.
FIG. 11 is an electric circuit diagram showing a circuit breaker 30H used in the eighth embodiment of the power supply circuit according to the present invention. This circuit breaker 30H is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30H is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30H shown in FIG. 11 is the same as the circuit breaker 30E shown in FIG. 8 except that the first and second semiconductor switches 331 and 332 connected in series are connected in parallel to each other, and the current direction The setting elements 333 and 334 are connected in series with the first and second semiconductor switches 331 and 332, respectively. The collector C of the first semiconductor switch 331 is connected to the current sensor 371 of the current monitor 37 through the current direction setting element 333, and its emitter E is connected to the main terminal 302. The collector C of the second semiconductor switch 332 is connected to the main terminal 302 through the current direction setting element 334, and its emitter E is connected to the current sensor 371. Protection diodes 335 and 336 are connected to the first and second semiconductor switches 331 and 332 in parallel, respectively. The anodes A of the protection diodes 335 and 336 are connected to the emitters E of the first and second semiconductor switches 331 and 332, and the cathodes K of the protection diodes 335 and 336 are connected to their collectors C.

  The current direction setting element 333 is connected to the collector C side of the first semiconductor switch 331, and its anode A is connected to the current sensor 371 and also to the emitter E of the second semiconductor switch 332. The cathode K of the current direction setting element 333 is connected to the collector C of the first semiconductor switch 331. The current direction setting element 334 is connected to the collector C side of the second semiconductor switch 332, and its anode A is connected to the main terminal 302 and to the emitter E of the first semiconductor switch 331. The cathode K of the current direction setting element 334 is connected to the collector C of the second semiconductor switch 332.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 333, the cathode K thereof, the collector C of the first semiconductor switch 331, and the emitter E thereof. The current i2 of the second polarity of the alternating current i flows through the anode A of the current direction setting element 334, the cathode K thereof, the collector C of the second semiconductor switch 332, and the emitter E thereof. The other configuration is the same as that of the circuit breaker 30E shown in FIG.

  Also in the eighth embodiment, in the same manner as the circuit breaker 30E shown in FIG. 8, the current flows through one of the first and second semiconductor switches 331 and 332, and the other is turned off. Since one of the semiconductor switches is turned off in a state where the current flowing through one of the other is turned off after the other is turned off, the surge voltage Vs is reduced when the semiconductor switches 331 and 332 are turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 331 and 332 from being destroyed without being generated.

Embodiment 9 FIG.
FIG. 12 is an electric circuit diagram showing a circuit breaker 30I used in the ninth embodiment of the power supply circuit according to the present invention. This circuit breaker 30I is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30I is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30I shown in FIG. 12 is changed to connect the first and second semiconductor switches 341 and 342 connected in series to each other in parallel in the circuit breaker 30F shown in FIG. The setting elements 343 and 344 are connected in series with the first and second semiconductor switches 341 and 342, respectively. The drain D of the first semiconductor switch 341 is connected to the current sensor 371 of the current monitor 37 through the current direction setting element 343, and its source S is connected to the main terminal 302. The drain D of the second semiconductor switch 342 is connected to the main terminal 302 through the current direction setting element 344, and its source S is connected to the current sensor 371. Parasitic diodes 345 and 346 are connected to the first and second semiconductor switches 341 and 342 in parallel, respectively. The anodes A of the parasitic diodes 345 and 346 are connected to the drains D of the first and second semiconductor switches 341 and 332, and the cathodes K of the protection diodes 345 and 346 are connected to their sources S.

  The current direction setting element 343 is connected to the drain D side of the first semiconductor switch 341, and its anode A is connected to the current sensor 371 and also to the source S of the second semiconductor switch 342. The cathode K of the current direction setting element 343 is connected to the drain D of the first semiconductor switch 341. The current direction setting element 344 is connected to the drain D side of the second semiconductor switch 342, and its anode A is connected to the main terminal 302 and to the source S of the first semiconductor switch 341. The cathode K of the current direction setting element 344 is connected to the source S of the second semiconductor switch 342.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 343, the cathode K thereof, the drain D of the first semiconductor switch 341, and the source S thereof. The current i2 of the second polarity of the alternating current i flows through the anode A of the current direction setting element 344, the cathode K thereof, the drain D of the second semiconductor switch 342, and the source S thereof. Others are the same as the circuit breaker 30F shown in FIG.

  Also in the ninth embodiment, in the same manner as the circuit breaker 30F shown in FIG. 9, in the state where the current flows through one of the first and second semiconductor switches 341 and 342, the other is turned off. Since one of the semiconductor switches is turned off in a state where the current flowing through one of the other is turned off after the other is turned off, the surge voltage Vs is reduced when the semiconductor switches 341 and 342 are turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 341 and 342 from being broken without being generated.

Embodiment 10 FIG.
FIG. 13 is an electric circuit diagram showing a circuit breaker 30J used in the tenth embodiment of the power supply circuit according to the present invention. This circuit breaker 30J is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30J is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  A circuit breaker 30J shown in FIG. 13 is the same as the circuit breaker 30D shown in FIG. 6 except that the current monitor 37 is replaced with a voltage monitor 38 and the controller 39A is replaced with a controller 39B. The voltage monitor 38 is built in the circuit breaker 30J, and outputs a monitor output Smv obtained by monitoring the voltages at both ends of the first and second semiconductor switches 321, 322. Based on the abnormality detection output Sf from the power conversion device 20 and the monitor output Smv from the voltage monitor 38, the control unit 39B sends the gate signals SG1 and SG2 to the gates G of the first and second semiconductor switches 321 and 322, respectively. The first semiconductor switch 321 and the second semiconductor switch 322 are controlled. Others are the same as the circuit breaker 30D shown in FIG.

  FIG. 14 is a waveform diagram for explaining the operation of the circuit breaker 30J. 14A shows the alternating current i, FIG. 14B shows the monitor output Smv of the voltage monitor 38, FIG. 14C shows the abnormality detection output Sf, and FIG. 14D shows the first semiconductor. The gate control signal SG1 for the switch 321 is shown, and FIG. 14E shows the gate control signal SG2 for the second semiconductor switch 322. As shown in FIG. 14B, the monitor output Smv of the voltage monitor 38 becomes a high level when the first polarity current i1 flows to the first semiconductor switch 321, and the second polarity current i2 becomes the second semiconductor switch 322. When it flows to the low level.

  As shown in FIG. 14A, in the state where the current i2 having the second polarity flows through the second semiconductor switch 322 and the monitor output Smv is at the low level as shown in FIG. When the abnormality detection output Sf changes from the high level to the low level at the timing t1 shown in c) and the current cutoff command Ioff is generated, the control unit 39B refers to the monitor output Smv, and at the timing t1, the current i2 of the second polarity is displayed. As shown in FIG. 14D, the gate control signal SG1 is changed from the high level to the low level, and the first semiconductor switch 321 is immediately turned off. At timing t1, the second polarity current i2 flows through the drain D and source S of the second semiconductor switch 322 and the current direction setting element 323, and the first polarity current i1 flows through the first semiconductor switch 321. I1 = 0. Since the first semiconductor switch 321 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 321 is turned off.

  Even after the first semiconductor switch 321 is immediately turned off at the timing t1, the control unit 39B applies the gate control signal SG2 supplied to the gate G of the second semiconductor switch 322 as shown in FIG. A cutoff standby Woff is applied, and the gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the drain D and source S of the second semiconductor switch 322 and the current direction setting element 323. The control unit 39B refers to the monitor output Smv, changes the gate control signal SG2 from the high level to the low level at the timing t3 after the current i2 of the second polarity disappears, and the second semiconductor switch 322 at the timing t3. To turn off. At this timing t3, the current i2 having the second polarity flowing through the second semiconductor switch 322 disappears, and I2 = 0. Even when the second semiconductor switch 322 is controlled to be in the OFF state, the surge voltage Vs is Does not occur. At the timing t3, the first semiconductor switch 321 has already been turned off, so that the current i1 having the first polarity does not flow.

  In the state where the current i1 of the first polarity flows through the first semiconductor switch 321 and the monitor output Smv is at a high level, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor is detected at the timing t1. The switch 322 is immediately turned off, and after the timing t1, the first semiconductor switch 321 loses the first polarity current i1 flowing through the first semiconductor switch 321 and the monitor output Smv changes from the high level to the low level. At the timing t3 after the change, it is turned off.

  As described above, in the circuit breaker 30J according to the tenth embodiment, when the current flows through one of the first and second semiconductor switches 321, 322, the other is turned off, and the other is turned off. After that, when the current flowing through one of the semiconductor switches is turned off, one of the semiconductor switches is turned off. Therefore, when the semiconductor switches 321 and 322 are turned off, the surge voltage Vs does not occur, and the semiconductor switch The AC lines 17U and 17W can be blocked while preventing the destruction of the 321 and 322.

Embodiment 11 FIG.
FIG. 15 is an electric circuit diagram showing a circuit breaker 30K used in the eleventh embodiment of the power supply circuit according to the present invention. This circuit breaker 30K is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30K is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC power line 17U, Shut off 17W.

  A circuit breaker 30K shown in FIG. 15 is the same as the circuit breaker 30E shown in FIG. 8, except that the current monitor 37 is replaced with a voltage monitor 38 and the controller 39A is replaced with a controller 39B. The voltage monitor 38 is built in the circuit breaker 30K, and outputs a monitor output Smv obtained by monitoring voltages at both ends of the first and second semiconductor switches 331 and 332. Based on the abnormality detection output Sf from the power conversion device 20 and the monitor output Smv from the voltage monitor 38, the control unit 39B sends the gate signals SG1 and SG2 to the gates G of the first and second semiconductor switches 331 and 332, respectively. The first and second semiconductor switches 331 and 332 are supplied. The other configuration is the same as that of the circuit breaker 30E shown in FIG.

  Also in this circuit breaker 30K, the first and second semiconductor switches 331 and 332 are controlled in the same manner as in FIG. Specifically, as shown in FIG. 14A, a second polarity current i2 flows through the second semiconductor switch 322, and the monitor output Smv is at a low level as shown in FIG. 14B. In FIG. 14C, when the abnormality detection output Sf changes from the high level to the low level at the timing t1 shown in FIG. 14C and the current interruption command Ioff is generated, the control unit 39B refers to the monitor output Smv. After confirming that the bipolar current i2 flows, as shown in FIG. 14D, the gate control signal SG1 is changed from the high level to the low level, and the first semiconductor switch 331 is immediately turned off. To do. At the timing t1, the second polarity current i2 flows through the collector C and the emitter E of the second semiconductor switch 332 and the current direction setting element 333, and the first polarity current i1 flows through the first semiconductor switch 331. I1 = 0. Since the first semiconductor switch 331 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 331 is turned off.

  Even after the first semiconductor switch 331 is immediately turned off at the timing t1, the control unit 39B sets the gate control signal SG2 supplied to the gate G of the second semiconductor switch 332 as shown in FIG. A cutoff standby Woff is applied, and the gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the collector C and emitter E of the second semiconductor switch 332 and the current direction setting element 333. The control unit 39B refers to the monitor output Smv, changes the gate control signal SG2 from the high level to the low level at the timing t3 after the current i2 of the second polarity disappears, and at the timing t3, the second semiconductor switch 332 To turn off. At this timing t3, the current i2 having the second polarity flowing through the second semiconductor switch 332 disappears, and I2 = 0. Even if the second semiconductor switch 332 is controlled to be in the off state, the surge voltage Vs is Does not occur. Further, at the timing t3, since the first semiconductor switch 331 has already been turned off, the current i1 having the first polarity does not flow.

  In the state where the current i1 of the first polarity flows through the first semiconductor switch 331 and the monitor output Smv is at a high level, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor at the timing t1. The switch 332 is immediately turned off. In the first semiconductor switch 331, the current i1 having the first polarity flowing through the first semiconductor switch 331 disappears after the timing t1, and the monitor output Smv changes from the high level to the low level. At the timing t3 after the change, it is turned off.

  As described above, in the circuit breaker 30K according to the eleventh embodiment, when the current flows through one of the first and second semiconductor switches 331 and 332, the other is turned off, and the other is turned off. After that, when the current flowing through one of the semiconductor switches is extinguished, one of the semiconductor switches is turned off. Therefore, when the semiconductor switches 331 and 332 are turned off, the surge voltage Vs does not occur, and the semiconductor switch The AC lines 17U and 17W can be blocked while preventing the destruction of the 331 and 332.

Embodiment 12 FIG.
FIG. 16 is an electric circuit diagram showing a circuit breaker 30L used in the twelfth embodiment of the power supply circuit according to the present invention. This circuit breaker 30L is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30L is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  A circuit breaker 30L shown in FIG. 16 is the same as the circuit breaker 30F shown in FIG. 9, except that the current monitor 37 is replaced with a voltage monitor 38 and the controller 39A is replaced with a controller 39B. The voltage monitor 38 is built in the circuit breaker 30L, and outputs a monitor output Smv obtained by monitoring voltages at both ends of the first and second semiconductor switches 341 and 342. Based on the abnormality detection output Sf from the power converter 20 and the monitor output Smv from the voltage monitor 38, the control unit 39B sends the gate signals SG1 and SG2 to the gates G of the first and second semiconductor switches 341 and 342, respectively. The first and second semiconductor switches 341 and 342 are controlled. Others are the same as the circuit breaker 30F shown in FIG.

  Also in this circuit breaker 30L, the first and second semiconductor switches 341 and 342 are controlled in the same manner as in FIG. Specifically, as shown in FIG. 14A, a second polarity current i2 flows through the second semiconductor switch 342, and the monitor output Smv is at a low level as shown in FIG. 14B. In FIG. 14C, when the abnormality detection output Sf changes from the high level to the low level at the timing t1 shown in FIG. 14C and the current interruption command Ioff is generated, the control unit 39B refers to the monitor output Smv. After confirming that the bipolar current i2 flows, the gate control signal SG1 is changed from the high level to the low level as shown in FIG. 14D, and the first semiconductor switch 341 is immediately turned off. To do. At timing t1, the second polarity current i2 flows through the drain D and source S of the second semiconductor switch 342 and the current direction setting element 343, and the first polarity current i1 flows through the first semiconductor switch 341. I1 = 0. Since the first semiconductor switch 341 is immediately turned off by the current cutoff command Ioff at the timing t1 when i1 = 0, the surge voltage Vs is not generated even if the semiconductor switch 341 is turned off.

  Even after the first semiconductor switch 341 is immediately turned off at the timing t1, the control unit 39B sets the gate control signal SG2 supplied to the gate G of the second semiconductor switch 342 as shown in FIG. A cutoff standby Woff is applied, and the gate control signal SG2 is maintained at a high level. For this reason, the current i2 of the second polarity continues to flow through the drain D and source S of the second semiconductor switch 342 and the current direction setting element 343. The control unit 39B refers to the monitor output Smv, changes the gate control signal SG2 from the high level to the low level at timing t3 after the current i2 of the second polarity disappears, and at this timing t3, the second semiconductor switch 342 To turn off. At this timing t3, the current i2 having the second polarity flowing through the second semiconductor switch 342 disappears, and I2 = 0. Even when the second semiconductor switch 332 is controlled to be in the off state, the surge voltage Vs is Does not occur. At the timing t3, the first semiconductor switch 341 has already been turned off, so that the current i1 having the first polarity does not flow.

  In the state where the current i1 having the first polarity flows through the first semiconductor switch 341 and the monitor output Smv is at a high level, when the cutoff instruction Ioff is given at the timing t1, the second semiconductor is output at the timing t1. The switch 342 is immediately turned off. In the first semiconductor switch 341, the current i1 having the first polarity flowing through the first semiconductor switch 341 disappears after the timing t1, and the monitor output Smv changes from the high level to the low level. At the timing t3 after the change, it is turned off.

  As described above, in the circuit breaker 30L according to the twelfth embodiment, when the current flows through one of the first and second semiconductor switches 341 and 342, the other is turned off and the other is turned off. After that, when the current flowing through one of the semiconductor switches is extinguished, one of the semiconductor switches is turned off. Therefore, when the semiconductor switches 341 and 342 are turned off, the surge voltage Vs does not occur, and the semiconductor switch The AC lines 17U and 17W can be blocked while preventing the destruction of the 341 and 342.

Embodiment 13 FIG.
FIG. 17 is an electric circuit diagram showing a circuit breaker 30M used in Embodiment 13 of the power supply circuit according to the present invention. This circuit breaker 30M is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30M is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30M shown in FIG. 17 is changed to connect the first and second semiconductor switches 321 and 322 connected in series to each other in parallel in the circuit breaker 30J shown in FIG. The setting elements 323 and 324 are connected in series with the first and second semiconductor switches 321 and 322, respectively. The drain D of the first semiconductor switch 321 is connected to the main terminal 301 through the current direction setting element 323, and its source S is connected to the main terminal 302. The drain D of the second semiconductor switch 322 is connected to the main terminal 302 through the current direction setting element 324, and its source S is connected to the main terminal 301.

  The current direction setting element 323 is connected to the drain D side of the first semiconductor switch 321, and its anode A is connected to the main terminal 301 and also to the source S of the second semiconductor switch 322. The cathode K of the current direction setting element 323 is connected to the drain D of the first semiconductor switch 321. The current direction setting element 324 is connected to the drain D side of the second semiconductor switch 322, and its anode A is connected to the main terminal 302 and to the source S of the first semiconductor switch 321. The cathode K of the current direction setting element 324 is connected to the drain D of the second semiconductor switch 322.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 323, the cathode K thereof, the drain D of the first semiconductor switch 321 and the source S thereof. The second polarity current i2 of the alternating current i flows through the anode A of the current direction setting element 324, the cathode K thereof, the drain D of the second semiconductor switch 322, and the source S thereof. Others are the same as the circuit breaker 30J shown in FIG.

  Also in the thirteenth embodiment, in the same manner as the circuit breaker 10J shown in FIG. 13, in the state where the current flows through one of the first and second semiconductor switches 321, 322, the other is turned off. Since the semiconductor switch 321 and 322 is turned off when one of the semiconductor switches 321 and 322 is turned off after the other is turned off, one of the semiconductor switches is turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 321 and 322 from being destroyed without being generated.

Embodiment 14 FIG.
FIG. 18 is an electric circuit diagram showing a circuit breaker 30N used in the fourteenth embodiment of the power supply circuit according to the present invention. This circuit breaker 30N is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30N is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a conduction failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  The circuit breaker 30N shown in FIG. 18 is changed to connect the first and second semiconductor switches 331 and 332 connected in series to each other in parallel in the circuit breaker 30K shown in FIG. The setting elements 333 and 334 are connected in series with the first and second semiconductor switches 331 and 332, respectively. The collector C of the first semiconductor switch 331 is connected to the main terminal 301 through the current direction setting element 333, and its emitter E is connected to the main terminal 302. The collector C of the second semiconductor switch 332 is connected to the main terminal 302 through the current direction setting element 334, and its emitter E is connected to the main terminal 301. Protection diodes 335 and 336 are connected to the first and second semiconductor switches 331 and 332 in parallel, respectively. The anodes A of the protection diodes 335 and 336 are connected to the emitters E of the first and second semiconductor switches 331 and 332, and the cathodes K of the protection diodes 335 and 336 are connected to their collectors C.

  The current direction setting element 333 is connected to the collector C side of the first semiconductor switch 331, and its anode A is connected to the main terminal 301 and also to the emitter E of the second semiconductor switch 332. The cathode K of the current direction setting element 333 is connected to the collector C of the first semiconductor switch 331. The current direction setting element 334 is connected to the collector C side of the second semiconductor switch 332, and its anode A is connected to the main terminal 302 and to the emitter E of the first semiconductor switch 331. The cathode K of the current direction setting element 334 is connected to the collector C of the second semiconductor switch 332.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 333, the cathode K thereof, the collector C of the first semiconductor switch 331, and the emitter E thereof. The current i2 of the second polarity of the alternating current i flows through the anode A of the current direction setting element 334, the cathode K thereof, the collector C of the second semiconductor switch 332, and the emitter E thereof. Others are the same as the circuit breaker 30K shown in FIG.

  Also in the fourteenth embodiment, in the same manner as the circuit breaker 30K shown in FIG. 15, in the state where current flows through one of the first and second semiconductor switches 331 and 332, the other is turned off. Since one of the semiconductor switches is turned off in a state where the current flowing through one of the other is turned off after the other is turned off, the surge voltage Vs is reduced when the semiconductor switches 331 and 332 are turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 331 and 332 from being destroyed without being generated.

Embodiment 15 FIG.
FIG. 19 is an electric circuit diagram showing a circuit breaker 30P used in the fifteenth embodiment of the power supply circuit according to the present invention. This circuit breaker 30P is also used as the circuit breaker 30 in the power supply circuit 10 shown in FIG. The circuit breaker 30P is disposed on each of the two AC lines 17U and 17W of the AC power line 17, and when an abnormality such as a continuity failure occurs in the semiconductor switches 211 and 212 of the power converter 20, the AC lines 17U and 17W. Shut off.

  19 is changed to connect the first and second semiconductor switches 341 and 342 connected in series to each other in parallel in the circuit breaker 30L shown in FIG. The setting elements 343 and 344 are connected in series with the first and second semiconductor switches 341 and 342, respectively. The drain D of the first semiconductor switch 341 is connected to the main terminal 301 through the current direction setting element 343, and its source S is connected to the main terminal 302. The drain D of the second semiconductor switch 342 is connected to the main terminal 302 through the current direction setting element 344, and its source S is connected to the main terminal 301. Parasitic diodes 345 and 346 are connected to the first and second semiconductor switches 341 and 342 in parallel, respectively. The respective anodes A of the parasitic diodes 345 and 346 are connected to the respective drains D of the first and second semiconductor switches 341 and 332, and the respective cathodes K of the parasitic diodes 345 and 346 are connected to their respective sources S.

  The current direction setting element 343 is connected to the drain D side of the first semiconductor switch 341, and its anode A is connected to the main terminal 301 and also to the source S of the second semiconductor switch 342. The cathode K of the current direction setting element 343 is connected to the drain D of the first semiconductor switch 341. The current direction setting element 344 is connected to the drain D side of the second semiconductor switch 342, and its anode A is connected to the main terminal 302 and to the source S of the first semiconductor switch 341. The cathode K of the current direction setting element 344 is connected to the drain D of the second semiconductor switch 342.

  The first polarity current i1 of the alternating current i flows through the anode A of the current direction setting element 343, the cathode K thereof, the drain D of the first semiconductor switch 341, and the source S thereof. The current i2 of the second polarity of the alternating current i flows through the anode A of the current direction setting element 344, the cathode K thereof, the drain D of the second semiconductor switch 342, and the source S thereof. Others are the same as the circuit breaker 30L shown in FIG.

  Also in the fifteenth embodiment, in the same manner as the circuit breaker 30L shown in FIG. 16, the current is flowing through one of the first and second semiconductor switches 341 and 342, and the other is turned off. Since one of the semiconductor switches is turned off in a state where the current flowing through one of the other is turned off after the other is turned off, the surge voltage Vs is reduced when the semiconductor switches 341 and 342 are turned off. The AC lines 17U and 17W can be interrupted while preventing the semiconductor switches 341 and 342 from being broken without being generated.

  The power supply circuit according to the present invention is used as, for example, a power supply circuit for a drive motor of an electric drive vehicle.

It is an electric circuit diagram showing the whole power supply circuit according to the present invention. It is an electric circuit diagram which shows the circuit interruption device used in Embodiment 1 of the electric power supply circuit by this invention. FIG. 4 is a waveform diagram for explaining the operation of the circuit breaker used in the first embodiment. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 2 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 3 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 4 of the power supply circuit by this invention. FIG. 10 is a waveform diagram for explaining the operation of the circuit breaker used in the fourth embodiment. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 5 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 6 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 7 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 8 of the power supply circuit by this invention. It is an electrical circuit diagram which shows the circuit breaker used in Embodiment 9 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 10 of the power supply circuit by this invention. FIG. 38 is a waveform diagram for explaining operation of the circuit breaker used in the tenth embodiment. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 11 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 12 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 13 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 14 of the power supply circuit by this invention. It is an electric circuit diagram which shows the circuit breaker used in Embodiment 15 of the power supply circuit by this invention.

Explanation of symbols

10: Power supply circuit, 11: DC power supply, 13: AC load, 15: DC power line,
17: AC power line, 20: Power converter, 30A to 30P: Circuit breaker,
32, 321, 322, 331, 332, 341, 342: semiconductor switch,
323, 324, 333, 334, 343, 344: current direction setting elements,
37: Current monitor, 38: Voltage monitor, 39, 39A, 39B: Control unit.

Claims (7)

A power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line,
A circuit breaker that cuts off the AC power line, and a current monitor that monitors the AC current flowing in the AC power line,
The circuit breaker includes at least one semiconductor switch disposed on the AC power line, and a controller that shuts off the semiconductor switch based on a monitor output of the current monitor,
The power supply circuit, wherein the semiconductor switch is turned off at a timing when the alternating current becomes substantially zero. A power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line,
A circuit breaker that cuts off the AC power line, and a current monitor that monitors the AC current flowing in the AC power line,
The circuit breaker includes: a first semiconductor switch for flowing a first polarity current through the AC power line; a second semiconductor switch for flowing a second polarity current opposite to the first polarity through the AC power line; A control unit that shuts off the first and second semiconductor switches based on a monitor output of the current monitor,
With the current flowing through the AC power line through one of the first and second semiconductor switches, the other is turned off, and the other is turned off, and then the AC power line is passed through the other. A power supply circuit characterized in that one of the currents flowing in is extinguished and one of them is turned off. A power supply circuit in which a power converter is connected to a DC power source through a DC power line, and an AC load is connected to the power converter through an AC power line,
A circuit breaker that cuts off the AC power line,
The circuit breaker includes: a first semiconductor switch for flowing a first polarity current through the AC power line; a second semiconductor switch for flowing a second polarity current opposite to the first polarity through the AC power line; A voltage monitor that monitors the voltage of the first and second semiconductor switches; and a control unit that shuts off the first and second semiconductor switches based on a monitor output of the voltage monitor;
In a state where current flows through the AC power line through one of the first and second semiconductor switches, the other is turned off, and after the other is turned off, the current is flowing through the other. One of the power supply circuits is turned off in a state in which is disappeared.   4. The power supply circuit according to claim 1, wherein the semiconductor switch or the first and second semiconductor switches are made of a nitride semiconductor or a silicon carbide semiconductor. 5. Supply circuit.   4. The power supply circuit according to claim 1, wherein the semiconductor switch or the first and second semiconductor switches are IGBTs or MOSFETs. 5.   4. The power supply circuit according to claim 2, wherein a current direction setting element is connected in parallel with each of the first and second semiconductor switches.   4. The power supply circuit according to claim 2, wherein a current direction setting element is connected in series with each of the first and second semiconductor switches.

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