Cutoff circuit, cutoff system, and electric power supply system

Abstract

A cutoff circuit (10) comprises a first circuit (1) and a second circuit (2). The first circuit (1) has a first relay (11) and a fuse (9) that is connected in series with the first relay (11). The second circuit (2) has a second relay (21). The second circuit (2) is connected in parallel with the first circuit (1). After the fuse (9) cuts off the electrical path of the first circuit (1), the second relay (21) is switched from off to on.

Description

Interruption circuit, interruption system, and power supply system

[0001] The present disclosure relates generally to an interruption circuit, an interruption system, and a power supply system, and more particularly to an interruption circuit, an interruption system, and a power supply system that include a fuse.

[0002] Patent Document 1 describes that in a vehicle, a main fuse for circuit protection is connected to the anode side of a high-voltage power supply serving as a power supply unit, and a main relay is connected downstream of the main fuse in the electrical flow direction. The main relay is a switch that cuts off or conducts current from the high-voltage power supply by opening and closing the current path to which it is connected.

[0003] The vehicle disclosed in Patent Document 1 also includes a precharge circuit connected in parallel to the main relay downstream of the main fuse. A precharge capacitor (hereinafter referred to as "capacitor"), which is a storage device that precharges (preliminarily charges) the vehicle when the vehicle is started, is connected downstream of the main relay and precharge circuit. The precharge circuit includes a resistor and a relay arranged downstream of the main fuse. The relay coil is connected to a low-voltage power supply and an ignition switch. When the ignition switch is turned on, current flows from the low-voltage power supply to the relay coil, closing the relay, and current from the high-voltage power supply flows through the precharge circuit to the precharge capacitor.

[0004] Furthermore, in the vehicle of Patent Document 1, the capacitor is provided with a voltage abnormality detection device that detects the charging voltage precharged by the capacitor. The voltage abnormality detection device energizes the coil of the main relay when the detected charging voltage is equal to or higher than a predetermined voltage (e.g., 70% of the rated voltage of 300 V of the high-voltage power supply). In other words, when the charging voltage of the capacitor is equal to or higher than the predetermined voltage, the voltage abnormality detection device determines that the charging voltage is appropriate for starting, and energizes the main relay to close (turn on) the main relay.

[0005] JP 2010-179889 A

[0006] In electrical equipment such as the vehicle described in Patent Document 1, if the main fuse is blown, the power supply from the high-voltage power supply to the capacitor is stopped. Therefore, in the case of an electric vehicle, for example, if the main fuse is blown while the vehicle is running, it may be necessary to move the vehicle by inertia to a space such as the shoulder of the road, which may make it difficult to use.

[0007] An interruption circuit according to one aspect of the present disclosure includes a first circuit and a second circuit. The first circuit includes a first relay and a fuse connected in series with the first relay. The second circuit includes a second relay connected in parallel with the first circuit. After the fuse interrupts the electrical path of the first circuit, the second relay is switched from off to on.

[0008] The interruption system according to one aspect of the present disclosure includes the interruption circuit and a control unit, the control unit controls operation of the fuse and the second relay, and the control unit switches the second relay from off to on after operating the fuse.

[0009] A power supply system according to an aspect of the present disclosure includes the interrupter circuit, a power supply, and an inverter, wherein the first circuit is connected between the positive electrode of the power supply and a DC terminal on a high potential side of the inverter.

[0010] A power supply system according to an aspect of the present disclosure includes the interrupter circuit, a power supply, and an inverter, wherein the first circuit is connected between the negative electrode of the power supply and a DC terminal on a low potential side of the inverter.

[0011] An interrupter circuit according to one aspect of the present disclosure includes a first circuit, a second circuit, a third circuit, and a fourth circuit. The first circuit includes a first relay. The second circuit includes a second relay and a resistor connected in series with the second relay, and is connected in parallel with the first circuit. The third circuit includes a third relay and is connected in series with the first circuit. The fourth circuit includes a fuse and a fourth relay connected in parallel with the fuse, and is connected in series with the first circuit and the third circuit. After the fuse operates, the fourth relay is switched from off to on.

[0012] The interruption system according to one aspect of the present disclosure includes the interruption circuit and a control unit, the control unit controls the operation of the fuse and the fourth relay, and the control unit switches the fourth relay from off to on after the fuse interrupts the electrical path.

[0013] A power supply system according to an aspect of the present disclosure includes the interrupter circuit, a power supply, and an inverter, wherein a series circuit of the first circuit and the fourth circuit is connected between a positive electrode of the power supply and a high-potential side DC terminal of the inverter.

[0014] The present disclosure has the advantage of enabling improved convenience.

[0015] FIG. 1 is a circuit diagram of a motor system including a power supply system according to a first embodiment of the present disclosure. FIG. 2 is a flowchart showing normal operation of the power supply system according to the first embodiment. FIG. 3 is a flowchart showing operation of the power supply system according to the first embodiment when an abnormality occurs. FIG. 4 is a flowchart showing operation of the power supply system according to the first embodiment when restarting after fuse operation. FIG. 5 is a circuit diagram of a motor system including a power supply system according to a second embodiment of the present disclosure. FIG. 6 is a flowchart showing operation of the power supply system according to the first embodiment when an abnormality occurs. FIG. 7 is a flowchart showing operation of the power supply system according to the first embodiment when an abnormality occurs. FIG. 8 is a flowchart showing operation of the power supply system according to the first embodiment when restarting after fuse operation. FIG. 9 is a circuit diagram of a motor system including a power supply system according to a third embodiment of the present disclosure. FIG. 10 is a flowchart showing operation of the power supply system according to the first embodiment when an abnormality occurs. FIG. 11 is a flowchart showing operation of the power supply system according to the first embodiment when an abnormality occurs. FIG. 12 is a flowchart showing operation of the power supply system according to the first embodiment when restarting after fuse operation.

[0016] The embodiments of the present disclosure will be described with reference to the drawings. The drawings described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0017] (1) Embodiment 1 As shown in Fig. 1, a motor system 200 of this embodiment includes a power supply system 100 and a motor 93. The motor 93 is, for example, a three-phase AC synchronous motor. The power supply system 100 supplies power to the motor 93. The motor system 200 is mounted on an electric device such as an electric vehicle.

[0018] (1.1) Power Supply System As shown in Fig. 1 , the power supply system 100 includes a power supply 91, an inverter 92, and an interruption system 20. The interruption system 20 includes an interruption circuit 10 and a control unit 5.

[0019] The power supply 91 supplies power to the inverter 92 for driving the motor 93. The power supply 91 is a DC power supply that outputs a DC voltage. The power supply 91 is, for example, a storage battery (battery) mounted in the electrical device. The power supply 91 includes, for example, a plurality of battery cells connected in series. The battery cells may be, for example, nickel-metal hydride battery cells or lithium-ion battery cells. The output voltage (rated voltage) of the power supply 91 is, for example, within the range of 100 V to 500 V.

[0020] The inverter 92 includes a capacitor C1, three high-side switching elements Q1, Q3, and Q5, and three low-side switching elements Q2, Q4, and Q6. The capacitor C1 is a smoothing capacitor. The capacitor C1 may be, for example, an electrolytic capacitor, but is not limited to this. Each of the switching elements Q1 to Q6 is an NPN-type bipolar transistor, but is not limited to this and may be a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), an IGBT, or the like.

[0021] The inverter 92 also has two DC terminals 921 and 922 and three AC terminals 923, 924, and 925. Note that the term "terminal" in this disclosure does not have to be a component for connecting an electric wire or the like, and may be, for example, a lead of an electronic component or a part of a conductor included in a circuit board.

[0022] Capacitor C1 is connected between two DC terminals 921 and 922. Also, three series circuits, each consisting of one high-side switching element and one low-side switching element, are connected in parallel to capacitor C1. Specifically, a series circuit of two switching elements Q1 and Q2, a series circuit of two switching elements Q3 and Q4, and a series circuit of two switching elements Q5 and Q6 are connected in parallel to both ends of capacitor C1. The connection points between two switching elements in each of the three series circuits (the connection points between the emitter of the high-side transistor and the collector of the low-side transistor) are connected to three AC terminals 923, 924, and 925, respectively.

[0023] The three AC terminals 923, 924, and 925 correspond to the U-phase, V-phase, and W-phase of the three-phase AC power, respectively. The three AC terminals 923, 924, and 925 are connected to the three-phase input terminals of the motor 93, respectively.

[0024] (1.2) Interrupting Circuit As shown in FIG. 1, the interrupting circuit 10 includes a first circuit 1, a second circuit 2, and a third circuit 3.

[0025] The first circuit 1 is connected between the positive electrode of the power supply 91 and a high-potential side DC terminal 921 of the inverter 92. The first circuit 1 constitutes part of a main circuit (high-potential side first main circuit) for supplying power from the power supply 91 to the inverter 92.

[0026] The first circuit 1 has a first relay 11 and a fuse 9. In the first circuit 1, a first end of the first relay 11 is connected to the positive electrode of the power source 91, a second end of the first relay 11 is connected to a first end of the fuse 9, and a second end of the fuse 9 is connected to a DC terminal 921 on the high potential side of the inverter 92. In the first circuit 1, the fuse 9 is arranged downstream of the first relay 11 in the electrical path.

[0027] The first relay 11 is a first main relay arranged on the high-potential side electric circuit. The first relay 11 is, for example, a mechanical relay. The first relay 11 has a relatively large current-carrying capacity (current capacity) so that the first relay 11 can pass the current output from the power supply 91. Although not particularly limited, the current-carrying capacity of the first relay 11 may be, for example, approximately 250 A to 500 A.

[0028] The fuse 9 is connected in series with the first relay 11. The fuse 9 is, for example, a pyro-fuse. When the fuse 9 operates, it cuts off both ends of the fuse 9, thereby cutting off the electrical path between both ends of the first circuit 1. Therefore, after the fuse 9 operates, current no longer flows through the first circuit 1, and power supply from the power source 91 to the inverter 92 via the first circuit 1 stops. Note that the fuse 9 is not limited to a pyro-fuse, and may be a fuse (for example, a blown fuse) that actively operates in response to the current flowing through the fuse 9.

[0029] It should be noted that a "pyro-fuse" is a fuse that cuts off an electrical circuit by explosive force using gunpowder or the like. In other words, "pyro-fuse" in this disclosure is included in "pyrotechnic fuse."

[0030] The second circuit 2 is connected in parallel with the first circuit 1. The second circuit 2 constitutes a precharge circuit for charging (precharge) the capacitor C1 of the inverter 92 when the electric device is started.

[0031] The second circuit 2 includes a second relay 21. The second relay 21 is a precharge relay. The second relay 21 is, for example, a mechanical relay or a semiconductor relay.

[0032] The second circuit 2 further includes a resistor 22 connected in series with the second relay 21. In the second circuit 2, a first end of the resistor 22 is connected to a first end of the first relay 11 of the first circuit 1, a second end of the resistor 22 is connected to a first end of the second relay 21, and a second end of the second relay 21 is connected to a second end of the fuse 9 of the first circuit 1.

[0033] The current value of the current flowing through the second circuit 2 is smaller than the current value of the current flowing through the first circuit 1. The current carrying capacity of the second relay 21 is smaller than the current carrying capacity of the first relay 11. Although not particularly limited, the current carrying capacity of the second relay 21 may be, for example, about 20 A.

[0034] The third circuit 3 is connected between the negative electrode of the power supply 91 and a DC terminal 922 on the low potential side of the inverter 92. In other words, the third circuit 3 is connected in series with the first circuit 1. The third circuit 3 constitutes part of a main circuit (a second main circuit on the low potential side) for supplying power from the power supply 91 to the inverter 92.

[0035] The third circuit 3 has a third relay 31. The third relay 31 is, for example, a mechanical relay. The third relay 31 is a second main relay arranged on the low-potential side electrical path. Although not particularly limited, the current carrying capacity of the third relay 31 may be, for example, approximately 250 A to 500 A.

[0036] (1.3) Control Unit The control unit 5 is mainly composed of a computer system having one or more processors and one or more memories. That is, the functions of the control unit 5 are realized by the one or more processors executing programs recorded in one or more memories of the computer system. The programs may be pre-recorded in the memory, provided via a telecommunications line such as the Internet, or provided by being recorded on a non-transitory recording medium such as a memory card.

[0037] The control unit 5 is, for example, an ECU (Electronic Control Unit) of an electric vehicle as an electrical device. The control unit 5 preferably operates by receiving a power supply from a power source independent of the power source 91.

[0038] The control unit 5 controls the operation of the interrupter circuit 10 .

[0039] The control unit 5 controls the on / off of the first relay 11, the second relay 21, and the third relay 31. The control unit 5 switches each relay on / off based on, for example, an instruction signal from a switch provided in the electrical device and a detected voltage received from a voltmeter that detects the voltage V1 across the capacitor C1 of the inverter 92. For example, if a switch is provided in the current path from a low-voltage power supply (for example, a power supply such as a storage battery independent of the power supply 91) to the coil of the mechanical relay, the control unit 5 may switch the mechanical relay on / off by controlling the on / off of this switch.

[0040] If the fuse 9 is a pyroelectric fuse, the control unit 5 further controls the operation of the fuse 9. As shown in FIG. 1 , the power supply system 100 further includes a current sensor 94 that detects the current I1 flowing through the interrupter circuit 10. The current sensor 94 includes, for example, a shunt resistor. The control unit 5 receives the detection result from the current sensor 94. For example, when the current value of the current I1 flowing through the interrupter circuit 10 exceeds a predetermined threshold, the control unit 5 determines that an abnormality has occurred in the electrical equipment and activates the fuse 9 (pyroelectric fuse). The control unit 5 also manages a flag indicating whether the fuse 9 has been activated. The flag is stored, for example, in the memory of a computer system that constitutes the control unit 5. If the fuse 9 is not activated, the flag is off. If the fuse 9 has been activated, the flag is on. If the fuse 9 is a pyroelectric fuse, the control unit 5 switches the flag from off to on when activating the fuse 9. If the fuse 9 is an actively operating fuse (e.g., a blown fuse), the control unit 5 switches the flag from off to on when it determines that the fuse 9 has operated based on the current I1 detected by the current sensor 94 or the voltage V1 across the capacitor C1.

[0041] The control unit 5 further controls the operation of the inverter 92. That is, the control unit 5 controls the operation (ON / OFF) of the switching elements Q1 to Q6 of the inverter 92.

[0042] (1.4) Operation of the Power Supply System The operation of the power supply system 100 of this embodiment will be described below. Note that the flowcharts in Figures 2 to 4 are examples, and the order of processing may be added or changed as appropriate.

[0043] (1.4.1) Normal Operation First, the operation of the power supply system 100 during normal operation when the fuse 9 is not activated (when the flag is off) will be described with reference to FIGS. 2 and 3. FIG.

[0044] Before the electric device is started, the first relay 11 to the third relay 31 are all in the OFF state. When the electric device is started (for example, when the ignition switch is turned on), the control unit 5 first switches the third relay 31 (second main relay) from OFF to ON (step ST1), and then switches the second relay 21 (pre-charge relay) from OFF to ON (step ST2). As a result, the capacitor C1 is charged (pre-charged) via the second circuit 2 and the third circuit 3 (pre-charge circuit and second main circuit).

[0045] The control unit 5 determines whether the voltage V1 across the capacitor C1 exceeds a predetermined threshold voltage Vth within a predetermined threshold time Tth after the second relay 21 (precharge relay) is switched on (steps ST3 and ST4).

[0046] If the voltage V1 across the terminals exceeds the threshold voltage Vth (ST3: Yes) before the threshold time Tth is exceeded (ST4: No), the control unit 5 determines that precharging is completed and switches the first relay 11 (first main relay) from off to on (step ST5), and then switches the second relay 21 (precharge relay) from on to off (step ST6). This enables power to be supplied from the power source 91 to the inverter 92 via the first circuit 1 and the third circuit 3 (first main circuit and second main circuit).

[0047] On the other hand, if the voltage V1 across the capacitor C1 does not exceed the threshold voltage Vth (ST3: No) and the threshold time Tth has elapsed (ST4: Yes) during startup, the control unit 5 determines that there is an abnormality in the power supply system 100. Then, the control unit 5 switches the second relay 21 (pre-charge relay) from on to off (step ST7) and switches the third relay 31 (second main relay) from on to off (step ST8) to stop operation. The control unit 5 may notify the occurrence of the abnormality using a speaker, a display, or the like provided in the electrical device.

[0048] After step ST6, if the current I1 flowing through the interruption circuit 10 is equal to or less than the threshold current Ith (ST9: No), the first relay 11 (first main relay) and the third relay 31 (second main relay) are maintained in the on state, and the supply of power from the power source 91 to the inverter 92 continues.

[0049] On the other hand, when the current I1 exceeds the threshold current Ith (ST9: Yes), the fuse 9 operates (step ST11). For example, if the fuse 9 is an active fuse such as a blown fuse, the fuse 9 operates (shuts off) by itself, or if the fuse 9 is a pyroelectric fuse, the fuse 9 operates (shuts off) under control of the control unit 5. This cuts off the power supply from the power supply 91 to the inverter 92. Furthermore, when the fuse 9 operates, the control unit 5 switches the third relay 31 (second main relay) from on to off (step ST12) and switches the first relay 11 (first main relay) from on to off (step ST13). Furthermore, the control unit 5 switches the flag from off to on. Furthermore, the control unit 5 notifies the occurrence of the abnormality using a speaker, display, or the like provided in the electrical device and terminates operation.

[0050] (1.4.2) At Restart Next, the operation of the power supply system 100 at restart (when the flag is on) after the fuse 9 has been operated will be described with reference to FIG.

[0051] Before restarting the electric device, the first relay 11 to the third relay 31 are all in the OFF state. When restarting the electric device (for example, when the ignition switch is turned on), the control unit 5 first checks whether there is any problem in supplying power from the power supply system 100 (step ST21). Examples of checks include checking that there are no breaks in the power supply system 100 other than the fuse 9, and checking that the relays and switching elements are operating normally.

[0052] If there is a problem (ST21: No), the control unit 5 notifies the user using a speaker, a display, or the like provided in the electrical device (step ST22), and ends the operation.

[0053] If it is confirmed that there is no problem (ST21: Yes), the control unit 5 switches the third relay 31 (second main relay) from OFF to ON (step ST23), and then switches the second relay 21 (pre-charge relay) from OFF to ON (step ST24). As a result, the capacitor C1 is charged (pre-charged) via the second circuit 2 and the third circuit 3 (pre-charge circuit and second main circuit).

[0054] The control unit 5 determines whether the voltage V1 across the capacitor C1 exceeds a predetermined threshold voltage Vth within a predetermined threshold time Tth after the second relay 21 (precharge relay) is switched on (steps ST25 and ST26).

[0055] If the voltage V1 across the terminals exceeds the threshold voltage Vth (ST25: Yes) before the threshold time Tth is exceeded (ST26: No), the control unit 5 determines that precharging is complete. In this case, the control unit 5 maintains the second relay 21 (precharge relay) and the third relay 31 (second main relay) in the on state. This enables power to be supplied from the power source 91 to the inverter 92 via the second circuit 2 and the third circuit 3 (precharge circuit and second main circuit).

[0056] On the other hand, during restart, if the voltage V1 across the capacitor C1 does not exceed the threshold voltage Vth (ST25: No) and the threshold time Tth has elapsed (ST26: Yes), the control unit 5 determines that there is an abnormality in the power supply system 100. Then, the control unit 5 switches the second relay 21 (pre-charge relay) from on to off (step ST27) and switches the third relay 31 (second main relay) from on to off (step ST28) to stop operation. The control unit 5 may notify the occurrence of the abnormality using a speaker, a display, or the like provided in the electrical device.

[0057] (1.5) Brief Summary As described above, in the power supply system 100 of this embodiment, the second relay 21 (pre-charge relay) of the second circuit 2, which is connected in parallel with the first circuit 1 having the fuse 9, is switched from off to on (ST24) after the fuse 9 operates (ST11). This makes it possible to supply power via the interrupter circuit 10 (pre-charge circuit) even after the fuse 9 operates, improving the convenience of electrical equipment equipped with the power supply system 100.

[0058] In this disclosure, "the fuse 9 operates" means that the fuse 9 cuts off the electrical connection between both ends thereof, thereby cutting off the electrical path of the first circuit 1.

[0059] Furthermore, in the power supply system 100 of this embodiment, the second relay 21 (pre-charge relay) is switched from off to on (ST2) before the first relay 11 (first main relay) is switched from off to on (ST5), and is switched from on to off (ST6) after the first relay 11 is turned on (ST5) and before the fuse 9 operates (ST11). In this way, by first bringing the second circuit 2 into conduction and then bringing the first circuit 1 into conduction, it is possible to reduce the possibility of an inrush current flowing through the fuse 9.

[0060] Furthermore, in the power supply system 100 of this embodiment, the current value of the current flowing through the second circuit 2 is smaller than the current value of the current flowing through the first circuit 1. Furthermore, the current carrying capacity of the second relay 21 is larger than the current carrying capacity of the first relay 11. In other words, a precharge relay mounted on an electrical device can be used as the second relay 21.

[0061] (2) Embodiment 2 A description will be given of a motor system 200A according to embodiment 2. In motor system 200A according to embodiment 2, the same components as those in motor system 200 according to embodiment 1 will be denoted by the same reference numerals and descriptions thereof will be omitted where appropriate.

[0062] 5, a motor system 200A of the present embodiment includes a power supply system 100A and a motor 93. The power supply system 100A includes an interruption system 20A instead of the interruption system 20 of the first embodiment. The interruption system 20A includes an interruption circuit 10A and a control unit 5A.

[0063] (2.1) Interrupting Circuit As shown in FIG. 5, the interrupting circuit 10A includes a first circuit 1A, a second circuit 2A, a third circuit 3A, and a fourth circuit 4A.

[0064] The first circuit 1A is connected between the negative electrode of the power supply 91 and a DC terminal 922 on the low potential side of the inverter 92. The first circuit 1A constitutes part of a main circuit (a second main circuit on the low potential side) for supplying power from the power supply 91 to the inverter 92.

[0065] The first circuit 1A has a first relay 11 and a fuse 9. The first relay 11 of the first circuit 1A is a second main relay arranged on the electric path on the low potential side.

[0066] In the first circuit 1A, a first end of the first relay 11 is connected to a DC terminal 922 on the low potential side of the inverter 92, a second end of the first relay 11 is connected to a first end of the fuse 9, and a second end of the fuse 9 is connected to the negative electrode of the power source 91. In the first circuit 1A, the fuse 9 is arranged downstream of the first relay 11 in the electrical path.

[0067] The second circuit 2A is connected in parallel to the first circuit 1A and is an auxiliary circuit for enabling power supply after the fuse 9 operates.

[0068] The second circuit 2A includes a second relay 21A. The second circuit 2A does not include a resistor. In the second circuit 2A, a first terminal of the second relay 21A is connected to a first terminal of the first relay 11 of the first circuit 1A, and a second terminal of the second relay 21A is connected to a second terminal of the fuse 9 of the first circuit 1A.

[0069] The second relay 21A of the second circuit 2A is an auxiliary relay. The second relay 21A is, for example, a mechanical relay. The current carrying capacity of the second relay 21A is, for example, the same as the current carrying capacity of the first relay 11. In the present disclosure, "the current carrying capacity of the two relays is the same" does not necessarily mean that the current carrying capacities are exactly the same, but may mean that the current carrying capacity of one relay is within a range of 90 to 110% of the current carrying capacity of the other relay. Although not particularly limited, the current carrying capacity of the second relay 21A may be, for example, approximately 250 A to 500 A.

[0070] Furthermore, the current value of the current flowing through the second circuit 2A is the same as the current value of the current flowing through the first circuit 1A. In the present disclosure, "the current values ​​of the currents flowing through the two circuits are the same" does not necessarily mean that the current values ​​are exactly the same, but may mean that the current value of the current flowing through one circuit is within a range of 90 to 110% of the current value of the current flowing through the other circuit.

[0071] The third circuit 3A is connected between the positive electrode of the power supply 91 and a high-potential side DC terminal 921 of the inverter 92. In other words, the third circuit 3A is connected in series with the first circuit 1A. The third circuit 3A constitutes part of a main circuit (high-potential side first main circuit) for supplying power from the power supply 91 to the inverter 92.

[0072] The third circuit 3A includes a third relay 31. The third relay 31 is a first main relay disposed on the high-potential side of the electrical circuit. In the third circuit 3A, a first terminal of the third relay 31 is connected to the positive electrode of the power source 91, and a second terminal of the third relay 31 is connected to a high-potential side DC terminal 921 of the inverter 92.

[0073] The fourth circuit 4A is connected in parallel with the third circuit 3A and constitutes a precharge circuit for charging (precharge) the capacitor C1 of the inverter 92 when the electric appliance is started.

[0074] The fourth circuit 4A includes a fourth relay 41 and a resistor 42 connected in series with the fourth relay 41. The fourth relay 41 is a precharge relay. The fourth relay 41 is, for example, a mechanical relay or a semiconductor relay. In the fourth circuit 4A, a first end of the resistor 42 is connected to a first end of the third relay 31 of the third circuit 3A, a second end of the resistor 42 is connected to a first end of the fourth relay 41, and a second end of the fourth relay 41 is connected to a second end of the third relay 31 of the third circuit 3A.

[0075] The current value of the current flowing through the fourth circuit 4A is smaller than the current value of the current flowing through the third circuit 3A. The current carrying capacity of the fourth relay 41 is smaller than the current carrying capacity of the third relay 31. Although not particularly limited, the current carrying capacity of the fourth relay 41 may be, for example, about 20 A.

[0076] (2.2) Control Unit The control unit 5A controls the operation of the interrupter circuit 10A. The control unit 5A controls the on / off of the first relay 11, the on / off of the second relay 21A, the on / off of the third relay 31, and the on / off of the fourth relay 41.

[0077] Furthermore, if the fuse 9 is a pyro fuse, the control unit 5A further controls the operation of the fuse 9. The control unit 5A also manages a flag indicating whether the fuse 9 has been operated.

[0078] The control unit 5A further controls the operation of the inverter 92.

[0079] (2.3) Operation of the Power Supply System The operation of the power supply system 100A of this embodiment will be described below. Note that the flowcharts in Figures 6 to 8 are examples, and the order of processing may be added or changed as appropriate.

[0080] (2.3.1) Normal Operation First, the operation of the power supply system 100A in normal operation (when the flag is off) when the fuse 9 is not activated will be described with reference to FIGS. 6 and 7. FIG.

[0081] Before the electric appliance is started, the first relay 11 to the fourth relay 41 are all in the OFF state. When the electric appliance is started, the control unit 5A first switches the first relay 11 (second main relay) from OFF to ON (step ST31), and then switches the fourth relay 41 (pre-charge relay) from OFF to ON (step ST32). As a result, the capacitor C1 is charged (pre-charged) via the fourth circuit 4A and the first circuit 1A (pre-charge circuit and second main circuit).

[0082] The control unit 5A also determines whether the voltage V1 across the capacitor C1 exceeds the threshold voltage Vth within the threshold time Tth after the fourth relay 41 (precharge relay) is switched on (steps ST33 and ST34).

[0083] If the voltage V1 across the terminals exceeds the threshold voltage Vth (ST33: Yes) before the threshold time Tth is exceeded (ST34: No), the control unit 5A determines that precharging is completed, switches the third relay 31 (first main relay) from off to on (step ST35), and then switches the fourth relay 41 (precharge relay) from on to off (step ST36). This enables power to be supplied from the power source 91 to the inverter 92 via the third circuit 3A and the first circuit 1A (first main circuit and second main circuit).

[0084] On the other hand, if the voltage V1 across the capacitor C1 does not exceed the threshold voltage Vth (ST33: No) and the threshold time Tth has elapsed (ST34: Yes) during startup, the control unit 5A determines that an abnormality has occurred in the power supply system 100A. Then, the control unit 5A switches the fourth relay 41 (precharge relay) from on to off (step ST37) and switches the first relay 11 (second main relay) from on to off (step ST38) to stop operation. The control unit 5A may notify the occurrence of the abnormality using a speaker, a display, or the like provided in the electrical device.

[0085] After step ST36, if the current I1 flowing through the interruption circuit 10A is equal to or less than the threshold current Ith (ST39: No), the third relay 31 (first main relay) and the first relay 11 (second main relay) are maintained in the on state, and power supply from the power source 91 to the inverter 92 continues.

[0086] On the other hand, when the current I1 exceeds the threshold current Ith (ST39: Yes), the fuse 9 operates (step ST41). This cuts off the power supply from the power supply 91 to the inverter 92. When the fuse 9 operates, the control unit 5A switches the first relay 11 (second main relay) from on to off (step ST42) and switches the third relay 31 (first main relay) from on to off (step ST43). The control unit 5A also switches the flag from off to on. The control unit 5A also notifies the occurrence of an abnormality using a speaker, a display, or the like provided in the electrical device and terminates operation.

[0087] (2.3.2) At Restart Next, the operation of the power supply system 100A at restart (when the flag is on) after the fuse 9 has been operated will be described with reference to FIG.

[0088] Before the restart of the electric appliance, the first relay 11 to the fourth relay 41 are all in the OFF state. When the electric appliance is restarted, the control unit 5A first checks whether there is any problem in supplying power from the power supply system 100A (step ST51).

[0089] If there is a problem (ST51: No), the control unit 5A notifies the user using a speaker, a display, or the like provided in the electrical device (step ST52), and ends the operation.

[0090] If it is confirmed that there is no problem (ST51: Yes), the control unit 5A switches the second relay 21A (auxiliary relay) from off to on (step ST53), and then switches the fourth relay 41 (precharge relay) from off to on (step ST54). As a result, the capacitor C1 is charged (precharged) via the fourth circuit 4A and the second circuit 2A (precharge circuit and auxiliary circuit).

[0091] The control unit 5A determines whether the voltage V1 across the capacitor C1 exceeds a predetermined threshold voltage Vth within a predetermined threshold time Tth after the fourth relay 41 (precharge relay) is switched on (steps ST55 and ST56).

[0092] If the voltage V1 across the terminals exceeds the threshold voltage Vth (ST55: Yes) before the threshold time Tth is exceeded (ST56: No), the control unit 5A determines that precharging is complete and switches the third relay 31 (first main relay) from off to on (step ST57), and then switches the fourth relay 41 (precharge relay) from on to off (step ST58). This enables power to be supplied from the power source 91 to the inverter 92 via the third circuit 3A and the second circuit 2A (first main circuit and auxiliary circuit).

[0093] On the other hand, during restart, if the voltage V1 across capacitor C1 does not exceed the threshold voltage Vth (ST55: No) and the threshold time Tth has elapsed (ST56: Yes), the control unit 5A determines that an abnormality has occurred in the power supply system 100A. Then, the control unit 5A switches the fourth relay 41 (precharge relay) from on to off (step ST59) and switches the second relay 21 (auxiliary relay) from on to off (step ST60) to stop operation. The control unit 5 may notify the occurrence of the abnormality using a speaker, display, or the like provided in the electrical device.

[0094] (2.4) Summary As described above, in the power supply system 100A of this embodiment, the second relay 21A (auxiliary relay) of the second circuit 2A, which is connected in parallel with the first circuit 1A having the fuse 9, is switched from OFF to ON (ST53) after the fuse 9 operates (ST41). This makes it possible to supply power via the interrupter circuit 10A (auxiliary circuit) even after the fuse 9 operates, improving the convenience of electrical equipment equipped with the power supply system 100A.

[0095] Furthermore, in the power supply system 100A of the present embodiment, the second relay 21A (auxiliary relay) is in the off state before the first relay 11 is switched from off to on (ST31), and is maintained in the off state from the time the first relay 11 is turned on (ST31) until the fuse 9 operates (ST41). In other words, the second relay 21A (auxiliary relay) is turned on only after the fuse 9 operates. This makes it possible to design the power supply path including the second circuit 2A (auxiliary circuit) for use when the fuse 9 operates independently from the normal power supply path including the first circuit 1A (second main circuit), improving the degree of freedom in design.

[0096] Furthermore, in the power supply system 100A of this embodiment, since the second circuit 2A does not have a resistor, it is possible to supply power with a current of the same value as before the fuse 9 operates, even after the fuse 9 operates.

[0097] (3) Third Embodiment A motor system 200B according to a third embodiment will be described. In the motor system 200B according to the third embodiment, the same components as those in the motor system 200 according to the first embodiment will be denoted by the same reference numerals and will not be described again.

[0098] 9, a motor system 200B of the present embodiment includes a power supply system 100B and a motor 93. The power supply system 100B includes an interruption system 20B instead of the interruption system 20 of the first embodiment. The interruption system 20B includes an interruption circuit 10B and a control unit 5B.

[0099] (3.1) Interrupting Circuit As shown in FIG. 9, an interrupting circuit 10B includes a first circuit 1B, a second circuit 2B, a third circuit 3B, and a fourth circuit 4B.

[0100] The first circuit 1B is connected (via the fourth circuit 4B) between the positive electrode of the power supply 91 and a high-potential side DC terminal 921 of the inverter 92. The first circuit 1B constitutes part of a main circuit (high-potential side first main circuit) for supplying power from the power supply 91 to the inverter 92.

[0101] The first circuit 1B has a first relay 11. The first relay 11 of the first circuit 1B is a first main relay arranged on the electric path on the high potential side.

[0102] The second circuit 2B is connected in parallel with the first circuit 1B and constitutes a precharge circuit for charging (precharge) the capacitor C1 of the inverter 92 when the electric device is started.

[0103] The second circuit 2B has a second relay 21 and a resistor 22 connected in series with the second relay 21. The second relay 21 is a precharge relay.

[0104] In the second circuit 2B, a first end of the resistor 22 is connected to a first end of the first relay 11 in the first circuit 1B, a second end of the resistor 22 is connected to a first end of the second relay 21, and a second end of the second relay 21 is connected to a second end of the first relay 11 in the first circuit 1B. The current value of the current flowing through the second circuit 2B is smaller than the current value of the current flowing through the first circuit 1B.

[0105] The third circuit 3B is connected between the negative electrode of the power supply 91 and a DC terminal 922 on the low potential side of the inverter 92. In other words, the third circuit 3B is connected in series with the first circuit 1B. The third circuit 3B constitutes part of a main circuit (a second main circuit on the low potential side) for supplying power from the power supply 91 to the inverter 92.

[0106] The third circuit 3B has a third relay 31. The third relay 31 of the third circuit 3B is a second main relay arranged on the electric path on the low potential side.

[0107] In the third circuit 3B, a first terminal of the third relay 31 is connected to the negative electrode of the power source 91, and a second terminal of the third relay 31 is connected to a DC terminal 922 on the low potential side of the inverter 92.

[0108] The fourth circuit 4B is connected in series with the first circuit 1B. The fourth circuit 4B is an auxiliary circuit that enables power supply after the fuse 9 operates. The fourth circuit 4B is connected in series with the first circuit 1B and the third circuit 3B.

[0109] The fourth circuit 4B has a fuse 9 and a fourth relay 41B connected in parallel with the fuse 9. The fourth relay 41B of the fourth circuit 4B is an auxiliary relay. The fourth relay 41B is, for example, a mechanical relay. The current carrying capacity of the fourth relay 41B is, for example, the same as the current carrying capacity of the first relay 11. In the fourth circuit 4B, a first terminal of the fourth relay 41B is connected to a first terminal of the fuse 9, and a second terminal of the fourth relay 41B is connected to a second terminal of the fuse 9.

[0110] A series circuit of the fourth circuit 4B and the first circuit 1B is connected between the positive electrode of the power supply 91 and a high-potential-side DC terminal 921 of the inverter 92. The fourth circuit 4B is disposed upstream of the first circuit 1B in the electrical path. Specifically, a first terminal of the fuse 9 of the fourth circuit 4B (a first terminal of the fourth relay 41B) is connected to the positive electrode of the power supply 91, a second terminal of the fuse 9 of the fourth circuit 4B (a second terminal of the fourth relay 41B) is connected to a first terminal of the first relay 11 of the first circuit 1B, and a second terminal of the first relay 11 of the first circuit 1B is connected to the high-potential-side DC terminal 921 of the inverter 92.

[0111] (3.2) Control Unit The control unit 5B controls the operation of the interrupter circuit 10B. The control unit 5B controls the on / off of the first relay 11, the on / off of the second relay 21, the on / off of the third relay 31, and the on / off of the fourth relay 41B.

[0112] Furthermore, if the fuse 9 is a pyro fuse, the control unit 5B further controls the operation of the fuse 9. The control unit 5B also manages a flag indicating whether or not the fuse 9 has been operated.

[0113] The control unit 5B further controls the operation of the inverter 92.

[0114] (3.3) Operation of the Power Supply System The operation of the power supply system 100B of this embodiment will be described below. Note that the flowcharts in Figures 10 to 12 are examples, and the order of processing may be added or changed as appropriate.

[0115] (3.3.1) Normal Operation First, the operation of the power supply system 100B in normal operation (when the flag is off) when the fuse 9 is not activated will be described with reference to FIGS. 10 and 11. FIG.

[0116] Before the electric appliance is started, the first relay 11 to the fourth relay 41B are all in the OFF state. When the electric appliance is started, the control unit 5B first switches the third relay 31 (second main relay) from OFF to ON (step ST71), and then switches the second relay 21 (pre-charge relay) from OFF to ON (step ST72). This causes the capacitor C1 to be charged (pre-charged) via the second circuit 2B and the third circuit 3B (pre-charge circuit and second main circuit).

[0117] In addition, the control unit 5B determines whether the voltage V1 across the capacitor C1 exceeds a predetermined threshold voltage Vth within a predetermined threshold time Tth after the second relay 21 (precharge relay) is switched on (steps ST73 and ST74).

[0118] If the voltage V1 across the terminals exceeds the threshold voltage Vth (ST73: Yes) before the threshold time Tth is exceeded (ST74: No), the control unit 5B determines that precharging is complete and switches the first relay 11 (first main relay) from off to on (step ST75), and then switches the second relay 21 (precharge relay) from on to off (step ST76). This enables power to be supplied from the power source 91 to the inverter 92 via the first circuit 1B and the third circuit 3B (the first main circuit and the second main circuit).

[0119] On the other hand, if the voltage V1 across capacitor C1 does not exceed the threshold voltage Vth (ST73: No) and the threshold time Tth has elapsed (ST74: Yes) during startup, the control unit 5B determines that an abnormality has occurred in the power supply system 100B. Then, the control unit 5B switches the second relay 21 (pre-charge relay) from on to off (step ST77) and switches the third relay 31 (second main relay) from on to off (step ST78) to stop operation. The control unit 5B may notify the occurrence of the abnormality using a speaker, a display, or the like provided in the electrical device.

[0120] After step ST76, if the current I1 flowing through the interruption circuit 10B is equal to or less than the threshold current Ith (ST79: No), the first relay 11 (first main relay) and the third relay 31 (second main relay) are maintained in the on state, and the supply of power from the power source 91 to the inverter 92 continues.

[0121] On the other hand, when the current I1 exceeds the threshold current Ith (ST79: Yes), the fuse 9 operates (step ST81). This cuts off the power supply from the power supply 91 to the inverter 92. When the fuse 9 operates, the control unit 5B switches the third relay 31 (second main relay) from on to off (step ST82) and switches the first relay 11 (first main relay) from on to off (step ST83). The control unit 5B also switches the flag from off to on. The control unit 5B also notifies the occurrence of an abnormality using a speaker, a display, or the like provided in the electrical device and terminates operation.

[0122] (3.3.2) At Restart Next, the operation of the power supply system 100B at restart (when the flag is on) after the fuse 9 has been operated will be described with reference to FIG.

[0123] Before the restart of the electric appliance, the first relay 11 to the fourth relay 41B are all in the OFF state. When the electric appliance is restarted, the control unit 5B first checks whether there is any problem in supplying power from the power supply system 100B (step ST91).

[0124] If there is a problem (ST91: No), the control unit 5B notifies the user using a speaker, a display, or the like provided in the electrical device (step ST92), and ends the operation.

[0125] If it is confirmed that there is no problem (ST91: Yes), the control unit 5B first switches the fourth relay 41B (auxiliary relay) from off to on (step ST93), then switches the third relay 31 (second main relay) from off to on (step ST94), and then switches the second relay 21 (pre-charge relay) from off to on (step ST95). As a result, the capacitor C1 is charged (pre-charged) via the second circuit 2B and the third circuit 3B (pre-charge circuit and second main circuit) and the fourth relay 41B.

[0126] The control unit 5B determines whether the voltage V1 across the capacitor C1 exceeds a predetermined threshold voltage Vth within a predetermined threshold time Tth after the second relay 21 (precharge relay) is switched on (steps ST96 and ST97).

[0127] If the voltage V1 across the power supply 91 exceeds the threshold voltage Vth (ST96: Yes) before the threshold time Tth is exceeded (ST97: No), the control unit 5B determines that precharging is complete and switches the first relay 11 (first main relay) from off to on (step ST98), and then switches the second relay 21 (precharge relay) from on to off (step ST99). This enables power to be supplied from the power supply 91 to the inverter 92 via the first circuit 1B and the third circuit 3B (the first main circuit and the second main circuit), and the fourth relay 41B.

[0128] On the other hand, during restart, if the voltage V1 across capacitor C1 does not exceed the threshold voltage Vth (ST96: No) and the threshold time Tth has elapsed (ST97: Yes), the control unit 5B determines that an abnormality has occurred in the power supply system 100B. Then, the control unit 5B switches the second relay 21 (pre-charge relay) from on to off (step ST100), switches the third relay 31 (second main relay) from on to off (step ST101), and switches the fourth relay 41B (auxiliary relay) from on to off (step ST102), thereby stopping operation. The control unit 5B may notify the occurrence of the abnormality using a speaker, a display, or the like provided in the electrical device.

[0129] (3.4) Summary As described above, in the power supply system 100B of this embodiment, the fourth relay 41B connected in parallel with the fuse 9 is switched from OFF to ON (ST93) after the fuse 9 has operated (ST81). This makes it possible to supply power via the interrupter circuit 10B (auxiliary circuit) even after the fuse 9 has operated, improving the convenience of electrical equipment equipped with the power supply system 100B.

[0130] Furthermore, in the power supply system 100B of this embodiment, the fourth relay 41B (auxiliary relay) is maintained in the off state until the fuse 9 operates (ST81). That is, the fourth relay 41B is turned on only after the fuse 9 operates. This makes it possible to independently design the fourth circuit 4B (auxiliary circuit) for use when the fuse 9 operates, improving the degree of freedom in designing the interrupter circuit 10B.

[0131] (4) Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the embodiment are listed below. The above embodiment and the modifications described below can be applied in appropriate combinations.

[0132] In one variation, the electrical equipment is not limited to a vehicle, but may be any electrical equipment that operates on DC power.

[0133] In one modified example, the control units 5, 5A, 5B are not limited to ECUs, but may be, for example, processors independent of the ECUs.

[0134] In one modification, the operation of the inverter 92 may be controlled by a processor separate from the control units 5, 5A, and 5B.

[0135] In one modified example, the first circuit 1 of the first embodiment may be connected between the negative electrode of the power supply 91 and the low-potential side DC terminal 922 of the inverter 92. In this case, the third circuit 3 is connected between the positive electrode of the power supply 91 and the high-potential side DC terminal 921 of the inverter 92.

[0136] In one modified example, the first circuit 1A of the second embodiment may be connected between the positive electrode of the power supply 91 and a high-potential side DC terminal 921 of the inverter 92. In this case, the third circuit 3A is connected between the negative electrode of the power supply 91 and a low-potential side DC terminal 922 of the inverter 92.

[0137] In one modified example, the fourth circuit 4B of the third embodiment may be connected between the negative electrode of the power supply 91 and the low-potential-side DC terminal 922 of the inverter 92. In other words, a series circuit of the fourth circuit 4B and the third circuit 3B may be connected between the negative electrode of the power supply 91 and the low-potential-side DC terminal 922 of the inverter 92.

[0138] (5) Aspects As can be seen from the above-described embodiments and modifications, the present specification discloses the following aspects.

[0139] The first embodiment of the interruption circuit (10, 10A) includes a first circuit (1, 1A) and a second circuit (2, 2A). The first circuit (1, 1A) includes a first relay (11) and a fuse (9) connected in series with the first relay (11). The second circuit (2, 2A) includes a second relay (21, 21A). The second circuit (2, 2A) is connected in parallel with the first circuit (1, 1A). After the fuse (9) interrupts the electrical path of the first circuit (1, 1A), the second relay (21, 21A) is switched from off to on.

[0140] According to this aspect, after the fuse (9) interrupts the electrical path of the first circuit (1, 1A), the second relay (21, 21A) of the second circuit (2, 2A) connected in parallel with the first circuit (1, 1A) having the fuse (9) is switched from OFF to ON. This makes it possible to supply power via the second circuit (2, 2A) of the interrupting circuit (10, 10A) even after the fuse (9) interrupts the electrical path of the first circuit (1, 1A), improving convenience.

[0141] In the interruption circuit (10) of the second aspect, in the first aspect, the second relay (21) is switched from off to on before the fuse (9) interrupts the electrical path and before the first relay (11) is switched from off to on. After the second relay (21) is switched from off to on, the first relay (11) is switched from off to on, and after the first relay (11) is switched from off to on, the second relay (21) is switched from on to off before the fuse (9) interrupts the electrical path of the first circuit (1, 1A).

[0142] According to this aspect, by first making the second circuit (2) conductive and then making the first circuit (1) conductive, it is possible to reduce the possibility of an inrush current flowing through the fuse (9).

[0143] In the interrupter circuit (10) of the third aspect, the current value of the current flowing through the second circuit (2) is smaller than the current value of the current flowing through the first circuit (1) in the second aspect.

[0144] According to this aspect, it is possible to use a precharge relay mounted on the electrical device as the second relay (21), and the interrupter circuit (10) can be realized without increasing the number of parts.

[0145] In the interrupter circuit (10) of the fourth aspect, in the second or third aspect, the current carrying capacity of the second relay (21) is greater than the current carrying capacity of the first relay (11).

[0146] According to this aspect, it is possible to use a precharge relay mounted on the electrical device as the second relay (21), and the interrupter circuit (10) can be realized without increasing the number of parts.

[0147] In the fifth aspect of the interruption circuit (10A), in the first aspect, before the fuse (9) interrupts the electrical path of the first circuit (1A) and before the first relay (11) is switched from off to on, the second relay (21A) is in the off state. The second relay (21A) is maintained in the off state from the time the first relay (11) is turned on until the fuse (9) interrupts the electrical path of the first circuit (1A).

[0148] According to this aspect, the second relay (21A) is maintained in the off state until the fuse (9) cuts off the electrical path of the first circuit (1A). Therefore, it becomes possible to design the power supply path including the second circuit (2A) for use when the fuse (9) is operating independently from the normal power supply path including the first circuit (1A), thereby improving the degree of freedom in design.

[0149] The interrupter circuit (10A) of the sixth aspect is the fifth aspect, further including a third circuit (3A) and a fourth circuit (4A). The third circuit (3A) has a third relay (31). The third circuit (3A) is connected in series with the first circuit (1A). The fourth circuit (4A) has a fourth relay (41) and a resistor (42) connected in series with the fourth relay (41). The fourth circuit (4A) is connected in parallel with the third circuit (3A). Before the third relay (31) is switched from off to on, the fourth relay (41) is switched from off to on. After the third relay (31) is turned on, the fourth relay (41) is switched from on to off before the fuse (9) interrupts the electrical path of the first circuit (1, 1A).

[0150] According to this aspect, it is possible to provide a first circuit (1) having a fuse (9) separately from a fourth circuit (4A) having a fourth relay (41) that functions as a precharge relay, thereby improving the degree of freedom in design.

[0151] In the seventh aspect of the interrupter circuit (10A), in the fifth or sixth aspect, the current value of the current flowing through the second circuit (2A) is the same as the current value of the current flowing through the first circuit (1A).

[0152] According to this aspect, even after the fuse (9) has interrupted the electrical path of the first circuit (1A), it is possible to supply a current equivalent to that before the fuse (9) interrupted the electrical path of the first circuit (1A), thereby improving convenience.

[0153] In the interrupter circuit (10A) of the eighth aspect, in any one of the fifth to seventh aspects, the current carrying capacity of the second relay (21A) is the same as the current carrying capacity of the first relay (11).

[0154] According to this aspect, even after the fuse (9) has cut off the electrical path of the first circuit (1A), it is possible to supply the same current as before the fuse (9) operated, thereby improving convenience.

[0155] A ninth aspect of the interruption system (20, 20A) includes the interruption circuit (10, 10A) of any one of the first to eighth aspects and a control unit (5, 5A). The control unit (5, 5A) controls the operation of the fuse (9) and the second relay (21, 21A). After the fuse (9) interrupts the electrical path of the first circuit (1, 1A), the control unit (5, 5A) switches the second relay (21, 21A) from off to on.

[0156] According to this aspect, it is possible to improve convenience.

[0157] A power supply system (100) of a tenth aspect includes the interrupter circuit (10) of any one of the first to eighth aspects, a power supply (91), and an inverter (92). The first circuit (1) is connected between the positive electrode of the power supply (91) and a high-potential side DC terminal (921) of the inverter (92).

[0158] According to this aspect, it is possible to improve convenience.

[0159] A power supply system (100A) of an eleventh aspect includes the interrupter circuit (10A) of any one of the first to eighth aspects, a power supply (91), and an inverter (92). The first circuit (1A) is connected between the negative electrode of the power supply (91) and a DC terminal (922) on the low potential side of the inverter (92).

[0160] According to this aspect, it is possible to improve convenience.

[0161] The interrupter circuit (10B) of the twelfth aspect includes a first circuit (1B), a second circuit (2B), a third circuit (3B), and a fourth circuit (4B). The first circuit (1B) includes a first relay (11). The second circuit (2B) includes a second relay (21) and a resistor (22) connected in series with the second relay (21). The second circuit (2B) is connected in parallel with the first circuit (1B). The third circuit (3B) includes a third relay (31). The third circuit (3B) is connected in series with the first circuit (1B). The fourth circuit (4B) includes a fuse (9) and a fourth relay (41B) connected in parallel with the fuse (9). The fourth circuit (4B) is connected in series with the first circuit (1B) and the third circuit (3B). After the fuse (9) cuts off the electrical path of the first circuit (1B), the fourth relay (41B) is switched from off to on.

[0162] According to this aspect, it is possible to improve convenience.

[0163] A thirteenth aspect of the interruption system (20B) includes an interruption circuit (10B) and a control unit (5B). The control unit (5B) controls the operation of the fuse (9) and the fourth relay (41B). After the fuse (9) interrupts the electrical path of the first circuit (1B), the control unit (5B) switches the fourth relay (41B) from off to on.

[0164] A power supply system (100B) of a fourteenth aspect includes the interrupter circuit (10B) of the twelfth aspect, a power supply (91), and an inverter (92). A series circuit of a first circuit (1B) and a fourth circuit (4B) is connected between the positive electrode of the power supply (91) and a high-potential side DC terminal (921) of the inverter (92).

[0165] 100, 100A, 100B Power supply system 20, 20A, 20B Breaking system 10, 10A, 10B Breaking circuit 1, 1A, 1B First circuit 11 First relay 2, 2A, 2B Second circuit 21, 21A Second relay 22 Resistor 3, 3A, 3B Third circuit 31 Third relay 4, 4A, 4B Fourth circuit 41, 41B Fourth relay 42 Resistor 5, 5A, 5B Control unit 9 Fuse 91 Power supply 92 Inverter 921 High potential side DC terminal 922 Low potential side DC terminal

Claims

1. An interrupting circuit comprising: a first circuit having a first relay and a fuse connected in series with the first relay; and a second circuit having a second relay and connected in parallel with the first circuit, wherein the second relay is switched from off to on after the fuse interrupts the electrical path of the first circuit.

2. The interruption circuit of claim 1, wherein the second relay is switched from off to on before the first relay is switched from off to on before the fuse interrupts the electrical circuit, the first relay is switched from off to on after the second relay is switched from off to on, and the second relay is switched from on to off after the first relay is switched from off to on before the fuse interrupts the electrical circuit.

3. The interrupter circuit according to claim 2, wherein the current value of the current flowing through the second circuit is smaller than the current value of the current flowing through the first circuit.

4. The interrupter circuit according to claim 2 or 3, wherein the current carrying capacity of the second relay is smaller than the current carrying capacity of the first relay.

5. The interruption circuit according to claim 1, wherein before the fuse interrupts the electrical circuit and before the first relay is switched from off to on, the second relay is in an off state, and the second relay is maintained in the off state from the time the first relay is turned on until the fuse interrupts the electrical circuit.

6. The interrupter circuit according to claim 5, further comprising: a third circuit having a third relay and connected in series with the first circuit; and a fourth circuit having a fourth relay and a resistor connected in series with the fourth relay and connected in parallel with the third circuit, wherein before the fuse interrupts the electric circuit, the fourth relay is switched from off to on before the third relay is switched from off to on; and after the third relay is turned on and before the fuse interrupts the electric circuit, the fourth relay is switched from on to off.

7. The interrupter circuit according to claim 5 or 6, wherein the current value of the current flowing through the second circuit is the same as the current value of the current flowing through the first circuit.

8. The interrupter circuit according to any one of claims 5 to 7, wherein the current carrying capacity of the second relay is the same as the current carrying capacity of the first relay.

9. A circuit breaking system comprising: the circuit breaking circuit according to any one of claims 1 to 8; and a control unit that controls the operation of the fuse and the second relay, wherein the control unit switches the second relay from off to on after the fuse has broken the electric circuit.

10. A power supply system comprising: the interrupter circuit according to any one of claims 1 to 8; a power supply; and an inverter, wherein the first circuit is connected between the positive electrode of the power supply and a DC terminal on the high potential side of the inverter.

11. A power supply system comprising: the interrupter circuit according to any one of claims 1 to 8; a power supply; and an inverter, wherein the first circuit is connected between the negative electrode of the power supply and a DC terminal on the low potential side of the inverter.

12. An interrupting circuit comprising: a first circuit having a first relay; a second circuit having a second relay and a resistor connected in series with the second relay, the second circuit being connected in parallel with the first circuit; a third circuit having a third relay and connected in series with the first circuit; and a fourth circuit having a fuse and a fourth relay connected in parallel with the fuse, the fourth circuit being connected in series with the first circuit and the third circuit, wherein the fourth relay is switched from off to on after the fuse interrupts the electric path.

13. A circuit breaking system comprising: the circuit breaking circuit according to claim 12; and a control unit that controls the operation of the fuse and the fourth relay, wherein the control unit switches the fourth relay from off to on after the fuse has broken the electric circuit.

14. A power supply system comprising the interrupter circuit according to claim 12, a power supply, and an inverter, wherein a series circuit of the first circuit and the fourth circuit is connected between the positive electrode of the power supply and a DC terminal on the high potential side of the inverter.

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