Power System

Abstract

To provide a power supply system that can properly execute a pre-charge operation even when an anomaly of some kind occurs on the power supply system so that it is impossible to complete the pre-charge operation with the power supplied from an inner power supply.SOLUTION: In the power supply system 1, in the case that a control device ECU determines that it is not possible to complete pre-charge operation with power supplied from a high voltage battery BAT-H even if setting a main contactor 51 into a state of shutdown and a pre-charge contactor 52 into a state of connection and that an external power supply is connected to a charger 71, the control device ECU executes the pre-charge operation by supplying power from the external power supply via the charger 71 to the high voltage circuit 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power supply system mounted on an electric vehicle or the like. [Background technology]

[0002] In recent years, efforts to reduce CO2 emissions and improve energy efficiency have been gaining momentum in an effort to realize a low-carbon or carbon-free society. As a result, the electrification of various devices, including vehicles, is progressing, and research and development of power supply systems for electrifying various devices, including vehicles, is being actively conducted.

[0003] In this type of power supply system, it is important to ensure electrical safety. For example, Patent Document 1 describes a power supply system that can reliably cut off current to an electric heater in the event of an abnormality. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-045498 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the technology described in Patent Document 1 is applied to a power supply system capable of performing precharging and connected to a storage device such as a capacitor, if the IGBT short-circuits and the user turns off the power supply system before the electric heater reaches a predetermined temperature, and the bimetal switch does not perform a cut-off operation and the power supply system remains in an off state, the next time the user turns on the power supply system, power will be supplied to the short-circuited electric heater, and precharging may not be performed properly.

[0006] The present invention provides a power supply system that contributes to reducing CO2 emissions and improving energy efficiency, and that can properly perform a precharge operation even when some abnormality occurs in the power supply system and the power supplied from the internal power supply is not sufficient to complete the precharge operation. [Means for solving the problem]

[0007] The present invention provides a main circuit to which the internal power supply and the first load are connected; a main contactor connected in series with the first load in the main circuit and switchable between a connected state and a disconnected state; a capacitor connected in series with the main contactor in the main circuit and connected in parallel with the first load; a precharge contactor connected in parallel with the main contactor and capable of switching between a connected state and a disconnected state; a charger connected to the first load and the capacitor and connectable to an external power source; a control device capable of controlling the main contactor, the pre-charge contactor, and the charger, A precharge operation for storing a predetermined amount of power in the capacitor can be performed, a power supply system capable of executing the precharge operation with power supplied from the internal power supply by bringing the main contactor into an interrupted state and the precharge contactor into a connected state, The control device When it is determined that the power supplied from the internal power source is not enough to complete the pre-charge operation even if the main contactor is in an interrupted state and the pre-charge contactor is in a connected state, and the external power source is connected to the charger, The precharge operation is performed by supplying power from the external power supply to the main circuit via the charger. [Effects of the Invention]

[0008] According to the present invention, even if some abnormality occurs in the power supply system and the power supplied from the internal power supply is not sufficient to complete the precharge operation, the precharge operation can be properly performed by supplying power to the main circuit from an external power supply via a charger. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a power supply system according to an embodiment of the present invention; [Figure 2] 2 is a flowchart showing the operation of the power supply system of FIG. 1. [Figure 3] 10 is a flowchart showing a modified example of the operation of the power supply system of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a power supply system of the present invention will be described below with reference to the accompanying drawings. The drawings are to be viewed in the direction indicated by the reference numerals. The power supply system of this embodiment is mounted on a vehicle.

[0011] <Power supply system configuration> First, the configuration of a power supply system 1 according to one embodiment of the present invention will be described with reference to FIG.

[0012] As shown in FIG. 1, the power supply system 1 includes a high-voltage circuit 10, a low-voltage circuit 20, and a DC-DC converter 30 that connects the high-voltage circuit 10 and the low-voltage circuit 20 and is capable of reducing the power flowing through the high-voltage circuit 10 and supplying it to the low-voltage circuit 20.

[0013] The high voltage circuit 10 is electrically connected to a high voltage battery BAT-H mounted on the vehicle and a battery heater 40 that heats the high voltage battery BAT-H.

[0014] The high-voltage battery BAT-H is a secondary battery that can be repeatedly charged and discharged, such as a lithium-ion battery. In this embodiment, the output voltage of the high-voltage battery BAT-H is 400 V.

[0015] The battery heater 40 includes a heating element 41, a switching element 42, and a breaker device 43. In the battery heater 40, the heating element 41, the switching element 42, and the breaker device 43 are connected in series.

[0016] The heating element 41 is, for example, a heating resistor, a ceramic heater, an induction heater, or the like, and is a load having a predetermined electrical resistance value.

[0017] The switching element 42 controls the power supplied to the heating element 41. In this embodiment, the switching element 42 is an IGBT (Insulated Gate Bipolar Transistor). The switching element 42 has a gate electrode 42a electrically connected to a gate driver 83 connected to the low-voltage circuit 20. When a control current is supplied from the gate driver 83 to the gate electrode 42a, the switching element 42 is in a connected state, and power is supplied to the heating element 41. On the other hand, when a control current is not supplied from the gate driver 83 to the gate electrode 42a, the switching element 42 is in a cut-off state, and the power supply to the heating element 41 is cut off.

[0018] The interrupter 43 operates to cut off the power supply to the heating element 41 when the temperature of the heating element 41 reaches or exceeds a predetermined temperature T0. In this embodiment, the interrupter 43 is a bimetal switch. The bimetal switch interrupter 43 is a normally closed switch that is normally in an energized state. When the temperature of the heating element 41 reaches or exceeds the predetermined temperature T0, the bimetal disc of the interrupter 43 operates to drive the rod, thereby switching to an interrupted state and cutting off the power supply to the heating element 41. Note that the interrupter 43 may also be a thermal fuse that cuts off the power supply to the heating element 41 when the temperature of the heating element 41 reaches or exceeds the predetermined temperature T0.

[0019] The switching element 42 and the breaker device 43 may be arranged on either the high potential side or the low potential side of the heating element 41. In this embodiment, the switching element 42 is arranged on the low potential side of the heating element 41, and the breaker device 43 is arranged on the high potential side of the heating element 41.

[0020] The high voltage circuit 10 is provided with a main contactor 51 that is connected in series with the battery heater 40 and can be switched between a connected state and a disconnected state.

[0021] The main contactor 51 is provided between the high potential side of the high voltage battery BAT-H in the high voltage circuit 10 and the battery heater 40. The main contactor 51 is switched between a connected state and a disconnected state by a first switch driver 81 connected to the low voltage circuit 20. When the main contactor 51 is in the connected state, the high voltage battery BAT-H and the battery heater 40 are electrically connected.

[0022] In this embodiment, a first high-voltage power line 11 is connected to the high-voltage circuit 10. One end 11a of the first high-voltage power line 11 is connected between the high-potential side of the high-voltage battery BAT-H and the main contactor 51 in the high-voltage circuit 10, and the other end 11b of the first high-voltage power line 11 is connected between the main contactor 51 and the battery heater 40 in the high-voltage circuit 10.

[0023] A pre-charge contactor 52 is provided on the first high-voltage power line 11. Therefore, the pre-charge contactor 52 is connected in parallel with the main contactor 51.

[0024] The precharge contactor 52 has a contactor portion 52a that can be switched between a connected state and a disconnected state by a second switch driver 82 connected to the low-voltage circuit 20, and a precharge resistor portion 52b that is an electrical resistor.

[0025] In this embodiment, a second high-voltage power line 12 is connected to the high-voltage circuit 10. One end 12a of the second high-voltage power line 12 is connected in the high-voltage circuit 10 between the other end 11b of the first high-voltage power line 11 and the battery heater 40, and the other end 12b of the second high-voltage power line 12 is connected in the high-voltage circuit 10 between the battery heater 40 and the low-potential side of the high-voltage battery BAT-H.

[0026] A power storage device CP is provided on the second high-voltage power line 12. Therefore, the power storage device CP is connected in series with the main contactor 51 and in parallel with the battery heater 40 in the high-voltage circuit 10.

[0027] The capacitor CP is an element that can store and discharge power as electrostatic energy. In this embodiment, the capacitor CP is a capacitor.

[0028] Without the capacitor CP, when the power supply system 1 transitions from an off state to an on state and the main contactor 51 is switched from a disconnected state to a connected state, high-voltage, large-current power from the high-voltage battery BAT-H rushes into the main contactor 51, potentially damaging the main contactor 51. Therefore, as described above, the precharge contactor 52 and the capacitor CP are provided. When the power supply system 1 transitions from an off state to an on state, the precharge contactor 52 is first switched from a disconnected state to a connected state while the main contactor 51 remains disconnected. Then, the precharge resistor 52b of the precharge contactor 52 adjusts the amount of current output from the high-voltage battery BAT-H, thereby precharging the capacitor CP and storing the power. In this way, the power supply system 1 can perform a precharge operation to store a predetermined amount of power in the capacitor CP. Then, when a predetermined amount of power is stored in the capacitor CP and pre-charging is completed, the potential difference between the high potential side and the low potential side decreases in the main contactor 51. Therefore, by switching the main contactor 51 from the disconnected state to the connected state after a predetermined amount of power is stored in the capacitor CP and pre-charging is completed, damage to the main contactor 51 can be prevented.

[0029] In this embodiment, a third high-voltage power line 13 is connected to the high-voltage circuit 10. One end 13a of the third high-voltage power line 13 is connected in the high-voltage circuit 10 between one end 11a of the second high-voltage power line 12 and the battery heater 40, and the other end 13b of the third high-voltage power line 13 is connected in the high-voltage circuit 10 between the battery heater 40 and the other end 12b of the second high-voltage power line 12.

[0030] An air conditioning heater 61 is provided on the third high-voltage power line 13. Therefore, in the high-voltage circuit 10, the air conditioning heater 61 is connected in parallel with the battery heater 40 and the power storage device CP.

[0031] The air conditioning heater 61 is a load that heats the air to be supplied to the vehicle interior in an air conditioning device (not shown) mounted on the vehicle.

[0032] In this embodiment, a fourth high-voltage power line 14 is connected to the high-voltage circuit 10. One end 14a of the fourth high-voltage power line 14 is connected to the third high-voltage power line 13 between one end 13a of the third high-voltage power line 13 and the air conditioning heater 61 in the high-voltage circuit 10, and the other end 14b of the fourth high-voltage power line 14 is connected to the third high-voltage power line 13 between the air conditioning heater 61 and the other end 13b of the third high-voltage power line 13 in the high-voltage circuit 10.

[0033] A charger 71 is provided on the fourth high-voltage power line 14. Therefore, in the high-voltage circuit 10, the charger 71 is connected to the battery heater 40, the air conditioning heater 61, and the capacitor CP. In the high-voltage circuit 10, the battery heater 40, the air conditioning heater 61, and the capacitor CP are connected in parallel with each other when viewed from the charger 71.

[0034] The charger 71 can be connected to an external power supply (not shown) installed outside the vehicle. The charger 71 can convert power supplied from the external power supply and supply it to the high-voltage circuit 10. Therefore, the high-voltage battery BAT-H can be charged with power supplied from the external power supply via the charger 71. The charger 71 can also store power supplied from the external power supply in the power storage device CP. That is, the charger 71 can perform pre-charging using power supplied from the external power supply. The charger 71 can also operate the battery heater 40 and the air conditioning heater 61 using power supplied from the external power supply. The charger 71 can convert power supplied from, for example, a general household AC power supply into DC power of a predetermined voltage and supply it to the high-voltage circuit 10.

[0035] The low-voltage circuit 20 is connected to a low-voltage battery BAT-L mounted on the vehicle and a control device ECU, which is connected to a system power switch PWR.

[0036] The low-voltage battery BAT-L is a secondary battery that can be repeatedly charged and discharged, such as a lithium-ion battery or a lead-acid battery. In this embodiment, the output voltage of the low-voltage battery BAT-L is 12 V.

[0037] The system power switch PWR is an operating unit mounted on a vehicle and capable of switching the power supply system 1 between an on state and an off state. The system power switch PWR can be turned on and off by a user. The user is, for example, a passenger in the vehicle equipped with the power supply system 1. Here, the on state of the power supply system 1 refers to a state in which the system power switch PWR is turned on, the vehicle's drive source is activated, and power necessary for driving the vehicle is supplied to the auxiliary equipment required for driving, and refers to a state in which the vehicle is running or a state in which the vehicle can run immediately. Furthermore, the off state of the power supply system 1 refers to a state in which the system power switch PWR is turned off, the vehicle's drive source is not activated, and power necessary for driving the vehicle is not supplied to the auxiliary equipment required for driving.

[0038] In the low voltage circuit 20, a first contact 20a is formed between the control device ECU and the high potential side of the low voltage battery BAT-L, and a second contact 20b is formed between the control device ECU and the low potential side of the low voltage battery BAT-L.

[0039] Furthermore, the low-voltage circuit 20 is connected to a first low-voltage power line 21 provided with a first switch driver 81, a second low-voltage power line 22 provided with a second switch driver 82, a third low-voltage power line 23 provided with a gate driver 83, and a fourth low-voltage power line 24 provided with a display device 90. One end of the first low-voltage power line 21, the second low-voltage power line 22, the third low-voltage power line 23, and the fourth low-voltage power line 24 is all connected to the first contact 20a and the other end is connected to the second contact 20b.

[0040] Therefore, in the low-voltage circuit 20, the control device ECU, the first switch driver 81, the second switch driver 82, the gate driver 83, and the display device 90 are connected in parallel with one another.

[0041] The control device ECU can control the first switch driver 81, the second switch driver 82, the gate driver 83, and the display device 90. Furthermore, the control device ECU can control the DC-DC converter 30, the air conditioning heater 61, and the charger 71. The control device ECU also includes a storage medium M that can store various types of information.

[0042] As described above, the first switch driver 81 is controlled by the control unit ECU and is capable of supplying a control current to the main contactor 51. The main contactor 51 is switched between a connected state and a disconnected state based on the control current supplied from the first switch driver 81. Therefore, the control unit ECU is capable of controlling the main contactor 51 to be switched between a connected state and a disconnected state via the first switch driver 81.

[0043] As described above, the second switch driver 82 is controlled by the control unit ECU and is capable of supplying a control current to the contactor portion 52a of the precharge contactor 52. The contactor portion 52a of the precharge contactor 52 is switched between a connected state and a disconnected state based on the control current supplied from the second switch driver 82. Therefore, the control unit ECU is capable of controlling the precharge contactor 52 to be switched between a connected state and a disconnected state via the second switch driver 82.

[0044] As described above, the gate driver 83 is controlled by the control unit ECU and is capable of supplying a control current to the gate electrode 42a of the switching element 42. The switching element 42 is switched between a connected state and a disconnected state based on the control current supplied to the gate electrode 42a from the gate driver 83. Therefore, the control unit ECU can control the switching element 42 to be switched between a connected state and a disconnected state via the gate driver 83.

[0045] The display device 90 is, for example, a liquid crystal display panel or an OLED (Organic Light Emitting Diode) panel that can display various information, and is arranged inside the vehicle cabin.

[0046] The DC-DC converter 30 is provided on a step-up / step-down power line 31. One end 31a of the step-up / step-down power line 31 is connected between one end 12a of the second high-voltage power line 12 and one end 13a of the third high-voltage power line 13 in the high-voltage circuit 10. The other end 31b of the step-up / step-down power line 31 is connected to a first contact 20a in the low-voltage circuit 20. The DC-DC converter 30 is capable of stepping down the power flowing through the high-voltage circuit 10 and supplying it to the low-voltage circuit 20 from the first contact 20a of the low-voltage circuit 20.

[0047] <Power supply system operation> Next, with reference to FIG. 2, an operation will be described when the system power switch PWR is operated in the power supply system 1 to transition the power supply system 1 from the off state to the on state.

[0048] First, when the system power switch PWR is operated, the control unit ECU switches the pre-charge contactor 52 from the disconnected state to the connected state (step S101). If there is no abnormality in the power supply system 1, power is output from the high-voltage battery BAT-H and supplied to the battery CP while a predetermined amount of power is consumed by the pre-charge resistor 52b of the pre-charge contactor 52. Then, a pre-charge operation is started to store a predetermined amount of power in the battery CP. In this way, by setting the main contactor 51 to the disconnected state and the pre-charge contactor 52 to the connected state, the pre-charge operation is performed using power supplied from the high-voltage battery BAT-H. At this time, because the main contactor 51 is in the disconnected state and the pre-charge contactor 52 is in the connected state, the amount of current of the power output from the high-voltage battery BAT-H is adjusted by the pre-charge resistor 52b of the pre-charge contactor 52. Then, the process proceeds to step S102.

[0049] In step S102, the control device ECU determines whether or not there is an abnormality in the pre-charge operation. More specifically, the control device ECU determines whether or not the pre-charge operation can be completed with the power supplied from the high-voltage battery BAT-H when the main contactor 51 is in the disconnected state and the pre-charge contactor 52 is in the connected state. If the pre-charge operation cannot be completed with the power supplied from the high-voltage battery BAT-H even when the main contactor 51 is in the disconnected state and the pre-charge contactor 52 is in the connected state, the control device ECU determines that there is an abnormality in the pre-charge operation. For example, a sensor (not shown) capable of detecting the amount of electricity stored in the electricity storage device CP is connected to the control device ECU. The sensor outputs an electrical signal indicating the amount of electricity stored in the electricity storage device CP. Then, based on the electrical signal output from the sensor, the control device ECU determines that there is an abnormality in the pre-charge operation when the electricity storage device CP does not store a predetermined amount of electricity even after a predetermined time has elapsed.

[0050] When the control unit ECU determines in step S102 that there is no abnormality in the precharge operation (step S102: NO), the control unit ECU proceeds to step S103.

[0051] In step S103, the control device ECU determines whether or not pre-charging has been completed. For example, the control device ECU determines whether or not a predetermined amount of power has been stored in the capacitor CP based on an electric signal output from the aforementioned sensor capable of detecting the amount of power stored in the capacitor CP. If the control device ECU determines that pre-charging has not been completed (step S103: NO), the control device ECU returns to step S102, and if the control device ECU determines that pre-charging has been completed (step S103: YES), the control device ECU proceeds to step S104.

[0052] In step S104, the control device ECU switches the main contactor 51 from the disconnected state to the connected state. At this time, the pre-charging of the capacitor CP has been completed and the potential difference between the high potential side and the low potential side of the main contactor 51 has become small, so the main contactor 51 can be switched from the disconnected state to the connected state without being damaged. Then, the process proceeds to step S105.

[0053] In step S105, the control unit ECU switches the precharge contactor 52 from the connected state to the disconnected state, and then ends the series of operations.

[0054] On the other hand, when the control unit ECU determines in step S102 that there is an abnormality in the precharge operation (step S102: YES), the control unit ECU proceeds to step S201.

[0055] In step S201, the control unit ECU switches the precharge contactor 52 from the connected state to the disconnected state, thereby stopping the power supply from the high-voltage battery BAT-H to the high-voltage circuit 10. Then, the process proceeds to step S202.

[0056] In step S202, the control device ECU determines whether the switching element 42 of the battery heater 40 has a short-circuit failure. For example, a sensor (not shown) capable of detecting whether the switching element 42 has a short-circuit failure is connected to the control device ECU. The sensor outputs an electrical signal indicating whether the switching element 42 has a short-circuit failure. The control device ECU determines whether the switching element 42 has a short-circuit failure based on the electrical signal output from the sensor. A short-circuit failure is a failure that causes the switching element 42 to be in a conductive state. A short-circuit failure includes, for example, a failure in which the gate electrode 42 a of the switching element 42 remains connected and stuck. Such a situation in which the gate electrode 42 a of the switching element 42 remains connected and stuck is also referred to as a stuck-on state.

[0057] Even if the system power switch PWR is operated while the switching element 42 is short-circuited, switching the pre-charge contactor 52 from a disconnected state to a connected state and performing a pre-charge operation using power supplied from the high-voltage battery BAT-H, the power supplied from the high-voltage battery BAT-H is also supplied to the heating element 41 of the battery heater 40 because of the short-circuited switching element 42. As a result, power is not properly stored in the capacitor CP, and the pre-charge operation is not properly performed. Therefore, in step S202, it can be determined whether the cause of the abnormality in the pre-charge operation is the short-circuited switching element 42.

[0058] If the control device ECU determines in step S202 that the switching element 42 of the battery heater 40 is not short-circuited (step S202: NO), the control device ECU determines that the cause of the abnormality in the pre-charge operation is unknown and ends the series of operations. Therefore, in this case, the main contactor 51 does not switch from the disconnected state to the connected state, and the series of operations ends. This improves the safety of the power supply system 1 when an abnormality occurs in the pre-charge operation.

[0059] When the control unit ECU determines in step S202 that the switching element 42 of the battery heater 40 has a short-circuit failure (step S202: YES), the control unit ECU proceeds to step S301.

[0060] In step S301, the control device ECU determines whether an external power source is connected to the charger 71. For example, a sensor (not shown) that can detect whether an external power source is connected to the charger 71 is connected to the control device ECU. The sensor outputs an electrical signal that indicates whether an external power source is connected to the charger 71. The control device ECU determines whether an external power source is connected to the charger 71 based on the electrical signal output from the sensor.

[0061] If the control device ECU determines in step S301 that an external power source is not connected to the charger 71 (step S301: NO), the control device ECU proceeds to step S302, where it causes the display device 90 to display information urging the user to connect the external power source to the charger 71. For example, it causes the display device 90 to display text information such as "Please connect the external power source to the charger." In step S302, in addition to causing the display device 90 to display the text information such as "Please connect the external power source to the charger," the control device ECU may also cause a notification unit (not shown) mounted on the vehicle to generate audio information such as "Please connect the external power source to the charger." Then, the control device ECU returns to step S301.

[0062] When the control device ECU determines in step S301 that an external power source is connected to the charger 71 (step S301: YES), the control device ECU proceeds to step S401.

[0063] In step S401, the control unit ECU supplies power from the external power supply to the high voltage circuit 10 via the charger 71, and starts a pre-charge operation using the power from the external power supply.

[0064] In this case, when the switching element 42 of the battery heater 40 is short-circuited, power is supplied from the external power source to the high-voltage circuit 10 via the charger 71, and the power supplied from the external power source to the high-voltage circuit 10 via the charger 71 is also supplied to the battery heater 40. Therefore, when a pre-charge operation is started using power from the external power source, power is stored in the capacitor CP and the temperature of the heating element 41 of the battery heater 40 increases. Then, when the temperature of the heating element 41 reaches or exceeds a predetermined temperature T0, the circuit breaker 43 performs a circuit breaker operation to cut off the power supply to the heating element 41.

[0065] At this time, the voltage of the power supplied from the external power source to the high-voltage circuit 10 via the charger 71 is higher than the voltage of the power supplied from the high-voltage battery BAT-H. The voltage of the power supplied from the external power source to the high-voltage circuit 10 via the charger 71 is, for example, 500 V.

[0066] This allows higher voltage power to be supplied from an external power source to the heating element 41 of the battery heater 40 via the charger 71, so that the heating element 41 of the battery heater 40 can be heated up more quickly and the cut-off device 43 can be shut off more quickly.

[0067] In this way, when the control device ECU performs a pre-charge operation using power supplied from the external power supply to the high-voltage circuit 10 via the charger 71, the control device ECU continues to supply power from the external power supply to the high-voltage circuit 10 via the charger 71 until the cut-off device 43 performs a cut-off operation. In this embodiment, the control device ECU continues to supply power from the external power supply to the high-voltage circuit 10 via the charger 71 even after the cut-off device 43 performs a cut-off operation. Then, the process proceeds to step S402.

[0068] As a result, the cutoff device 43 can be operated to cut off the power using the power from the external power source via the charger 71, so that unnecessary discharge of the high-voltage battery BAT-H can be avoided.

[0069] In step S402, the control device ECU determines whether or not precharging is complete. For example, the control device ECU determines whether or not a predetermined amount of power has been stored in the capacitor CP based on an electrical signal output from the aforementioned sensor capable of detecting the amount of power stored in the capacitor CP. If the control device ECU determines that precharging is not complete, it continues the precharging operation using power from the external power supply (loop of NO in step S402), and if the control device ECU determines that precharging is complete (YES in step S402), it proceeds to step S403, where it ends the precharging operation using power from the external power supply, and proceeds to step S404.

[0070] In step S404, the control unit ECU calculates the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H. BAT-H It is determined whether the potential difference ΔV between the positive electrode 1 and the negative electrode 2 is equal to or less than a predetermined potential difference ΔVset. The predetermined potential difference ΔVset is, for example, 10 [V].

[0071] In step S404, the control unit ECU calculates the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H. BAT-H If it is determined that the potential difference ΔV is larger than the predetermined potential difference ΔVset (step S404: NO), the process proceeds to step S405, where the precharge contactor 52 is switched from the disconnected state to the connected state, and the process returns to step S404.

[0072] In step S404, the control unit ECU calculates the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H. BAT-H If it is determined that the potential difference ΔV between the first terminal and the second terminal is equal to or smaller than the predetermined potential difference ΔVset (step S404: YES), the process proceeds to step S501.

[0073] In step S501, the control unit ECU switches the main contactor 51 from the disconnected state to the connected state, and then proceeds to step S502.

[0074] Therefore, when the interrupter 43 performs an interruption operation using the power supplied from the external power source to the high-voltage circuit 10 via the charger 71, the control unit ECU determines whether the circuit voltage Vc of the high-voltage circuit 10 and the output voltage V of the high-voltage battery BAT-H are equal to each other after the interrupter 43 performs an interruption operation. BAT-H When the potential difference ΔV between the high-voltage circuit 10 and the high-voltage battery BAT-H is greater than the predetermined potential difference ΔVset, the precharge contactor 52 is switched to the connected state, power is consumed by the precharge resistor portion 52b of the precharge contactor 52, and the circuit voltage Vc of the high-voltage circuit 10 and the output voltage V of the high-voltage battery BAT-H are BAT-H When the potential difference ΔV between the terminals becomes equal to or smaller than a predetermined potential difference ΔVset, the main contactor 51 is switched to the connected state.

[0075] This allows the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H to BAT-H When the main contactor 51 is switched from the disconnected state to the connected state due to the potential difference ΔV between the terminals, it is possible to prevent a large current from rushing into the main contactor 51 and damaging the main contactor 51.

[0076] In step S502, the control unit ECU switches the precharge contactor 52 to a disconnected state. If the precharge contactor 52 is in a disconnected state, the control unit ECU maintains the disconnected state, and if the precharge contactor 52 is in a connected state, the control unit ECU switches the precharge contactor 52 to a disconnected state. Then, the series of operations ends.

[0077] As described above, in the power supply system 1 of this embodiment, even if the main contactor 51 is in the disconnected state and the pre-charge contactor 52 is in the connected state, the control device ECU determines that the pre-charge operation cannot be completed with the power supplied from the high-voltage battery BAT-H, and if an external power source is connected to the charger 71, it supplies power from the external power source to the high-voltage circuit 10 via the charger 71 to perform the pre-charge operation.

[0078] As a result, even if some abnormality occurs in the power supply system 1 and the power supplied from the high-voltage battery BAT-H is not sufficient to complete the pre-charge operation, power can be supplied to the high-voltage circuit 10 from an external power source via the charger 71, allowing the pre-charge operation to be performed properly.

[0079] Furthermore, in the power supply system 1 of this embodiment, when the switching element 42 has a short-circuit failure and an external power supply is connected to the charger 71, the control device ECU supplies power from the external power supply to the high-voltage circuit 10 via the charger 71 to perform a pre-charge operation.

[0080] As a result, even if the switching element 42 has a short-circuit fault and the circuit breaker 43 is not performing a circuit breaker operation, power can be supplied to the high-voltage circuit 10 from an external power source via the charger 71, causing the circuit breaker 43 to perform a circuit breaker operation, and the pre-charge operation can be performed appropriately.

[0081] <Modification of the operation of the power supply system> Next, a modified example of the operation when the system power switch PWR is operated in the power supply system 1 to transition the power supply system 1 from the off state to the on state will be described with reference to Fig. 3. Steps S101 to S404 are the same as the operations described above. Here, the operations from step S404 onwards will be described.

[0082] In step S404, the control unit ECU calculates the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H. BAT-H If it is determined that the potential difference ΔV is greater than the predetermined potential difference ΔVset (step S404: NO), proceed to step S415, operate the air conditioning heater 61 and / or the DC-DC converter 30, consume power in the air conditioning heater 61 and / or the DC-DC converter 30, and return to step S404 again.

[0083] In step S404, the control unit ECU calculates the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H.BAT-H If it is determined that the potential difference ΔV between the first terminal and the second terminal is equal to or smaller than the predetermined potential difference ΔVset (step S404: YES), the process proceeds to step S601.

[0084] In step S601, the control device ECU ends the operation of the air conditioning heater 61 and / or the DC-DC converter 30, and proceeds to step S602.

[0085] In step S602, the control unit ECU switches the main contactor 51 from the disconnected state to the connected state, and ends the series of operations.

[0086] Therefore, when the interrupter 43 performs an interruption operation using the power supplied from the external power source to the high-voltage circuit 10 via the charger 71, the control unit ECU determines whether the circuit voltage Vc of the high-voltage circuit 10 and the output voltage V of the high-voltage battery BAT-H are equal to each other after the interrupter 43 performs an interruption operation. BAT-H When the potential difference ΔV between the high voltage circuit 10 and the DC-DC converter 30 is greater than the predetermined potential difference ΔVset, the air conditioning heater 61 and / or the DC-DC converter 30 are operated to consume power, and the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H are BAT-H When the potential difference ΔV between the terminals becomes equal to or smaller than a predetermined potential difference ΔVset, the main contactor 51 is switched to the connected state.

[0087] This allows the circuit voltage Vc of the high voltage circuit 10 and the output voltage V of the high voltage battery BAT-H to BAT-H When the main contactor 51 is switched from the disconnected state to the connected state due to the potential difference ΔV between the terminals, it is possible to prevent a large current from rushing into the main contactor 51 and damaging the main contactor 51.

[0088] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiment may be combined in any manner without departing from the spirit of the invention.

[0089] For example, in this embodiment, the power supply system 1 is mounted on a vehicle, but it may also be mounted on something other than a vehicle.

[0090] Also, for example, in this embodiment, in step S415, the air conditioning heater 61 and / or the DCDC converter 30 are operated to consume power by the air conditioning heater 61 and / or the DCDC converter 30, but any load other than the air conditioning heater 61 and / or the DCDC converter 30 connected to the power supply system 1 may be operated to consume power by the load.

[0091] Furthermore, for example, in this embodiment, even after the cutoff device 43 performs the cutoff operation in steps S401 to S403, the power supply from the external power source to the high-voltage circuit 10 via the charger 71 continues until the pre-charge is completed. However, the cutoff operation of the cutoff device 43 may be used as a trigger to terminate the power supply from the external power source to the high-voltage circuit 10 via the charger 71, switch the pre-charge contactor 52 from the cut-off state to the connected state, and perform the pre-charge operation using the power from the high-voltage battery BAT-H.

[0092] This specification describes at least the following: In parentheses, components corresponding to those in the above-described embodiments are shown as examples, but the present invention is not limited to these.

[0093] (1) a main circuit (high voltage circuit 10) to which an internal power supply (high voltage battery BAT-H) and a first load (heat generating element 41) are connected; a main contactor (main contactor 51) connected in series with the first load in the main circuit and capable of switching between a connected state and a disconnected state; a capacitor (capacitor CP) connected in series with the main contactor in the main circuit and connected in parallel with the first load; a precharge contactor (precharge contactor 52) connected in parallel with the main contactor and capable of switching between a connected state and a disconnected state; a charger (charger 71) connected to the first load and the capacitor and connectable to an external power source; a control device (control device ECU) capable of controlling the main contactor, the pre-charge contactor, and the charger; A precharge operation for storing a predetermined amount of power in the capacitor can be performed, a power supply system (power supply system 1) capable of executing the precharge operation with power supplied from the internal power supply by bringing the main contactor into an interrupted state and the precharge contactor into a connected state, The control device When it is determined that the power supplied from the internal power source is not enough to complete the pre-charge operation even if the main contactor is in an interrupted state and the pre-charge contactor is in a connected state, and the external power source is connected to the charger, a power supply system that supplies power from the external power supply to the main circuit via the charger to perform the precharge operation;

[0094] According to (1), even if some abnormality occurs in the power supply system and the power supplied from the internal power supply is not sufficient to complete the precharge operation, the precharge operation can be properly performed by supplying power to the main circuit from an external power supply via the charger.

[0095] (2) The power supply system according to (1), The power supply system includes: a switching element (switching element 42) connected in series with the first load in the main circuit and controlling the power supplied to the first load; a circuit breaker (43) connected in series with the first load in the main circuit and configured to cut off power supply to the first load when the temperature of the first load reaches or exceeds a predetermined temperature (predetermined temperature T0), The control device When the switching element has a short-circuit fault and the external power supply is connected to the charger, a power supply system that supplies power from the external power supply to the main circuit via the charger to perform the precharge operation;

[0096] According to (2), even if the switching element has a short-circuit fault and the circuit breaker is not performing a circuit breaker operation, power can be supplied to the main circuit from an external power source via a charger, causing the circuit breaker to perform a circuit breaker operation, and the pre-charge operation can be performed appropriately.

[0097] (3) The power supply system according to (2), The control device When the precharge operation is performed using power supplied from the external power supply to the main circuit via the charger, The power supply system continues to supply power from the external power supply to the main circuit via the charger until the breaker device operates.

[0098] According to (3), the breaker device can be operated by power from an external power source via a charger, so unnecessary discharge of the internal power source can be avoided.

[0099] (4) The power supply system according to (3), A power supply system, wherein a voltage of the power supplied from the external power supply to the main circuit via the charger is higher than a voltage of the power supplied from the internal power supply.

[0100] According to (4), higher voltage power can be supplied to the first load from the external power source via the charger, so that the temperature of the first load can be increased more quickly, and the circuit breaker can be caused to perform a circuit breaker operation more quickly.

[0101] (5) The power supply system according to (4), The control device controlling the main contactor and the pre-charge contactor to be in an interrupted state while power is being supplied from the external power source to the main circuit via the charger; When the circuit breaker is operated by the power supplied from the external power supply to the main circuit via the charger, After the circuit breaker operates, the precharge contactor is switched to the connected state, and the circuit voltage of the main circuit (circuit voltage Vc) and the output voltage of the internal power supply (V BAT-H a potential difference (potential difference ΔV) between the power supply and the main contactor becomes equal to or less than a predetermined value (predetermined potential difference ΔVset), the power supply system switches the main contactor to a connected state.

[0102] According to (5), when the main contactor is switched from a disconnected state to a connected state due to the potential difference between the circuit voltage of the main circuit and the output voltage of the internal power supply, a large current can be prevented from rushing into the main contactor and damaging the main contactor.

[0103] (6) The power supply system according to (4), The power supply system includes: Further, a second load (an air conditioning heater 61, a DC-DC converter 30) is connected to the main circuit. The control device controlling the main contactor and the pre-charge contactor to be in an interrupted state while power is being supplied from the external power source to the main circuit via the charger; When the circuit breaker is operated by the power supplied from the external power supply to the main circuit via the charger, After the circuit breaker operates, the second load consumes power, and the circuit voltage of the main circuit (circuit voltage Vc) and the output voltage of the internal power supply (VBAT-H a potential difference (potential difference ΔV) between the power supply and the main contactor becomes equal to or less than a predetermined value (predetermined potential difference ΔVset), the power supply system switches the main contactor to a connected state.

[0104] According to (6), when the main contactor is switched from a disconnected state to a connected state due to the potential difference between the circuit voltage of the main circuit and the output voltage of the internal power supply, it is possible to prevent a large current from rushing into the main contactor and damaging the main contactor. [Explanation of symbols]

[0105] 1 Power System 10 High voltage circuit (main circuit) 30 DC / DC converter (second load) 41 Heating element (first load) 42 Switching element 43 Circuit Breaker 51 Main Contactor 52 Precharge Contactor 61 Air conditioning heater (second load) 71 Charger BAT-H High voltage battery (internal power supply) CP capacitor ECU control unit T0 Predetermined temperature Vc Circuit voltage V BAT-H Output Voltage ΔV potential difference ΔVset Predetermined value (predetermined potential difference)

Claims

1. a main circuit to which the internal power supply and a first load are connected; a main contactor connected in series with the first load in the main circuit and switchable between a connected state and a disconnected state; a capacitor connected in series with the main contactor in the main circuit and connected in parallel with the first load; a precharge contactor connected in parallel with the main contactor and capable of switching between a connected state and a disconnected state; a charger connected to the first load and the capacitor and connectable to an external power source; a control device capable of controlling the main contactor, the pre-charge contactor, and the charger, A precharge operation for storing a predetermined amount of power in the capacitor can be performed, a power supply system capable of executing the precharge operation with power supplied from the internal power supply by bringing the main contactor into an interrupted state and the precharge contactor into a connected state, The control device When it is determined that the power supplied from the internal power source is not enough to complete the pre-charge operation even if the main contactor is in an interrupted state and the pre-charge contactor is in a connected state, and the external power source is connected to the charger, a power supply system that supplies power from the external power supply to the main circuit via the charger to perform the precharge operation;

2. 2. The power supply system of claim 1, The power supply system includes: a switching element connected in series with the first load in the main circuit to control power supplied to the first load; a cutoff device connected in series with the first load in the main circuit and configured to cut off power supply to the first load when the temperature of the first load reaches or exceeds a predetermined temperature, The control device When the switching element has a short-circuit fault and the external power supply is connected to the charger, a power supply system that supplies power from the external power supply to the main circuit via the charger to perform the precharge operation;

3. 3. The power supply system according to claim 2, The control device When the precharge operation is performed using power supplied from the external power supply to the main circuit via the charger, The power supply system continues to supply power from the external power supply to the main circuit via the charger until the breaker device operates.

4. 4. The power supply system according to claim 3, A power supply system, wherein a voltage of the power supplied from the external power supply to the main circuit via the charger is higher than a voltage of the power supplied from the internal power supply.

5. 5. The power supply system according to claim 4, The control device controlling the main contactor and the pre-charge contactor to be in an interrupted state while power is being supplied from the external power source to the main circuit via the charger; When the circuit breaker is operated by the power supplied from the external power supply to the main circuit via the charger, a power supply system in which, after the circuit breaker operates, the precharge contactor is switched to a connected state, and when a potential difference between a circuit voltage of the main circuit and an output voltage of the internal power supply becomes equal to or less than a predetermined value, the main contactor is switched to a connected state.

6. 5. The power supply system according to claim 4, The power supply system includes: a second load connected to the main circuit; The control device controlling the main contactor and the pre-charge contactor to be in an interrupted state while power is being supplied from the external power source to the main circuit via the charger; When the circuit breaker is operated by the power supplied from the external power supply to the main circuit via the charger, and a power supply system in which, after the circuit breaker has operated, power is consumed by the second load, and when a potential difference between a circuit voltage of the main circuit and an output voltage of the internal power supply becomes equal to or less than a predetermined value, the power supply system switches the main contactor to a connected state.

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