Power supply system and method for determining abnormality of precharge device in power supply system

Abstract

To make it possible to appropriately determine an abnormality of a precharge device for executing precharge of a capacitor of a power control device connected to a power storage device.SOLUTION: A power supply system according to the present disclosure includes: a power storage device; a power control device including a capacitor and connected to the power storage device; a precharge device for executing precharge of the capacitor of the power control device in response to a system startup request; and a control device. The control device transmits a target voltage of the capacitor to the precharge device in response to the system startup request, and determines whether there is an abnormality in a communication state with the precharge device. When the abnormality in the communication state has not been determined, the control device determines whether the precharge has been completed, on the basis of a detection value from a predetermined sensor. The control device determines that the precharge device is normal, when the precharge has been completed, and determines that there is occurrence of an abnormality in the precharge device, when the precharge has not been completed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power supply system including a precharge device that precharges a capacitor of a power control device connected to a power storage device, and a method for determining an abnormality in the precharge device in the power supply system. [Background technology]

[0002] Conventionally, a power supply system for a vehicle is known that includes a battery, an inverter, a boost converter, a system main relay, a high-voltage capacitor, a low-voltage capacitor, an auxiliary battery, a DC / DC converter, and an electronic control unit (see, for example, Patent Document 1). In response to a system startup request, the electronic control unit of this power supply system controls the system main relay and the DC / DC converter so that the difference between the voltage of the battery and the voltage of the low-voltage capacitor becomes a predetermined voltage with the system main open, thereby precharging the low-voltage capacitor and the high-voltage capacitor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-099129 Summary of the Invention [Problem to be solved by the invention]

[0004] When precharging a low-voltage capacitor, etc., a malfunction may occur that cannot be determined to be a communication abnormality between the electronic control unit and the DC / DC converter, such as the DC / DC converter repeatedly resetting and recovering. In such cases, not only does the power supply system become unusable, but the inability to determine the abnormality makes it difficult to subsequently implement appropriate fail-safe measures or repairs.

[0005] Therefore, a main object of the present disclosure is to make it possible to properly determine an abnormality in a precharge device that precharges a capacitor of a power control device connected to a power storage device. [Means for solving the problem]

[0006] The power supply system of the present disclosure includes a power storage device, a power control device including a capacitor and connected to the power storage device, and a precharge device that precharges the capacitor of the power control device in response to a system startup request, and includes a control device that transmits a target voltage of the capacitor to the precharge device in response to the system startup request, determines whether or not there is an abnormality in the communication state with the precharge device, and when the abnormality in the communication state has not been confirmed, determines whether or not the precharge has been completed based on the detection value of a specified sensor, determines that the precharge device is normal when the precharge has been completed, and determines that an abnormality has occurred in the precharge device when the precharge has not been completed.

[0007] A control device of a power supply system disclosed herein transmits a target voltage for a capacitor to a precharge device in response to a system startup request and determines whether or not there is an abnormality in communication with the precharge device. Furthermore, when an abnormality in communication with the precharge device has not been determined, the control device determines whether precharge has been completed based on a detection value of a predetermined sensor. The control device then determines that the precharge device is normal when precharge has been completed, and determines that an abnormality has occurred in the precharge device when precharge has not been completed. This makes it possible to properly determine an abnormality in the precharge device that precharges the capacitor of a power control device connected to a power storage device, even when communication between the control device and the precharge device is unstable and it is not possible to determine that there is an abnormality in the communication.

[0008] The method for determining an abnormality in a precharge device in a power supply system disclosed herein is a method for determining an abnormality in a precharge device in a power supply system including a storage device, a power control device including a capacitor and connected to the storage device, and a precharge device that precharges the capacitor of the power control device in response to a system startup request, the method transmitting a target voltage of the capacitor to the precharge device in response to the system startup request, determining whether or not there is an abnormality in the communication state with the precharge device, and when the abnormality in the communication state has not been confirmed, determining whether or not the precharge has been completed based on the detection value of a specified sensor, determining that the precharge device is normal when the precharge has been completed, and determining that an abnormality has occurred in the precharge device when the precharge has not been completed.

[0009] According to this method, even if the communication state between the control device and the precharge device is unstable and it is not possible to determine whether an abnormality has occurred in the communication state, it is possible to properly determine an abnormality in the precharge device that precharges the capacitor of the power control device connected to the storage device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram showing a vehicle including a power supply system of the present disclosure. [Figure 2] 4 is a flowchart illustrating an example of a routine executed by a control device of the power supply system of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0012] 1 is a schematic diagram showing a hybrid vehicle V as a vehicle including a power supply system 1 of the present disclosure. In addition to the power supply system 1, the hybrid vehicle V shown in the figure includes an engine EG, a single-pinion planetary gear PG, motor generators MG1 and MG2 that exchange power with the power supply system 1, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 10 that controls the entire vehicle. The power supply system 1 also includes a high-voltage battery (electricity storage device) 2, a power control device (hereinafter referred to as "PCU") 3 that exchanges power with the high-voltage battery 2 to drive the motor generators MG1 and MG2, a positive-side system main relay SMRB (hereinafter referred to as "positive-side relay SMRB") and a negative-side system main relay SMRG (hereinafter referred to as "negative-side relay SMRG"), a low-voltage battery (second electricity storage device) 4 that has a lower voltage than the high-voltage battery 2, and a bidirectional DC / DC converter (voltage conversion device) 5.

[0013] The engine EG is an internal combustion engine that generates power through the explosive combustion of a mixture of air and hydrocarbon fuel such as gasoline, diesel, or LPG, and is controlled by an engine electronic control unit (not shown). The planetary gear PG includes a sun gear connected to the motor generator MG1 (rotor), a ring gear connected to the output shaft, and a planetary carrier that rotatably supports multiple pinion gears and is connected to the crankshaft of the engine EG. The output shaft is connected to left and right wheels (drive wheels) W via a differential gear DF ​​and drive shafts DS.

[0014] Both motor generators MG1 and MG2 are synchronous generator motors (three-phase AC motors). Motor generator MG1 operates mainly as a generator driven by engine EG in load operation to generate electric power. Motor generator MG2 is connected to the output shaft via a reduction gear mechanism (not shown) and operates mainly as an electric motor driven by at least one of electric power from high-voltage battery 2 and electric power from motor generator MG1 to output drive torque to the output shaft. Furthermore, motor generator MG2 outputs regenerative braking torque to the output shaft when braking hybrid vehicle V. These motor generators MG1 and MG2 exchange electric power with high-voltage battery 2 via PCU 3, and can also exchange electric power with each other via PCU 3.

[0015] The HVECU10 includes a microcomputer having a CPU, ROM, RAM, input / output interfaces, etc. (not shown), various drive circuits, various logic ICs, etc. The HVECU10 is connected to an engine electronic control unit (not shown) and the like via a shared communication line CB of the hybrid vehicle V, which is a CAN bus, and is also connected to various sensors such as a start switch SS, an accelerator pedal position sensor, a shift position sensor, and a vehicle speed sensor. When the hybrid vehicle V is traveling, the HVECU10 sets the required torque required for traveling based on the accelerator opening and vehicle speed, and also sets the required power and target rotation speed for the engine EG, torque command values ​​for the motor generators MG1 and MG2, etc.

[0016] The high-voltage battery 2 of the power supply system 1 is, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery having a rated output voltage of 200 to 800 V. A positive power line PL is connected to the positive terminal of the high-voltage battery 2 via a positive relay SMRB, and a negative power line NL is connected to the negative terminal of the high-voltage battery 2 via a negative relay SMRG. The high-voltage battery 2 also includes a voltage sensor 21 that detects a terminal voltage VB of the high-voltage battery 2 and a current sensor 22 that detects a current (charge / discharge current) IB flowing through the high-voltage battery 2. The terminal voltage VB of the high-voltage battery 2 detected by the voltage sensor 21 and the current IB detected by the current sensor 22 are transmitted to the HVECU 10 directly via a signal line (not shown) or via a shared communication line CB by a battery electronic control unit (not shown) that manages the high-voltage battery 2.

[0017] In this embodiment, the positive relay SMRB and the negative relay SMRG are normally open contact (mechanical) relays including a coil, a movable contact, and a fixed contact, and are controlled to open and close by the HVECU10. That is, when the driver turns on the start switch SS to request system startup of the hybrid vehicle V (and the power supply system 1), the HVECU10 outputs a closing command to the positive and negative relays SMRB, SMRG. When the positive and negative relays SMRB, SMRG are normally closed, the high-voltage battery 2 and the PCU3 are electrically connected.

[0018] Furthermore, when the driver turns off the start switch SS to request a system shutdown of the hybrid vehicle V (and the power supply system 1), the HVECU10 outputs an open command to the positive and negative relays SMRB, SMRG. This causes the positive and negative relays SMRB, SMRG to open, and the electrical connection between the high-voltage battery 2 and the PCU3 is released. The positive and negative relays SMRB and SMRG may be contact-type hybrid relays or semiconductor relays that do not have coils.

[0019] The PCU 3 of the power supply system 1 includes a first inverter 31, a second inverter 32, a step-up / step-down converter 33, and a motor electronic control unit (hereinafter referred to as "MGECU") 30. The first inverter 31 drives the motor generator MG1, and the second inverter 32 drives the motor generator MG2. The first and second inverters 31, 32 each include six transistors (not shown) (e.g., insulated gate bipolar transistors (IGBTs)) and six diodes (not shown) connected in parallel in the reverse direction to each transistor.

[0020] The buck-boost converter 33 can boost the power from the high-voltage battery 2 and reduce the voltage from the motor generators MG1 and MG2. As shown in FIG. 1 , the buck-boost converter 33 includes two transistors (e.g., insulated gate bipolar transistors) Tra and Trb, two diodes Da and Db connected in parallel in the opposite direction to the transistors Tra and Trb, and a reactor L. The MGECU 30 includes a microcomputer having a CPU, ROM, RAM, input / output interface, etc. (not shown), various drive circuits, various logic ICs, etc., and is connected to the HVECU 10 and the like via a shared communication line CB. The MGECU 30 controls the first and second inverters 31 and 32 and the buck-boost converter 33.

[0021] The PCU 3 further includes a filter capacitor (first capacitor) 34, a smoothing capacitor (second capacitor) 35, and voltage sensors 36 and 37. The positive terminal of the filter capacitor 34 is electrically connected to the positive power line PL (one end of the reactor L) between the positive relay SMRB and the step-up / step-down converter 33. The negative terminal of the filter capacitor 34 is electrically connected to the negative power line NL between the negative relay SMRG and the step-up / step-down converter 33. This allows the filter capacitor 34 to smooth the voltage on the high-voltage battery 2 side of the step-up / step-down converter 33. The voltage sensor 36 detects the inter-terminal voltage (pre-step-up voltage) VL of the filter capacitor 34.

[0022] The positive terminal of the smoothing capacitor 35 is electrically connected to the high-voltage power line HPL (the collector of the transistor Tra of the buck-boost converter 33) between the buck-boost converter 33 and the first and second inverters 31 and 32. The negative terminal of the smoothing capacitor 35 is electrically connected to the negative-side power line NL and the emitter of the transistor Trb of the buck-boost converter 33 between the buck-boost converter 33 and the first and second inverters 31 and 32. This allows the smoothing capacitor 35 to smooth the voltage on the motor generators MG1 and MG2 side of the buck-boost converter 33. The voltage sensor 37 detects the voltage VH across the smoothing capacitor 35 (boosted voltage). The voltage VL across the filter capacitor 34 detected by the voltage sensor 36 and the voltage VH across the smoothing capacitor 35 detected by the voltage sensor 37 are transmitted to the MGECU 30 and are also transmitted to the HVECU 10 directly via a signal line (not shown) or by the MGECU 30 via the shared communication line CB.

[0023] Furthermore, the MGECU 30 acquires command signals from the HVECU 10, the rotational position of the rotor of the motor generator MG1, the rotational position of the rotor of the motor generator MG2, a current value from a current sensor (not shown) of the step-up / step-down converter 33, terminal voltages VL and VH from voltage sensors 36 and 37, phase currents applied to the motor generators MG1 and MG2, etc. Based on these signals, the MGECU 30 generates gate signals (switching control signals) to the first and second inverters 31 and 32 and the step-up / step-down converter 33, and controls the switching thereof.

[0024] The low-voltage battery 4 of the power supply system 1 is, for example, a lead-acid battery having a rated output voltage of about 12-14V, and is connected to multiple auxiliaries (low-voltage auxiliaries) via low-voltage power lines. A bidirectional DC / DC converter (DDC) 5 is connected to a positive-side power line PL between a positive-side relay SMRB and the PCU 3, and is also connected to a negative-side power line NL between a negative-side relay SMRG and the PCU 3. The bidirectional DC / DC converter 5 is also connected to the low-voltage battery 4 and multiple auxiliaries via the low-voltage power lines. In addition to the bidirectional DC / DC converter 5, high-voltage auxiliaries such as an air conditioner compressor (inverter compressor) and a converter to AC 100V are connected to the positive-side power line PL and the negative-side power line NL.

[0025] The bidirectional DC / DC converter 5 reduces the power on the positive-side power line PL side, i.e., the side of the high-voltage battery 2 and PCU 3 (step-up / step-down converter 33), and supplies it to the low-voltage power line side, i.e., various accessories and the low-voltage battery 4. The bidirectional DC / DC converter 5 can also boost the power from the low-voltage battery 4 and supply it to the positive-side power line PL side, i.e., the side of the high-voltage battery 2 and PCU 3. In this embodiment, the bidirectional DC / DC converter 5 includes a voltage conversion circuit 50, a voltage sensor 51 that detects the voltage on the high-voltage battery 2 and PCU 3 sides of the voltage conversion circuit 50, a voltage sensor (not shown) that detects the voltage on the low-voltage battery 4 side of the voltage conversion circuit 50, and a control circuit 55 that feedback-controls the voltage conversion circuit 50 so that the detected value of the voltage sensor 51 becomes a required value. As shown in FIG. 1 , the control circuit 55 of the bidirectional DC / DC converter 5 is connected to the HVECU 10 via a shared communication line (CAN bus) CB of the hybrid vehicle V.

[0026] When the driver turns on the start switch SS to request system startup of the hybrid vehicle V (power supply system 1), the bidirectional DC / DC converter 5 (voltage conversion circuit 50) boosts the power from the low-voltage battery 4 as a power source and supplies it to the PCU 3 before closing the positive and negative relays SMRB and SMRG. That is, the HVECU 10 transmits a target voltage Vtag to the control circuit 55 via the shared communication line CB, and the control circuit 55 performs feedback control on the voltage conversion circuit 50 so that the detection value of the voltage sensor 51 becomes the target value. The target voltage Vtag is a required value of the voltage output from the voltage conversion circuit 50 in response to the system startup request. This allows the filter capacitor 34 and smoothing capacitor 35 of the PCU 3 to be precharged (recharged) before closing the positive and negative relays SMRB and SMRG, thereby preventing a large inrush current from flowing through the positive power line PL or the PCU 3 when the positive and negative relays SMRB and SMRG are closed.

[0027] In this embodiment, the voltage conversion circuit 50 of the bidirectional DC / DC converter 5 is connected to the HVECU10 via a backup communication line (direct line) BL. The HVECU10 transmits a precharge start command to the voltage conversion circuit 50 via the backup communication line BL as needed to precharge the filter capacitor 34 and the smoothing capacitor 35. After transmitting the precharge start command, the HVECU10 transmits a precharge stop command to the voltage conversion circuit 50 via the backup communication line BL to stop precharging the filter capacitor 34 and the smoothing capacitor 35 when a predetermined condition is met.

[0028] Next, a control procedure of the power supply system 1 when the driver turns on the start switch SS to start the system of the hybrid vehicle V will be described with reference to Fig. 2. Fig. 2 is a flowchart showing an example of a routine executed by the HVECU10 when the start switch SS is turned on to request system startup of the hybrid vehicle V.

[0029] 2, when the driver turns on the start switch SS, the HVECU10 (CPU) acquires the inter-terminal voltage VB of the high-voltage battery 2 detected by the voltage sensor 21 (step S100). Furthermore, in step S100, the HVECU10 sets the acquired inter-terminal voltage VB as the target voltage Vtag of the filter capacitor 34 and the smoothing capacitor 35 (precharge) of the PCU 3, and transmits the target voltage Vtag to the control circuit 55 of the bidirectional DC / DC converter 5 via the shared communication line CB.

[0030] When no abnormality is occurring in the CAN communication via the shared communication line CB or in the bidirectional DC / DC converter 5, the control circuit 55 starts feedback control of the voltage conversion circuit 50 with the positive and negative relays SMRB, SMRG open so that the detection value of the voltage sensor 51 becomes the target voltage Vtag from the HVECU 10. Furthermore, when the detection value of the voltage sensor 51 becomes the target voltage Vtag, the control circuit 55 performs feedback control of the voltage conversion circuit 50 so that the detection value is maintained at the target voltage Vtag.

[0031] After transmitting the target voltage Vtag to the control circuit 55 of the bidirectional DC / DC converter 5, the HVECU 10 determines, according to a predetermined procedure, whether an abnormality has occurred in the CAN communication via the shared communication line CB (step S110). If no abnormality is detected in the CAN communication via the shared communication line CB, i.e., if the abnormality in the CAN communication has not been confirmed (step S120: NO), the HVECU 10 acquires the inter-terminal voltage VL of the filter capacitor 34 detected by the voltage sensor 36, and determines whether precharging of the filter capacitor 34 and the like has been completed based on the acquired inter-terminal voltage VL and the target voltage Vtag set in step S100 (step S130). In step S130, the HVECU 10 determines, for example, whether a state in which the inter-terminal voltage VL of the filter capacitor 34 is equal to or greater than a threshold value (predetermined value) Vref obtained by subtracting a predetermined relatively small positive value from the inter-terminal voltage VB of the high-voltage battery 2 has continued for a predetermined time tref.

[0032] If the state in which the inter-terminal voltage VL of the filter capacitor 34 is equal to or higher than the threshold value Vref continues for the time tref, the HVECU 10 determines that the bidirectional DC / DC converter 5 and the like are normal and that the precharging of the filter capacitor 34 and the like by the bidirectional DC / DC converter 5 has been completed (step S140: YES). In this case, the HVECU 10 transmits a precharge stop command to the control circuit 55 via the shared communication line CB to stop the operation of the bidirectional DC / DC converter 5 (step S150), and ends the routine of FIG.

[0033] Furthermore, if the state in which the inter-terminal voltage VL of the filter capacitor 34 is equal to or higher than the threshold value Vref does not continue for a predetermined time tref, the HVECU 10 determines that an abnormality, a disconnection, or the like has occurred in the bidirectional DC / DC converter 5 and that precharging of the filter capacitor 34, etc. by the bidirectional DC / DC converter 5 has not been completed normally (step S140: NO). In this case, the HVECU 10 turns on a precharge abnormality flag indicating that an abnormality, a disconnection, etc. has occurred in the bidirectional DC / DC converter 5, turns on a predetermined warning light provided on an instrument panel, etc. (not shown) (step S160), and ends the routine of FIG. 2. If the precharge abnormality flag is turned on in step S160, the HVECU 10 prohibits operation of the power supply system 1, transition to a READY-ON state (driving permitted state) in which driving of the hybrid vehicle V is permitted, and operation of the bidirectional DC / DC converter 5.

[0034] On the other hand, if an abnormality has occurred in the CAN communication via the shared communication line CB, i.e., if the abnormality in the CAN communication has been confirmed (step S120: YES), the HVECU10 turns on a CAN communication abnormality flag indicating that an abnormality has occurred in the CAN communication (step S121). Furthermore, the HVECU10 transmits a pre-charge start command to the voltage conversion circuit 50 of the bidirectional DC / DC converter 5 via the backup communication line BL (step S125). In response to the pre-charge start command, the voltage conversion circuit 50 of the bidirectional DC / DC converter 5 boosts the power from the low-voltage battery 4 according to a predetermined procedure and supplies the boosted power to the filter capacitor 34 and smoothing capacitor 35 of the PCU 3. As a result, the filter capacitor 34 and smoothing capacitor 35 are pre-charged with power from the voltage conversion circuit 50.

[0035] After the process of step S125, the HVECU10 acquires the inter-terminal voltage VL of the filter capacitor 34 and compares the acquired inter-terminal voltage VL with the threshold value Vref to determine whether precharging of the filter capacitor 34 and the like has been completed (step S130). If the inter-terminal voltage VL of the filter capacitor 34 remains equal to or greater than the threshold value Vref for the time tref, the HVECU10 determines that the bidirectional DC / DC converter 5 and the like are normal and that precharging of the filter capacitor 34 and the like by the bidirectional DC / DC converter 5 has been completed (step S140: YES). In this case, since the CAN communication abnormality flag was turned on in step S121, the HVECU10 transmits a precharging stop command to the control circuit 55 via the backup communication line LB to stop operation of the bidirectional DC / DC converter 5 (step S150), and ends the routine of FIG. 2. Thereafter, the HVECU10 transitions the hybrid vehicle V (and the power supply system 1) to a fail-safe mode corresponding to the abnormality in CAN communication.

[0036] Furthermore, if the state in which the inter-terminal voltage VL of the filter capacitor 34 is equal to or higher than the threshold value Vref does not continue for the predetermined time tref, the HVECU 10 determines that an abnormality has occurred in the bidirectional DC / DC converter 5 or the like, and that precharging of the filter capacitor 34 or the like by the bidirectional DC / DC converter 5 has not been completed normally (step S140: NO). In this case, the HVECU 10 turns on a precharge abnormality flag and turns on a predetermined warning light (step S160), and ends the routine of Fig. 2. Thereafter, the HVECU 10 transitions the hybrid vehicle V (and the power supply system 1) to a fail-safe mode corresponding to the abnormality in CAN communication, and in response to the precharge abnormality flag being turned on, inhibits transition to the READY-ON state (traveling permitted state) and operation of the bidirectional DC / DC converter 5.

[0037] As described above, the HVECU10 serving as the control device of the power supply system 1 transmits the target voltage Vtag of the filter capacitor 34 and the smoothing capacitor 35 of the PCU 3 to the control circuit 55 of the bidirectional DC / DC converter 5 serving as a precharge device in response to a system startup request made by operating the start switch SS (step S100), and determines whether or not there is an abnormality in CAN communication with the bidirectional DC / DC converter 5 (control circuit 55) (step S110). Furthermore, when an abnormality in CAN communication with the bidirectional DC / DC converter 5 has not been determined (step S120: NO), the HVECU10 determines whether or not precharge has been completed based on the detection value of the voltage sensor 36, i.e., the inter-terminal voltage VL of the filter capacitor 34 (step S130). When precharge has been completed, the HVECU10 determines that the bidirectional DC / DC converter 5 and the like are normal (steps S140: YES, S150), and when precharge has not been completed, determines that an abnormality has occurred in the bidirectional DC / DC converter 5 and the like (steps S140: NO, S160). As a result, even if the CAN communication between the HVECU10 and the bidirectional DC / DC converter 5 (control circuit 55) is unstable and it is not possible to determine that an abnormality has occurred in the communication state (CAN communication) between them, it is possible to properly determine an abnormality in the bidirectional DC / DC converter 5, which precharges the filter capacitor 34 and smoothing capacitor 35 of the PCU 3 connected to the high-voltage battery 2.

[0038] In the above embodiment, the bidirectional DC / DC converter 5 is connected to the HVECU10 via the backup communication line BL. When an abnormality in CAN communication is confirmed (step S120: YES), the HVECU10 transmits a pre-charge start command to the bidirectional DC / DC converter 5 via the backup communication line BL (step S125), and determines whether pre-charge is completed based on the detection value (inter-terminal voltage VL) of the voltage sensor 36 after transmitting the pre-charge start command (step S130). When pre-charge is completed, the HVECU10 determines that the bidirectional DC / DC converter 5 and the like are normal (steps S140: YES, S150), and when pre-charge is not completed, determines that an abnormality has occurred in the bidirectional DC / DC converter 5 and the like (steps S140: NO, S160). This makes it possible to properly determine whether there is an abnormality in the bidirectional DC / DC converter 5 that precharges the filter capacitor 34 and smoothing capacitor 35 of the PCU 3, even if it is determined that an abnormality has occurred in the CAN communication (communication state) between the HVECU 10 and the bidirectional DC / DC converter 5.

[0039] Furthermore, the HVECU 10 determines that precharging is complete when the terminal voltage VL of the filter capacitor 34 detected by the voltage sensor 36 remains equal to or greater than the threshold value (predetermined value) Vref for at least the time tref (predetermined time) (steps S130 and S140: YES). This allows the HVECU 10 to properly determine whether precharging is complete. However, the determination process in step S130 may determine whether both the terminal voltage VL of the filter capacitor 34 and the terminal voltage VH of the smoothing capacitor 35 have fluctuated in accordance with the target voltage Vtag, or may determine whether only the terminal voltage VH of the smoothing capacitor 35 has fluctuated in accordance with the target voltage Vtag.

[0040] The hybrid vehicle V also includes a low-voltage battery 4 having a lower voltage than the high-voltage battery 2, and a bidirectional DC / DC converter 5 as a pre-charge device connected to the HVECU 10 via a shared communication line CB (CAN bus). The bidirectional DC / DC converter 5 adjusts the power from the low-voltage battery 4 to a target voltage Vtag in response to a system startup request, and pre-charges the filter capacitor 34 and smoothing capacitor 35 of the PCU 3. This makes it possible to pre-charge the filter capacitor 34 and smoothing capacitor 35 of the PCU 3 using the power of the low-voltage battery 4.

[0041] However, if the hybrid vehicle V is a plug-in hybrid vehicle (PHEV), an external charging device such as a charger connected to a household power source or a charger installed at a stand may be used as the pre-charging device, and the power from the external charging device may be adjusted to the target voltage Vtag to pre-charge the filter capacitor 34, etc. In this case, for example, when the communication state between the control device of the hybrid vehicle V and the external charging device is unstable and it has not been determined that an abnormality has occurred in the communication state (CAN communication) between them, the processing of steps S130-S160 in FIG. 2 may be executed.

[0042] Furthermore, a precharge circuit including a precharge relay and a resistor may be installed in parallel with the negative-side system main relay SMRG, for example, in the negative-side power line NL of the power supply system 1. In such a power supply system 1, the processing of steps S130-S160 in Fig. 2 may be executed when it has not been determined that an abnormality has occurred in the communication state between a control device such as the HVECU10 and the precharge circuit. Furthermore, in this case, the bidirectional DC / DC converter 5 may be replaced with a DC / DC converter that does not have the function of boosting power from the low-voltage battery 4.

[0043] Furthermore, in the power supply system 1, the backup communication line BL between the bidirectional DC / DC converter 5 (voltage conversion circuit 50) and the HVECU 10 may be omitted. In this case, the processing of steps S130-S160 in FIG. 2 only needs to be executed when an abnormality in the CAN communication has not been confirmed (step S120: NO).

[0044] Furthermore, the vehicle including the above-described power supply system 1 is not limited to a two-motor (series-parallel) hybrid vehicle V having a planetary gear PG for power distribution. In other words, the vehicle on which the power supply system 1 is mounted may be a one-motor hybrid vehicle, a series hybrid vehicle, a parallel hybrid vehicle, or an electric vehicle (BEV).

[0045] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0046] The invention of the present disclosure can be used in the power supply system manufacturing industry and the like. [Explanation of symbols]

[0047] 1 power supply system, 2 high-voltage battery (energy storage device), 3 power control unit (PCU), 34 filter capacitor, 35 smoothing capacitor, 36, 37 voltage sensor, 4 low-voltage battery, 5 bidirectional DC / DC converter, 50 voltage conversion circuit, 55 control circuit, 10 hybrid electronic control unit (HVECU), BL backup communication line, CB shared communication line, MG1, MG2 motor generators.

Claims

1. A power supply system including a power storage device, a power control device including a capacitor and connected to the power storage device, and a precharge device that precharges the capacitor of the power control device in response to a system startup request, A power supply system comprising a control device that transmits a target voltage of the capacitor to the precharge device in response to the system startup request, determines whether or not there is an abnormality in the communication state with the precharge device, and when the abnormality in the communication state has not been determined, determines whether or not the precharge has been completed based on the detection value of a specified sensor, determines that the precharge device is normal when the precharge has been completed, and determines that an abnormality has occurred in the precharge device when the precharge has not been completed.

2. 2. The power supply system according to claim 1, Further, a second power storage device having a lower voltage than the power storage device is provided, the precharge device is a voltage conversion device that adjusts the power from the second power storage device to the target voltage and precharges the capacitor; The control device sets the target voltage in response to the system startup request, transmits the target voltage to a control circuit of the voltage conversion device via CAN communication, and determines whether an abnormality has occurred in the CAN communication.

3. 3. The power supply system according to claim 2, the predetermined sensor is a voltage sensor that detects a voltage of the capacitor, The control device determines that the precharge is completed when a state in which the detected value of the voltage sensor is equal to or greater than a predetermined value continues for a predetermined time or longer.

4. 4. The power supply system according to claim 2, the voltage conversion device is connected to the control device via a backup communication line; When an abnormality in the CAN communication is confirmed, the control device sends a pre-charge start command to the voltage conversion device via the backup communication line, and after sending the pre-charge start command, determines whether the pre-charge has been completed based on the detection value of the specified sensor, and determines that the voltage conversion device is normal when the pre-charge has been completed, and determines that an abnormality has occurred in the voltage conversion device when the pre-charge has not been completed.

5. 1. A method for determining an abnormality in a precharge device in a power supply system including a power storage device, a power control device including a capacitor and connected to the power storage device, and a precharge device that precharges the capacitor of the power control device in response to a system startup request, comprising: transmitting a target voltage of the capacitor to the precharge device in response to the system startup request; determining whether or not there is an abnormality in the communication state with the precharge device; When the abnormality in the communication state has not been confirmed, it is determined whether or not the precharge has been completed based on a detection value of a predetermined sensor; determining that the precharge device is normal when the precharge is completed, and determining that an abnormality has occurred in the precharge device when the precharge is not completed; A method for determining an abnormality in a precharge device in a power supply system.

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