Control device and program

Abstract

In a power supply system, an electric load (21) and a capacitor (22) are connected to a battery (11) via an electric pathway (12, 13). Meanwhile, a power supply switch (15, 16) is connected to the electric pathway, and a serial-connection body constituted of a pre-charge switch (17) and a current limiting resistor (18) is connected in parallel to the power supply switch. In response to a system startup request, a control device (30) pre-charges the capacitor by energizing the pre-charge switch before energizing the power supply switch. The control device comprises: an abnormality determination unit that determines whether an energization abnormality, in which the energization continues via the pre-charge switch even after the pre-charge of the capacitor has been completed after the pre-charge switch has been turned ON, has occurred; and a switch control unit that, if it is determined that the energization abnormality has occurred, turns OFF the pre-charge switch, and does not permit the pre-charge switch to be turned ON until a prescribed period of time elapses.

Description

Control device and program CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2023-007291 filed on January 20, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a control device and a program for a power supply system.

[0003] A known power supply system has a configuration in which a main relay is provided in an electrical path connected to a battery, and a series connection of a pre-charge relay and a current-limiting resistor is connected in parallel to the main relay. For example, Patent Document 1 discloses a technology for a power supply control device that controls the on / off of each relay in response to a power connection request, in which the main relay is maintained in an on state without being turned off even if a power cutoff request is received if the elapsed time since the pre-charge relay was turned off is shorter than a predetermined time. Patent Document 1 also discloses a technology for forcibly turning off each relay when an abnormality is detected in the battery, load, main relay, or pre-charge relay.

[0004] JP 2011-114974 A

[0005] In a power supply system, when the precharge relay is in the on state, a current abnormality may occur, causing current to continue to flow even after precharge is complete, due to a malfunction of an electrical device or a short circuit in the electrical path. In this case, the technology in Patent Document 1 simply shuts off all relays when an abnormality is detected, but does not specify how to limit precharge in response to subsequent system startup requests (power supply connection requests). Therefore, there is a concern that precharge may be performed again in response to the next system startup request, even though the current abnormality has occurred, causing the current limiting resistor to overheat.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a control device and a program that can take appropriate measures when a current flow abnormality occurs after precharging.

[0007] In order to solve the above problems, the present disclosure is applied to a power supply system in which an electrical load and a capacitor are connected to a battery via an electrical path, and a power switch is connected to the electrical path, and a series connection of a pre-charge switch and a current limiting resistor is connected in parallel to the power switch, and a control device that, in response to a system startup request, causes current to flow through the pre-charge switch before current flows through the power switch, thereby pre-charging the capacitor, and includes: an abnormality determination unit that determines whether an electrical current abnormality has occurred in which current continues to flow through the pre-charge switch even after pre-charging of the capacitor is completed after the pre-charge switch is turned on; and a switch control unit that, when it is determined that the electrical current abnormality has occurred, turns off the pre-charge switch and does not allow the pre-charge switch to be turned on until a predetermined period has elapsed.

[0008] In a power supply system, it is conceivable that an abnormal current flow may occur in which current continues to flow even after precharging is completed while the precharge switch is in the on state. Taking this into consideration, the system determines whether an abnormal current flow has occurred after the precharge switch is turned on, and if it is determined that an abnormal current flow has occurred, turns off the precharge switch and does not permit the precharge switch to be turned on again until a predetermined period of time has elapsed. This prevents overheating of the current limiting resistor when an abnormal current flow occurs. As a result, appropriate measures can be taken when an abnormal current flow occurs after precharging.

[0009] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic configuration diagram of a power supply system, Fig. 2 is a flowchart showing a procedure for relay control, Fig. 3 is a time chart for explaining the relay control in more detail, Fig. 4 is a schematic configuration diagram of a power supply system according to a second embodiment, Fig. 5 is a flowchart showing the procedure for relay control in the second embodiment, Fig. 6 is a time chart for explaining the relay control in the second embodiment in more detail, and Fig. 7 is a diagram showing the relationship between the current integrated value and standby time TB.

[0010] First Embodiment Hereinafter, an embodiment of a power supply system according to the present disclosure will be described with reference to the drawings. In the following embodiments and modifications, identical or equivalent parts are designated by the same reference numerals in the drawings, and the same explanations are incorporated herein by reference.

[0011] This embodiment realizes a high-voltage power supply system to be mounted on an electrically powered vehicle such as an electric vehicle or a hybrid vehicle, and is configured to drive a high-voltage electrical load with power supplied from a high-voltage power supply. Fig. 1 shows a schematic configuration of the power supply system in this embodiment.

[0012] 1, a battery 11, which is a high-voltage power source, is connected to a positive electrode path 12 and a negative electrode path 13 as positive and negative electrical paths, and a high-voltage electrical load 21 is connected to each of the paths 12 and 13. The battery 11 is, for example, a high-voltage lithium-ion storage battery with a storage voltage of several hundred volts. The high-voltage electrical load 21 includes an inverter that drives a vehicle driving motor (not shown).

[0013] Between the battery 11 and the high-voltage electrical load 21, a main relay 15 is connected to the positive electrode path 12, and a ground relay 16 is connected to the negative electrode path 13. A series connection of a pre-charge relay 17 and a current limiting resistor 18 is also connected to the positive electrode path 12 in parallel with the main relay 15. In this embodiment, the main relay 15 corresponds to the "power switch," and the pre-charge relay 17 corresponds to the "pre-charge switch."

[0014] A capacitor 22 is connected in parallel to a high-voltage electrical load 21 between the positive electrode path 12 and the negative electrode path 13 .

[0015] The power supply system is provided with a control device 30 including a microcomputer, various memories, and the like. A start signal is input to the control device 30 from a start switch 31 that starts the power supply system, and a current signal is input to the control device 30 from a current sensor 32 provided in the negative electrode path 13, for example. The start switch 31 is a vehicle start switch (start switch) operated by a user to start the vehicle, or an associated switch that is turned on when the vehicle start switch is turned on. The start signal (on signal) input from the start switch 31 to the control device 30 corresponds to a "system start request." Although not shown, the control device 30 may be appropriately supplied with input information such as battery information indicating the voltage, temperature, etc. of the battery 11, and operating state information indicating the operating state of the traction motor that serves as the vehicle's driving source.

[0016] The control device 30 has a relay control function for controlling the on / off of the main relay 15 , the ground relay 16 and the precharge relay 17 , and a load control function for controlling the operation of the high-voltage electrical load 21 .

[0017] When the control device 30 receives a start signal (system start request) output from the start switch 31, it turns on the ground relay 16 and the pre-charge relay 17 before turning on the main relay 15. This causes current to flow from the battery 11 via the pre-charge relay 17 and the current limiting resistor 18, pre-charging the capacitor 22. In other words, current is passed through the pre-charge relay 17 before current is passed through the main relay 15, thereby charging the capacitor 22. Furthermore, the control device 30 turns on the main relay 15 and turns off the pre-charge relay 17 after a predetermined time TA has elapsed since the pre-charge relay 17 was turned on. This enables power to be supplied from the battery 11 to the high-voltage electrical load 21.

[0018] When pre-charging is performed, current is passed through the current limiting resistor 18, and the current limiting resistor 18 is heated in accordance with the amount of current. In this case, if a current flow abnormality occurs in which current continues to flow through the pre-charge relay 17 even after pre-charging is complete, for example, due to a short circuit abnormality on the high-voltage electrical load 21 side, there is a concern that the current limiting resistor 18 will be excessively heated.

[0019] Therefore, in this embodiment, the control device 30 is configured to include an abnormality determination unit that determines whether an electrical conduction abnormality has occurred, in which current continues to flow through the pre-charge relay 17 even after the pre-charge relay 17 has been turned on and charging of the capacitor 22 has been completed, and a switch control unit that, when it is determined that an electrical conduction abnormality has occurred, turns off the pre-charge relay 17 and does not allow the pre-charge relay 17 to be turned on until a predetermined period of time has elapsed. In this embodiment, when an electrical conduction abnormality has occurred, the pre-charge relay 17 is not allowed to be turned on for the predetermined period of time until a waiting time TB set in a timer has elapsed, and after the waiting time TB has elapsed, the pre-charge relay 17 is allowed to be turned on.

[0020] FIG. 2 is a flowchart showing the procedure of the relay control. This process is carried out by the control device 30 at predetermined intervals after the start switch 31 is turned on.

[0021] 2, in step S11, it is determined whether or not the waiting time TB set in the timer remains, in other words, whether or not the waiting time TB is greater than 0. This waiting time TB is set when an abnormality in power supply occurs, and if the waiting time TB is 0, the process proceeds to the subsequent step S12. In step S12, the main relay 15 is turned off, and the ground relay 16 and precharge relay 17 are turned on. This starts precharging.

[0022] Then, in step S13, the process waits for a predetermined time TA to elapse since the precharge relay 17 was turned on, and in the following step S14, it is determined whether the current Ir flowing through the current limiting resistor 18 is less than a predetermined threshold value TH1 based on the detection value of the current sensor 32. In this embodiment, the current Ir at the time when the predetermined time TA has elapsed is detection information of the current flowing through the current limiting resistor 18 and corresponds to a parameter indicating the magnitude of the current flowing during the precharge current-carrying period. The predetermined time TA is determined based on the time required to complete precharging of the capacitor 22, and the current Ir should normally be zero or near zero when the predetermined time TA has elapsed. In other words, if the power supply system is normal, the current Ir will be less than the threshold value TH1, and the result of step S14 will be affirmative, leading to step S15.

[0023] In step S15, the main relay 15 and the ground relay 16 are turned on, and the precharge relay 17 is turned off, thereby enabling power supply from the battery 11 to the high voltage electrical load 21.

[0024] Then, in step S16, it is determined whether or not the start switch 31 has been turned off. If the start switch 31 has been turned off, the process proceeds to step S17, where the main relay 15, the ground relay 16, and the precharge relay 17 are all turned off.

[0025] On the other hand, if it is determined in step S14 that the current Ir is equal to or greater than the threshold value TH1, the process proceeds to step S18. In step S18, the main relay 15, the ground relay 16, and the precharge relay 17 are all turned off. In step S19, a waiting time TB is set in a timer. The waiting time TB may be, for example, several tens of seconds to several minutes. Also, in step S19, the user may be notified of the occurrence of an abnormality. This notification may be made continuously until the waiting time TB has elapsed. The notification may be made by an on-board audio device or display device, or by a portable device carried by the user.

[0026] After the standby time TB is set, the result of step S11 is negative until the standby time TB has elapsed after each subsequent ON of the start switch 31. As a result, current is prohibited from passing through the pre-charge relay 17 until the standby time TB has elapsed, i.e., until the current limiting resistor 18 has completely cooled down.

[0027] Figure 3 is a time chart for explaining the relay control in more detail. In Figure 3, it is assumed that an abnormality in the power supply system occurs, but for comparison, the current change during normal operation is shown by a dashed line. When the start switch 31 is in the OFF state, all of the relays 15 to 17 are in the OFF state as an initial state.

[0028] 3 , at timing t1, the start switch 31 is turned on, turning on the ground relay 16 and pre-charge relay 17, and pre-charge begins. At this time, the current Ir rises sharply at the beginning of pre-charge and then gradually decreases as the charging of the capacitor 22 progresses. If the system is operating normally, as shown by the dashed-dotted line, pre-charge is completed and the current Ir becomes zero before the lapse of a predetermined time TA. Thereafter, although not shown, at timing t2, the main relay 15 and ground relay 16 are turned on and the pre-charge relay 17 is turned off. This enables power to be supplied from the battery 11 to the high-voltage electrical load 21.

[0029] On the other hand, if an abnormality in the electrical current flows in the power supply system, the current Ir becomes larger than when the system is normal after timing t1, and the current Ir continues to flow even after pre-charging is complete. In other words, if a malfunction of an electrical device or a short circuit in the electrical path occurs, an abnormal current is added to the original pre-charge current when the pre-charge relay 17 is turned on. Therefore, an excess current flows while the pre-charge relay 17 is turned on, which promotes heat generation in the current-limiting resistor 18.

[0030] At timing t2, the current Ir exceeds the threshold value TH1, turning off all relays. After timing t2, a waiting time TB is set. Therefore, even if a system startup request is made by turning on the startup switch 31 at timing t3, the precharge relay 17 remains off. At timing t4, the waiting time TB has elapsed, and the current limiting resistor 18 has cooled down.

[0031] Thereafter, at timing t5, when the start switch 31 is turned on and a system start request is made, the ground relay 16 and pre-charge relay 17 are turned on, and pre-charging begins. The current flow abnormality is resolved at timing t5, and at timing t6, after a predetermined time TA has elapsed, the main relay 15 and ground relay 16 are turned on, and the pre-charge relay 17 is turned off. This enables power to be supplied from the battery 11 to the high-voltage electrical load 21. Thereafter, at timing t7, the start switch 31 is turned off, and the main relay 15 and ground relay 16 are turned off.

[0032] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0033] In the power supply system, it is conceivable that an electrical conduction abnormality may occur in which current continues to flow even after pre-charging is completed while the pre-charge relay 17 is in the on state. In consideration of this, it is determined whether an electrical conduction abnormality has occurred after the pre-charge relay 17 is turned on, and if it is determined that an electrical conduction abnormality has occurred, the pre-charge relay 17 is turned off and is not permitted to be turned on until a predetermined period (standby time TB) has elapsed. This makes it possible to prevent overheating of the current limiting resistor 18 when an electrical conduction abnormality occurs. As a result, appropriate measures can be taken when an electrical conduction abnormality occurs after pre-charging.

[0034] After the pre-charge relay 17 is turned on, the temperature of the current limiting resistor 18 rises in accordance with the amount of current flowing through the current limiting resistor 18. In this case, the presence or absence of an electrical current abnormality can be determined appropriately because the configuration is such that the presence or absence of an electrical current abnormality is determined based on detection information about the current flowing after the pre-charge relay 17 is turned on.

[0035] When it is determined that a current-carrying abnormality has occurred, the pre-charge relay 17 is permitted to be turned on based on the lapse of a predetermined period of time, i.e., the completion of cooling of the current-limiting resistor 18. This prevents unnecessary restriction of pre-charging when the current-carrying abnormality is temporary and is resolved. Therefore, it is possible to prevent the vehicle from becoming immobile after the current-limiting resistor 18 has cooled.

[0036] When the ON operation of the precharge relay 17 is restricted in response to the occurrence of a current flow abnormality, the system is configured to notify the user of the occurrence of the abnormality within the restricted period. This allows the user to be conveniently informed of the cause if the vehicle does not start despite the user turning on the start switch 31. It also allows the user to be urged to have the problem repaired.

[0037] Second Embodiment Next, a second embodiment will be described, which is a partial modification of the first embodiment. Fig. 4 shows a schematic configuration of a power supply system in this embodiment. Fig. 4 differs from Fig. 1 in that a temperature sensor 41 is provided to detect the temperature (resistance temperature Tr) of the current limiting resistor 18 instead of the current sensor 32. In this embodiment, a current abnormality is determined based on the resistance temperature Tr after the start of pre-charging, and the pre-charge relay 17 is not allowed to turn on for a predetermined period of time until the resistance temperature Tr drops to a predetermined temperature after the determination, and is then allowed to turn on after the resistance temperature Tr drops.

[0038] FIG. 5 is a flowchart showing the procedure of relay control in the second embodiment. This process is carried out by the control device 30 at predetermined intervals after the start switch 31 is turned on.

[0039] 5, in step S21, it is determined whether the standby flag F is set to 1, in other words, whether a current flow abnormality has been determined to have occurred due to the temperature of the current limiting resistor 18 at some point in the past, and whether this history has been stored as flag information. In the initial state where no abnormality determination has been made, the standby flag F = 0. Then, if the standby flag F is 0, the process proceeds to step S24. In step S24, the main relay 15 is turned off, and the ground relay 16 and precharge relay 17 are turned on. This starts precharging.

[0040] Next, in step S25, the process waits for a predetermined time TA to elapse since the precharge relay 17 was turned on. In the following step S26, the process determines whether the resistance temperature Tr is less than a predetermined threshold value TH11 based on the value detected by the temperature sensor 41. In this embodiment, the resistance temperature Tr at the time the predetermined time TA has elapsed is the detected temperature information of the current limiting resistor 18 and corresponds to a parameter indicating the magnitude of the current flowing during the precharge current flow period. The threshold value TH11 is predetermined based on the amount of current required to charge the capacitor 22. The threshold value TH11 may also be determined as a relative temperature based on the resistance temperature Tr at the start of the precharge current flow. If the power supply system is normal, the resistance temperature Tr will be less than the threshold value TH11, and the process proceeds to step S27.

[0041] In step S27, the main relay 15 and the ground relay 16 are turned on, and the precharge relay 17 is turned off, thereby enabling power supply from the battery 11 to the high voltage electrical load 21.

[0042] Then, in step S28, it is determined whether or not the start switch 31 has been turned off. If the start switch 31 has been turned off, the process proceeds to step S29, where the main relay 15, the ground relay 16, and the precharge relay 17 are all turned off.

[0043] On the other hand, if it is determined in step S26 that the resistance temperature Tr is equal to or higher than the threshold value TH11, the process proceeds to step S30. In step S30, the main relay 15, the ground relay 16, and the precharge relay 17 are all turned off. In step S31, the standby flag F is set to 1. Also, in step S31, it is preferable to notify the user that an abnormality has occurred.

[0044] After the standby flag F is set, step S21 is affirmatively determined each time the start switch 31 is turned on, and the process proceeds to step S22. In step S22, it is determined whether the resistance temperature Tr is less than a predetermined threshold value TH12. The threshold value TH12 is a temperature lower than the threshold value TH11 used in step S26. The process proceeds to step S22 in a negative manner until the resistance temperature Tr falls below the threshold value TH12. As a result, current flow through the precharge relay 17 is prohibited until cooling of the current limiting resistor 18 is completed. When the resistance temperature Tr falls below the threshold value TH12, the process proceeds to step S23, where the standby flag F is reset to 0. Thereafter, the process from step S24 onward is carried out as described above.

[0045] Fig. 6 is a time chart for explaining the relay control in more detail. In Fig. 6, it is assumed that an abnormality in the electrical current is occurring in the power supply system, but for the purpose of comparison, the change in resistance temperature during normal operation is shown by a dashed line.

[0046] 6 , at timing t11, the start switch 31 is turned on, turning on the ground relay 16 and pre-charge relay 17, and pre-charging begins. At this time, as the charging of the capacitor 22 progresses, the resistance temperature Tr gradually rises. If the system is operating normally, as shown by the dashed-dotted line, pre-charging is completed before the predetermined time TA has elapsed, and current flow is stopped, causing the resistance temperature Tr to change from rising to falling. After that, at timing t12 (not shown), the main relay 15 and ground relay 16 are turned on, and the pre-charge relay 17 is turned off.

[0047] On the other hand, if a current abnormality occurs in the power supply system, the temperature rise rate becomes larger after timing t11 compared to when the system is normal, and the resistance temperature Tr continues to rise even after pre-charging is complete. As a result, at timing t12, the resistance temperature Tr exceeds the threshold value TH11, and all relays are turned off. Also, at timing t12, the standby flag F is set to 1. It is also possible to configure the system so that all relays are turned off when the resistance temperature Tr reaches the threshold value TH11.

[0048] After that, even if a system startup request is made by turning on the startup switch 31 at timing t13, the standby flag F is 1 and the resistance temperature Tr is equal to or higher than the threshold value TH12, so the precharge relay 17 remains off. However, at timing t14, the resistance temperature Tr falls below the threshold value TH12 as the current limiting resistor 18 cools.

[0049] Thereafter, when a system startup request is made by turning on the start switch 31 at timing t15, the resistance temperature Tr is less than the threshold value TH12, so the standby flag F is reset to 0, and the ground relay 16 and pre-charge relay 17 are turned on to start pre-charging. At timing t15, the abnormal current flow has been resolved, and any subsequent excessive increase in the resistance temperature Tr is suppressed. Therefore, at timing t16, the main relay 15 and ground relay 16 transition to an on state, and the pre-charge relay 17 transitions to an off state. Thereafter, at timing t17, the start switch 31 is turned off, and the main relay 15 and ground relay 16 are turned off.

[0050] According to the second embodiment described above, the presence or absence of an electrical conduction abnormality is determined based on the detection information of the temperature of the current limiting resistor 18 after the precharge relay 17 is turned on, so that the occurrence of an electrical conduction abnormality can be determined appropriately.

[0051] Furthermore, after it is determined that an abnormality in electrical current has occurred, the pre-charge relay 17 is not permitted to be turned on for a predetermined period of time until the temperature (resistance temperature Tr) of the current limiting resistor 18 drops to a predetermined temperature. This makes it possible to suitably prevent the pre-charge relay 17 from being turned on before the temperature drops.

[0052] (Other Embodiments) The above embodiment may be modified as follows, for example.

[0053] In the first embodiment, the current Ir at the time when the predetermined time TA has elapsed is acquired as a parameter indicating the magnitude of the current flowing during the pre-charge current-carrying period. However, this may be changed. For example, the parameter may be an integrated current value, which is an integrated value of the current flowing after the pre-charge relay 17 is turned on. Alternatively, the parameter may be the maximum current flowing immediately after the pre-charge relay 17 is turned on.

[0054] It is also possible to use both detection information about the current flowing through the current limiting resistor 18 and detection information about the temperature of the current limiting resistor 18 as parameters indicating the magnitude of the current flow during the pre-charge current-carrying period. For example, it may be determined that an abnormal current flow has occurred on the condition that the current Ir is equal to or greater than a predetermined value and the resistance temperature Tr is equal to or greater than a predetermined value after a predetermined time TA has elapsed. Alternatively, it may be determined that an abnormal current flow has occurred based on either the integrated current value after the pre-charge relay 17 is turned on being equal to or greater than a predetermined value, or the resistance temperature Tr being equal to or greater than a predetermined value, whichever occurs first.

[0055] The amount of heat generated by the current limiting resistor 18 changes depending on the amount of current flowing through it after the precharge relay 17 is turned on, and the length of the predetermined period required for the current limiting resistor 18 to cool also changes. Taking this into consideration, the predetermined period may be variably set based on a parameter indicating the magnitude of the current flowing through it during the precharge current flow period. For example, using the relationship shown in FIG. 7 , the control device 30 may set the standby time TB to a longer time the greater the integrated current value after the precharge relay 17 is turned on. Alternatively, the control device 30 may set the standby time TB to a longer time the greater the current Ir at the time the predetermined time TA has elapsed, or the greater the resistance temperature Tr at the time the predetermined time TA has elapsed. In short, it is sufficient that the predetermined period is lengthened as the integrated value of the current flowing through the current limiting resistor 18 after the precharge relay 17 is turned on (i.e., the amount of heat generated by the current limiting resistor 18) increases.

[0056] As a result, after the occurrence of a current-carrying abnormality, the completion of cooling of the current-limiting resistor 18 is determined at an appropriate timing, and pre-charging is permitted. By being able to optimize the determination of cooling of the current-limiting resistor 18, it is possible to prevent unnecessary restriction of pre-charging in cases where the current-carrying abnormality is temporary and is resolved.

[0057] In the above embodiment, the main relay 15 is provided in the positive electrode side path 12 as a power switch, and the pre-charge relay 17 and the current limiting resistor 18 are connected in parallel to the main relay 15. However, this configuration may be modified so that the ground relay 16 is provided in the negative electrode side path 13 as a power switch, and the pre-charge relay 17 and the current limiting resistor 18 are connected in parallel to the ground relay 16. Furthermore, instead of providing the main relay 15 and the ground relay 16 in the positive electrode side and the negative electrode side paths 12, 13, respectively, only one of the positive electrode side main relay 15 and the negative electrode side ground relay 16 may be provided, and that relay may serve as a power switch.

[0058] As the power switch or precharge switch, a switching device other than a relay may be used. For example, a semiconductor switch may be used.

[0059] In the above embodiment, the present disclosure is applied to a high-voltage power supply system for an electric vehicle, but it can also be applied to other applications, such as power supply systems for various mobile objects such as aircraft and ships, and power supply systems for stationary devices.

[0060] The controller and methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the controller and methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the controller and methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0061] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. The present invention is applied to a power supply system in which an electric load (21) and a capacitor (22) are connected to a battery (11) via an electric path (12, 13), and power switches (15, 16) are connected to the electric path, and a series connection of a pre-charge switch (17) and a current limiting resistor (18) is connected in parallel to the power switch, A control device (30) that precharges the capacitor by conducting current through the precharge switch prior to conducting current through the power switch in response to a system startup request, an acquisition unit that acquires at least one of detection information of a current flowing through the current limiting resistor after the precharge switch is turned on and detection information of a temperature of the current limiting resistor as a parameter indicating the magnitude of the current flowing during a precharge current-carrying period in which the precharge switch is turned on; an abnormality determination unit that determines, based on the parameters acquired by the acquisition unit, whether or not an abnormality in current flow occurs, in which current continues to flow through the precharge switch even after precharging of the capacitor is completed after the precharge switch is turned on; and a switch control unit that turns off the precharge switch when it is determined that the current flow abnormality has occurred, and does not permit the precharge switch to be turned on until a predetermined period has elapsed; a setting unit that sets the predetermined period based on the parameters acquired by the acquisition unit; Equipped with The setting unit extends the predetermined period as the parameter indicates a larger integrated value of the current flowing after the precharge switch is turned on.

2. 2 . The control device according to claim 1 , wherein the switch control unit permits the precharge switch to be turned on when it is determined that the abnormal current flow has occurred and the predetermined period has elapsed.

3. The present invention is applied to a power supply system in which an electric load (21) and a capacitor (22) are connected to a battery (11) via an electric path (12, 13), and power switches (15, 16) are connected to the electric path, and a series connection of a pre-charge switch (17) and a current limiting resistor (18) is connected in parallel to the power switch, a program for precharging the capacitor by passing current through the precharge switch prior to passing current through the power switch in response to a system startup request, The control device an acquisition step of acquiring at least one of detection information of a current flowing through the current limiting resistor after the precharge switch is turned on and detection information of a temperature of the current limiting resistor as a parameter indicating the magnitude of the current flowing in a precharge current-carrying period in which the precharge switch is turned on; an abnormality determination step of determining whether or not an abnormality in current conduction has occurred, in which current continues to flow through the precharge switch even after precharging of the capacitor is completed after the precharge switch is turned on, based on the parameters acquired in the acquisition step; a switch control step of turning off the precharge switch when it is determined that the current flow abnormality has occurred, and not permitting the precharge switch to be turned on until a predetermined period of time has elapsed; a setting step of setting the predetermined period based on the parameters acquired in the acquisition step; Execute In the setting step, the predetermined period is lengthened as the parameter has a larger integrated value of the current flowing after the precharge switch is turned on.