Vehicle power supply management system

Abstract

A vehicle power supply management system (1) is provided with a control device (30) for controlling the connection / disconnection states of contactors (4, 5, 7). When there is no ready request during execution of precharge control for increasing the voltage of capacitors (14, 24) and when the voltage of the capacitors (14, 24) reaches the voltage of a battery (2), if the number of times of energization is equal to or greater than a first predetermined number of times, the control device (30) turns on the main contactor (4), turns off the precharge contactor (7), and executes first standby control for maintaining the connection state of the main contactor (4) until the number of times of energization becomes less than the first predetermined number of times. When receiving a forced disconnection request during execution of the first standby control, the control device (30) performs off-control for turning off the main contactor (4) and the precharge contactor (7).

Description

Vehicle Power Management System

[0001] This case relates to a power management system for a vehicle.

[0002] In a conventional main power supply circuit (main circuit) for supplying power from an on-board battery to an inverter that generates drive power for an on-board motor, a smoothing circuit is connected in parallel to the inverter, and a pre-charge circuit is connected in parallel to the main contactor. The smoothing circuit is a circuit in which a capacitor is interposed, and the pre-charge circuit is a circuit in which a pre-charge contactor and a pre-charge resistor are interposed. Connecting the pre-charge contactor before connecting the main contactor reduces inrush current and improves protection of the main power supply circuit.

[0003] When connecting the precharge contactor, the temperature of the precharge resistor rises depending on the number of times and duration of current application. Therefore, for example, if the main power supply is repeatedly turned on and off within a short period of time, the precharge resistor may become excessively hot. Therefore, it has been proposed to count the number of times the precharge resistor is energized and, if the number of times within a set time reaches a set number, to implement control that interrupts precharge control (energization of the precharge resistor). Such control can prevent the precharge resistor from becoming excessively hot (see, for example, Patent Document 1).

[0004] Patent No. 4086807

[0005] However, in the above-described control, even if the ignition switch (main power switch) is repeatedly turned on and off due to driver error or carelessness, the pre-charge control is interrupted due to the increased number of energizations. This makes it difficult to recover from pre-charge control interrupted due to driver error or carelessness. Note that the term "vehicle start" here refers not only to when the vehicle starts to travel, but also when external charging begins or when the air conditioner is turned on.

[0006] Therefore, instead of the above-described control, it is conceivable to delay the interruption of the power supply between the vehicle battery and the inverter when the OFF operation is performed after the number of times of power supply within a set time has reached a set number. As a result, if the ON operation is performed again while the power supply interruption is delayed, it is not necessary to perform the precharge control again, so that the startability of the vehicle can be ensured while suppressing excessive temperature rise of the precharge resistor. However, with such control, the interruption of the power supply is delayed even when an earlier interruption of the power supply is necessary, which may compromise the safety of the vehicle.

[0007] One of the objectives of the present invention, which was devised in light of the above-mentioned problems, is to provide a vehicle power supply management system that can improve the protection of the main circuit and the starting performance of the vehicle with a simple configuration while ensuring the safety of the vehicle. However, in addition to this objective, another objective of the present invention is to achieve the effects derived from the respective configurations shown in the "Description of Embodiments" below, which cannot be obtained with conventional technology.

[0008] The disclosed invention can be realized as the following disclosed embodiments (application examples) and solves at least part of the above-mentioned problems. Each embodiment from embodiment 2 onwards is an embodiment that can be selected as an additional embodiment, and each embodiment can be omitted. None of the embodiments from embodiment 2 onwards discloses an embodiment or configuration that is essential to the present invention.

[0009] Aspect 1. The disclosed vehicle power management system includes a main contactor disposed in a main circuit connected to a battery and an inverter circuit that controls the frequency of power supplied to a motor, a pre-charge contactor and a pre-charge resistor disposed in a pre-charge circuit connected in parallel to the main contactor, a capacitor disposed in a smoothing circuit connected in parallel to the inverter circuit, and a control device. The control device performs pre-charge control, which connects the pre-charge contactor to increase the voltage of the capacitor in response to a ready request that indicates a request to turn the main circuit on, and main control, which connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery.

[0010] The control device maintains the precharge contactor in a connected state until the capacitor voltage reaches the battery voltage, even if the ready request is no longer received during the precharge control. If the ready request is no longer received during the precharge control and the capacitor voltage reaches the battery voltage, the control device determines the number of times the precharge resistor has been energized in a predetermined period immediately preceding the current time. If the number of times the precharge resistor has been energized is equal to or greater than a first predetermined number, the control device performs first standby control to connect the main contactor and disconnect the precharge contactor, and maintain the main contactor in a connected state until the number of times the precharge resistor has been energized in a predetermined period immediately preceding the current time becomes less than the first predetermined number. If a forced disconnection request, which means a request to forcibly disconnect the main circuit, is received during the first standby control, the control device performs off control to disconnect the main contactor and the precharge contactor.

[0011] Aspect 2. In an aspect including the above aspect 1, it is preferable that the control device, when performing the off control, inherits the number of energizations determined during the implementation of the first standby control without resetting it. In this case, if the ready request is received during the implementation of the off control, it is preferable to perform the precharge control if the number of energizations in the most recent predetermined period of time based on the current time is less than a second predetermined number. Aspect 3. In an aspect including the above aspect 2, it is preferable that the first predetermined number is less than the second predetermined number.

[0012] Aspect 4. In an aspect including the above-mentioned Aspect 1, it is preferable that the forced disconnection request includes a first request meaning a request to forcibly put the main circuit into a disconnected state due to an abnormality in a high-voltage circuit system connected to the battery. In this case, it is preferable that the control device performs a first determination to determine whether the first request has been received before performing a ready determination to determine whether the ready request has been received while the first standby control is being performed. Aspect 5. In an aspect including the above-mentioned Aspect 4, it is preferable that the control device performs the off control if it receives the first request before the voltage of the capacitor reaches the voltage of the battery while the precharge control is being performed.

[0013] Aspect 6. In an aspect including the above-described Aspect 1, it is preferable that the forced disconnection request includes a second request meaning a request to forcibly put the main circuit into a disconnected state by performing a predetermined operation. In this case, it is preferable that the control device, while performing the first standby control, performs a ready determination to determine whether the ready request has been received, and then performs a second determination to determine whether the second request has been received. Aspect 7. In an aspect including the above-described Aspect 6, it is preferable that, when the control device receives the second request, it performs second standby control to maintain the connection state of the main contactor or the pre-charge contactor until a standby time has elapsed, and then performs the off control.

[0014] The disclosed vehicle power supply management system can ensure the safety of the vehicle while improving the protection of the main circuit and the startability of the vehicle with a simple configuration.

[0015] 1 is a circuit diagram showing the configuration of a power supply management system for a vehicle; FIG. 2 is a graph showing changes in capacitor voltage over time due to pre-charge control; FIG. 3 is a flowchart showing the procedure of off control; FIG. 4 is a flowchart showing the procedure of countdown control; FIG. 5 is a flowchart showing the procedure of pre-charge control; FIG. 6 is a flowchart showing the procedure of main control; FIG. 7 is a flowchart showing the procedure of first standby control; and FIG. 8 is a flowchart showing the procedure of second standby control.

[0016] The disclosed vehicle power management system can be realized as in the following embodiments. The power management system of this embodiment is applied to an electric vehicle (e.g., an electric vehicle, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV)), etc.) equipped with a traction motor and battery. The motor is, for example, an AC motor / generator, and has the functions of consuming battery power to rotate and drive the wheels, and generating electricity using the inertial rotation of the wheels. A plug-in hybrid vehicle is a hybrid vehicle that can externally charge the battery or receive external power from the battery. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable that supplies power from an external charging facility, and an outlet (outlet) for external power supply.

[0017] 1 is a circuit diagram showing the configuration of a vehicle power supply management system 1 according to an embodiment. This power supply management system 1 includes a main circuit 3 for supplying power from a battery 2 mounted on the vehicle to two motors (a first motor 10 and a second motor 20). The battery 2 may be, for example, a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride battery, or a fuel cell.

[0018] The first motor 10 is, for example, a front motor that drives the front wheels of the vehicle, and the second motor 20 is, for example, a rear motor that drives the rear wheels of the vehicle. Note that one of the two motors 10, 20 can be omitted. Furthermore, in a vehicle in which the left and right wheels are controlled by individual motors, for example, the first motor 10 may be the right wheel motor and the second motor 20 may be the left wheel motor. In a vehicle in which all four wheels are controlled by individual motors, four motors may be provided.

[0019] A first inverter 11 (front inverter) is connected to the first motor 10, and a second inverter 21 (rear inverter) is connected to the second motor 20. These inverters 11, 21 are conversion devices that convert DC power on the battery 2 side into AC power on the motors 10, 20 side, and vice versa. Inside the first inverter 11, a first inverter circuit 12 related to DC-AC conversion and a first smoothing circuit 13 for voltage smoothing are provided.

[0020] The first inverter circuit 12 has multiple switching elements (e.g., IGBTs, MOSFETs, etc.) built in. Polyphase AC power is generated from DC power by switching each switching element on and off at high frequency. The magnitude of the drive torque generated by the first motor 10 can be adjusted by changing the pulse width of the AC voltage output from the first inverter circuit 12. The first smoothing circuit 13 is a circuit connected in parallel to the first inverter circuit 12.

[0021] A first capacitor 14, which is an electric storage element, is interposed in the first smoothing circuit 13. The first capacitor 14 has a function of suppressing pulsation of the DC voltage output from the battery 2. For example, if the output voltage of the battery 2 temporarily drops, the voltage drop is compensated for by the charge stored in the first capacitor 14. In other words, temporary changes and noise components in the DC voltage introduced from the battery 2 to the first inverter circuit 12 are absorbed by the function of the first capacitor 14. This stabilizes the voltage fluctuations input to the first inverter circuit 12, and ultimately stabilizes the AC voltage generated by the first inverter 11.

[0022] The second inverter 21 has a configuration similar to that of the first inverter 11. A second inverter circuit 22 and a second smoothing circuit 23 are provided inside the second inverter 21. The second smoothing circuit 23 is connected in parallel to the second inverter circuit 22. A second capacitor 24 is also interposed in the second smoothing circuit 23. The main circuit 3 is connected to the battery 2 and the first inverter circuit 12, which controls the frequency of the power supplied to the first motor 10, and is also connected to the battery 2 and the second inverter circuit 22, which controls the frequency of the power supplied to the second motor 20.

[0023] A P contactor 4 (positive electrode side contactor) and an N contactor 5 (negative electrode side contactor) are installed in the main circuit 3. These are both main contactors for connecting and disconnecting the current flowing through the main circuit 3. The P contactor 4 is installed between the inverter circuits 12, 22 and the positive electrode of the battery 2, and the N contactor 5 is installed between the inverter circuits 12, 22 and the negative electrode of the battery 2. The connection and disconnection states of the P contactor 4 and the N contactor 5 are controlled by a control device 30, which will be described later.

[0024] A precharge circuit 6 is connected in parallel to one of the main contactors 4, 5. The precharge circuit 6 is a circuit for suppressing inrush current when the main contactors 4, 5 are connected. FIG. 1 shows an example in which the precharge circuit 6 is connected in parallel to the P contactor 4. A precharge contactor 7 and a precharge resistor 8 (precharge resistor) are interposed in series in the precharge circuit 6. When the control device 30 connects the P contactor 4 and the N contactor 5, the precharge contactor 7 is controlled to be connected before the P contactor 4.

[0025] The control device 30 is a computer (Electronic Control Unit, ECU) for controlling the connection and disconnection states of the P contactor 4, the N contactor 5, and the precharge contactor 7. The control device 30 has a built-in processor (arithmetic processing device) and memory (storage device). The contents of the control performed by the control device 30 (control program) are stored in the memory, and the contents are executed by being read into the processor as appropriate.

[0026] Information related to the battery 2 (battery information) and information related to the motors 10, 20 and inverters 11, 21 (motor information) are input to the control device 30. The battery information is input to the control device 30, for example, via a Battery Management Unit (BMU, not shown) that manages the battery 2. The battery information may include information on the voltage and current of the battery 2, as well as status information of the battery 2 (e.g., whether or not there is a leakage current). The motor information is input to the control device 30, for example, via a Motor Control Unit (MCU, not shown) that controls the motors 10, 20 by driving the inverters 11, 21. The motor information may include voltage information of the first capacitor 14 and the second capacitor 24 of the inverters 11, 21, as well as status information of the motors 10, 20 (e.g., whether or not there is a failure in the motors 10, 20) and status information of the switching elements of the inverter circuits 12, 22 (e.g., temperature information of the switching elements).

[0027] Also connected to the control device 30 are a power switch 31 and a brake sensor 32. The power switch 31 is a button-type changeover switch for turning the main power supply of the vehicle on and off, and the brake sensor 32 is a sensor for detecting depression of the brake pedal. The control device 30 uses information related to the operation state of the power switch 31 and information related to depression of the brake pedal to control the on / off state of the main power supply of the vehicle (the connection / disconnection states of the P contactor 4, N contactor 5, and pre-charge contactor 7).

[0028] The power switch 31 may include a display device (such as a light source or a display) for visually indicating the state of the vehicle's main power supply. For example, an LED (Light Emitting Diode) may be attached to the pressing surface of the power switch 31. The LED is turned off when the main power supply is off (all contactors 4, 5, and 7 are disconnected) and is turned on when the main power supply is on (P contactor 4 is connected). The LED may also flash when the main power supply is transitioning from off to on (pre-charge contactor 7 is connected).

[0029] [2. Control] As described above, the control device 30 of this embodiment controls the connection / disconnection states of the P contactor 4, the N contactor 5, and the precharge contactor 7. The control device 30 controls the connection / disconnection states of the contactors 4, 5, and 7 based on the presence or absence of a ready request, the presence or absence of a forced disconnection request, and the number of times X that the precharge resistor 8 is energized (the number of precharges X).

[0030] Here, the ready request is a signal or flag indicating that a vehicle user (not limited to the driver or passenger but also including a vehicle mechanic) or an electronic control device other than the control device 30 is requesting that the main circuit 3 be connected. When there is no ready request (when there is no request to connect the main circuit 3) and predetermined acceptance conditions are met, the control device 30 determines that it has received a ready request (a request to connect the main circuit 3) (there is a request to connect the main circuit 3).

[0031] The control device 30 determines that a "ready request has been made" when, for example, any of the following acceptance conditions 1 to 3 is satisfied. Note that acceptance condition 1 below is not limited to the following operations as long as it is an operation that can at least confirm that the user intends to turn on the vehicle's main power supply and complete preparations to run the vehicle (a request to turn on the vehicle's main power supply). Acceptance condition 1: When the power switch 31 is pressed for a time shorter than the determination time described below, with the brake pedal depressed. Acceptance condition 2: When a charging gun for external charging is inserted into the inlet of the on-board charger (when external charging is requested). Acceptance condition 3: When the air conditioner is operated with the vehicle's main power supply turned off (when a pre-air conditioning command is issued via wireless communication or when the reserved time for pre-air conditioning arrives).

[0032] Furthermore, when the control device 30 receives a ready request, it determines that a "ready request is present" (maintains the "ready request is present" state) until a predetermined disappearance condition is met. Then, when a predetermined disappearance condition is met while a ready request is present, it determines that the "ready request (main circuit 3 connection request) has disappeared (there is no main circuit 3 connection request)."

[0033] For example, the control device 30 determines that there is no ready request when any of the following conditions 1 to 3 are met. When the ready request is lost, the control device 30 determines that there is no ready request (maintains the state of no ready request) until a predetermined acceptance condition (for example, any of the above conditions 1 to 3) is met. Note that the conditions for determining whether there is a ready request are not limited to the conditions exemplified here, and known conditions can also be applied. Condition 1: When the brake pedal is depressed and the power switch 31 is pressed for a time shorter than the determination time described below. Condition 2: When the charging gun inserted into the inlet of the on-board charger is removed. Condition 3: When the air conditioner that was operating while the vehicle's main power supply was off is stopped (when an instruction to end pre-AC is given via wireless communication or when the reserved time for ending pre-AC arrives).

[0034] A forced disconnection request is a signal or flag that indicates a request to "forcefully put the main circuit 3 into a disconnected state" regardless of the connection state of the main circuit 3. The presence or absence of a forced disconnection request is determined regardless of the presence or absence of a ready request. In this embodiment, the forced disconnection request includes two types: a first request and a second request.

[0035] The first request is a signal or flag indicating that a request to "forcefully disconnect the main circuit 3" has been made due to an abnormality in the high-voltage circuit system connected to the battery 2. The first request is determined regardless of the intention of the occupant. The high-voltage circuit system includes at least the battery 2 and the motors 10, 20 that operate using the power of the battery 2, and may also include circuits and devices (e.g., the main circuit 3 and inverters 11, 21) that connect the battery 2 and the motors 10, 20. The high-voltage circuit system may also include a BMU that manages the battery 2 and an MCU that controls the motors 10, 20.

[0036] Abnormalities in the high-voltage circuit system include, for example, leakage of the battery 2 and failure of the motors 10, 20. Abnormalities in the high-voltage circuit system may include a communication breakdown (communication error) between the BMU and the control device 30, a communication breakdown (communication error) between the MCU and the control device 30, a detection error of the voltage of the capacitors 14, 24 provided in the inverters 11, 21, an overheating of the switching elements of the inverter circuits 12, 22, etc.

[0037] When the above abnormality is detected, the control device 30 determines that "a first request has been received (first request present)," and maintains the "first request present" state while the above abnormality is detected. Furthermore, when the above abnormality is no longer detected, the control device 30 determines that "the first request has disappeared (first request absent)," and maintains the "first request absent" state. Note that even if the control device 30 receives a first request while it is receiving a ready request, it does not consider the ready request to have disappeared, and maintains the ready request present state. In other words, the ready request and the first request are managed separately, with the acceptance or disappearance of one request not affecting the acceptance or disappearance of the other.

[0038] The second request is a signal or flag indicating that a predetermined operation by the user has requested that the main circuit 3 be forcibly disconnected. The second request is made, for example, by a mechanic when servicing the vehicle. When the main circuit 3 is disconnected in accordance with the second request, the power supply from the battery 2 to the inverters 11, 21 is cut off (the power supply state is cut off). This reduces the risk of electric shock to the mechanic during vehicle maintenance, ensuring the safety of the vehicle.

[0039] In this embodiment, the predetermined operation is defined as the operation of pressing the power switch 31 for a predetermined determination time (e.g., 5 seconds) or more while the brake pedal is depressed. Note that the predetermined operation is not limited to this, and may be any operation that at least confirms that the user is requesting to "forcefully shut off the main circuit 3." A maintenance shutoff switch may be provided in the vehicle in addition to the power switch 31, and the predetermined operation may be the operation of pressing the shutoff switch.

[0040] When a predetermined operation is performed, the control device 30 determines that a "second request has been received (second request present)" and maintains the "second request present" state. Note that if a predetermined operation is performed while a ready request has been received, the control device 30 may also consider the ready request to have disappeared at the same time as determining that a "second request has been made" or after determining that a "second request has been made." In the following, this embodiment will be described assuming that the ready request also disappears at the same time as determining that a "second request has been made." If the ready request is also considered to have disappeared due to a predetermined operation, the above-mentioned disappearance condition 1 may also be defined as "when the power switch 31 is pressed while the brake pedal is depressed."

[0041] The control device 30 may determine that "the second request has disappeared (there is no second request)" when any of the above-described ready request acceptance conditions 1 to 3 is satisfied. Furthermore, the control device 30 may determine that "the second request has disappeared (there is no second request)" when the main circuit 3 is connected while a ready request has been received. Note that, for safety reasons during maintenance, the conditions for disappearance of the second request do not need to include the above-described acceptance condition 3. In this case, it is preferable that the above-described acceptance condition 3 be "when the air conditioner is operated with the vehicle's main power supply turned off and there is no second request."

[0042] The precharge count X is a variable that represents the number of times that the precharge resistor 8 has been energized (or the number of times that the precharge contactor 7 has been successfully connected) within a predetermined period of time immediately preceding the current time (for example, approximately 50 to 300 seconds). The value of the precharge count X is incremented by 1 when the precharge contactor 7 is connected during precharge control, which will be described later, and energization of the precharge resistor 8 is confirmed. When control other than precharge control is being performed, the value of the precharge count X is decremented by 1 for each predetermined period.

[0043] Therefore, the value of the precharge count X increases when the current to the precharge resistor 8 is repeatedly turned on and off within a relatively short period of time, and then decreases slowly over a relatively long period of time. Also, if the current to the precharge resistor 8 is turned on and off infrequently, for example, once within the above-mentioned predetermined period, the value of the precharge count X hardly increases.

[0044] The value of the number of precharge times X roughly corresponds to the temperatures of the precharge resistor 8 and the precharge contactor 7. For example, the larger the value of the number of precharge times X, the more likely it is that the temperatures of the precharge resistor 8 and the precharge contactor 7 are high, and the smaller the value of the number of precharge times X, the more likely it is that the temperatures of the precharge resistor 8 and the precharge contactor 7 are low. The above-mentioned predetermined period is set taking into consideration, for example, how easily the precharge resistor 8 and the precharge contactor 7 retain heat when current is applied (rate of temperature rise), how easily they cool down when current is not applied (rate of temperature drop), and their thermal capacity.

[0045] The control device 30 performs off control, precharge control, main control, first standby control, and second standby control based on the presence or absence of the above-mentioned ready request, the presence or absence of the forced disconnection request, and the precharge count X. These controls are performed mutually exclusively. Each control performed by the control device 30 will be described in detail below.

[0046] [2-1. OFF Control] OFF control is a control for maintaining all contactors (P contactor 4, N contactor 5, pre-charge contactor 7) in the OFF state. In OFF control, all contactors 4, 5, 7 are maintained in the OFF state, thereby cutting off the power supply from the battery 2 to the inverters 11, 21. This reduces the risk of electric shock and ensures the safety of the vehicle. In addition, the operating time of the main contactors 4, 5 and pre-charge contactor 7 can be shortened, which can suppress wear and deterioration and prevent waste of power from the battery 2. Note that even during OFF control, power from a low-voltage battery (not shown) is supplied to the control device 30.

[0047] If a ready request is received while off control is being performed, precharge control is performed. However, even if a ready request is received while off control is being performed, if there is a first request, off control continues without transitioning to precharge control. Also, even if a ready request is received while off control is being performed, off control continues without transitioning to precharge control if the precharge count X is equal to or greater than a second predetermined count (e.g., 10 times). In other words, off control transitions to precharge control only when a ready request is received without a first request being received while off control is being performed, and the precharge count X is less than the second predetermined count (e.g., 0 to 9 times).

[0048] [2-2. Precharge Control] Precharge control is control for increasing the voltages of the first capacitor 14 and the second capacitor 24 (control for charging the first capacitor 14 and the second capacitor 24) by connecting the N contactor 5 and the precharge contactor 7 while keeping the P contactor 4 disconnected. When the precharge contactor 7 is connected during precharge control and it is confirmed that current is flowing through the precharge resistor 8, the control device 30 executes a calculation to add (increment) 1 to the value of the precharge count X.

[0049] When the voltages of these capacitors 14, 24 reach the battery voltage, the control device 30 determines that precharging is complete, terminates precharge control, and instead performs main control. Furthermore, even if the ready request is no longer received during precharge control (more precisely, before precharge is completed), the precharge control is not interrupted. That is, the precharge contactor 7 remains connected until the capacitor voltage reaches the battery voltage. However, in this embodiment, if a first request is received before precharge is completed (during precharge), the precharge control is interrupted and off control is performed.

[0050] 2 is a graph showing the relationship between the battery voltage and the capacitor voltage during precharge control. When the precharge contactor 7 is connected at time A, precharge of the capacitors 14 and 24 begins. This causes the voltage of each capacitor to rise and gradually approach the battery voltage. Time B is the time when the capacitor voltage reaches the battery voltage (the time when the capacitor voltage is nearly equal to the battery voltage and the difference between the capacitor voltage and the battery voltage is equal to or less than a predetermined small value). When the capacitor voltages of both capacitors 14 and 24 reach the battery voltage, precharge of the capacitors 14 and 24 is completed.

[0051] In this embodiment, the transition from precharge control to main control occurs only if a ready request is received at the time precharge is completed. On the other hand, if there is no ready request at the time precharge is completed (i.e., if the ready request is no longer present during precharge control and the capacitor voltage has reached the battery voltage), the precharge count X is determined, and one of first standby control, second standby control, and off control is performed depending on the precharge count X. Note that the above-mentioned "if the ready request is no longer present during precharge control" also includes the case where the ready request is no longer present due to the receipt of a second request. Furthermore, in this embodiment, as described above, if a first request is received during precharge, off control is performed, and the presence or absence of a first request is not taken into account when precharge is completed.

[0052] In this embodiment, if the precharge count X is equal to or greater than a first predetermined count (e.g., 7), the first standby control is implemented, and if the precharge count X is less than the first predetermined count (e.g., 0 to 6), the second standby control or the off control is implemented. The first predetermined count is preferably set to a count (smaller value) than the second predetermined count used in determining the precharge count X during the off control described above. This makes it easier for the first standby control to be implemented before the precharge count X reaches the second predetermined count. Therefore, even if a new ready request is received during the off control after the first standby control, described below, the transition to the precharge control is less likely to be prohibited.

[0053] [2-3. Main Control] The main control is a control in which the P contactor 4 and the N contactor 5 are connected while the precharge contactor 7 is disconnected, and power is supplied to the inverters 11 and 21. The state in which the main control is being performed corresponds to the state in which the main circuit 3 is connected (for example, the state in which preparations for running the vehicle are complete), and is a state in which the ready request is fulfilled.

[0054] Main control continues as long as the ready request remains. However, if a forced disconnection request is received while main control is being performed, main control is terminated and off control is performed. In this embodiment, if a first request is received while main control is being performed, off control is performed (the system transitions directly to off control) even if a ready request has been received. Furthermore, if a second request is received while main control is being performed, off control or second standby control is performed before off control is performed. Note that, when a second request is received, the ready request may be considered to have disappeared as described above, or the control may be continued without the ready request being disappeared depending on the conditions for accepting the ready request.

[0055] If the ready request disappears without receiving a forced disconnection request during main control (if the ready request disappears due to the satisfaction of any of the disappearance conditions 1 to 3), one of first standby control, second standby control, and off control is implemented. At this time, the control device 30 may select one of the first standby control, second standby control, and off control in consideration of the precharge count X. For example, the control device 30 may select the first standby control when the precharge count X is equal to or greater than a first predetermined count (e.g., 7 times), and may select the second standby control or off control when the precharge count X is less than the first predetermined count (e.g., 0 to 6 times).

[0056] [2-4. First Standby Control] The first standby control is performed when the precharge count X is determined to be equal to or greater than a first predetermined count (e.g., seven times) during the precharge control (when precharge is completed) and during the main control. In the first standby control, the P contactor 4 and the N contactor 5 are connected, the precharge contactor 7 is disconnected, and the P contactor 4 and the N contactor 5 are maintained connected until the precharge count X falls below the first predetermined count (e.g., 0 to 6 times). In other words, the first standby control delays the disconnection of the power supply (allowing the precharge resistor 8 to cool while the main contactors 4 and 5 are connected) so that the main control can be immediately restored if a ready request is received again after the start of the first standby control. Therefore, the first standby control can also be described as part of the main control. After the precharge count X falls below the first predetermined count, either the off control or the second standby control may be performed.

[0057] If a forced disconnection request is received during the first standby control, the first standby control is terminated and the off control is performed. In this embodiment, if the first request is received during the first standby control, the off control is performed (the control directly transitions to the off control). If a second request is received during the first standby control, the off control is performed, or the off control is performed via the second standby control. In this way, if a forced disconnection request is received during the first standby control, the off control is performed, thereby enabling the power supply state to be quickly cut off (the forced disconnection request can be responded to), thereby ensuring the safety of the vehicle.

[0058] In this embodiment, when a forced disconnection request is received during the first standby control and the control transitions to the off control, the precharge count X determined during the first standby control is carried over without being reset. Furthermore, in the subsequent off control, even if a ready request is received, the control transitions to the precharge control only if the precharge count X is less than the second predetermined count (e.g., 0 to 9 times), as described above. This improves the protection of the precharge resistor 8.

[0059] More specifically, if a forced disconnection request is received while the first standby control is being performed, the off control is performed without waiting for the precharge count X to become less than a first predetermined count (for example, 0 to 6 times). In other words, if a forced disconnection request is received while the first standby control is being performed, the off control may be performed even if the precharge count X is relatively large (for example, 10 times).

[0060] Here, when a forced disconnection request is received and the control transitions to off control, if the precharge count X determined during the first standby control is reset to 0, the correspondence between the precharge count X and the temperatures of the precharge resistor 8 and the precharge contactor 7 may deviate. Furthermore, if a ready request is received during off control and precharge control is performed regardless of the value of the precharge count X, the protection of the precharge resistor 8 may be impaired.

[0061] In particular, if the forced disconnection request is received due to a user error or carelessness, there is a possibility that a ready request will be received again immediately after the start of the off control and at a stage when the precharge count X is relatively high (for example, 10 times). If precharge control is performed in response to this ready request, there is a risk that the precharge resistor 8 will heat up excessively.

[0062] Furthermore, if the forced disconnection request is received due to a transient abnormality in the high-voltage circuit system, the forced disconnection request (first request) will disappear when the transient abnormality is resolved, and precharge control can be performed in response to the ready request. Note that an example of a transient abnormality in the high-voltage circuit system is a temporary communication error between the control device 30 and the BMU.

[0063] In contrast to this, in this embodiment, when a forced disconnection request is received during execution of first standby control and a transition to off control is made, the precharge count X is carried over without being reset, so that the correspondence relationship between the precharge count X and the temperatures of the precharge resistor 8 and the precharge contactor 7 is maintained. Furthermore, in the subsequent off control, even if a ready request is received, a transition to precharge control is made only if the precharge count X is less than a second predetermined number (for example, 0 to 9 times), so that the protection of the precharge resistor 8 is improved.

[0064] If a ready request is received again during first standby control, main control is performed. During first standby control, a ready determination to determine whether a ready request has been received is performed after a first determination to determine whether a first request has been received and before a second determination to determine whether a second request has been received. In other words, in first standby control, when determining whether or not to continue control, the first request takes priority over a ready request, which takes priority over a second request.

[0065] [2-5. Second Standby Control] The second standby control is a control that maintains the connected state of the N contactor 5 and the connected state of the P contactor 4 or the pre-charge contactor 7 until a predetermined standby time has elapsed. In other words, the second standby control is a control that maintains the connected state of the main contactors 4, 5 or the connected state of the N contactor 5 and the pre-charge contactor 7 until the standby time has elapsed.

[0066] The second standby control is implemented when the precharge count X is less than a first predetermined count (for example, 0 to 6 counts) in the determination of the precharge count X during the execution of the precharge control, main control, and first standby control described above, or when a second request is received during the execution of the main control and first standby control. The above "when a second request is received during the execution of the first standby control" may include a case where a second request was received during the execution of the precharge control before the execution of the first standby control.

[0067] The standby time determined by the second standby control is a time that can be arbitrarily set (for example, several seconds to several tens of seconds) without depending on the above-mentioned predetermined period. In other words, the second standby control is a control that further delays the cutoff of the power supply state (maintaining the power supply state in preparation for the possibility of receiving another ready request). If another ready request is received during the second standby control (i.e., before the standby time has elapsed), the main control is executed. Furthermore, if a first request is received during the second standby control, the execution of the second standby control is terminated and the off control is executed. During the execution of the second standby control, the ready determination is executed after the first determination. Note that, if the second standby control can be substantially omitted, the off control may be executed immediately after it is confirmed that there is no ready request.

[0068] In this embodiment, different standby times are applied depending on whether or not a second request is present. Hereinafter, the standby time used when there is no second request will be referred to as the normal standby time, and the standby time used when there is a second request will be referred to as the reduced standby time (standby time). The reduced standby time is set to at least equal to or less than the normal standby time. More preferably, the reduced standby time is set to a time (e.g., a few seconds) shorter than the estimated time required from the time a predetermined operation for maintenance is performed until the maintenance work begins.

[0069] In other words, the second standby control, which is implemented in response to the second request, is implemented in consideration of the fact that there is a time lag between the execution of the predetermined operation and the start of maintenance work. In this way, when the second request is received, the power supply state is not immediately switched to the off control, but the second standby control is implemented to delay the interruption of the power supply state, thereby allowing a new ready request received immediately after the second request is received. For example, if the second request is received due to a user's erroneous operation or carelessness, or if the vehicle needs to be moved immediately after the predetermined operation is performed for maintenance, the new ready request can be met without impairing the startability of the vehicle.

[0070] There are three methods for delaying the interruption of the energized state in the second standby control. The first method is to turn on the P contactor 4 and the N contactor 5 and turn them off after a standby time. The second method is to turn on the pre-charge contactor 7 and the N contactor 5 and turn them off after a standby time. The third method is to first turn on the pre-charge contactor 7 and the N contactor 5, then turn on the P contactor 4 and the N contactor 5, and turn them off after a total standby time. This method is a combination of the first and second methods.

[0071] In this embodiment, when the precharge count X is less than the first predetermined count (i.e., when the second request has not been received) and the second standby control is to be performed, the second standby control is performed using a third method. Here, the time when the precharge contactor 7 and the N contactor 5 are first turned on is defined as a first standby time, and the time when the P contactor 4 and the N contactor 5 are next turned on is defined as a second standby time. The respective standby times are set so that the sum of these times is equal to the normal standby time.

[0072] In this embodiment, two types of shortened standby times are used: a third standby time and a fourth standby time. The third standby time is a shortened standby time that is applied when a second request is received before the first standby time has elapsed (including when the second standby control is performed in response to the second request). The third standby time is set to at least the first standby time or less. In the second standby control, if the second request is received (or was received) before the first standby time has elapsed, the pre-charge contactor 7 and the N contactor 5 are maintained in a connected state until the third standby time has elapsed, and then the control is switched to OFF control.

[0073] The fourth standby time is a shortened standby time that is applied when the second request is received after the first standby time has elapsed while the second standby control is being performed. The fourth standby time is set to be at least equal to or shorter than the second standby time. As described above, the timing at which the fourth standby time is applied is the timing at which the first standby time has elapsed since the start of the second standby control. In other words, the fourth standby time is applied after the interruption of the energized state has been delayed by at least the first standby time. Therefore, taking this into consideration, the fourth standby time is more preferably set to be shorter than the third standby time.

[0074] In the second standby control, if a second request is received after the first standby time has elapsed, the P contactor 4 and the N contactor 5 are maintained in a connected state until the fourth standby time has elapsed, and then the control shifts to OFF control. In this way, when there is a second request, the third standby time and the fourth standby time are applied as appropriate depending on whether or not the first standby time has elapsed, and the second standby control is completed earlier than when no second request has been received.

[0075] Tables 1 to 5 below summarize the outlines, start conditions, and end conditions of each of the off control, precharge control, main control, first standby control, and second standby control performed by the control device 30. As described above, these controls are performed mutually exclusively. Therefore, the start condition of each control corresponds to the end condition of a control other than the control in question, and the end condition of each control corresponds to the start condition of a control other than the control in question. In Tables 1 to 5 below, at the end of each condition listed as a start condition and an end condition, the symbols for the end condition and start condition in the other table that correspond to the condition are shown in parentheses.

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] [3. Flowchart] Figure 3 is a flowchart showing the procedure for the OFF control. In step A1, the P contactor 4, N contactor 5, and precharge contactor 7 are all turned OFF. At this time, if any of the contactors 4, 5, and 7 are ON, that ON state is switched to an OFF state. Also, if all of the contactors 4, 5, and 7 are already OFF, that OFF state is maintained. Note that there may be a delay in the timing of turning off each of the contactors 4, 5, and 7.

[0082] In the next step A2, it is determined whether or not there is a first request. If it is determined that there is a first request, the process proceeds to step A5, where countdown control is executed. The countdown control is a subroutine for timing the above-mentioned predetermined period and decrementing the precharge count X. After the countdown control is executed, the off control for this control cycle ends. In the next control cycle, the off control continues, and step A1 is executed again. In other words, in the off control, the control continues as long as there is a first request, and transition to other control is prohibited.

[0083] On the other hand, if it is determined in step A2 that the first request is not present, the process proceeds to step A3, where it is determined whether the value of the precharge count X is less than 10 (less than a second predetermined number, for example, 0 to 9 times). If it is determined here that the value of the precharge count X is 10 or greater (greater than or equal to the second predetermined number), the process proceeds to step A5. Then, after the countdown control is executed, the off control for this control cycle ends. In the next control cycle, the off control continues, and step A1 is executed again. In other words, in the off control, even if the value of the precharge count X is 10 or greater, transition to another control is prohibited, and the off control continues until the value of the precharge count X becomes less than 10.

[0084] If it is determined in step A3 that the value of the precharge count X is less than 10, the process proceeds to step A4, where it is determined whether or not a ready request has been made. If it is determined here that a ready request has been made, the off control ends and precharge control begins. On the other hand, if it is determined in step A4 that a ready request has not been made, the process proceeds to step A5. Then, after the countdown control is executed, the off control for this control cycle ends. In the next control cycle, the off control continues, and step A1 is executed again. In other words, the off control continues until a new ready request is made.

[0085] 4 is a flowchart showing the procedure for countdown control (subroutine). In this subroutine, a calculation is performed to decrease the value of the precharge count X by one each time a predetermined period elapses. A variable Z in the flow is a variable for measuring the predetermined period, and its initial value is 0. In this flow, the time it takes for the value of variable Z to count up to 100 (this subroutine is executed 100 times) corresponds to the predetermined period. Note that the count number of variable Z may be a variable value that depends on the precharge count X. In other words, the predetermined period for decreasing the value of the precharge count X by one may be given as a function of the precharge count X.

[0086] In step S1, it is determined whether the value of the precharge count X is 1 or greater. If this condition is met, the process proceeds to step S2. On the other hand, if the condition of step S1 is not met (if the precharge count X is 0), steps S2 to S5 are skipped and the subroutine ends. In step S2, an operation is performed to add (increment) 1 to the value of variable Z. In the following step S3, it is determined whether the value of variable Z is 100. If this condition is met, the process proceeds to step S4, where an operation is performed to subtract (decrement) 1 from the value of the precharge count X. Furthermore, in the following step S5, the value of variable Z is reset to 0. If the condition of step S3 is not met, steps S4 and S5 are skipped and the subroutine ends.

[0087] 5 is a flowchart showing the procedure for precharge control. In step B1, the P contactor 4 is turned off, and the N contactor 5 and precharge contactor 7 are turned on. In the following step B2, it is determined whether or not the precharge resistor 8 is energized, and step B1 is repeated until this condition is met. If the condition of step B2 is met, the process proceeds to step B3, where 1 is added to the value of the precharge count X, and the process proceeds to step B4.

[0088] In step B4, it is determined whether or not a first request exists. If it is determined that a first request exists, the off control is initiated. On the other hand, if it is determined that a first request does not exist in step B4, it is determined in step B5 whether or not the capacitor voltage has reached the battery voltage. If it is determined that the capacitor voltage has not reached the battery voltage, the process returns to step B4.

[0089] That is, steps B4 and B5 are repeated until the capacitor voltage reaches the battery voltage. Here, even if the ready request is no longer received before the capacitor voltage reaches the battery voltage, the precharge contactor 7 remains connected until the capacitor voltage reaches the battery voltage. On the other hand, if the first request is received before the capacitor voltage reaches the battery voltage, in other words, if the first request is received during precharge, the process proceeds to the Yes route in step B4, where the precharge control is forcibly interrupted and off control is performed. If the boosting of the capacitor voltage is completed without receiving the first request and the condition in step B5 is met, the process proceeds to step B6.

[0090] In step B6, it is determined whether or not a ready request has been made. If a ready request has been made, pre-charge control is terminated and main control is initiated. On the other hand, if a ready request has not been made, the process proceeds to step B7. In step B7, it is determined whether the value of the pre-charge count X is 7 or more (a first predetermined count or more). If this condition is met, pre-charge control is terminated and first standby control is initiated. If this condition is not met, pre-charge control is terminated and either off control or second standby control is initiated.

[0091] 6 is a flowchart showing the procedure of the main control. In step C1, the P contactor 4 and the N contactor 5 are turned on, and the precharge contactor 7 is turned off. In step C2, countdown control is executed.

[0092] In the following step C3, it is determined whether or not a first request has been made. If it is determined that there is no first request, the process proceeds to step C4, where it is determined whether or not there is a ready request. On the other hand, if it is determined that there is a first request, the main control is forcibly interrupted and off control is initiated. In other words, the first determination (step C3) is performed before the ready determination (step C4). As a result, if an abnormality has occurred in the high-voltage circuit system, the off control is initiated promptly, thereby suppressing the occurrence of a secondary abnormality in the high-voltage circuit system.

[0093] If it is determined in step C4 that a ready request has been made, the main control for this control cycle is terminated. In the next control cycle, the main control continues, and step C1 is executed again. In other words, in the main control, the processes of steps C1 to C4 are repeated as long as the state in which a ready request has been made continues without receiving a first request.

[0094] On the other hand, if it is determined in step C4 that there is no ready request, the process proceeds to step C5, where it is determined whether or not there is a second request. If it is determined that there is a second request, the main control is forcibly interrupted, and the off control or second standby control is initiated. In other words, the second determination (step C5) is performed after the ready determination (step C4). As a result, if a ready request is received again immediately after a second request is received due to a user error or carelessness and the ready request is deemed to have disappeared, the process of step C4 is performed based on the ready request before the process of step C5, and the main control continues. Therefore, unnecessary off control or unnecessary second standby control is prevented from being performed.

[0095] If it is determined in step C5 that the second request has not been made, the process proceeds to step C6, where it is determined whether the value of the precharge count X is equal to or greater than 7 (a first predetermined count or greater). If this condition is met, the main control ends and the first standby control starts. If this condition is not met, the main control ends and the off control or the second standby control starts.

[0096] 7 is a flowchart showing the procedure of the first standby control. In step D1, the P contactor 4 and the N contactor 5 are turned on, and the precharge contactor 7 is turned off. In step D2, a countdown control is executed.

[0097] In the following step D3, it is determined whether or not a first request has been made. If it is determined that there is no first request, the process proceeds to step D4, where it is determined whether or not there is a ready request. On the other hand, if it is determined that there is a first request, the first standby control is forcibly interrupted and the off control is initiated. That is, here too, as in the main control, the first determination (step D3) is performed before the ready determination (step D4). Note that, if it is determined in step D3 that there is a first request, the value of the precharge count X and the value of the variable Z are carried over to the off control as they are. Therefore, even in the off control, the countdown control continues, and it is determined whether or not to transition to the precharge control based on the carried over precharge count X (the determination in step A3 in FIG. 3 is performed).

[0098] If it is determined in step D4 that a ready request has been made, the first standby control ends and the main control starts. At this time, the value of the precharge count X and the value of the variable Z are retained. Therefore, the countdown control continues even during the main control.

[0099] On the other hand, if it is determined in step D4 that there is no ready request, the process proceeds to step D5, where it is determined whether there is a second request. If it is determined that there is a second request, the first standby control is forcibly interrupted, and either the off control or the second standby control is initiated. That is, here too, as in the main control, the second determination (step D5) is performed after the ready determination (step D4). Note that, if it is determined in step D5 that there is a second request, the value of the precharge count X and the value of the variable Z are directly passed on to the off control or the second standby control, just as when it is determined that there is a first request in step D3.

[0100] If it is determined in step D5 that the second request is not present, the process proceeds to step D6, where it is determined whether the value of the precharge count X is equal to or greater than 7 (equal to or greater than a first predetermined count). If this condition is met, the first standby control for this control cycle ends. In the next control cycle, the first standby control continues, and step D6 is executed again. That is, in the first standby control, the processes of steps D1 to D6 are repeated until the value of the precharge count X becomes less than 7 (less than a first predetermined count, for example, 0 to 6) without receiving a forced disconnection request or a ready request. If the value of the precharge count X becomes less than 7 without receiving a forced disconnection request or a ready request, the determination in step D6 becomes negative, the first standby control ends, and either the off control or the second standby control is initiated.

[0101] 8 is a flowchart showing the procedure of the second standby control. In step E1 of FIG. 8, the N contactor 5 and the precharge contactor 7 are turned on, and the P contactor 4 is turned off. In step E2, countdown control is executed.

[0102] In the following step E3, it is determined whether or not a first request has been made. If it is determined that there is no first request, the process proceeds to step E4, where it is determined whether or not there is a ready request. On the other hand, if it is determined that there is a first request, the second standby control is forcibly interrupted and the off control is initiated. In other words, here too, the first determination (step E3) is performed before the ready determination (step E4). Furthermore, if it is determined that there is a first request in step E3, the value of the precharge count X and the value of the variable Z are directly carried over to the off control.

[0103] If it is determined in step E4 that a ready request has been made, the second standby control ends and the main control starts, with the values ​​of the precharge count X and the variable Z remaining unchanged.

[0104] On the other hand, if it is determined in step E4 that there is no ready request, the process proceeds to step E5, where it is determined whether there is a second request. That is, here too, the second determination (step E5) is performed after the ready determination (step E4).

[0105] If it is determined in step E5 that a second request has been received, the process proceeds to step E6, where it is determined whether a third standby time has elapsed since the start of the second standby control. If it is determined in step E6 that the third standby time has not elapsed, the process returns to step E2, and steps E2 to E6 are repeated until the third standby time has elapsed without receiving a first request or a ready request and without the second request being lost. Then, when the condition of step E6 is met, the second standby control ends and the off control is started. In other words, if a second request has been received in the second standby control, it is determined whether or not to continue the control based on the third standby time. Note that even when the condition of step E6 is met, the value of the precharge count X and the value of the variable Z are directly carried over to the off control.

[0106] On the other hand, if it is determined in step E5 that the second request has not been received, the process proceeds to step E7, where it is determined whether or not the first standby time has elapsed since the start of the second standby control. If it is determined in step E7 that the first standby time has not elapsed, the process returns to step E2, and the processes of steps E2 to E7 are repeated until the first standby time has elapsed without receiving a forced disconnection request or a ready request. Then, if the condition of step E7 is met, the process proceeds to step E8.

[0107] In step E8, the P contactor 4 and the N contactor 5 are turned on, and the precharge contactor 7 is turned off, and the process proceeds to step E9. Steps E9 to E14 are substantially the same as steps E2 to E7, except for the standby time. That is, countdown control is executed in step E9. If a first request is received, the process proceeds from step E10 via the Yes route, where the second standby control is forcibly interrupted and off control is initiated. If a first request is not received but a ready request is received, the process proceeds from step E11 via the Yes route, where the second standby control ends and main control is initiated. If a second request is received after the first standby time has elapsed, the processes of steps E9 to E13 are repeated until steps E12 and E13 are satisfied, i.e., until the fourth standby time has elapsed without the second request being lost. If the condition of step E13 is satisfied, the second standby control ends and off control is initiated. If the second request has not been received, the processes of steps E9 to E14 are repeated until step E14 is satisfied, that is, from the end of the first standby time until the end of the second standby time. When the condition of step E14 is satisfied, the second standby control is ended and the OFF control is started.

[0108] [4. Actions and Effects] (1) The above-described power supply management system 1 for a vehicle includes main contactors 4 and 5 installed in a main circuit 3 connected to inverter circuits 12 and 22 that control the frequency of power supplied to motors 10 and 20, and to a battery 2. The power supply management system 1 also includes a pre-charge contactor 7 and a pre-charge resistor 8 installed in a pre-charge circuit 6 connected in parallel to the main contactor 4, and capacitors 14 and 24 installed in smoothing circuits 13 and 23 connected in parallel to the inverter circuits 12 and 22. The power supply management system 1 includes a control device 30 that performs pre-charge control, which connects the pre-charge contactor 7 in response to a ready request to increase the voltage of the capacitors 14 and 24, and main control, which connects the main contactors 4 and 5 and disconnects the pre-charge contactor 7 after the voltage of the capacitors 14 and 24 reaches the voltage of the battery 2.

[0109] Even if a ready request is no longer received during precharge control, the control device 30 maintains the precharge contactor 7 in a connected state until the voltage of the capacitors 14, 24 reaches the voltage of the battery 2. Furthermore, if a ready request is no longer received during precharge control and the voltage of the capacitors 14, 24 reaches the voltage of the battery 2, the control device 30 determines the number of times the precharge resistor 8 has been energized (precharge count X) in a predetermined period immediately preceding the current time. If the number of energizations is equal to or greater than a first predetermined count (e.g., seven times), the control device 30 executes first standby control. The first standby control is a control that connects the main contactors 4, 5 and disconnects the precharge contactor 7, maintaining the main contactors 4, 5 in a connected state until the precharge count X falls below the first predetermined count. If a forced disconnection request is received during first standby control, the control device 30 executes off control. The off control is a control that disconnects the main contactors 4, 5 and the precharge contactor 7.

[0110] According to the above configuration, even if the ready request is lost while precharge control is being performed, the precharge contactor 7 can be maintained in a connected state until precharge is completed. As a result, if a ready request is received again before precharge is completed, main control can be performed after precharge is completed without interrupting the power supply to the main circuit 3. In particular, if the loss of the ready request during precharge control is due to a user error or carelessness, precharge control is not interrupted, making recovery easy. Therefore, the protection of the main circuit 3 (power supply circuit) and the startability of the vehicle can be improved with a simple configuration.

[0111] Furthermore, if a ready request is no longer received during the execution of the precharge control and the voltage of the capacitors 14, 24 reaches the voltage of the battery 2 (precharge is completed) without receiving another ready request, the precharge count X is determined. If the precharge count X is equal to or greater than a first predetermined count (e.g., seven or more), the first standby control is executed. As a result, if the precharge count X is relatively large, the precharge contactor 7 is disconnected while delaying the interruption of the energized state in the main circuit 3, thereby cooling the precharge resistor 8 while maintaining the energized state of the main circuit 3. This improves the protection of the precharge resistor 8. Furthermore, if a new ready request is received during the execution of the first standby control, the control can be immediately switched to the main control, improving the startability of the vehicle.

[0112] Furthermore, when the number of precharge cycles X is relatively small, even if the main circuit 3 is deenergized, the time required for the subsequent precharge control (the time required to increase the capacitor voltage) can be shortened. Therefore, the protection of the main circuit 3 and the startability of the vehicle can be improved with a simple configuration.

[0113] If a forced disconnection request is received while the first standby control is being performed, the OFF control is performed. This allows the main contactors 4, 5 and the pre-charge contactor 7 to be disconnected without waiting for the pre-charge count X to become less than a first predetermined count (for example, 0 to 6 times). Therefore, if a forced disconnection request is received, the power supply state can be cut off more quickly, ensuring the safety of the vehicle.

[0114] (2) In the above-described power management system 1, when a forced disconnection request is received during the first standby control and the control transitions to the off control, the precharge count X determined during the first standby control is carried over to the off control without being reset. Furthermore, when a ready request is received during the subsequent off control, the precharge control is executed if the precharge count X is less than a second predetermined count.

[0115] This makes it possible to maintain the correspondence between the precharge count X and the temperatures of the precharge resistor 8 and the precharge contactor 7, thereby making it possible to appropriately manage the temperatures of the precharge resistor 8 and the precharge contactor 7. Furthermore, even if a ready request is received while the off control is being performed, if the precharge count X is equal to or greater than the second predetermined count (for example, 10 times), the precharge control is not performed, thereby improving the protection of the precharge resistor 8.

[0116] (3) In the power management system 1, the first predetermined number of times is set to be smaller than the second predetermined number of times. The first predetermined number of times is a determination threshold used to determine the number of precharge times X when a ready request has not been received at the time precharge is completed. The second predetermined number of times is a determination threshold used to determine the number of precharge times X performed during the execution of the off control.

[0117] In the precharge control, if there is no ready request when the precharge is completed and the number of precharges X is equal to or greater than a first predetermined number (for example, 7 times), the first standby control is executed to cool down the precharge resistor 8. In the off control, even if a ready request is received during the execution of the off control, if the number of precharges X is equal to or greater than a second predetermined number (for example, 10 times), transition to the precharge control is prohibited.

[0118] In other words, in the above configuration, if there is no ready request when the precharge is completed, the first standby control is executed when the precharge count X is equal to or greater than the first predetermined count, which is smaller than the second predetermined count. In other words, the first standby control can be executed before the precharge count X reaches the second predetermined count.

[0119] Therefore, the first standby control can cool the precharge resistor 8, thereby preventing the precharge count X from reaching the second predetermined count. Even if a forced disconnection request is received during the first standby control and the off control is performed without waiting for the precharge count X to become less than the first predetermined count (for example, 0 to 6), the precharge count X is prevented from reaching the second predetermined count as described above, thereby improving the startability of the vehicle. In other words, even if a ready request is received immediately after the off control is initiated following a forced disconnection request during the first standby control, the transition to precharge control is less likely to be prohibited based on the determination of the precharge count X during the off control, thereby improving the startability of the vehicle.

[0120] In particular, if the forced disconnection request during the first standby control is received due to a user error, carelessness, or a transient abnormality in the high-voltage circuit system, it is possible that a ready request will occur again immediately after the forced disconnection request is received (or the first request will disappear immediately after the first request is received). However, with the above configuration, the pre-charge control can be started early after the start of the off control, thereby significantly improving the startability of the vehicle. Furthermore, even if a ready request is received because the vehicle needs to be moved immediately after the second request is received during the first standby control, the pre-charge control can be started early, thereby improving the startability of the vehicle.

[0121] (4) In the above-described power supply management system 1, while the first standby control is being performed, a first determination is made to determine whether a first request has been received before a ready determination is made to determine whether a ready request has been received. In other words, while the first standby control is being performed, the presence or absence of a first request is determined with priority over the presence or absence of a ready request, and if a first request has been received, the off control is forcibly performed. The first request is a request included in the forced disconnection request, and is a signal or flag indicating that a request has been made to "forcefully disconnect the main circuit 3" due to an abnormality in the high-voltage circuit system connected to the battery 2.

[0122] As a result, when the first request is received while the first standby control is being performed, even if a ready request is received, the control does not transition to the main control, but the off control is forcibly performed, and the power supply from the battery 2 to the inverters 11, 21 is cut off. Therefore, the occurrence of a secondary abnormality in the high-voltage circuit system due to the continuation of the power supply from the battery 2 to the inverters 11, 21 can be suppressed, and the vehicle can be appropriately protected.

[0123] (5) Furthermore, in the above-described power supply management system 1, if a first request is received during pre-charge, the pre-charge control is interrupted and the power-off control is forcibly performed. This prevents secondary abnormalities from occurring in the high-voltage circuit system due to the continued supply of power from the battery 2 to the inverters 11 and 21 via the pre-charge circuit 6. This allows the vehicle to be appropriately protected.

[0124] (6) In the above-described power supply management system 1, while the first standby control is being performed, a ready determination is performed to determine whether a ready request has been received before a second determination is performed to determine whether a second request has been received. In other words, while the first standby control is being performed, the presence or absence of a ready request is determined with priority over the presence or absence of a second request, and if a ready request has been received, main control is performed. The second request is a request included in the forced disconnection request, and is a signal or flag indicating that a predetermined operation has been performed to "forcefully place the main circuit 3 in a disconnected state."

[0125] As described above, the first standby control is performed when there is no ready request when precharging is completed and the precharging count X is equal to or greater than a first predetermined count. The above-described "when there is no ready request when precharging is completed" also includes a case where the ready request is deemed to have disappeared due to a second request being received during precharging (during execution of precharge control). If the second request received during execution of precharge control is due to a user error or carelessness, there is a possibility that a ready request will be received immediately after the start of the first standby control.

[0126] In the above-described power supply management system 1, while the first standby control is being performed, the presence or absence of a ready request is determined with priority over the presence or absence of a second request. As a result, if a ready request is received immediately after a second request is received due to an erroneous operation or carelessness as described above, the off control is not unnecessarily performed and the system transitions to main control, thereby improving the startability of the vehicle.

[0127] (7) Furthermore, in the above-described power supply management system 1, when a second request is received, second standby control is performed to maintain the connected state of the main contactor 4 or the pre-charge contactor 7 until the shortened standby time has elapsed, and then the off control is performed. As a result, when the second request is received due to a user's erroneous operation or carelessness, or when it becomes necessary to move the vehicle immediately after a predetermined operation for maintenance is performed, the off control is not performed unnecessarily and there is no need to perform the pre-charge control again, thereby improving the startability of the vehicle.

[0128] Additionally, the power supply management system 1 can perform off control when the number of times the pre-charge resistor 8 is energized is less than a first predetermined number of times (for example, 0 to 6 times). By performing off control, the operating time of the main contactors 4, 5 and the pre-charge contactor 7 can be shortened, and wear and deterioration can be suppressed. In addition, waste of power from the battery 2 can be prevented.

[0129] Furthermore, in the power supply management system 1, the second standby control can be performed when the number of times that the precharge resistor 8 has been energized is less than a first predetermined number of times (for example, 0 to 6 times). By performing the second standby control, it is no longer necessary to perform the precharge control again when a new ready request occurs, which can significantly improve the startability of the vehicle.

[0130] In the second standby control, the control device 30 waits while maintaining the connected state of the pre-charge contactor 7 during the initial first standby time, and then during the subsequent second standby time, it disconnects the pre-charge contactor 7 and maintains the connected state of the main contactors 4, 5. This type of control can significantly improve the startability of the vehicle, and can promote cooling of the pre-charge resistor 8 while suppressing wear and deterioration of the P contactor 4 to some extent.

[0131] [5. Other] The above-described embodiments are merely illustrative and are not intended to exclude various modifications or applications of techniques not explicitly described in the present embodiments. Each configuration of the present embodiments can be modified in various ways without departing from the spirit of the present embodiments. Furthermore, each configuration of the present embodiments can be selected or combined as needed.

[0132] For example, in the above embodiment, a circuit configuration in which the precharge circuit 6 is connected in parallel to the P contactor 4 is exemplified, but the precharge circuit 6 may be connected in parallel to the N contactor 5, or a precharge circuit 6 may be provided for each of a plurality of main contactors. Also, a main contactor that connects and disconnects the circuit on the side of the second motor 20 may be provided separately from the main contactor that connects and disconnects the circuit on the side of the first motor 10. Regardless of the specific circuit structure, if the ready request disappears during execution of precharge control, control that maintains the connection state of the precharge contactor 7 until the capacitor voltage reaches the battery voltage can be performed, thereby achieving the same effects as those of the above embodiment.

[0133] In the above embodiment, the third method is used in the second standby control, which is performed when no second request is received. However, either the first method or the second method may be used. When the first method is used, there is no need to perform precharge control again when a new ready request occurs during the second standby control, which significantly improves the startability of the vehicle. When the second method is used, the number of times the P contactor 4 is driven can be reduced when transitioning from precharge control to second standby control, thereby suppressing wear and deterioration of the P contactor 4. Furthermore, precharge control can be completed in an extremely short time, which significantly improves the protection of the main circuit 3 and the startability of the vehicle. The second standby control may be omitted.

[0134] In the above embodiment, if a first request is received during execution of the main control, the control is immediately switched to the off control, and if a second request is received, the control is switched to the second standby control and then to the off control, but the method of executing the main control is not limited to this. For example, if a forced disconnection request (first request, second request) is received during the main control while the vehicle is traveling, the control may postpone the transition to the off control and may switch to the off control after confirming that the vehicle has stopped.

[0135] In the above embodiment, the forced disconnection request included two types of requests, the first request and the second request, but the forced disconnection request may include only the first request, or only the second request. In the above embodiment, the second determination was performed only when the ready determination determined that there was no ready request, but the second determination may also be performed when the ready determination determined that there was a ready request. The forced disconnection request is sufficient as long as it is a signal or flag that at least signifies a request to "forcefully put the main circuit 3 into a disconnected state," and may include other requests that arise for reasons different from the first and second requests.

[0136] The present invention is applicable to the manufacturing industry of power management systems applied to vehicles, and also applicable to the manufacturing industry of vehicles equipped with such power management systems.

[0137] REFERENCE SIGNS LIST 1 Power supply management system 2 Battery 3 Main circuit 4 P contactor (main contactor) 5 N contactor (main contactor) 6 Pre-charge circuit 7 Pre-charge contactor 8 Pre-charge resistor 10 First motor (motor) 11 First inverter (inverter) 12 First inverter circuit (inverter circuit) 13 First smoothing circuit (smoothing circuit) 14 First capacitor (capacitor) 20 Second motor (motor) 21 Second inverter (inverter) 22 Second inverter circuit (inverter circuit) 23 Second smoothing circuit (smoothing circuit) 24 Second capacitor (capacitor) 30 Control device 31 Power switch 32 Brake sensor X Number of pre-charges (number of times of energization)

Claims

1. A control device comprising: a main contactor disposed in a main circuit connected to a battery and an inverter circuit that controls the frequency of power supplied to a motor; a pre-charge contactor and a pre-charge resistor disposed in a pre-charge circuit connected in parallel to the main contactor; a capacitor disposed in a smoothing circuit connected in parallel to the inverter circuit; and a control device that performs pre-charge control for increasing the voltage of the capacitor by connecting the pre-charge contactor in response to a ready request, which means a request to keep the main circuit connected, and main control for connecting the main contactor and disconnecting the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery, wherein the control device: maintains the connected state of the pre-charge contactor until the voltage of the capacitor reaches the voltage of the battery, even if the ready request is no longer present during the implementation of the pre-charge control; and determines the number of times that the pre-charge resistor has been energized in a predetermined period immediately preceding the current time, when the ready request is no longer present during the implementation of the pre-charge control and the voltage of the capacitor has reached the voltage of the battery, a first standby control is implemented in which, when the number of times that the current is applied is equal to or greater than a first predetermined number, the main contactor is connected and the pre-charge contactor is disconnected, and the connected state of the main contactor is maintained until the number of times that the current is applied during a predetermined period in the most recent past based on a current time becomes less than the first predetermined number; and when a forced disconnection request, which means a request to forcibly put the main circuit in a disconnected state, is received while the first standby control is being implemented, an off control is implemented in which the main contactor and the pre-charge contactor are disconnected.

2. A power management system for a vehicle as described in claim 1, characterized in that, when the control device performs the off control, it takes over the number of times of current flow determined during the implementation of the first standby control without resetting it, and when the ready request is received during the implementation of the off control, it performs the precharge control if the number of times of current flow during a specified period in the most recent past based on the current time is less than a second specified number.

3. The vehicle power supply management system according to claim 2, wherein the first predetermined number of times is less than the second predetermined number of times.

4. A power supply management system for a vehicle as described in any one of claims 1 to 3, characterized in that the forced disconnection request includes a first request meaning a request to forcibly turn the main circuit into a disconnected state due to an abnormality in a high-voltage circuit system connected to the battery, and the control device performs a first determination to determine whether the first request has been received before performing a ready determination to determine whether the ready request has been received while the first standby control is being performed.

5. A power supply management system for a vehicle as described in claim 4, characterized in that the control device performs the off control when the first request is received before the voltage of the capacitor reaches the voltage of the battery while the precharge control is being performed.

6. A power supply management system for a vehicle as described in any one of claims 1 to 3, characterized in that the forced disconnection request includes a second request meaning a request to forcibly turn the main circuit into a disconnected state by performing a specified operation, and the control device, while performing the first standby control, performs a ready determination to determine whether the ready request has been received, and then performs a second determination to determine whether the second request has been received.

7. A vehicle power management system as described in claim 6, characterized in that, when the control device receives the second request, it performs a second standby control for maintaining the connection state of the main contactor or the pre-charge contactor until a standby time has elapsed, and then performs the off control.

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