Vehicle power 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

Technical Field

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

Background Art

[0002] Conventionally, in a main power supply circuit (main circuit) for supplying power of an in-vehicle battery to an inverter that generates driving power for an in-vehicle motor, a smoothing circuit is connected in parallel to the inverter, and a precharge circuit is connected in parallel to a main contactor. A smoothing circuit is a circuit in which a capacitor is interposed, and a precharge circuit is a circuit in which a precharge contactor and a precharge resistor are interposed. By connecting the precharge contactor prior to the connection of the main contactor, the inrush current is reduced, and the protection performance of the main power supply circuit is improved.

[0003] When the precharge contactor is connected, the temperature of the precharge resistor rises according to the number of energization times and the energization time. Therefore, for example, when the on / off operation of the main power supply is repeated within a short time, there is a risk that the precharge resistor will overheat. Thus, it has been proposed to implement control to count the number of energization times of the precharge resistor and interrupt the precharge control (energization to the precharge resistor) when the number of energization times within a set time reaches a set number. By such control, overheating of the precharge resistor can be suppressed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the control system described above, even if the ignition switch (main power switch) is repeatedly switched on and off due to driver error or inattention, the pre-charge control will be interrupted due to the increased number of energization cycles. Consequently, the vehicle's starting ability is easily impaired, and there is a particular problem in that recovery from pre-charge control interrupted due to error or inattention is difficult. Note that vehicle starting here includes not only starting to drive, but also starting when external charging begins and when the air conditioner is activated.

[0006] Therefore, instead of the control described above, it is conceivable to delay the disconnection of the power supply between the vehicle battery and the inverter if the number of times the power is supplied within a set time reaches the set number and the system is turned off. This eliminates the need to perform pre-charge control again if the system is turned on again while the disconnection of the power supply is being delayed, thus ensuring the vehicle's starting ability while suppressing overheating of the pre-charge resistor. However, with such control, even when it is necessary to disconnect the power supply early, the disconnection of the power supply is delayed, which may compromise the safety of the vehicle.

[0007] One of the objectives of this invention is to provide a vehicle power management system that addresses the aforementioned challenges, improving the protection of the main circuit and the starting performance of the vehicle with a simple configuration while ensuring vehicle safety. However, beyond this objective, another objective of this invention is to achieve effects and benefits derived from the various configurations described in the "Modes for Carrying Out the Invention" section below, which cannot be obtained with conventional technology. [Means for solving the problem]

[0008] The disclosed invention can be realized in the following embodiments (application examples) and solves at least some of the above-mentioned problems. Each of the embodiments from Embodiment 2 onward is an additional embodiment that can be appropriately selected and each of the embodiments can be omitted. None of the embodiments from Embodiment 2 onward disclose any embodiments or configurations that are essential to this case.

[0009] Embodiment 1. The vehicle power management system disclosed comprises an inverter circuit that controls the frequency of power supplied to the motor, a main contactor interposed in a main circuit connected to a battery, a precharge contactor and a precharge resistor interposed in a precharge circuit connected in parallel to the main contactor, a capacitor interposed in a smoothing circuit connected in parallel to the inverter circuit, and a control device. The control device performs precharge control, which increases the voltage of the capacitor by connecting the precharge contactor in response to a ready request, which means a request to connect the main circuit, and main control, which connects the main contactor and disconnects the precharge contactor after the voltage of the capacitor reaches the voltage of the battery.

[0010] The control device maintains the connection state of the precharge contactor until the voltage of the capacitor reaches the voltage of the battery, even if the ready request ceases during the execution of the precharge control. If the ready request ceases during the execution of the precharge control and the voltage of the capacitor reaches the voltage of the battery, the control device determines the number of times the precharge resistor has been energized in the most recent predetermined period in the past relative to the current time. If the number of energizations is equal to or greater than a first predetermined number, the control device performs a first standby control, which connects the main contactor and disconnects the precharge contactor, and maintains the connection state of the main contactor until the number of energizations in the most recent predetermined period in the past relative to the current time falls below the first predetermined number. If a forced disconnection request is received during the execution of the first standby control, meaning a request to forcibly disconnect the main circuit, the control device performs an off control to disconnect the main contactor and the precharge contactor.

[0011] Embodiment 2. In an embodiment including Embodiment 1 described above, it is preferable that when the control device performs the off-control, it inherits the number of times the power was supplied determined during the first standby control without resetting it. In this case, if the ready request is received during the off-control, it is preferable to perform the pre-charge control if the number of times the power was supplied in the most recent predetermined period in the past based on the current time is less than the second predetermined number. Embodiment 3. In an embodiment including Embodiment 2 described above, it is preferable that the first predetermined number of times is less than the second predetermined number of times.

[0012] Embodiment 4. In an embodiment including Embodiment 1 described above, it is preferable that the forced disconnection request includes a first request meaning a request to forcibly disconnect the main circuit due to an abnormality in the 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. Embodiment 5. In an embodiment including Embodiment 4 described above, 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] Embodiment 6. In embodiments including Embodiment 1 described above, it is preferable that the forced disconnection request includes a second request meaning a request to forcibly disconnect the main circuit as a result of a predetermined operation. In this case, it is preferable that the control device performs a ready determination to determine whether it has received the ready request while the first standby control is being performed, and then performs a second determination to determine whether it has received the second request. Embodiment 7. In embodiments including Embodiment 6 described above, when the control device receives the second request, it is preferable to perform a second standby control that maintains the connection state of the main contactor or the precharge contactor until the standby time has elapsed, and then perform the off control. [Effects of the Invention]

[0014] According to the disclosed vehicle power management system, it is possible to ensure vehicle safety while improving the protection of the main circuit and the starting performance of the vehicle with a simple configuration. [Brief explanation of the drawing]

[0015] [Figure 1] This is a circuit diagram showing the configuration of the vehicle's power management system. [Figure 2] This graph shows the change in capacitor voltage over time due to precharge control. [Figure 3] This is a flowchart showing the procedure for turning off control. [Figure 4] This is a flowchart showing the procedure for countdown control. [Figure 5] This is a flowchart showing the pre-charge control procedure. [Figure 6] This is a flowchart showing the main control procedure. [Figure 7] This is a flowchart showing the procedure for the first standby control. [Figure 8] Flowchart of the procedure for the second standby control. [Modes for carrying out the invention]

[0016] The power management system of the disclosed vehicle can be realized as follows. The power management system of this embodiment is applied to an electric vehicle equipped with a motor for driving and a battery [for example, an electric vehicle, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), etc.]. The motor is, for example, an alternating current motor generator, and has functions of consuming the power of the battery to drive the wheels to rotate and generating electricity by using the inertial rotation of the wheels. In addition, a plug-in hybrid electric vehicle means a hybrid electric vehicle capable of external charging of the battery or external power supply from the battery. A plug-in hybrid electric vehicle is provided with a charging port (inlet) for inserting a charging cable through which power is supplied from an external charging facility and a socket (outlet) for external power supply.

Embodiment

[0017] [1. Configuration] FIG. 1 is a circuit diagram showing the configuration of a vehicle power management system 1 as an embodiment. This power management system 1 is provided with a main circuit 3 for supplying the power of a battery 2 mounted on the vehicle to two motors (first motor 10, second motor 20). The battery 2 is, for example, a secondary battery such as a lithium-ion secondary battery, a nickel-hydrogen battery, or a fuel cell.

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

[0019] The first motor 10 is connected to the first inverter 11 (front inverter), and the second motor 20 is connected to the second inverter 21 (rear inverter). These inverters 11 and 21 are conversion devices that convert between DC power from the battery 2 and AC power from the motors 10 and 20. Inside the first inverter 11, there is a first inverter circuit 12 for DC-AC conversion and a first smoothing circuit 13 for voltage smoothing.

[0020] The first inverter circuit 12 incorporates multiple switching elements (e.g., IGBTs and MOSFETs). By frequently switching each switching element, multiphase AC power is generated from DC power. 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 connected in parallel to the first inverter circuit 12.

[0021] A first capacitor 14, which is an energy storage element, is interposed in the first smoothing circuit 13. The first capacitor 14 has the function of suppressing pulsations in the DC voltage output from the battery 2. For example, if the output voltage of the battery 2 temporarily drops, the drop in voltage 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 action of the first capacitor 14. As a result, voltage fluctuations input to the first inverter circuit 12 are stabilized, and consequently, the AC voltage generated by the first inverter 11 is stabilized.

[0022] The configuration of the second inverter 21 is the same as that of the first inverter 11. Inside the second inverter 21, there is a second inverter circuit 22 and a second smoothing circuit 23. The second smoothing circuit 23 is connected in parallel with 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 first inverter circuit 12, which controls the frequency of the power supplied to the first motor 10, and to the battery 2, and is also connected to the second inverter circuit 22, which controls the frequency of the power supplied to the second motor 20, and to the battery 2.

[0023] The main circuit 3 is equipped with a P contactor 4 (positive electrode contactor) and an N contactor 5 (negative electrode contactor). Both are main contactors for switching the energization state of the main circuit 3. The P contactor 4 is interposed between the inverter circuits 12 and 22 and the positive electrode of the battery 2, and the N contactor 5 is interposed between the inverter circuits 12 and 22 and the negative electrode of the battery 2. The disconnection state of the P contactor 4 and the N contactor 5 is controlled by a control device 30, which will be described later.

[0024] A precharge circuit 6 is connected in parallel to either the main contactor 4 or 5. The precharge circuit 6 is a circuit that suppresses the inrush current when the main contactors 4 and 5 are connected. Figure 1 shows an example in which the precharge circuit 6 is connected in parallel to the P contactor 4. The precharge circuit 6 has a precharge contactor 7 and a precharge resistor 8 (precharge register) interposed in series. 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 disconnection state of the P contactor 4, N contactor 5, and precharge contactor 7. The control device 30 has a built-in processor (arithmetic processing unit) and memory (storage device). The content of the control performed by the control device 30 (control program) is stored in memory and executed by appropriately reading the contents into the processor.

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

[0027] Furthermore, a power switch 31 and a brake sensor 32 are connected to the control device 30. The power switch 31 is a button-type toggle switch for turning the vehicle's main power on and off, and the brake sensor 32 is a sensor that detects the degree to which the brake pedal is depressed. The control device 30 uses information regarding the operation status of the power switch 31 and information regarding the degree to which the brake pedal is depressed to control the on / off state of the vehicle's main power (the open / closed state 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 display) for visually indicating the status of the vehicle's main power supply. For example, an LED (Light Emitting Diode) that turns off when the main power supply is off (all contactors 4, 5, and 7 are disconnected) and lights up when the main power supply is on (P contactor 4 is connected) may be mounted on the pressing surface of the power switch 31. In addition, this LED may be made to blink 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 in this embodiment controls the open / closed state of the P contactor 4, N contactor 5, and precharge contactor 7. The control device 30 controls the open / closed state of each contactor 4, 5, and 7 based on whether or not there is a ready request, whether or not there is a forced disconnection request, and the number of times the precharge resistor 8 is energized X (number of precharges X).

[0030] Here, a ready request is a signal or flag that indicates that the vehicle user (including not only the driver and passengers but also the vehicle's maintenance personnel) 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 (there is no request to connect the main circuit 3) the control device 30 determines that a ready request (a request to connect the main circuit 3) has been received (there is a request to connect the main circuit 3) when the predetermined acceptance conditions are met.

[0031] The control device 30 determines that "ready request has been made" if, for example, any of the following acceptance conditions 1 to 3 are met. Note that acceptance condition 1 below only needs to be an operation that can confirm that the user has the intention 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), and does not have to be one of the operations listed below. • Acceptance condition 1: When the brake pedal is depressed and the power switch 31 is pressed for a shorter time than the judgment time described later. • Acceptance condition 2: When an external charging gun is inserted into the inlet of the onboard charger (when external charging is requested) • Acceptance condition 3: When the air conditioner is operated while the vehicle's main power is off (when pre-conditioning is instructed via wireless communication or when the scheduled time for pre-conditioning has arrived)

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

[0033] The control device 30 determines "no ready request" if, for example, any of the following disappearance conditions 1 to 3 are met. When a ready request disappears, the control device 30 determines "no ready request" (maintains the "no ready request" state) until a predetermined acceptance condition (for example, any of the above acceptance conditions 1 to 3) is met. Note that the conditions for determining the presence or absence of a ready request are not limited to the conditions exemplified herein, but any known conditions can be applied. • Disappearance Condition 1: When the brake pedal is depressed, the power switch 31 is pressed for a shorter time than the judgment time described later. • Condition for loss 2: If the charging gun that was inserted into the inlet of the onboard charger is removed. • Disappearance condition 3: When the air conditioner, which was operating while the vehicle's main power was off, is stopped (when the termination of pre-air conditioning is instructed via wireless communication or when the scheduled time for termination of pre-air conditioning has arrived).

[0034] A forced disconnection request is a signal or flag that indicates a request to "forcibly disconnect main circuit 3" regardless of its connection status. The presence or absence of a forced disconnection request is determined regardless of the presence or absence of a ready request. In this embodiment, there are two types of forced disconnection requests: a first request and a second request.

[0035] The first requirement is a signal or flag indicating that a malfunction in the high-voltage circuit system connected to battery 2 requires the "main circuit 3 to be forcibly disconnected." The first requirement is determined regardless of the occupant's intentions. The high-voltage circuit system includes at least battery 2 and motors 10 and 20 that operate using the power of battery 2, and may include circuits and devices connecting battery 2 and motors 10 and 20 (e.g., main circuit 3 and inverters 11 and 21). The high-voltage circuit system may also include a BMU that manages battery 2 and an MCU that controls motors 10 and 20.

[0036] Examples of abnormalities in the high-voltage circuit system include leakage current from battery 2 and failure of motors 10 and 20. Abnormalities in the high-voltage circuit system may also include communication interruption (communication error) between the BMU and control device 30, communication interruption (communication error) between the MCU and control device 30, voltage detection errors of capacitors 14 and 24 provided on inverters 11 and 21, and overheating of switching elements in inverter circuits 12 and 22.

[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 as long as 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. In addition, even if the control device 30 receives a first request while a ready request is being received, it does not consider the ready request to have disappeared and maintains the "ready request present" state. In other words, ready requests and first requests are managed individually, without the acceptance or disappearance of one request affecting the acceptance or disappearance of the other.

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

[0039] In this embodiment, the predetermined operation is defined as the operation in which the power switch 31 is pressed for a predetermined judgment time (for example, 5 seconds) or longer while the brake pedal is depressed. However, the predetermined operation is not limited to any operation that can confirm that the user is requesting to "forcibly disconnect the main circuit 3". The vehicle may also be provided with a maintenance cutoff switch separate from the power switch 31, and the predetermined operation may be the operation in which this cutoff switch is pressed.

[0040] When a predetermined operation is performed, the control device 30 determines that a "second request has been received (second request exists)" and maintains the "second request exists" state. If a predetermined operation is performed while a ready request is received, the control device 30 may consider the ready request to have disappeared at the same time as, or after, determining that a "second request exists". In this embodiment, it will be explained that the ready request disappears at the same time as the determination that a "second request exists". When the ready request is considered to have disappeared due to a predetermined operation, the above 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 (no second request)" if any of the above-described acceptance conditions 1 to 3 for the ready request are met. Furthermore, if the main circuit 3 is connected while a ready request has been received, the control device 30 may also determine that "the second request has disappeared (no second request)." For safety reasons during maintenance, the acceptance condition 3 described above does not necessarily have to be included in the conditions for the disappearance of the second request. In this case, it is preferable that the acceptance condition 3 described above is "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 the precharge resistor 8 has been energized (or the number of times the precharge contactor 7 has been successfully connected) in a predetermined period in the most recent past (for example, about 50 to 300 seconds) relative to the current time. The value of precharge count X is incremented by 1 when the precharge contactor 7 is connected and energization to the precharge resistor 8 is confirmed during the precharge control described later. The value of precharge count X is decremented by 1 each predetermined period when control other than precharge control is being performed.

[0043] Therefore, the value of the precharge cycle X increases when the current to the precharge resistor 8 is repeatedly switched on and off in 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 switched on and off at a low frequency, for example, once during the predetermined period, the value hardly increases.

[0044] The value of the precharge cycle X roughly corresponds to the temperature of the precharge resistor 8 and the precharge contactor 7. For example, a larger value of the precharge cycle X indicates a higher probability that the temperature of the precharge resistor 8 and the precharge contactor 7 is high, while a smaller value of the precharge cycle X indicates a higher probability that the temperature of the precharge resistor 8 and the precharge contactor 7 is low. The predetermined period described above is set considering factors such as how easily the precharge resistor 8 and the precharge contactor 7 retain heat when energized (rate of temperature rise), how easily they cool down when not energized (rate of temperature decrease), and their heat 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 a ready request, the presence or absence of a forced disconnection request, and the number of precharge cycles X. These controls are performed mutually exclusive of each other. The following describes in detail each control performed by the control device 30.

[0046] [2-1. Off-control] Off-control is a control that keeps all contactors (P contactor 4, N contactor 5, pre-charge contactor 7) in the off state. With off-control, all contactors 4, 5, and 7 are kept in the off state, which cuts off the power supply from battery 2 to inverters 11 and 21. This reduces the risk of electric shock and ensures vehicle safety. In addition, the operating time of the main contactors 4 and 5 and the pre-charge contactor 7 can be shortened, reducing wear and deterioration, and preventing the waste of power from battery 2. Even when off-control is in operation, 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 in operation, pre-charge control will be implemented. However, even if a ready request is received while off-control is in operation, if there is a first request, it will continue without transitioning to pre-charge control. Also, even if a ready request is received while off-control is in operation, if the number of pre-charge cycles X is equal to or greater than the second predetermined number (e.g., 10 cycles), it will continue without transitioning to pre-charge control. In other words, off-control will only transition to pre-charge control if a ready request is received without a first request being received while off-control is in operation, and the number of pre-charge cycles X is less than the second predetermined number (e.g., 0 to 9 cycles).

[0048] [2-2. Precharge Control] Precharge control is a control method that increases the voltage of the first capacitor 14 and the second capacitor 24 (a control method that charges the first capacitor 14 and the second capacitor 24) by connecting the N contactor 5 and the precharge contactor 7 while the P contactor 4 is disconnected. When the precharge contactor 7 is connected during precharge control and current is confirmed to flow to the precharge resistor 8, the control device 30 performs a calculation to add (increment) 1 to the value of the precharge count X.

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

[0050] Figure 2 is a graph showing the relationship between battery voltage and capacitor voltage during pre-charge control. When the pre-charge contactor 7 is connected at time A, pre-charging of capacitors 14 and 24 begins. As a result, the voltage of each capacitor rises and asymptotically approaches the battery voltage. Time B is the time when the capacitor voltage reaches the battery voltage (the time when the capacitor voltage becomes approximately equal to the battery voltage, and the difference between the capacitor voltage and the battery voltage becomes less than or equal to a predetermined small value). Pre-charging of capacitors 14 and 24 is completed when the capacitor voltages of both capacitors 14 and 24 reach the battery voltage.

[0051] In this embodiment, the system transitions from precharge control to main control only if a ready request is received when precharge is complete. On the other hand, if there is no ready request when precharge is complete (i.e., the ready request disappears during precharge control and the capacitor voltage reaches the battery voltage), the number of precharges X is determined, and either first standby control, second standby control, or off control is implemented according to the number of precharges X. Note that the above-mentioned "when the ready request disappears during precharge control" also includes the case where the ready request disappears as a result of receiving a second request. Furthermore, in this embodiment, as described above, off control is implemented if a first request is received during precharge, so the presence or absence of a first request is not considered when precharge is complete.

[0052] In this embodiment, if the number of precharges X is equal to or greater than a first predetermined number (e.g., 7 times), the first standby control is performed, and if the number of precharges X is less than the first predetermined number (e.g., 0 to 6 times), the second standby control or off control is performed. Preferably, the first predetermined number is set to a number (small value) less than the second predetermined number used in determining the number of precharges X during the execution of the off control described above. This makes it easier for the first standby control to be performed before the number of precharges X reaches the second predetermined number. Therefore, even if a new ready request is received during the off control after the first standby control described later, it becomes less likely that the transition to precharge control will be prohibited.

[0053] [2-3. Main Control] The main control is a control that connects the P contactor 4 and N contactor 5 while keeping the precharge contactor 7 disconnected, and supplies power 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 the vehicle is ready to run), and the ready request has been fulfilled.

[0054] Main control continues as long as the ready request persists. However, if a forced disconnection request is received during the execution of main control, the execution of main control is terminated and off control is performed. In this embodiment, if the first request is received during the execution of main control, off control is performed (it transitions directly to off control) even if a ready request has been received. Also, if the second request is received during the execution of main control, off control or off control is performed after a second standby control. Note that if the second request is received, as described above, the ready request may be considered to have disappeared, or, depending on the conditions for receiving the ready request, the ready request may not be considered to have disappeared and the execution of control may continue.

[0055] If, during the execution of main control, the ready request disappears without receiving a forced disconnection request (the ready request disappears due to the fulfillment of any of the disappearance conditions 1 to 3), then either the first standby control, the second standby control, or the off control will be implemented. At this time, the control device 30 may select one of the first standby control, the second standby control, or the off control, taking into consideration the number of precharges X. For example, if the number of precharges X is equal to or greater than a first predetermined number (e.g., 7 times), the control device 30 may select the first standby control, and if the number of precharges X is less than a first predetermined number (e.g., 0 to 6 times), it may select the second standby control or the off control.

[0056] [2-4. First Standby Control] The first standby control is performed when the number of precharges X is greater than or equal to a first predetermined number (e.g., 7 times) during the execution of the precharge control described above (when precharging is completed) and during the execution of the main control. In the first standby control, the P contactor 4 and N contactor 5 are connected, the precharge contactor 7 is disconnected, and the connection state of the P contactor 4 and N contactor 5 is maintained until the number of precharges X falls below a first predetermined number (e.g., 0 to 6 times). In other words, the first standby control is a control that delays the disconnection of the energized state (cooling the precharge resistor 8 while the main contactors 4 and 5 remain connected) so that the system can immediately return to main control if a ready request is received again after the start of the first standby control. For this reason, the first standby control can also be described as a part of the main control. After the number of precharges X falls below a first predetermined number, either off control or second standby control may be performed.

[0057] In the first standby control, if a forced disconnection request is received during its execution, the execution is terminated and off control is implemented. In this embodiment, if the first request is received during the execution of the first standby control, off control is implemented (it transitions directly to off control). If the second request is received during the execution of the first standby control, off control is implemented, or off control is implemented after the second standby control. In this way, if a forced disconnection request is received during the execution of the first standby control, off control is implemented, enabling a rapid interruption of the power supply (responding to the forced disconnection request), thereby ensuring the safety of the vehicle.

[0058] In this embodiment, when a forced disconnection request is received during the execution of the first standby control and the system transitions to off control, the number of precharges X determined during the execution of the first standby control is carried over without being reset. Furthermore, in the subsequent off control, even if a ready request is received, the system transitions to precharge control only if the number of precharges X is less than the second predetermined number (for example, 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 in progress, the off control is implemented without waiting for the number of precharge cycles X to fall below a predetermined number (e.g., 0 to 6 cycles). In other words, if a forced disconnection request is received while the first standby control is in progress, the off control may be implemented even if the number of precharge cycles X is relatively high (e.g., 10 cycles).

[0060] Here, when a forced disconnection request is received and the system transitions to off control, if the number of precharges X determined during the first standby control is reset to 0, the correspondence between the number of precharges X and the temperatures of the precharge resistor 8 and precharge contactor 7 may diverge. Also, if a ready request is received during off control, and precharge control is performed regardless of the value of the number of precharges X, the protective effect of the precharge resistor 8 may be compromised.

[0061] In particular, if the forced disconnection request was received due to user error or negligence, there is a possibility that another ready request will be received immediately after the start of the off control and at a relatively high stage (e.g., 10 times) when the number of precharge cycles X is relatively high. If precharge control is performed in response to this ready request, the precharge resistor 8 may overheat excessively.

[0062] Furthermore, if the acceptance of a forced disconnection request was due to a transient anomaly in the high-voltage circuit system, the forced disconnection request (first request) will disappear once the transient anomaly is resolved, and pre-charge control may be implemented in response to the ready request. An example of a transient anomaly in the high-voltage circuit system is a temporary communication error between the control device 30 and the BMU.

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

[0064] In the first standby control, if a ready request is received again during its execution, the main control is executed. During the execution of the first standby control, the ready determination, which determines whether a ready request has been received, is performed after the first determination, which determines whether the first request has been received, and before the second determination, which determines whether the second request has been received. In other words, in the first standby control, when determining whether the control should continue, the first request takes precedence over the ready request, and the ready request takes precedence over the second request.

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

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

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

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

[0069] In other words, the second standby control implemented in response to the second request is a control implemented considering that there is a time leeway between the completion of a prescribed operation and the commencement of maintenance work. Thus, when a second request is received, instead of immediately switching to off control, the cutoff of the power supply is delayed by the implementation of the second standby control, allowing the system to respond to a new ready request received immediately after the second request. For example, if the receipt of the second request was due to user error or negligence, or if it becomes necessary to move the vehicle immediately after a prescribed operation has been performed for maintenance, the system can respond to a new ready request without compromising the vehicle's ability to start.

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

[0071] In this embodiment, when the number of pre-charge cycles X is less than the first predetermined number (i.e., when no second request has been received) and the second standby control is to be performed, the second standby control is performed using a third method. Here, the time for first turning on the pre-charge contactor 7 and the N contactor 5 is defined as the first standby time, and the time for then turning on the P contactor 4 and the N contactor 5 is defined as the second standby time. Each standby time is set such that the sum of these times equals 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 applied when a second request is received before the first standby time has elapsed (including cases where the second standby control is implemented as a result of receiving the second request). The third standby time is set to be at least the same as or less than the first standby time. In the second standby control, if a second request is received (or was received) before the first standby time has elapsed, the connection state of the pre-charge contactor 7 and the N contactor 5 is maintained until the third standby time has elapsed, and then the system switches to off control.

[0073] The fourth standby time is a shortened standby time that is applied when the second standby control is in progress and a second request is received after the first standby time has elapsed. The fourth standby time is set to be at least less than or equal to the second standby time. As described above, the timing at which the fourth standby time is applied is after 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 power supply state has been delayed for at least the first standby time. For this reason, the fourth standby time is more preferably set to be shorter than the third standby time, taking this point into consideration.

[0074] In the second standby control, if a second request is received after the first standby time has elapsed, the connection state of P contactor 4 and N contactor 5 is maintained until the fourth standby time has elapsed, after which the system switches to off control. In this way, when a second request is received, the third and fourth standby times are applied appropriately depending on whether or not the first standby time has elapsed, so that the second standby control is completed earlier than when no second request is received.

[0075] Tables 1 to 5 below summarize the outlines, start conditions, and end conditions for each of the off-control, pre-charge control, main control, first standby control, and second standby control performed by the control device 30. As mentioned above, these controls are performed mutually exclusive. Therefore, the start condition of each control corresponds to the end condition of another control, and the end condition of each control corresponds to the start condition of another control. In Tables 1 to 5 below, the symbols of the end condition and start condition in the corresponding table are shown in parentheses at the end of each condition listed in the start and end conditions.

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3]

[0079] [Table 4]

[0080] [Table 5]

[0081] [3. Flowchart] Figure 3 is a flowchart showing the procedure for off-control. In step A1, all P contactor 4, N contactor 5, and pre-charge contactor 7 are turned off. At this time, if any of contactors 4, 5, or 7 are on, their on state is switched to the off state. If all contactors 4, 5, and 7 were already off, their off state is maintained. There may be a delay in the timing of turning off each contactor 4, 5, and 7.

[0082] In the following 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, and the countdown control is executed. The countdown control is a subroutine that measures the predetermined period and decrements the number of precharges 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 off-control, the control continues as long as there is a first request, and transition to other controls is prohibited.

[0083] On the other hand, if it is determined in step A2 that there is no first request, the process proceeds to step A3, where it is determined whether the value of the precharge count X is less than 10 (less than the second predetermined number, for example, 0 to 9 times). If it is determined that the value of the precharge count X is 10 or more (greater than or equal to the second predetermined number), the process proceeds to step A5. 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 off control, even if the value of the precharge count X is 10 or more, transition to other controls is prohibited and continues until the value of the precharge count X becomes less than 10.

[0084] In step A3, if it is determined that the value of the precharge count X is less than 10, the process proceeds to step A4, where it is determined whether there is a ready request. If a ready request is determined to exist, the off-control ends and precharge control begins. On the other hand, if it is determined in step A4 that there is no ready request, the process proceeds to step A5. 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 occurs.

[0085] Figure 4 is a flowchart showing the procedure for the countdown control (subroutine). In this subroutine, a calculation is performed to decrease the value of the precharge count X by 1 each time a predetermined period has elapsed. The variable Z in the flow is a variable used to measure 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 of variable Z may be a variable value corresponding to the precharge count X. That is, the predetermined period for decreasing the value of the precharge count X by 1 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 in step S1 is not met (i.e., the precharge count X is 0), steps S2 to S5 are skipped and the subroutine terminates. 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. In the following step S5, the value of variable Z is reset to 0. If the condition in step S3 is not met, steps S4 to S5 are skipped and the subroutine terminates.

[0087] Figure 5 is a flowchart showing the pre-charge control procedure. 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 in 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 there is a first request. If it is determined that there is a first request, off control is started. On the other hand, if it is determined in step B4 that there is no first request, then in step B5, it is determined 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] In other words, steps B4 and B5 are repeated until the capacitor voltage reaches the battery voltage. Here, even if the ready request is not received before the capacitor voltage reaches the battery voltage, the connection state of the precharge contactor 7 is maintained 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 precharging, the process proceeds to the Yes route in step B4, the precharge control is forcibly interrupted, and the off control is implemented. If the capacitor voltage is boosted without receiving the first request and the conditions in step B5 are met, the process proceeds to step B6.

[0090] In step B6, it is determined whether or not there is a ready request. If there is a ready request, the precharge control ends and the main control starts. On the other hand, if there is no ready request, the process proceeds to step B7. In step B7, it is determined whether or not the value of the precharge count X is 7 or greater (at least the first predetermined count). If this condition is met, the precharge control ends and the first standby control starts. If this condition is not met, the precharge control ends and either the off control or the second standby control starts.

[0091] Figure 6 is a flowchart showing the main control procedure. In step C1, the P contactor 4 and N contactor 5 are turned on, and the pre-charge contactor 7 is turned off. In step C2, countdown control is performed.

[0092] In the following step C3, it is determined whether or not there is a first request. 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 started. In other words, the first determination (step C3) is performed before the ready determination (step C4). As a result, if an abnormality occurs in the high-voltage circuit system, off control is started immediately, thus suppressing the occurrence of secondary abnormalities in the high-voltage circuit system.

[0093] If a ready request is detected in step C4, the main control for this control cycle ends. In the next control cycle, the main control continues, and step C1 is executed again. In other words, in the main control, as long as the ready request state continues without receiving a first request, the processing of steps C1 to C4 is repeated.

[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 there is a second request. If it is determined that there is a second request, the main control is forcibly interrupted, and either 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 second request is received due to user error or negligence, and the ready request is deemed to have disappeared, and then another ready request is received immediately afterward, the processing in step C4 is performed before the processing in step C5 based on that ready request, and the main control continues. Therefore, the execution of unnecessary off control or unnecessary second standby control is suppressed.

[0095] If it is determined in step C5 that there is no second request, the process proceeds to step C6, where it is determined whether the value of the precharge count X is 7 or greater (greater than or equal to the first predetermined count). If this condition is met, the main control ends and the first standby control begins. If this condition is not met, the main control ends and either the off control or the second standby control begins.

[0096] Figure 7 is a flowchart showing the procedure for the first standby control. In step D1, the P contactor 4 and N contactor 5 are turned on, and the pre-charge contactor 7 is turned off. In step D2, countdown control is performed.

[0097] In the following step D3, it is determined whether or not there is a first request. 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 begins. In other words, here as with the main control, the first determination (step D3) is performed before the ready determination (step D4). 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. Therefore, the countdown control continues even in the off control, and it is determined whether or not to transition to precharge control based on the carried-over precharge count X (the determination in step A3 in Figure 3 is performed).

[0098] In step D4, if a ready request is detected, the first standby control ends and the main control begins. At this time, the value of the precharge count X and the value of variable Z are carried over. Therefore, the countdown control continues in the main control as well.

[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 off control or second standby control is started. In other words, here as with the main control, the second determination (step D5) is performed after the ready determination (step D4). 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 carried over to either off control or second standby control, just as when it is determined that there is a first request in step D3.

[0100] In step D5, if it is determined that there is no second request, the process proceeds to step D6, where it is determined whether the value of the precharge count X is 7 or greater (greater than or equal to the first predetermined number of times). 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. In other words, 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 the first predetermined number of times, for example, 0 to 6 times) without receiving a forced disconnection request or a ready request. When 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 is not met, the first standby control ends, and either off control or the second standby control begins.

[0101] Figure 8 is a flowchart showing the procedure for the second standby control. In step E1 of Figure 8, the N contactor 5 and pre-charge contactor 7 are turned on, and the P contactor 4 is turned off. In step E2, countdown control is performed.

[0102] In the following step E3, it is determined whether or not there is a first request. 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 started. In other words, here again, the first determination (step E3) is performed before the ready determination (step E4). Also, 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 carried over to the off control.

[0103] In step E4, if a ready request is detected, the second standby control ends and the main control begins. At this time, the value of the precharge count X and the value of variable Z remain 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. In other words, here too, the second determination (step E5) is performed after the ready determination (step E4).

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

[0106] On the other hand, if it is determined in step E5 that there is no second request, the process proceeds to step E7, where it is determined whether the first waiting time has elapsed since the start of the second waiting control. If it is determined in step E7 that the first waiting time has not elapsed, the process returns to step E2, and steps E2 to E7 are repeated until the first waiting time has elapsed without receiving a forced disconnection request or a ready request. Then, if the condition in step E7 is met, the process proceeds to step E8.

[0107] In step E8, the P contactor 4 and N contactor 5 are turned on, the precharge contactor 7 is turned off, and the process proceeds to step E9. Steps E9 to E14 are almost identical to steps E2 to E7, except for the difference in waiting times. That is, countdown control is performed in step E9. If a first request is received, the process proceeds to the Yes route from step E10, the second standby control is forcibly interrupted, and the off control begins. If there is no first request and a ready request is received, the process proceeds to the Yes route from step E11, the second standby control ends, and the main control begins. If a second request is received after the first waiting time has elapsed, the process of steps E9 to E13 is repeated until steps E12 and E13 are met, that is, until the fourth waiting time has elapsed without the second request disappearing. When the condition of step E13 is met, the second standby control ends and the off control begins. If no second request is received, the process of steps E9 to E14 is repeated until step E14 is met, that is, from the end of the first waiting time until the end of the second waiting time. When the condition in step E14 is met, the second standby control ends and the off control begins.

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

[0109] The control device 30 maintains the connection state of the precharge contactor 7 until the voltage of capacitors 14 and 24 reaches the voltage of battery 2, even if there is no ready request during the execution of precharge control. Furthermore, if there is no ready request during the execution of precharge control and the voltage of capacitors 14 and 24 reaches the voltage of battery 2, the control device 30 determines the number of times the precharge resistor 8 has been energized (precharge count X) in the most recent predetermined past period based on the current time. If the number of energizations is equal to or greater than a first predetermined number (for example, 7 times), the first standby control is performed. The first standby control is a control that connects the main contactors 4 and 5 and disconnects the precharge contactor 7, and maintains the connection state of the main contactors 4 and 5 until the precharge count X falls below the first predetermined number. If the control device 30 receives a forced disconnection request during the execution of the first standby control, it performs off control. Off control is a control that disconnects the main contactors 4 and 5 and the precharge contactor 7.

[0110] With the above configuration, even if a ready request is lost during pre-charge control, the connection state of the pre-charge contactor 7 can be maintained until pre-charging is complete. As a result, if a ready request is received again before pre-charging is complete, main control can be performed after pre-charging is complete without interrupting the power supply to the main circuit 3. In particular, if the loss of a ready request during pre-charge control is due to user error or negligence, pre-charge control will not be interrupted, making recovery easier. Therefore, the protection of the main circuit 3 (power supply circuit) and the starting performance of the vehicle can be improved with a simple configuration.

[0111] Furthermore, if there are no more ready requests during pre-charge control, and the voltage of capacitors 14 and 24 reaches the voltage of battery 2 without receiving another ready request (i.e., pre-charging is complete), the number of pre-charge cycles X is determined. If this number of pre-charge cycles X is greater than or equal to a first predetermined number (for example, 7 or more), the first standby control is performed. This allows the pre-charge resistor 8 to be cooled while maintaining the energized state of the main circuit 3 by disconnecting the pre-charge contactor 7 while delaying the interruption of the energized state of the main circuit 3 when the number of pre-charge cycles X is relatively high. Therefore, the protection of the pre-charge resistor 8 can be improved. In addition, if a new ready request is received while the first standby control is being performed, the system can immediately switch to main control, thus improving the vehicle's starting performance.

[0112] Furthermore, even if the power supply to the main circuit 3 is interrupted when the number of pre-charge cycles X is relatively small, the time required for subsequent pre-charge control (the time required to raise the capacitor voltage) can be shortened. Therefore, the protection of the main circuit 3 and the starting performance of the vehicle can be improved with a simple configuration.

[0113] If a forced disconnection request is received while the first standby control is in operation, the off control is implemented. This allows the main contactors 4 and 5 and the pre-charge contactor 7 to be disconnected without waiting for the pre-charge count X to fall below a predetermined number (e.g., 0 to 6 times). Therefore, when a forced disconnection request is received, the power supply can be cut off more quickly, thus ensuring vehicle safety.

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

[0115] This allows the correspondence between the number of precharge cycles X and the temperatures of the precharge resistor 8 and precharge contactor 7 to be maintained, thereby enabling proper temperature control of the precharge resistor 8 and precharge contactor 7. Furthermore, even if a ready request is received while off-control is in operation, if the number of precharge cycles X is greater than or equal to a second predetermined number (for example, 10 times), precharge control will not be performed, thus improving the protection of the precharge resistor 8.

[0116] (3) In the power management system 1 described above, the first predetermined number of times is set to be less 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 when off control is performed.

[0117] In pre-charge control, if there is no ready request when pre-charging is complete, and the number of pre-charge cycles X is equal to or greater than a first predetermined number (e.g., 7 cycles), the first standby control is performed to cool the pre-charge resistor 8. In off control, even if a ready request is received during its execution, if the number of pre-charge cycles X is equal to or greater than a second predetermined number (e.g., 10 cycles), the transition to pre-charge control is prohibited.

[0118] In other words, in the above configuration, if there is no ready request when precharging is complete, the first standby control is performed when the number of precharging cycles X is equal to or greater than the first predetermined number, which is less than the second predetermined number. In other words, the first standby control may be performed before the number of precharging cycles X reaches the second predetermined number.

[0119] Therefore, the precharge resistor 8 can be cooled during the first standby control, which prevents the precharge count X from reaching the second predetermined number. Furthermore, even if the off control is implemented without waiting for the precharge count X to fall below the first predetermined number (e.g., 0 to 6 times) due to a forced disconnection request during the first standby control, the vehicle's starting performance can be improved because, as described above, the precharge count X is prevented from reaching the second predetermined number. In other words, even if a ready request is received immediately after the off control is initiated due to a forced disconnection request during the first standby control, the transition to precharge control is less likely to be prohibited by the determination of the precharge count X during the off control, thus improving the vehicle's starting performance.

[0120] In particular, if the forced disconnection request received during the first standby control is due to user error, negligence, 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 it is received). However, with the above configuration, the system can transition to pre-charge control early after the start of off control, significantly improving the vehicle's starting performance. Also, if a ready request is received immediately after the second request is received during the first standby control because the vehicle needs to be moved, the system can transition to pre-charge control early, further improving the vehicle's starting performance.

[0121] (4) In the power management system 1 described above, during the execution of the first standby control, 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, during the execution of the first standby control, the presence or absence of a first request takes precedence over the presence or absence of a ready request, and if a first request is found, the off control is forcibly executed. The first request is a request included in the forced disconnection request, and is a signal or flag that indicates that a malfunction in the high-voltage circuit system connected to the battery 2 has resulted in a request to "forcibly disconnect the main circuit 3".

[0122] As a result, if a first request is received while the first standby control is in operation, even if a ready request has been received, the system will not switch to main control, but will instead be forced to perform off control, cutting off the power supply from battery 2 to inverters 11 and 21. Therefore, the system can prevent secondary malfunctions from occurring in the high-voltage circuit system due to the continued power supply from battery 2 to inverters 11 and 21, thereby properly protecting the vehicle.

[0123] (5) Furthermore, in the power management system 1 described above, if a first request is received during pre-charging, the pre-charge control is interrupted and off control is forcibly implemented. Therefore, the power supply from the battery 2 to the inverters 11 and 21 via the pre-charge circuit 6 is continued, which suppresses secondary abnormalities in the high-voltage circuit system. Thus, the vehicle can be properly protected.

[0124] (6) In the power management system 1 described above, 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 while the first standby control is being performed. In other words, while the first standby control is being performed, the presence or absence of a ready request takes precedence over the presence or absence of a second request, and if a ready request is received, the main control is performed. The second request is a request included in the forced disconnection request, and is a signal or flag that indicates that a predetermined operation has been performed and a request has been made to "forcibly disconnect the main circuit 3".

[0125] As described above, the first standby control is performed when there is no ready request at the time pre-charging is complete and the number of pre-charge cycles X is equal to or greater than the first predetermined number. Furthermore, the above-mentioned "when there is no ready request at the time pre-charging is complete" includes cases where the ready request is deemed to have disappeared due to receiving a second request during pre-charging (while pre-charge control is being performed). Here, if the second request received during pre-charge control was due to user error or negligence, there is a possibility that a ready request will be received immediately after the start of the first standby control.

[0126] In the power management system 1 described above, during the execution of the first standby control, 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 has been received due to an error or negligence as described above, the system will transition to main control without unnecessarily performing off control, thereby improving the vehicle's starting performance.

[0127] (7) Furthermore, in the power management system 1 described above, when a second request is received, a second standby control is performed to maintain the connection state of the main contactor 4 or precharge contactor 7 until the shortened standby time has elapsed, and then an off control is performed. This prevents the off control from being performed unnecessarily if the reception of the second request is due to user error or negligence, or if it becomes necessary to move the vehicle immediately after a predetermined operation has been performed for maintenance, and eliminates the need to perform precharge control again, thereby improving the starting performance of the vehicle.

[0128] In addition, the power management system 1 described above may perform an off-control when the number of times the pre-charge resistor 8 is energized is less than a first predetermined number (for example, 0 to 6 times). By performing the off-control, the operating time of the main contactors 4 and 5 and the pre-charge contactor 7 can be shortened, thereby suppressing wear and deterioration. Furthermore, it is possible to prevent the wasteful use of power from the battery 2.

[0129] Furthermore, in the power management system 1 described above, a second standby control can be performed if the number of times the precharge resistor 8 is energized is less than a first predetermined number (for example, 0 to 6 times). By performing the second standby control, it becomes unnecessary to perform precharge control again when a new ready request arises, thus greatly improving the starting performance of the vehicle.

[0130] In the second standby control described above, the control device 30 maintains the connection state of the pre-charge contactor 7 during the first standby period, and then disconnects the pre-charge contactor 7 during the subsequent second standby period, maintaining the connection state of the main contactors 4 and 5. This control significantly improves the starting performance of the vehicle and promotes the cooling of the pre-charge resistor 8 while suppressing wear and deterioration of the P contactor 4 to some extent.

[0131] [5. Others] The above embodiments are merely illustrative examples, and there is no intention to exclude various modifications or applications of techniques not explicitly stated in these embodiments. Each configuration of these embodiments can be modified in various ways without departing from their intended purpose. Furthermore, each configuration of these 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 illustrated, but the precharge circuit 6 may also be connected in parallel to the N contactor 5, or a precharge circuit 6 may be provided for each of the multiple main contactors. In addition, a main contactor that disconnects and disconnects the circuit on the second motor 20 side may be provided separately from the main contactor that disconnects and disconnects the circuit on the first motor 10 side. Regardless of the specific circuit structure, if a ready request is not received during the execution of precharge control, the same effects as in the above embodiment can be achieved by implementing control that maintains the connection state of the precharge contactor 7 until the capacitor voltage reaches the battery voltage.

[0133] Furthermore, in the above embodiment, the third method was employed in the second standby control performed when no second request is received. However, the first method or the second method may also be employed. If the first method is employed, it becomes unnecessary to perform pre-charge control again when a new ready request arises during the execution of the second standby control, thereby greatly improving the vehicle's starting performance. If the second method is employed, the number of times the P contactor 4 is driven can be reduced when transitioning from pre-charge control to second standby control, thereby suppressing wear and deterioration of the P contactor 4. In addition, pre-charge control can be completed in a very short time, greatly improving the protection of the main circuit 3 and the vehicle's starting performance. Note that the second standby control is optional.

[0134] In the above embodiment, if a first request was received during the execution of main control, the system transitioned directly to off control, and if a second request was received, it transitioned to off control after going through second standby control. However, the method of executing main control is not limited to this. For example, in main control, if a forced disconnection request (first request, second request) is received while the vehicle is running, the transition to off control may be postponed, and the system may be switched to off control only after confirming that the vehicle has stopped.

[0135] In the above embodiment, the forced disconnection request included two types of requests, a first request and a second request. However, the forced disconnection request may include only the first request, or only the second request. Also, in the above embodiment, the second determination was performed only when the ready determination determined that there was no ready request. However, the second determination may also be performed when the ready determination determined that there is a ready request. The forced disconnection request only needs to be something (signal or flag) that means at least a request to "forcibly disconnect the main circuit 3," and may include other requests that arise for reasons different from the first and second requests. [Industrial applicability]

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

[0137] 1. Power Management System 2 batteries 3 Main Circuit 4 P Contactor (Main Contactor) 5 N Contactor (Main Contactor) 6. Precharge circuit 7 Pre-charge contactor 8 Precharge resistors 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 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 Pre-charge count (number of times powered on)

Claims

1. A main contactor is interposed in the main circuit, which is connected to an inverter circuit that controls the frequency of power supplied to the motor and a battery, A precharge contactor and a precharge resistor are interposed in a precharge circuit connected in parallel to the main contactor. A capacitor is interposed in a smoothing circuit connected in parallel to the inverter circuit, The control device includes a pre-charge control that increases the voltage of the capacitor by connecting the pre-charge contactor in response to a ready request, which means a request to connect the main circuit, and a main control that connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery, The control device, Even if the ready request ceases during the execution of the precharge control, the connection state of the precharge contactor is maintained until the voltage of the capacitor reaches the voltage of the battery. If the ready request ceases to exist during the execution of the precharge control, and the voltage of the capacitor reaches the voltage of the battery, the number of times the precharge resistor has been energized in the most recent predetermined period in the past, with respect to the current time, is determined. If the number of energization cycles is equal to or greater than a first predetermined number, a first standby control is performed in which the main contactor is connected and the precharge contactor is disconnected, and the connection state of the main contactor is maintained until the number of energization cycles in the most recent predetermined past period based on the current time falls below the first predetermined number. If a forced disconnection request is received during the execution of the first standby control, which means a request to forcibly disconnect the main circuit, then an off control is performed to disconnect the main contactor and the precharge contactor. When performing the off-control described above, the number of times the power is supplied, which was determined during the execution of the first standby control, is carried over without being reset. If the ready request is received while the off-control is being performed, the pre-charge control is performed if the number of times the power is applied in the most recent predetermined period in the past, based on the current time, is less than the second predetermined number. A vehicle power management system characterized by the following features.

2. The first predetermined number of times is less than the second predetermined number of times. A vehicle power management system according to claim 1, characterized in that

3. The aforementioned forced disconnection request includes a first request that means a request to forcibly disconnect the main circuit due to an abnormality in the high-voltage circuit system connected to the battery, The control device performs a first determination to determine whether it has received the first request before performing a ready determination to determine whether it has received the ready request while the first standby control is being performed. A vehicle power management system according to claim 1 or 2, characterized in that

4. If the control device receives the first request before the voltage of the capacitor reaches the voltage of the battery while the precharge control is being performed, it will perform the off control. A vehicle power management system according to claim 3, characterized in that

5. The aforementioned forced disconnection request includes a second request that means a request to forcibly disconnect the main circuit as a result of a predetermined operation being performed. The control device, while performing the first standby control, performs a ready determination to determine whether it has received the ready request, and then performs a second determination to determine whether it has received the second request. A vehicle power management system according to claim 1 or 2, characterized in that

6. When the control device receives the second request, it performs a second standby control that maintains the connection state of the main contactor or the precharge contactor until the waiting time has elapsed, and then performs the off control. A vehicle power management system according to claim 5, characterized in that

7. A main contactor is interposed in the main circuit, which is connected to an inverter circuit that controls the frequency of power supplied to the motor and a battery, A precharge contactor and a precharge resistor are interposed in a precharge circuit connected in parallel to the main contactor. A capacitor is interposed in a smoothing circuit connected in parallel to the inverter circuit, The control device includes a pre-charge control that increases the voltage of the capacitor by connecting the pre-charge contactor in response to a ready request, which means a request to connect the main circuit, and a main control that connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery, The control device, Even if the ready request ceases during the execution of the precharge control, the connection state of the precharge contactor is maintained until the voltage of the capacitor reaches the voltage of the battery. If the ready request ceases to exist during the execution of the precharge control, and the voltage of the capacitor reaches the voltage of the battery, the number of times the precharge resistor has been energized in the most recent predetermined period in the past, with respect to the current time, is determined. If the number of energization cycles is equal to or greater than a first predetermined number, a first standby control is performed in which the main contactor is connected and the precharge contactor is disconnected, and the connection state of the main contactor is maintained until the number of energization cycles in the most recent predetermined past period based on the current time falls below the first predetermined number. If a forced disconnection request is received during the execution of the first standby control, which means a request to forcibly disconnect the main circuit, then an off control is performed to disconnect the main contactor and the precharge contactor. The aforementioned forced disconnection request includes a first request that means a request to forcibly disconnect the main circuit due to an abnormality in the high-voltage circuit system connected to the battery, The control device performs a first determination to determine whether it has received the first request before performing a ready determination to determine whether it has received the ready request while the first standby control is being performed. A vehicle power management system characterized by the following features.

8. A main contactor is interposed in the main circuit, which is connected to an inverter circuit that controls the frequency of power supplied to the motor and a battery, A precharge contactor and a precharge resistor are interposed in a precharge circuit connected in parallel to the main contactor. A capacitor is interposed in a smoothing circuit connected in parallel to the inverter circuit, The control device includes a pre-charge control that increases the voltage of the capacitor by connecting the pre-charge contactor in response to a ready request, which means a request to connect the main circuit, and a main control that connects the main contactor and disconnects the pre-charge contactor after the voltage of the capacitor reaches the voltage of the battery, The control device, Even if the ready request ceases during the execution of the precharge control, the connection state of the precharge contactor is maintained until the voltage of the capacitor reaches the voltage of the battery. If the ready request ceases to exist during the execution of the precharge control, and the voltage of the capacitor reaches the voltage of the battery, the number of times the precharge resistor has been energized in the most recent predetermined period in the past, with respect to the current time, is determined. If the number of energization cycles is equal to or greater than a first predetermined number, a first standby control is performed in which the main contactor is connected and the precharge contactor is disconnected, and the connection state of the main contactor is maintained until the number of energization cycles in the most recent predetermined past period based on the current time falls below the first predetermined number. If a forced disconnection request is received during the execution of the first standby control, which means a request to forcibly disconnect the main circuit, then an off control is performed to disconnect the main contactor and the precharge contactor. The aforementioned forced disconnection request includes a second request that means a request to forcibly disconnect the main circuit as a result of a predetermined operation being performed. The control device, while performing the first standby control, performs a ready determination to determine whether it has received the ready request, and then performs a second determination to determine whether it has received the second request. A vehicle power management system characterized by the following features.

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