Vehicle power system

Abstract

A vehicle power supply system (100) includes: a sensor unit (20) for detecting the battery state of a battery (11); and a control unit (30) for instructing the connection and disconnection of power between the battery and an electrical load (13) based on the battery state. The sensor unit includes: a detection unit (21) for detecting the battery state of the battery; a switch drive unit (23) for driving and controlling a switch (23a) disposed between the battery and the electrical load; and a control unit (24) for controlling the switch drive unit. The control unit switches the connection and disconnection of power between the battery and the electrical load based on instructions from the control unit, and, in the event of an abnormality, determines whether to maintain the connection between the battery and the electrical load based on the battery state, and switches the connection and disconnection based on this determination.

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2021-136438, filed on August 24, 2021, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a power supply system for vehicles. Background Technology

[0004] Previously, a power supply system was known, comprising: a sensor unit that detects the state of a battery (voltage, current, ground fault, etc.); and an ECU that receives detection results from the sensor unit and controls the opening and closing of a relay switch based on the received detection results, the relay switch switching the connection and disconnection of power between the battery and an electrical load (including a generator such as a rotary motor) (e.g., Patent Document 1).

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-16247 Summary of the Invention

[0008] However, in the case of a power system like that in Patent Document 1, where communication between the sensor unit and the ECU becomes impossible, in order to prevent over-discharge and over-charge of the battery, the relay switch is generally disconnected to cut off the power supply between the battery and the electrical load to ensure safety.

[0009] However, in the case of electric vehicles, which use a rotating motor as the main unit, if the power supply from the battery is interrupted, there is a problem that the electric vehicle will stop immediately.

[0010] This disclosure is made in view of the above-mentioned technical problems, and its object is to provide a vehicle power system that can supply power from a battery for a short period of time even if communication is interrupted.

[0011] A first approach to solving the aforementioned technical problem is a vehicle power supply system, comprising: a sensor unit that detects the battery state of a battery capable of supplying power to an electrical load; and a control unit that receives the battery state from the sensor unit via a communication path and instructs the connection and disconnection of power between the battery and the electrical load based on the input battery state. The sensor unit includes: a detection unit that detects the battery state of the battery; and a switch driving unit that drives a switch between the battery and the electrical load. The system includes a switch drive unit and a control unit that controls the switch drive unit. The control unit controls the switch drive unit according to an instruction from the control unit, thereby switching the power supply and disconnection between the battery and the electrical load. In the event of an anomaly in the control unit or the communication path, the control unit determines whether to maintain the power supply between the battery and the electrical load based on the battery status detected by the detection unit, and controls the switch drive unit based on this determination, thereby switching the power supply and disconnection between the battery and the electrical load.

[0012] Therefore, even if communication is interrupted due to an abnormality in the control unit or communication path, the control unit can still determine whether to maintain power between the battery and the electrical load based on the battery status detected by the detection unit, and drive the control switch unit based on this decision. Thus, if the battery is not malfunctioning, power can be supplied from the battery to the electrical load for a short period of time.

[0013] A second approach to solving the aforementioned technical problem is a vehicle power supply system, comprising: a sensor unit that detects the battery state of a battery capable of supplying power to an electrical load; and a control unit that receives the battery state from the sensor unit via a communication path and instructs the battery to be energized and de-energized from the electrical load based on the input battery state. The sensor unit includes: a detection unit that detects the battery state of the battery; and a switch driving unit that, based on the instructions of the control unit, controls the switching of the battery to the electrical load. A switch unit installed between the battery and the electrical load is driven and controlled to switch the power supply and disconnection between the battery and the electrical load. The control unit is configured to output a normal notification signal at regular intervals during normal operation. When the notification signal is input from the control unit at regular intervals, the switch drive unit maintains the power supply between the battery and the electrical load. When the notification signal is not input from the control unit at regular intervals, the switch drive unit is driven and controlled to disconnect the power supply between the battery and the electrical load after a predetermined grace period.

[0014] In the event of a communication interruption due to an anomaly in the control unit or communication path, notification signals are no longer input to the switch drive unit. Therefore, if the switch drive unit does not input notification signals at regular intervals, it determines that an anomaly has occurred and, after a predetermined grace period, performs drive control on the switch unit to disconnect the power supply between the battery and the electrical load. Thus, even in the event of an anomaly, power can be supplied from the battery to the electrical load for a short period. Attached Figure Description

[0015] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The accompanying drawings are described below.

[0016] Figure 1 It is a diagram showing the structure of a vehicle's power supply system.

[0017] Figure 2 This is a diagram showing the structure of the control unit and sensor unit.

[0018] Figure 3 This is a flowchart of the switch control process.

[0019] Figure 4 This is a diagram showing the structure of the control unit and sensor unit in the second embodiment.

[0020] Figure 5 This is a flowchart of the switch-driven processing.

[0021] Figure 6 This is a diagram showing the structure of the control unit and sensor unit in the third embodiment.

[0022] Figure 7 This is a flowchart of the switch drive indication process.

[0023] Figure 8 This is a diagram showing the structure of the sensor unit according to the fourth embodiment.

[0024] Figure 9 This is a timing diagram showing the input and output timing of signals in the fourth embodiment.

[0025] Figure 10 This is a timing diagram showing the input and output timing of signals in a variation of the fourth embodiment.

[0026] Figure 11 This is a diagram showing the structure of the sensor unit according to the fifth embodiment.

[0027] Figure 12 This is a diagram showing the structure of the sensor unit in a modified example of the fifth embodiment.

[0028] Figure 13 This is a diagram showing the structure of the vehicle power supply system according to the sixth embodiment. Detailed Implementation

[0029] Hereinafter, with reference to the accompanying drawings, embodiments of applying a vehicle power system to a vehicle (e.g., an electric vehicle) will be described. Furthermore, in the following embodiments, the same or equivalent parts are labeled with the same symbols in the drawings, and the descriptions of the parts with the same symbols are cited.

[0030] (First Implementation)

[0031] like Figure 1 As shown, the vehicle power system 100 includes: a battery pack 10; a sensor unit 20 that detects the battery state of the battery pack 10; and a control unit 30 that is connected to the sensor unit 20, acquires the battery state from the sensor unit 20, and implements various controls based on the battery state.

[0032] The battery pack 10, for example, has an inter-terminal voltage of over 100V and is composed of multiple battery modules 11 connected in series. Each battery module 11 is composed of multiple battery cells 12 connected in series. For example, lithium-ion batteries or nickel-metal hydride batteries can be used as battery cells 12. In this embodiment, the battery corresponds to the battery module 11.

[0033] The battery pack 10 is connected to the electrical load 13 via an electrical path and supplies power to the electrical load 13. Furthermore, the electrical load 13 includes a rotary motor, and the battery pack 10 supplies power to drive the rotary motor. Additionally, there is a possibility that the battery pack 10 is charged by the rotary motor.

[0034] A system main relay SMR is installed in the electrical paths L1 and L2 connecting the battery pack 10 and the electrical load 13. In addition, capacitor C1 is connected in parallel with the electrical load 13.

[0035] Sensor unit 20 is provided for each battery module 11 to detect (monitor) the battery status of each battery module 11. Battery status may also include voltage, current, SOC, SOH, internal impedance, battery temperature, etc. In this embodiment, voltage and current are used as examples to illustrate the battery status of each battery module 11. However, sensor unit 20 is not limited to each battery module 11; it may also be provided for each of multiple battery cells 12, each battery cell 12, or each battery pack 10. Alternatively, it may detect the battery status of each battery cell 12 or the battery pack 10.

[0036] based on Figure 2 The sensor unit 20 will be described in detail below. The sensor unit 20 includes a current detection unit 21 that detects the current of the battery module 11 being detected, and a voltage detection unit 22 that detects the voltage of the battery module 11 being detected. Furthermore, in the electrical path connecting the battery module 11 being detected and the electrical load 13 (or between battery modules 11 connected in series), a switch 23a is provided as a switching unit that switches between energizing and de-energizing the battery module 11 being detected and the electrical load 13. The sensor unit 20 includes a switch drive unit 23 that implements the on / off control of this switch 23a. The switch 23a is, for example, a relay switch. The switch 23a can also be implemented using a thermal fuse.

[0037] Additionally, the sensor unit 20 includes a control unit 24 for implementing various controls. The control unit 24 may be configured as a microcomputer, including a CPU and memory. The control unit 24 is connected to the current detection unit 21, the voltage detection unit 22, and the switch drive unit 23. Furthermore, the control unit 24 is connected to the MCU 31 of the control unit 30 via communication path L38, communication IFs 25 and 35, and insulating elements 26 and 36, receiving instructions from the control unit 30 and performing various processes based on these instructions. For example, when the control unit 30 instructs the detection of the battery state of the battery module 11, the control unit 24 receives the battery state (current and voltage) from the current detection unit 21 and the voltage detection unit 22, and outputs the received battery state to the control unit 30.

[0038] Furthermore, when the control unit 30 instructs the battery module 11, which is being detected, to be de-energized, the control unit 24 instructs the switch drive unit 23 to de-energize the switch 23a. When the control unit 24 inputs the de-energization instruction, the switch drive unit 23 disconnects the switch 23a and cuts off the power supply to the battery module 11.

[0039] Next, the control unit 30 will be described. The control unit 30 includes an MCU (Micro Controller Unit) 31. The MCU 31 is a type of microcomputer that includes a CPU or memory. The MCU 31 receives requests from the vehicle (throttle opening, etc.) and, based on these requests and the battery status, instructs the power supply from the battery pack 10 to the electrical load 13. Specifically, the MCU 31 performs the activation control of the system main relay SMR. Furthermore, when the electrical load 13 includes a rotary motor or the like, the MCU 31 sometimes performs the activation control of the system main relay SMR and controls the charging of the battery pack 10.

[0040] In addition, if an abnormality occurs in the battery pack 10, the MCU 31 will cut off the power supply from the battery pack 10 to the electrical load 13. Specifically, the MCU 31 will execute the disconnection control of the system main relay SMR and instruct the disconnection control of switch 23a.

[0041] In addition, the control unit 30 is connected to the auxiliary power supply 32, and the power supplied from the auxiliary power supply 32 is supplied to the power generation unit 33 provided in the control unit 30. The power generation unit 33 converts the power supplied by the auxiliary power supply 32 into drive power for the control unit 30, and supplies the drive power to the various components constituting the control unit 30, such as the MCU 31.

[0042] As described above, the MCU 31 of the control unit 30 is configured to switch the power-on and power-off between the battery pack 10 (including the battery module 11) and the electrical load based on requests from the vehicle and the battery status. Therefore, if the MCU 31's communication with the sensor unit 20 is interrupted due to some fault and it cannot obtain the battery status from the sensor unit 20, the MCU 31 cannot perform power-on and power-off switching. Similarly, power-on and power-off switching cannot be performed even if the MCU 31 malfunctions.

[0043] In the event of an anomaly in communication path L38 or MCU 31, it is desirable to disconnect the power supply between battery pack 10 and electrical load 13 for safety reasons. However, in the case of an electric vehicle, disconnecting the power supply between battery pack 10 and electrical load 13 would also disconnect the power supply to the rotary motor (vehicle drive source) contained in electrical load 13, causing the vehicle to stop immediately. Therefore, the vehicle may stop and block the path of other vehicles on the road, becoming a problem.

[0044] On the other hand, even if the communication path L38 or MCU 31 malfunctions, the battery pack 10 or electrical load 13, and the electrical paths L1 and L2 therebetween, may not malfunction. Therefore, if the battery pack 10, etc., are not malfunctioning, it is preferable to supply power to the electrical load 13 for a short period of time, allowing the vehicle to move without causing obstruction. Therefore, in this embodiment, the sensor unit 20 is configured as follows, so that even if communication with the control unit 30 is interrupted, power can be supplied from the battery pack 10 for a short period of time. Hereinafter, based on Figure 3 The structure of the sensor unit 20 will be described specifically by the switching control process implemented by the control unit 24. The switching control process is implemented by the control unit 24 at predetermined intervals.

[0045] The control unit 24 determines whether the communication path L38 and the MCU 31 are functioning correctly (step S101). Specifically, the control unit 24 detects open circuits in the communication path L38 (including malfunctions of components located in the communication path L38) and malfunctions in the MCU 31. Open circuits in the communication path L38 can be detected by various methods, such as checking the voltage in the communication path L38 or using an open circuit detection circuit. Similarly, in the absence of a response from the MCU 31, malfunctions in the MCU 31 can be detected by various methods. These malfunction determination methods can also be well-known methods.

[0046] If the determination result in step S101 is positive (when communication path L38 and MCU 31 are normal), the control unit 24 inputs a switch control signal from the control unit 30 and controls the switching on and off of switch 23a based on the input switch control signal (step S102).

[0047] In addition, the MCU 31 of the control unit 30 acquires switch control information related to the on / off state of the switch 23a, such as vehicle requests and battery status, and outputs a switch control signal indicating the on / off state of the switch 23a based on the switch control information.

[0048] On the other hand, if the determination result in step S101 is negative (in the case of an abnormality in communication path L38 or MCU 31), the control unit 24 acquires the battery status (current and voltage) from the current detection unit 21 and the voltage detection unit 22 (step S103). Then, based on the acquired battery status, the control unit 24 determines whether the battery module 11 being detected is normal (step S104). Specifically, the control unit 24 determines whether the input current and voltage are within a predetermined normal value range. In addition, in this embodiment, the determination of whether it is normal is based on current and voltage, but it can also be based on either one. Alternatively, values ​​other than current and voltage can be input and combined with them for determination, or the determination can be based on values ​​other than current and voltage.

[0049] If the determination result in step S104 is positive (within the normal value range), the control unit 24 implements power-on maintenance control to keep the switch drive unit 23 in the on state (power-on state) of switch 23a (step S105). Then, after a predetermined time has elapsed, the control unit 24 implements the processing of step S103 again.

[0050] On the other hand, if the determination result in step S104 is negative (not within the normal value range), the control unit 24 performs power-on / off control on the switch drive unit 23 to make the switch 23a open (power-on / off state) (step S106). Specifically, the control unit 24 instructs the switch drive unit 23 to cut off the power to the switch 23a. When the power-on / off input is received from the control unit 24, the switch drive unit 23 disconnects the switch 23a and cuts off the power to the battery module 11.

[0051] Based on the structure of this embodiment, the following excellent effects can be achieved.

[0052] In the event of an anomaly in the control unit 30 or communication path L38, the control unit 24 acquires the battery status from the current detection unit 21 and the voltage detection unit 22, and determines whether to maintain power supply between the battery module 11 and the electrical load 13 based on the acquired battery status. If the control unit 24 determines that power supply between the battery module 11 and the electrical load 13 has been cut off, it instructs the switch drive unit 23 to cut off power based on this determination. The switch drive unit 23 then performs disconnection control of the switch 23a based on this power-off instruction. Therefore, in the event of an anomaly in the control unit 30 or communication path L38, the interruption of power supply from the battery module 11 can be suppressed, allowing the vehicle to stop immediately.

[0053] In the event of an anomaly in the control unit 30 or the communication path L38, the control unit 24 acquires the battery status every predetermined time interval and determines whether to maintain power based on the battery status. Therefore, after deciding to maintain power, if an anomaly occurs in the battery module 11, power is cut off, thus protecting the battery module 11 and the like.

[0054] (A variation of the first embodiment)

[0055] • In the first embodiment described above, after determining that power should be maintained, the control unit 24 can also cut off the power if a predetermined retreat time has elapsed. The retreat time is expected to be the time required for the vehicle to move to the side of the road without obstructing other vehicles (for example, about 5 minutes). This allows for more reliable protection of the battery module 11, etc.

[0056] In the first embodiment described above, a power generation unit that receives power from the battery module 11 to generate drive power for the sensor unit 20 may also be provided in the sensor unit 20. Therefore, even if the power line between the sensor unit 20 and the control unit 30 is disconnected, the sensor unit 20 can still be driven.

[0057] (Second Implementation)

[0058] The structure of the first embodiment described above can also be modified as in the second embodiment described below. Hereinafter, in the second embodiment, the differences from the structures described in the above embodiments will be mainly described. Furthermore, in the second embodiment, the vehicle power supply system 100 of the first embodiment will be used as an example to illustrate the basic structure.

[0059] Reference Figure 4The structures of the control unit 30 and sensor unit 20 in the second embodiment will be described. First, the structure of the control unit 30 will be described. The MCU 31 of the control unit 30 acquires switch control information related to the on / off state of the switch 23a, such as vehicle requests and battery status. Then, the MCU 31 determines whether to turn the switch 23a on or off based on the switch control information and outputs a switch control signal indicating whether the switch 23a is on or off to the sensor unit 20. For example, when the battery pack 10 is normal, the MCU 31 outputs a switch control signal indicating that the switch 23a is on; on the other hand, when the battery pack 10 is malfunctioning, the MCU 31 outputs a switch control signal indicating that the switch 23a is off.

[0060] In addition, when the control unit 30 and communication path L38 are functioning normally, the MCU 31 outputs a notification signal indicating that the control unit 30 and communication path L38 are functioning normally after a certain period T1. The certain period T1 can be any period, for example, 5 seconds.

[0061] Next, the sensor unit 20 will be described. For example... Figure 4 As shown, the control unit 24 is omitted in the sensor unit 20 of the second embodiment. Therefore, when the control unit 30 instructs the current detection unit 21 and voltage detection unit 22 to detect the battery state of the battery module 11, which is to be detected, the current detection unit 21 and voltage detection unit 22 in the second embodiment directly input the instruction. Then, when the battery state is instructed to be detected, the current detection unit 21 and voltage detection unit 22 are configured to detect the battery state (current and voltage) and output the input battery state to the control unit 30. Alternatively, the current detection unit 21 and voltage detection unit 22 may also be configured to detect the battery state (current and voltage) at predetermined intervals and output the input battery state to the control unit 30.

[0062] Furthermore, when a switch control signal is input from the control unit 30, the switch drive unit 23 is configured to switch the on / off state of the switch 23a based on the switch control signal. That is, the switch drive unit 23 performs drive control of the switch 23a.

[0063] Furthermore, the switch drive unit 23 is configured to have a drive latching function, maintaining the switch 23a in the on state if a notification signal is input from the control unit 30 before a certain period T1 has elapsed. On the other hand, it is configured to switch the switch 23a to the off state if no notification signal is input from the control unit 30 after a certain period T1 has elapsed. Hereinafter, based on... Figure 5 The switch drive processing used to implement this function will be described. The switch drive processing is performed by the switch drive unit 23 at predetermined intervals.

[0064] The switch drive unit 23 determines whether a notification signal has been input from the control unit 30 within a certain period T1 (step S201). If the determination result is positive, the switch drive unit 23 determines that the communication path or MCU 31 is normal (step S202). Then, the control unit 24 maintains the switch 23a in the on state (step S203).

[0065] On the other hand, if the determination result in step S201 is negative, the switch drive unit 23 determines that an abnormality has occurred in the communication path L38 or MCU 31 (step S204). Then, the switch drive unit 23 keeps the switch 23a in the ON state until a predetermined grace time Ton has elapsed (step S205). The grace time Ton is expected to be the time (e.g., about 5 minutes) that allows the vehicle to move to the side of the road without obstructing other vehicles, and is as short as possible. After the grace time Ton has elapsed, the switch drive unit 23 switches the switch 23a to the OFF state and cuts off the power to the battery module 11 (step S206).

[0066] The effects of the second embodiment will be explained.

[0067] If a notification signal is received from the control unit 30 before a certain period T1 has elapsed, the switch drive unit 23 determines that the communication path L38 is normal and maintains the switch 23a in the on state. On the other hand, if no notification signal is received from the control unit 30 after a certain period T1, it determines that some kind of abnormality has occurred and switches the switch 23a to the off state. Thus, even without the control unit 24 that determines abnormalities, a simple mechanism can maintain power supply for a short period of time and then cut off the power supply.

[0068] (A variation of the second embodiment)

[0069] • In the second embodiment described above, the switch driving unit 23 may also decide whether to maintain the on state of switch 23a based on the battery state detected by the current detection unit 21 or the voltage detection unit 22.

[0070] (Third Implementation)

[0071] The structure of the first embodiment described above can also be modified as in the third embodiment described below. Hereinafter, in the third embodiment, the parts that differ from the structures described in the above embodiments will be mainly described. Furthermore, in the third embodiment, the vehicle power supply system 100 of the first embodiment will be used as an example to illustrate the basic structure.

[0072] The sensor unit 20 in the third embodiment will be described. For example... Figure 6As shown, the control unit 24 is omitted in the sensor unit 20 of the third embodiment. Therefore, the current detection unit 21 and voltage detection unit 22 in the third embodiment are configured to detect the battery state (current and voltage) when instructed by the control unit 30 to detect the battery state of the battery module 11 as the detection target (or at every predetermined period), and output the input battery state to the control unit 30. Alternatively, the current detection unit 21 and voltage detection unit 22 may also be configured to detect the battery state (current and voltage) at predetermined periods and output the input battery state to the control unit 30.

[0073] In addition, similar to the second embodiment, the MCU 31 is configured to output a switch control signal, and the switch drive unit 23 is configured to switch the on / off state of the switch 23a based on the switch control signal when the switch control signal is input from the control unit 30.

[0074] Furthermore, the switch drive unit 23 is connected to the sensor-side power generation unit 29 provided in the sensor unit 20, and supplies drive power from the sensor-side power generation unit 29. The sensor-side power generation unit 29 is connected to the power generation unit 33 of the control unit 30, and supplies power from the power generation unit 33. A power supply switch 37 is provided between the power generation unit 33 and the sensor-side power generation unit 29, and is turned on and off by the MCU 31. That is, the switch drive unit 23 uses the power supplied from the power generation unit 33 as drive power and maintains the on state of switch 23a. Therefore, when the power supply switch 37 switches to the off state and cuts off the supply of drive power from the control unit 30, the on state of switch 23a cannot be maintained, but it switches to the off state.

[0075] The structure of the control unit 30 in the third embodiment will be described. The MCU 31 of the control unit 30 executes at predetermined intervals. Figure 7 The switch drive indication process is shown. The MCU 31 determines whether the communication path L38 and the sensor unit 20 are functioning correctly (step S301). Specifically, the MCU 31 detects a break in the communication path L38 (including an abnormality in a component located in the communication path L38) and an abnormality in the sensor unit 20. The method for detecting a break in the communication path L38 is the same as in the first embodiment. An abnormality in the sensor unit 20 can be detected by various methods, such as no response from the sensor unit 20 or an abnormal signal being input from the sensor unit 20. These abnormality determination methods can also be well-known methods.

[0076] If the determination result is positive, i.e., under normal conditions, MCU 31 outputs a switch control signal based on battery status, etc. (step S302). Then, the switch drive indication process ends.

[0077] On the other hand, if the determination result in step S301 is negative, that is, if an abnormality occurs in the communication path L38 or the sensor unit 20, a determination is made on whether to maintain the on state of switch 23a based on the latest battery state just acquired (step S303).

[0078] If the determination result in step S303 is positive, the MCU 31 maintains the power supply to the sensor unit 20 for a predetermined grace period Ton (step S304). Therefore, since drive power continues to be supplied to the switch drive unit 23, the on state of switch 23a can be maintained. Furthermore, in step S304, the MCU 31 can also notify external devices such as the host ECU of any abnormalities. The grace period Ton is the same as in the second embodiment.

[0079] Then, after a grace period of Ton, the MCU 31 stops supplying drive power to the sensor unit 20 (step S305). As a result, the switch drive unit 23 cannot maintain the on state of switch 23a, and switch 23a is switched to the off state. Consequently, the power supply between the battery module 11 and the electrical load 13 can be cut off.

[0080] Furthermore, if the determination result in step S303 is positive, MCU 31 proceeds to step S305 and stops supplying drive power to sensor unit 20. Thus, similarly as described above, the power supply between battery module 11 and electrical load 13 can be cut off.

[0081] The effects of the third embodiment will be explained.

[0082] In the event of an anomaly in communication path L38 or sensor unit 20, after a grace period Ton, MCU 31 stops supplying drive power to sensor unit 20 and switches switch 23a to the off state. Thus, even if sensor unit 20 does not include a control unit 24 for anomaly detection, it is possible to maintain power for a short period using a simple mechanism before cutting off power.

[0083] (A variation of the third embodiment)

[0084] The third embodiment described above can also be combined with the first embodiment or the second embodiment described above. Therefore, regardless of whether either the control unit 30 or the sensor unit 20 malfunctions, the vehicle can be prevented from stopping immediately.

[0085] • In the third embodiment described above, if an abnormality occurs in the communication path L38, it is determined whether to maintain the on state of switch 23a based on the latest battery status. However, it is also possible to maintain the on state without making a determination until the grace period Ton has elapsed.

[0086] (Fourth Implementation)

[0087] The structure of the first embodiment described above can also be modified as in the fourth embodiment described below. Hereinafter, in the third embodiment, the parts that differ from the structures described in the above embodiments will be mainly described. Furthermore, in the fourth embodiment, the vehicle power supply system 100 of the first embodiment will be used as an example to describe the basic structure.

[0088] like Figure 8 As shown, the sensor unit 20 of the fourth embodiment includes a plurality of current detection units 21 (two in this embodiment). Furthermore, unlike the first embodiment, the voltage detection unit 22 may or may not be included.

[0089] The two current detection units 21 each detect current at different locations. In the fourth embodiment, there is a first current detection unit 21a and a second current detection unit 21b. The first current detection unit 21a detects the current (first current value) at a first position P1 on the electrical path near the battery module 11, which is the detection object of the sensor unit 20. The second current detection unit 21b is farther away from the battery module 11 than the first current detection unit 21a, and detects the current (second current value) at a second position P2 on the electrical path near the switch 23a.

[0090] The first current detection unit 21a detects the current at the first position P1, and outputs a first detection signal indicating the message if the current value is above a predetermined first threshold. The second current detection unit 21b detects the current at the second position P2, and outputs a second detection signal indicating the message if the current value is above a predetermined second threshold. In the second embodiment, the first threshold and the second threshold are set to the same value Th.

[0091] The first current detection unit 21a and the second current detection unit 21b are connected to the AND circuit AND1, and the first detection signal and the second detection signal are configured to be input to the AND circuit AND1. Figure 9 As shown, when the first detection signal and the second detection signal are input, the AND1 circuit outputs an overcurrent detection signal.

[0092] In the fourth embodiment, the switch drive unit 231 is connected to the AND circuit AND1 and is configured to input an overcurrent detection signal. After the overcurrent detection signal is input from the AND circuit AND1, the switch drive unit 231 switches the switch 23a from the ON state to the OFF state.

[0093] The effects of the fourth embodiment will be explained.

[0094] Because it detects whether an overcurrent occurs at two different locations (first location P1 and second location P2), it is more resistant to noise and can suppress false detections.

[0095] (A variation of the fourth embodiment)

[0096] In the fourth embodiment described above, the first threshold and the second threshold are the same value, but as... Figure 10 As shown, the values ​​Th1 and Th2 can also be different. Therefore, even if noise is generated, malfunctions can be suppressed.

[0097] In the fourth embodiment described above, the first current detection unit 21a and the second current detection unit 21b may have different sampling rates or internal error counts. For example, the first current detection unit 21a may be configured to output a first detection signal when the number of times exceeding a first threshold (first count) is greater than or equal to the first internal error count, and the second current detection unit 21b may be configured to output a second detection signal when the number of times exceeding a second threshold (second count) is greater than or equal to the second internal error count. Alternatively, the first current detection unit 21a may be configured to output a first detection signal when the time exceeding the first threshold is greater than or equal to a first time, and the second current detection unit 21b may be configured to output a second detection signal when the time exceeding the second threshold is greater than or equal to a second time. Therefore, in the event of an overcurrent occurring within a very short time due to noise or other factors, false detections can be suppressed.

[0098] In the fourth embodiment described above, the first current detection unit 21a can be either a Hall sensor or a shunt resistor. Similarly, the second current detection unit 21b can be either a Hall sensor or a shunt resistor. Therefore, appropriate modifications can be made according to the required specifications.

[0099] • In the fourth embodiment and its variations described above, it may also be implemented by appropriately combining it with the second embodiment or the third embodiment described above.

[0100] (Fifth Implementation)

[0101] The structure of the fourth embodiment described above can also be modified as in the fifth embodiment described below. Hereinafter, in the fifth embodiment, the parts that differ from the structures described in the previous embodiments will be mainly described. Furthermore, in the fifth embodiment, the vehicle power supply system 100 of the fourth embodiment will be used as an example to illustrate the basic structure.

[0102] like Figure 11 As shown, in the fifth embodiment, a discharge circuit 51 for rapidly discharging the charge of capacitor C1 is provided between battery module 11 and electrical load 13. Discharge circuit 51 is connected in parallel with capacitor C1, battery module 11, and electrical load 13. Discharge circuit 51 is composed of a series connection of resistor R10 and switch 23b. Switch 23b is typically set to the open state (energized off state).

[0103] The sensor unit 20 of the fifth embodiment, like that of the fourth embodiment, includes a first current detection unit 21a, a second current detection unit 21b, an AND circuit AND1, and a switch driving unit 231. Furthermore, in addition to the above-described structure, the sensor unit 20 of the fifth embodiment also includes a second switch driving unit 232. For convenience, in the fifth embodiment, the switch driving unit 231 is referred to as the first switch driving unit 231.

[0104] The second switch drive unit 232 is connected to the output terminal of the delay circuit D1 and the AND1 circuit via the delay circuit D1. For example... Figure 11 As shown, when the first detection signal and the second detection signal are input to AND circuit AND1 and the overcurrent detection signal is output from AND circuit AND1, the overcurrent detection signal is input to the second switch drive unit 232 by delaying the input to the first switch drive unit 231 by a predetermined time through delay circuit D1.

[0105] The second switch drive unit 232 switches switch 23b to the ON state after receiving an overcurrent detection signal. Thus, after a predetermined time delay following the switching delay from the OFF state of switch 23a by the first switch drive unit 231, switch 23b becomes ON. Therefore, the charge on capacitor C1 is discharged through discharge circuit 51.

[0106] The effects of the fifth embodiment described above will be explained.

[0107] After the power supply to the battery module 11 is cut off and a predetermined time has elapsed, the second switch drive unit 232 sets the switch 23b to the on state and discharges the charge of the capacitor C1 through the discharge circuit 51. Thus, the charge of the capacitor C1 can be discharged quickly.

[0108] (A variation of the fifth embodiment)

[0109] In the fifth embodiment described above, the second switch drive unit 232 is configured to set the switch 23b to the on state after the power supply to the battery module 11 has been cut off and a predetermined time has elapsed. As another example, it could also be as follows... Figure 12 As shown, a connection determination circuit 52 is included to determine whether switch 23a has been switched to the off state. Furthermore, the second switch drive unit 232 may also be configured to switch switch 23b to the on state when the connection determination circuit 52 determines that switch 23a has been switched to the off state.

[0110] • In the fifth embodiment and its variations described above, it may also be implemented by appropriate combination with the second embodiment or the third embodiment described above.

[0111] (Sixth Implementation Method)

[0112] The structure of the fifth embodiment described above can also be modified as in the sixth embodiment described below. Hereinafter, in the fifth embodiment, the parts that differ from the structures described in the previous embodiments will be mainly described. Furthermore, in the sixth embodiment, the vehicle power supply system 100 of the fifth embodiment will be used as an example to describe the basic structure.

[0113] like Figure 13 As shown, the battery pack 10 in the sixth embodiment consists of a first battery module 61 and a second battery module 62. Furthermore, the first battery module 61 and the second battery module 62 are configured to be able to change between series and parallel connections.

[0114] In detail, the first battery module 61 and the second battery module 62 are connected in series via switch F1. A first connection switch S1 is connected in parallel with the first battery module 61. One end of the first connection switch S1 is connected to the positive electrical path L1, and the other end is connected between switch F1 and the second battery module 62. Similarly, a second connection switch S2 is connected in parallel with the second battery module 62. One end of the second connection switch S2 is connected to the negative electrical path L2, and the other end is connected between switch F1 and the first battery module 61.

[0115] When the first battery module 61 and the second battery module 62 are connected in series, the first connection switch S1 and the second connection switch S2 are switched to the off state. When the first battery module 61 and the second battery module 62 are connected in parallel, the first connection switch S1 and the second connection switch S2 are switched to the on state.

[0116] The first connection switch S1 and the second connection switch S2 can be switched on and off by the control unit 30 or the sensor unit 20, or by a higher-level ECU, etc. Furthermore, when power is supplied from the battery pack 10 to the electrical load 13, the first battery module 61 and the second battery module 62 are connected in series. On the other hand, when power is supplied from the rotary motor included in the electrical load 13 to the battery pack 10 (i.e., when it is being charged), the first battery module 61 and the second battery module 62 are connected in parallel.

[0117] Furthermore, in the sixth embodiment, the sensor unit 20 is provided with a low-voltage substrate 63 with low driving power and a high-voltage substrate 64 with higher driving power than the low-voltage substrate 63. A first current detection unit 21a is provided on the low-voltage substrate 63, and a second current detection unit 21b is provided on the high-voltage substrate 64.

[0118] In the sixth embodiment, the first current detection unit 21a detects the current flowing in the electrical path between the first battery module 61 and the second battery module 62 at a first location P11 that is closer to the negative terminal of the first battery module 61 than the connection point of the second connection switch S2. The first location P11 is a location where the current from the first battery module 61 can be detected regardless of the connection method.

[0119] Furthermore, in the sixth embodiment, the second current detection unit 21b detects the current flowing in a second location P12, which is closer to the positive terminal of the second battery module 62 than the connection point of the first connection switch S1, in the electrical path between the first battery module 61 and the second battery module 62. The second location P12 is a location where the current from the second battery module 62 can be detected regardless of the connection method.

[0120] In the sixth embodiment, the first current detection unit 21a and the second current detection unit 21b are connected to the anomaly determination circuit 53. The anomaly determination circuit 53 is disposed on the high-voltage substrate 64. The anomaly determination circuit 53 is configured to input connection information related to whether the first battery module 61 and the second battery module 62 are connected in series.

[0121] When the first battery module 61 and the second battery module 62 are connected in series, the anomaly detection circuit 53 outputs an overcurrent detection signal after being input with a first detection signal and a second detection signal. On the other hand, when the first battery module 61 and the second battery module 62 are connected in parallel (not in series), the anomaly detection circuit 53 outputs an overcurrent detection signal after being input with either the first detection signal or the second detection signal.

[0122] The sensor unit 20 of the sixth embodiment is similar to that of the fifth embodiment, including a first switch driving unit 231 and a second switch driving unit 232.

[0123] In the sixth embodiment, the first switch driving unit 231 is connected to the fault determination circuit 53 and is configured to input an overcurrent detection signal. After the first switch driving unit 231 inputs an overcurrent detection signal from the fault determination circuit 53, it switches the switch 23a from the on state to the off state.

[0124] The second switch drive unit 232 is connected to the output terminal of the fault determination circuit 53 via a delay circuit D1. Similar to the fifth embodiment, when an overcurrent detection signal is output from the fault determination circuit 53, the overcurrent detection signal is input to the second switch drive unit 232 with a predetermined delay compared to the input to the first switch drive unit 231 via the delay circuit D1.

[0125] After receiving an overcurrent detection signal, the second switch drive unit 232 switches switch 23b to the ON state. Thus, after a predetermined time delay following the switching delay from the OFF state of switch 23a by the first switch drive unit 231, switch 23b becomes ON. Therefore, the charge on capacitor C1 is discharged through the discharge circuit 51.

[0126] In addition to the effects of the fifth embodiment, the sixth embodiment described above also has the following effects.

[0127] When power is supplied from the battery pack 10 to the electrical load 13, the first battery module 61 and the second battery module 62 are connected in series. On the other hand, when power is supplied from the rotary motor included in the electrical load 13 to the battery pack 10 (i.e., when it is being charged), the first battery module 61 and the second battery module 62 are connected in parallel. Therefore, it is possible to make the power supplied to the electrical load 13 high voltage, while on the other hand, it is possible to reduce the charging voltage. Therefore, the structure for boosting the charging voltage supplied from the rotary motor can be omitted or simplified.

[0128] When the first battery module 61 and the second battery module 62 are connected in series, the anomaly detection circuit 53 outputs an overcurrent detection signal after being input with a first detection signal and a second detection signal. Conversely, when the first battery module 61 and the second battery module 62 are connected in parallel, the anomaly detection circuit 53 outputs an overcurrent detection signal after being input with either the first detection signal or the second detection signal. Therefore, overcurrent can be appropriately detected depending on the connection method. Furthermore, during charging, since the power supply to the electrical load 13 other than the rotating motor and the battery pack 10 is cut off, noise to the battery pack 10 is expected to decrease. Therefore, when the first battery module 61 and the second battery module 62 are connected in parallel, overcurrent can be appropriately detected by detecting overcurrent.

[0129] (A variation of the sixth embodiment)

[0130] • In the above embodiments, it is also possible to configure the system so that, regardless of the connection state, an overcurrent detection signal is output after the first detection signal and the second detection signal are output.

[0131] • In the sixth embodiment and its variations described above, it may also be implemented by appropriate combination with the second embodiment or the third embodiment described above.

[0132] • In the sixth embodiment described above, the sensor unit 20 is configured as a low-voltage substrate 63 and a high-voltage substrate 64, but it may not be separated.

[0133] In the sixth embodiment described above, in the event of an abnormality, the first battery module 61 and the second battery module 62 may be connected in parallel. Alternatively, if it is determined that no overcurrent has occurred, they may be connected in series.

[0134] In the sixth embodiment described above, regardless of the connection method, the first location P11 can be changed to any location that can detect the current from the first battery module 61. Similarly, regardless of the connection method, the second location P12 can be changed to any location that can detect the current from the second battery module 62.

[0135] The following describes the characteristic structures extracted from the above embodiments.

[0136] [Structure 1]

[0137] A vehicle power supply system (100) includes: a sensor unit (20) that detects the battery state of a battery (11) capable of supplying power to an electrical load (13); and a control unit (30) that receives the battery state from the sensor unit via a communication path (L38) and instructs the connection and disconnection of power between the battery and the electrical load based on the input battery state.

[0138] The aforementioned sensor unit includes:

[0139] The testing unit (21) tests the battery status of the aforementioned storage battery;

[0140] The switch drive unit (23) drives and controls the switch unit (23a) disposed between the battery and the electrical load; and

[0141] Control unit (24), the control unit controls the switch drive unit.

[0142] The aforementioned control unit

[0143] - Based on the instructions from the control unit, the switch drive unit is controlled to switch the energization and de-energization between the battery and the electrical load.

[0144] - In the event that an abnormality has occurred in the control unit or the communication path, the detection unit determines whether to maintain the power supply between the battery and the electrical load based on the battery status detected by the detection unit, and controls the switch drive unit based on the decision to switch the power supply between the battery and the electrical load.

[0145] [Structure 2]

[0146] A vehicle power supply system (100) includes: a sensor unit (20) that detects the battery state of a battery (11) capable of supplying power to an electrical load (13); and a control unit (30) that receives the battery state from the sensor unit via a communication path (L38) and instructs the connection and disconnection of power between the battery and the electrical load based on the input battery state.

[0147] The aforementioned sensor unit includes: a detection unit (21) that detects the battery status of the aforementioned storage battery; and

[0148] The switch drive unit (23) drives and controls the switch unit (23a) located between the battery and the electrical load based on the instructions of the control unit, so as to switch the power supply and disconnection between the battery and the electrical load.

[0149] The control unit described above is configured to output a notification signal indicating normal operation at regular intervals during normal operation.

[0150] When the aforementioned switch drive unit receives the aforementioned notification signal from the aforementioned control unit at regular intervals, it maintains the power supply between the aforementioned battery and the aforementioned electrical load. On the other hand, when the aforementioned notification signal is not received from the aforementioned control unit at regular intervals, after a predetermined grace period, it drives the aforementioned switch unit to cut off the power supply between the aforementioned battery and the aforementioned electrical load.

[0151] [Structure 3]

[0152] Based on the vehicle power supply system described in Structure 1 or 2, wherein,

[0153] The control unit includes a power generation unit (33), which converts the power supplied from the auxiliary power source and generates drive power.

[0154] The power generation unit is configured to supply drive power to the switch drive unit.

[0155] In the event that communication from the aforementioned sensor unit is cut off, or in the event that there is a communication from the aforementioned sensor unit indicating that an anomaly has occurred, the aforementioned control unit determines, based on the recently input battery status, whether to maintain power between the aforementioned battery and the aforementioned electrical load for a specified period, and based on this decision, maintains or stops the supply of the aforementioned drive power.

[0156] [Structure 4]

[0157] Based on the vehicle power supply system described in any of structures 1 to 3, wherein,

[0158] The aforementioned detection unit includes: a first current detection unit (21a), which detects a first current value at a first location (P1) on the electrical path between the battery and the electrical load; and a second current detection unit (21b), which detects a second current value at a second location (P2) on the electrical path that is different from the first location.

[0159] When the first current value is above a first threshold and the second current value is above a second threshold, the aforementioned switch drive unit performs drive control on the aforementioned switch unit to cut off the power supply between the aforementioned battery and the aforementioned electrical load.

[0160] [Structure 5]

[0161] Based on the vehicle power supply system described in Structure 4, wherein,

[0162] When the number of times the first current value is above the first threshold is a predetermined first number or more, and when the number of times the second current value is above the second threshold is a second number or more different from the first number, the switch drive unit performs drive control on the switch unit to cut off the power supply between the battery and the electrical load.

[0163] [Structure 6]

[0164] Based on the vehicle power supply system described in structure 4 or 5, wherein,

[0165] The aforementioned storage battery is a battery pack (10) consisting of a first battery module (61) and a second battery module (62).

[0166] The first battery module and the second battery module described above are configured to be able to change between series connection and parallel connection.

[0167] The aforementioned first location is a location (P11) where the current from the aforementioned first battery module can be detected regardless of the connection method.

[0168] The aforementioned second location is a location where the current from the aforementioned second battery module can be detected regardless of the connection method (P12).

[0169] When the first battery module and the second battery module are connected in series, the aforementioned switch drive unit drives the switch unit to cut off the power supply between the battery and the electrical load when the first current value is above a first threshold and the second current value is above a second threshold.

[0170] When the first battery module and the second battery module are connected in parallel, when the first current value is above the first threshold or when the second current value is above the second threshold, the switch section is driven to cut off the power supply between the battery and the electrical load.

[0171] [Structure 7]

[0172] Based on the vehicle power supply system described in any of structures 1 to 6, wherein,

[0173] A discharge circuit (51) is provided, which discharges the charge of the capacitor connected in parallel with the electrical load after the power is cut off by the switch drive unit.

[0174] While this disclosure has been described based on embodiments, it should be understood that this disclosure is not limited to the above embodiments and structures. This disclosure also includes various modifications and equivalent variations. Furthermore, various combinations and arrangements, and consequently, combinations and arrangements containing only one element, or more than or less thereof, also fall within the scope and spirit of this disclosure.

Claims

1. A power supply system for a vehicle, the power supply system for a vehicle comprising: A sensor unit that detects the battery status of a storage battery capable of supplying power to an electrical load; and a control unit, wherein the control unit receives the battery status from the sensor unit via a communication path, and instructs the energizing and de-energizing of the battery and the electrical load based on the input battery status, characterized in that, The sensor unit includes a detection unit that detects the battery status of the battery. A switch drive unit, which drives and controls a switch unit disposed between the battery and the electrical load; and The control unit controls the switch drive unit. The control unit - Based on instructions from the control unit, the switch drive unit is controlled to switch the energization and de-energization between the battery and the electrical load, and If an anomaly is detected in the control unit or the communication path, based on the battery status detected by the detection unit, a decision is made on whether to maintain power between the battery and the electrical load. Based on this decision, the switch drive unit is controlled to switch between power supply and disconnection between the battery and the electrical load. The detection unit includes: a first current detection unit, which detects a first current value at a first location on the electrical path between the battery and the electrical load; and a second current detection unit, which detects a second current value at a second location on the electrical path that is different from the first location. When the first current value is above a first threshold and the second current value is above a second threshold, the switch driving unit drives the switch to cut off the power supply between the battery and the electrical load. The switch drive unit drives the switch unit to cut off the power supply between the battery and the electrical load when the number of times the first current value is above the first threshold is a predetermined first number and the number of times the second current value is above the second threshold is a second number different from the first number.

2. A power supply system for a vehicle, the power supply system for a vehicle comprising: A sensor unit that detects the battery status of a storage battery capable of supplying power to an electrical load; and a control unit, wherein the control unit receives the battery status from the sensor unit via a communication path, and instructs the energizing and de-energizing of the battery and the electrical load based on the input battery status, characterized in that, The sensor unit includes: The detection unit detects the battery status of the storage battery; and A switch drive unit, based on instructions from the control unit, drives and controls a switch unit disposed between the battery and the electrical load to switch the energization and de-energization between the battery and the electrical load. The control unit is configured to output a notification signal indicating normal operation at regular intervals during normal operation. When the switch drive unit receives the notification signal from the control unit at regular intervals, it maintains power between the battery and the electrical load. Conversely, when no notification signal is received from the control unit at regular intervals, after a predetermined grace period, it drives the switch unit to disconnect the power between the battery and the electrical load. The detection unit includes: a first current detection unit, which detects a first current value at a first location on the electrical path between the battery and the electrical load; and a second current detection unit, which detects a second current value at a second location on the electrical path that is different from the first location. When the first current value is above a first threshold and the second current value is above a second threshold, the switch driving unit drives the switch to cut off the power supply between the battery and the electrical load. The switch drive unit drives the switch unit to cut off the power supply between the battery and the electrical load when the number of times the first current value is above the first threshold is a predetermined first number and the number of times the second current value is above the second threshold is a second number different from the first number.

3. The vehicle power supply system as described in claim 1 or 2, characterized in that, The storage battery is a battery pack consisting of a first battery module and a second battery module. The first battery module and the second battery module are configured to be able to change between series connection and parallel connection. The first location is a location where the current from the first battery module can be detected regardless of the connection method. The second location is a location where the current from the second battery module can be detected regardless of the connection method. The switch drive unit When the first battery module and the second battery module are connected in series, if the first current value is above a first threshold and the second current value is above a second threshold, the switch is driven to cut off the power supply between the battery and the electrical load. When the first battery module and the second battery module are connected in parallel, when the first current value is above a first threshold or when the second current value is above a second threshold, the switch is driven to cut off the power supply between the battery and the electrical load.

4. The vehicle power supply system as described in any one of claims 1 to 3, characterized in that, The control unit includes a power generation unit that converts the power supplied from the auxiliary power source and generates drive power. The power generation unit is configured to supply drive power to the switch driving unit. In the event that communication from the sensor unit is cut off, or in the event of communication from the sensor unit indicating an anomaly, the control unit, based on the recently input battery state, decides whether to maintain power between the battery and the electrical load for a specified period, and based on this decision, maintains or stops the supply of drive power.

5. The vehicle power supply system as described in any one of claims 1 to 4, characterized in that, A discharge circuit is provided, which discharges the charge of the capacitor connected in parallel with the electrical load after the power is cut off by the switch drive unit.

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