Energization control method and energization control system

Abstract

A battery control device (12) capable of electrically communicating with a vehicle control device (11) acquires state information of a high-voltage battery (13) that can be electrically connected to a charge / discharge circuit (15) via a switching device (16). If an abnormality has occurred in the reception of an activation signal transmitted from the vehicle control device (11), the battery control device (12) determines whether the input / output current of the high-voltage battery (13) is in a low current state on the basis of the state information of the high-voltage battery (13), and carries out control to electrically open the switching device (16) if it is determined that the input / output current is in the low current state.

Description

Power Supply Control Method and Power Supply Control System 【0001】 The present invention relates to a power supply control method and a power supply control system. 【0002】 In vehicles such as hybrid vehicles and electric vehicles, a battery control device for managing a battery is mounted. For example, Patent Document 1 describes a technique in which a battery electronic control unit as a battery control device is connected to a hybrid electronic control unit as a vehicle control device via a communication port to exchange various control signals and data. Control communication in a vehicle is performed using a communication network such as CAN (Controller Area Network). 【0003】 Japanese Unexamined Patent Application Publication No. 2017 - 226328 【0004】 When a communication abnormality occurs during vehicle travel, the battery control device can cut off the connection of the battery by immediately switching an opening / closing device such as a relay or a contact provided on a power line connecting a charge / discharge circuit including a drive motor and the battery to an open state. However, when the opening / closing device is opened in a high current state, the opening / closing device is likely to be damaged by melting. Therefore, the cost of component replacement and the burden on the user due to labor increase, which may cause inconvenience to the user. 【0005】 The present invention has been made in view of the above problems, and an object thereof is to provide a power supply control method and a power supply control system that prevent damage to components and safely cut off the connection of the battery. 【0006】 To achieve the above object, the power supply control method according to the present invention acquires state information based on the result of monitoring the state of a battery that can be electrically connected to a charge / discharge circuit via an opening / closing device by a second control device capable of electrical communication with a first control device. When an abnormality occurs in receiving an activation signal transmitted from the first control device, the second control device determines whether or not the input / output current of the battery is in a low current state based on the state information of the battery. Based on the determination that it is in a low current state, the second control device performs control to electrically open the opening / closing device. 【0007】 According to the present invention, it is possible to safely disconnect the battery connection while preventing damage to components. 【0008】 This is a diagram showing an example configuration of an in-vehicle system according to the present invention. This is a flowchart showing an example of control processing according to the present invention. This is a timing chart showing the energization control method in Example 1. This is a timing chart showing the energization control method in Example 2. This is a timing chart showing the energization control method in Example 3. This is a timing chart showing the energization control method in Example 4. This is a timing chart showing the energization control method in Example 5. This is a timing chart showing the energization control method in Example 6. 【0009】 (Example of System Configuration) Figure 1 shows an example of the configuration of an in-vehicle system 10 according to an embodiment of the present invention. The in-vehicle system 10 is installed in vehicles such as hybrid vehicles and electric vehicles. The in-vehicle system 10 comprises a vehicle control device 11, a battery control device 12, a high-voltage battery 13, a low-voltage battery 14, a charge / discharge circuit 15, and a switch / switch device 16. The in-vehicle system 10 is an example of a power supply control system that controls the power supply state by switching the electrical connection and disconnection between the high-voltage battery 13 and the charge / discharge circuit 15 using the switch / switch device 16. 【0010】 The vehicle control device 11 is configured using, for example, a microcomputer that acts as an ECU (Electronic Control Unit), and is capable of controlling the vehicle's starting, stopping, driving using power, and other operations. The microcomputer that constitutes the vehicle control device 11 only needs to include a processor such as a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input / output ports, and communication ports. The vehicle control device 11 is an example of a first control device capable of controlling the operation of a vehicle. 【0011】The battery control device 12 is configured using a microcomputer that is a separate ECU from the vehicle control device 11, for example, and performs control related to the high-voltage battery 13. The battery control device 12 is also called a BMS (Battery Management System). The microcomputer that makes up the battery control device 12 only needs to include a processor such as a CPU, ROM, RAM, input / output ports, and communication ports. The battery control device 12 is an example of a second control device that can control the energized state of the high-voltage battery 13. 【0012】 The battery control device 12 is connected to both terminals of the high-voltage battery 13 and can acquire state information regarding the state of the high-voltage battery 13. For example, the state information of the high-voltage battery 13 indicates the result of the state of the high-voltage battery 13 being detected by various sensors. The state information of the high-voltage battery 13 may include the current value as the input / output current flowing through the high-voltage battery 13, the voltage value between the two terminals of the high-voltage battery 13, and the temperature of the high-voltage battery 13. In addition, the battery control device 12 may acquire state information that can identify the State of Charge (SOC) of the high-voltage battery 13 by calculation based on the detection results. Furthermore, the battery control device 12 may acquire any other information indicating the state of the high-voltage battery 13 identified by calculation based on the detection results as state information. 【0013】 The battery control device 12 may acquire detection signals output from a battery monitoring circuit, such as a CS (Cell Sensor), as part of the status information. The battery monitoring circuit may include a voltage sensor and a temperature sensor, and a current sensor may be provided separately, or the current sensor may be included in the battery monitoring circuit. In this way, the battery control circuit 12 acquires status information based on the results of monitoring the high-voltage battery 13. 【0014】The vehicle control device 11 and the battery control device 12 can communicate with each other via a communication line 21, and can transmit various control signals and data. The communication line 21 can be any harness that enables CAN communication. The vehicle control device 11 periodically transmits a start signal to the battery control device 12, for example, in a 100-millisecond cycle. The vehicle control device 11 also receives information such as detection results from the battery control device 12. In this way, the battery control device 12 can communicate with the vehicle control device 11 via the communication line 21. 【0015】 The high-voltage battery 13 is a power storage element capable of supplying a relatively high power supply voltage, such as approximately 350 [V]. The high-voltage battery 13 can be a main battery used as a power source for the drive motor included in the charge / discharge circuit 15. Furthermore, the high-voltage battery 13 only needs to be capable of storing and re-discharging power supplied from the generator included in the charge / discharge circuit 15. In this way, the in-vehicle system 10 is configured to transmit power between the high-voltage battery 13 and the charge / discharge circuit 15. 【0016】 The high-voltage battery 13 may be a battery pack containing multiple battery cells. The electrode terminals of the multiple battery cells contained in the high-voltage battery 13 may be electrically connected by a conductive member called a busbar. The high-voltage battery 13 is typically a lithium-ion battery, but it may be any secondary battery such as a nickel-metal hydride battery or a lead-acid battery. 【0017】 The low-voltage battery 14 is a power storage element capable of supplying a relatively low power voltage, such as 12V. The low-voltage battery 14 can be any auxiliary battery used to power low-voltage components, including the vehicle control device 11 and battery control device 12, navigation, power windows, brakes, door locks, etc. The low-voltage battery 14 can be any secondary battery, such as a lead-acid battery. 【0018】The charge / discharge circuit 15 can be configured to include a drive motor, a generator, and a power control unit. The drive motor generates a driving force that rotates the drive wheels when the vehicle is accelerating. The generator is connected to the vehicle's engine to generate electricity. The power control unit performs power conversion and other operations in response to the drive motor and generator. The drive motor and generator can be configured using one or more AC rotary motors referred to as a motor generator. The power control unit can be configured using a converter, inverter, capacitor, etc. Furthermore, the charge / discharge circuit 15 may also include a charger that takes power for charging the high-voltage battery 13 from an external commercial power source, such as a charging connector and other DC power inlets. 【0019】 The switchgear 16 is installed in the power line connecting the high-voltage battery 13 and the charge / discharge circuit 15, and can be switched between a closed state, which electrically connects them, and an open state, which electrically disconnects them. Thus, the closed state of the switchgear 16 is an electrically closed state, and the open state of the switchgear 16 is an electrically open state. The switchgear 16 may include a relay or contactor that mechanically opens and closes contacts. 【0020】 The relay included in the switchgear 16 may be a system main relay (SMR) installed on a power line that enables power to be supplied to the entire in-vehicle system 10. The switchgear 16 may also include a charging relay installed on a power line that enables power to be supplied for charging from the charger of the charge / discharge circuit 15 to the high-voltage battery 13. Furthermore, the switchgear 16 may also include a high-voltage relay installed on a high-voltage power line, such as a power line that enables power to be supplied for driving from the high-voltage battery 13 to the power control unit of the charge / discharge circuit 15. The charging relay is an example of a first relay. The system main relay is an example of a second relay. The high-voltage relay is an example of a third relay. 【0021】(Control Processing) Next, the operation of the in-vehicle system 10, particularly the operation when controlling the switchgear 16 to the open state in the event of a communication abnormality, will be described. Figure 2 is a flowchart showing an example of control processing performed by the battery control device 12. This control processing is performed in response to the fulfillment of predetermined processing start conditions, such as the occurrence of a timer interrupt. 【0022】 When the control process is executed, the battery control device 12 first determines whether the start signal from the vehicle control device 11 is normal (step S01). The start signal is periodically transmitted from the vehicle control device 11 to the battery control device 12 via the communication line 21. The start signal has a predetermined frame structure. The battery control device 12 only needs to check the frame structure of the received signal to determine whether or not it has received the start signal normally. 【0023】 If the start signal is normal (step S01; Yes), the battery control device 12 terminates the control process. On the other hand, if the start signal is not normal (step S01; No), the battery control device 12 determines whether the unreceived diagnosis period has elapsed (step S02). The unreceived diagnosis period can be a predetermined determination period, such as 2 seconds. The battery control device 12 may use, for example, a watchdog timer to determine whether a timeout has occurred corresponding to the elapsed unreceived diagnosis period. An error interrupt may occur in the battery control device 12 in response to a watchdog timer timeout. In this case, the processing from step S03 onwards in the control process shown in Figure 2 may be executed as an interrupt process corresponding to the occurrence of an error interrupt. 【0024】If the unreceived diagnosis period has not elapsed (Step S02; No), the battery control device 12 terminates the control process. If the unreceived diagnosis period has elapsed (Step S02; Yes), the battery control device 12 performs the first abnormality control (Step S03). The first abnormality control includes caution output control. Caution output control is a control that causes an alert output using an output device in response to an abnormality in communication related to the start signal. The output device here can be any device capable of outputting an alert, including a display device, a lighting device such as a lamp, a sound output device such as a speaker, or some or all of these. For example, the battery control device 12 sends a caution request to the vehicle control device 11 to light a communication abnormality or general-purpose alert lamp in response to an abnormality in communication related to the start signal. The caution request should continue until the current condition corresponding to the elapsed first relay control waiting period, which will be described later, is met. 【0025】 Following step S03, the battery control device 12 determines whether or not there is an abnormality in the current sensor (step S04). The battery control device 12 only needs to be able to determine whether or not there is an abnormality in the current sensor based on the results of a sensor check performed at a predetermined timing, or based on the results of receiving a detection signal corresponding to the current value detected by the current sensor. In step S04, the battery control device 12 only needs to be able to determine that there is an abnormality in the current sensor if the current measurement function fails, including not only abnormalities due to failure of the current sensor itself (hardware error), but also abnormalities due to communication failure or software error of the battery control device 12. 【0026】If there is no abnormality in the current sensor (step S04; No), the battery control device 12 acquires state information including the current value (step S05). The state information may be information indicating various physical quantities, including current value, voltage value, temperature, state of charge (SOC), and some or all of these, based on detection signals from various sensors provided in correspondence with the high-voltage battery 13. The state information may also include information indicating arbitrary states such as component temperature, based on detection signals from various sensors provided in correspondence with detection target components of the in-vehicle system 10 that are different from the high-voltage battery 13. Information indicating the current value output from the current sensor that detects the input and output current of the high-voltage battery 13 is also called battery current information. In this way, the battery control device 12 in step S05 acquires state information including battery current information. 【0027】 If there is an abnormality in the current sensor (step S04; Yes), the battery control device 12 acquires status information other than the current value (step S06). 【0028】 The battery control device 12 may acquire state information by receiving detection signals from various sensors at the time step S05 or step S06 is executed, or by performing calculations based on the detection signals. Alternatively, the battery control device 12 may acquire state information by reading from memory in step S05 or step S06, which is stored periodically in memory such as RAM in response to detection signals from various sensors, or by reading state information stored as a result of calculations based on the detection signals, at a time prior to executing step S05 or step S06. 【0029】Subsequently, the battery control device 12 determines whether the input / output current of the high-voltage battery 13 is in a low-current state based on the acquired state information of the high-voltage battery 13 (step S07). For example, if state information including the current value detected by the current sensor is acquired in step S05, and the current value shown in the battery current information is less than a predetermined value set in advance as a low-current determination value, regardless of whether it is the input or output current, then it is determined in step S07 that the battery is in a low-current state. In the case of using such a current value, the low-current determination value may be, for example, 10 [A]. The low-current determination value can be set according to the specifications of the relay included in the switchgear 16, the discharge speed of the high-voltage battery 13, or one or both of these. If state information other than the current value is acquired in step S06, and the physical quantity identified from that state information is within a predetermined determination range corresponding to the low-current determination value, then it is determined in step S07 that the battery is in a low-current state. 【0030】 If the low current state is not present (Step S07; No), the battery control device 12 terminates the control process. If the low current state is present (Step S07; Yes), the battery control device 12 determines whether the first relay control standby period has elapsed (Step S08). The first relay control standby period is a predetermined determination period, such as approximately 2 seconds. The battery control device 12 only needs to be able to determine the elapsed time of the first relay control standby period by measuring the duration of the low current state by updating the stored value in the low current timer. The low current timer can be configured using a timer circuit built into the battery control device 12 or a timer area provided in RAM, etc. The first relay control standby period can be set according to the specifications of the relay included in the switchgear 16, the discharge speed of the high-voltage battery 13, or one or both of these. 【0031】If the first relay control waiting period has not elapsed (step S08; No), the battery control device 12 repeats step S08 and waits until that period has elapsed. Then, if the first relay control waiting period has elapsed (step S08; Yes), the battery control device 12 performs the second abnormality control (step S09). The second abnormality control includes the first relay control. The first relay control is a control to electrically open the charging relay, which is the first relay among the relays included in the switchgear 16. The battery control device 12 transmits a control command to the vehicle control device 11 to electrically open the charging relay. The battery control device 12 only needs to electrically open the charging relay of the switchgear 16 by direct control. 【0032】 After step S09, the battery control device 12 determines whether the second relay control standby period has elapsed (step S10). The second relay control standby period is a predetermined determination period, such as one second after the first relay control standby period has elapsed. The second relay control standby period can be set as a buffer period from entering safe mode until the system shuts down, according to the specifications of the in-vehicle system 10. 【0033】 If the second relay control waiting period has not elapsed (step S10; No), the battery control device 12 repeats step S10 and waits until that period has elapsed. Then, if the second relay control waiting period has elapsed (step S10; Yes), the battery control device 12 performs system shutdown control (step S11) and terminates the control process. The system shutdown control includes second relay control. The second relay control is a control that electrically opens the system main relay, which is the second relay among the relays included in the switchgear 16. The battery control device 12 transmits a control command to the vehicle control device 11 to electrically open the system main relay. The battery control device 12 may electrically open some or all of the system main relays in the switchgear 16 by direct control. The vehicle control device 11 may electrically open some or all of the system main relays based on the control command from the battery control device 12. 【0034】 Between the second abnormality control in step S09 and the system shutdown control in step S11, the vehicle control device 11 should electrically open the high-voltage relay, which is the third relay, based on the control command from the battery control device 12. The high-voltage relay should be electrically opened by the vehicle control device 11 in response to the elapsed of a predetermined waiting time for opening, such as 0.63 seconds, after the charging relay has been electrically opened. 【0035】 In this manner, the battery control device 12 included in the in-vehicle system 10, when it detects an abnormality in receiving the start signal transmitted from the vehicle control device 11, determines that the input / output current of the high-voltage battery 13 is in a low-current state based on the status information of the high-voltage battery 13, and then controls the switching device 16 provided between the high-voltage battery 13 and the charge / discharge circuit 15 to electrically open. This prevents melting of the various relays included in the switching device 16, safely disconnecting the high-voltage battery 13, and furthermore, allows the system to be stopped without inconveniencing the user by requiring parts replacement or other burdens. 【0036】 (Example 1) The energization control method in Example 1 of the present invention will be described with reference to the timing chart in Figure 3. In Figure 3, the battery control device 12 uses the current values ​​of the input and output currents flowing to the high-voltage battery 13 to control the electrical opening of the various relays included in the switchgear 16. 【0037】At timing T01 shown in Figure 3, the battery control device 12 determines that the start signal from the vehicle control device 11 is not normal, according to step S01 of the control process shown in Figure 2. The period D01 from timing T01 to timing T02 shown in Figure 3 is the unreceived diagnosis period. At timing T02, after the period D01 has elapsed from timing T01, the battery control device 12 determines that the unreceived diagnosis period has elapsed, according to step S02 of the control process shown in Figure 2. In this case, the battery control device 12 performs the first abnormality control in step S03 shown in Figure 2, corresponding to the confirmation that the communication diagnosis is NG. For example, the battery control device 12 sends a caution request to the vehicle control device 11 to provide a warning output, such as lighting a warning lamp. At this time, the abnormality type of the battery control device 12 changes from normal to abnormal FT1. In the abnormal FT1 state, the warning output by sending a caution request continues. 【0038】 In this embodiment 1, the battery control device 12 determines that there is no abnormality in the current sensor in step S04 of the control process shown in Figure 2. In response to this determination result, the battery control device 12 acquires state information including the current value in step S05 of the control process shown in Figure 2. Using the current value indicated by the battery current information included in this state information, the battery control device 12 determines whether or not it is in a low current state in step S07 of the control process shown in Figure 2. 【0039】 At timing T03 shown in Figure 3, regardless of whether the current value shown in the battery current information is the input or output current, if that current value falls below a predetermined value CT1 set as a low current determination value, the battery control device 12 determines that the input and output current of the high-voltage battery 13 is in a low current state. Any current value that is less than the predetermined value CT1, regardless of whether it is the input or output current, falls within the first determination range corresponding to Embodiment 1. When such a current value falls within the first determination range, in response to the determination that a low current state has been reached, the battery control device 12 measures the elapsed time using a low current timer and determines whether the first relay control standby period has elapsed in step S08 shown in Figure 2. 【0040】 The period D02 from timing T03 to timing T04 shown in Figure 3 is the first relay control waiting period. At timing T04, after the period D02 has elapsed from timing T03, the battery control device 12 determines that the first relay control waiting period has elapsed according to step S08 of the control process shown in Figure 2. In this case, the battery control device 12 performs the second abnormality control in step S09 shown in Figure 2. For example, the battery control device 12 sends a relay disconnection request to the vehicle control device 11 to perform control to open various relays. At this time, the abnormality type of the battery control device 12 changes from abnormality FT1 to abnormality FT2. As a result, the first relay control is performed, and the charging relay, which is the first relay, becomes electrically open. 【0041】 The period D03 from timing T04 to timing T06 shown in Figure 3 is the second relay control waiting period. At timing T06, after the period D03 has elapsed from timing T04, the battery control device 12 determines that the second relay control waiting period has elapsed according to step S10 of the control process shown in Figure 2. In this case, the battery control device 12 performs the system shutdown control in step S11 shown in Figure 2. For example, the battery control device 12 performs the second relay control and electrically opens the system main relay, which is the second relay, to an open state. As a result, the in-vehicle system 10 is shut down and enters a sleep state. 【0042】 Between timing T04 and timing T06 as shown in Figure 3, a period D04, which is the open waiting time, is set. At timing T05, after the period D04 has elapsed from timing T04, the vehicle control device 11 electrically opens the high-voltage relay, which is the third relay, to the open state. 【0043】As described above, when the current value indicated by the battery current information included in the acquired state information is within a first determination range such as less than a predetermined value CT1, the battery control device 12 of Embodiment 1 determines that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 can independently control the opening device 16 to be electrically opened without cooperative control with the charge / discharge circuit 15. As a result, while reducing the control burden of the battery control device 12, it is possible to prevent the melting of various relays included in the opening device 16 and safely cut off the connection of the high-voltage battery 13. Furthermore, the system can be stopped without causing inconvenience to the user due to the burden of component replacement or the like. In addition, since the attention output is continuously performed corresponding to the state of the abnormality FT1, the occurrence of the abnormality can be appropriately transmitted to the user at a stage before the system stops. 【0044】 (Embodiment 2) Referring to the timing chart of FIG. 4, the energization control method in Embodiment 2 of the present invention will be described. In FIG. 4, the battery control device 12 performs control for electrically opening various relays included in the opening device 16 using the OCV (Open Circuit Voltage) and CCV (Closed Circuit Voltage) in the high-voltage battery 13. 【0045】 From timing T11 to timing T12 shown in FIG. 4, the same control as from timing T01 to timing T02 in Embodiment 1 shown in FIG. 3 is performed. In Embodiment 2 shown in FIG. 4, when the period D01, which is an un-received diagnosis period, has elapsed at timing T12, the battery control device 12 determines that there is an abnormality in the current sensor according to step S04 of the control process shown in FIG. 2. Corresponding to this determination result, the battery control device 12 acquires state information other than the current value according to step S06 of the control process shown in FIG. 2. The state information of Embodiment 2 may include the voltage value between both poles of the high-voltage battery 13 and the state of charge (SOC) specified by the calculation of the battery control device 12. 【0046】The battery control device 12 acquires the voltage value between both poles of the high-voltage battery 13 as closed-circuit voltage information indicated by the closed-circuit voltage value (CCV) of the high-voltage battery 13. Further, the battery control device 12 acquires the state of charge (SOC) specified by calculation as state-of-charge information capable of estimating the open-circuit voltage value (OCV) of the high-voltage battery 13. The battery control device 12 may estimate the open-circuit voltage value (OCV) from the state of charge (SOC) using, for example, SOC-OCV characteristic data of the high-voltage battery 13 stored in advance in a memory such as a ROM. The open-circuit voltage information indicated by the open-circuit voltage value (OCV) may be included in the state information of the high-voltage battery 13 acquired by the battery control device 12 by calculation. 【0047】 When there is an abnormality in receiving the start signal transmitted from the vehicle control device 11 and when there is an abnormality in current measurement using the current sensor, the battery control device 12 may transmit a request to prohibit charging and discharging of the high-voltage battery 13 to the charge and discharge circuit 15 or a command to set the charge and discharge available power of the high-voltage battery 13 to zero. 【0048】 The battery control device 12 determines whether it is in a low-current state according to step S07 of the control process shown in FIG. 2 using the open-circuit voltage value (OCV) of the high-voltage battery 13 estimated from the state-of-charge information and the closed-circuit voltage value (CCV) of the high-voltage battery 13 indicated by the closed-circuit voltage information. In this case, when the absolute value of the difference between the open-circuit voltage value (OCV) and the closed-circuit voltage value (CCV) of the high-voltage battery 13 is less than a predetermined value VT1 corresponding to the low-current determination value, the battery control device 12 determines that it is in a low-current state. When the absolute value of the difference between the open-circuit voltage value (OCV) and the closed-circuit voltage value (CCV) is less than the predetermined value VT1, the difference is within the second determination range corresponding to Embodiment 2. 【0049】At timing T13 shown in Figure 4, the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state because the difference between the open-circuit voltage (OCV) and closed-circuit voltage (CCV) of the high-voltage battery 13 is within a second determination range, such as being less than a predetermined value VT1. From timing T13 to timing T16 shown in Figure 4, the same control is performed as from timing T03 to timing T06 in Embodiment 1 shown in Figure 3. 【0050】 When the high-voltage battery 13 is in a discharge state, for example, in response to the decrease in input and output current, the voltage drop due to internal resistance based on Ohm's law (V=IR) also decreases, causing the closed-circuit voltage (CCV) to rise and the difference between it and the open-circuit voltage (OCV) to become smaller. Therefore, if the difference between the open-circuit voltage (OCV) and the closed-circuit voltage (CCV) is within a second determination range, such as less than a predetermined value VT1, it can be determined that the input and output current of the high-voltage battery 13 is in a low-current state. 【0051】 As described above, in the battery control device 12 of Embodiment 2, if there is an abnormality in the current measurement using the current sensor, and the difference between the open-circuit voltage value (OCV) estimated from the charge state information included in the acquired state information and the closed-circuit voltage value (CCV) indicated by the closed-circuit voltage information is within a second determination range such as less than a predetermined value VT1, then the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 becomes capable of electrically opening the switchgear 16. As a result, even if there is an abnormality in the current measurement of the high-voltage battery 13, the connection to the high-voltage battery 13 can be safely disconnected while preventing melting of the various relays included in the switchgear 16, and furthermore, the system can be stopped without causing inconvenience to the user due to the burden of replacing parts. Similar to Embodiment 1, a warning output is continuously issued in response to the abnormal FT1 state, so that the user can be appropriately informed of the occurrence of an abnormality before the system is stopped. 【0052】(Example 3) The energization control method in Example 3 of the present invention will be described with reference to the timing chart in Figure 5. In Figure 5, the battery control device 12 uses the busbar resistance corrected voltage and the busbar resistance uncorrected voltage of the high-voltage battery 13 to control the electrical opening of the various relays included in the switchgear 16. 【0053】 From timing T21 to timing T22 shown in Figure 5, the same control is performed as from timing T01 to timing T02 in Embodiment 1 shown in Figure 3. In Embodiment 3 shown in Figure 5, if the period D01, which is the unreceived diagnosis period, has elapsed at timing T22, the battery control device 12 determines that there is an abnormality in the current sensor by step S04 of the control process shown in Figure 2. In response to this determination result, the battery control device 12 acquires state information other than the current value by step S06 of the control process shown in Figure 2. The battery control device 12 only needs to have a function to acquire the corrected voltage value after correcting the voltage drop amount due to the busbar resistance based on the detection signals from various sensors. The state information in Embodiment 3 only needs to include corrected voltage information showing the corrected voltage value after correcting the voltage drop amount due to the busbar resistance, and uncorrected voltage information showing the uncorrected voltage value before correcting the voltage drop amount due to the busbar resistance. 【0054】 The battery control device 12 uses the corrected voltage value shown in the corrected voltage information and the uncorrected voltage value shown in the uncorrected voltage information to determine whether or not the system is in a low current state in step S07 of the control process shown in Figure 2. In this case, the battery control device 12 determines that the system is in a low current state if the absolute value of the difference between the corrected voltage value and the uncorrected voltage value is less than a predetermined value VT2 that is set in advance in accordance with the low current determination value. The difference between the corrected voltage value and the uncorrected voltage value becomes a difference within the third determination range corresponding to Embodiment 3 when its absolute value is less than the predetermined value VT2. 【0055】At timing T23 shown in Figure 5, the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state because the difference between the corrected voltage value and the uncorrected voltage value of the high-voltage battery 13 is within a third determination range, such as less than a predetermined value VT2. From timing T23 to timing T26 shown in Figure 5, the same control is performed as from timing T03 to timing T06 in Embodiment 1 shown in Figure 3. 【0056】 When the high-voltage battery 13 is in a discharge state, for example, the voltage drop due to the busbar resistance based on Ohm's law (V=IR) decreases in response to the decrease in input and output current, causing the pre-correction voltage value to rise and the difference between it and the corrected voltage value to become smaller. Therefore, if the difference between the corrected voltage value and the pre-correction voltage value is within a third determination range, such as less than a predetermined value VT2, it can be determined that the input and output current of the high-voltage battery 13 is in a low-current state. 【0057】 As described above, the battery control device 12 of Embodiment 3 acquires state information including corrected voltage information, which shows the corrected voltage value after correcting the voltage drop due to the busbar resistance, and uncorrected voltage information, which shows the uncorrected voltage value before correcting the voltage drop due to the busbar resistance, when there is an abnormality in the current measurement using the current sensor. If the difference between the corrected voltage value shown in the corrected voltage information and the uncorrected voltage value shown in the uncorrected voltage information is within a third determination range, such as less than a predetermined value VT2, it is determined that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 becomes capable of electrically opening the switchgear 16. As a result, even if there is an abnormality in the current measurement of the high-voltage battery 13, it is possible to safely disconnect the connection of the high-voltage battery 13 while preventing melting of various relays included in the switchgear 16, and furthermore, the system can be stopped without causing inconvenience to the user due to the burden of replacing parts. Similar to Embodiment 1, a warning output is continuously issued in response to the abnormal state of FT1, so that the user can be appropriately informed of the occurrence of an abnormality before the system is stopped. 【0058】(Example 4) The energization control method in Example 4 of the present invention will be described with reference to the timing chart in Figure 6. In Figure 6, the battery control device 12 uses the voltage value at the busbar of the high-voltage battery 13 to control the electrical opening of various relays included in the switchgear 16. 【0059】 From timing T31 to timing T32 shown in Figure 6, the same control is performed as from timing T01 to timing T02 in Embodiment 1 shown in Figure 3. In Embodiment 4 shown in Figure 6, if the period D01, which is the period for unreceived diagnosis, has elapsed at timing T32, the battery control device 12 determines that there is an abnormality in the current sensor by step S04 of the control process shown in Figure 2. In response to this determination result, the battery control device 12 acquires state information other than the current value by step S06 of the control process shown in Figure 2. The state information in Embodiment 4 only needs to include the voltage value at the busbar of the high-voltage battery 13. The battery control device 12 acquires the voltage value at the busbar of the high-voltage battery 13 as busbar voltage information. 【0060】 The voltage value at the busbar can be any voltage value detected between multiple detection points provided on the busbar by, for example, a voltage sensor included in the battery monitoring circuit (CS). The battery control device 12 uses the voltage value at the busbar indicated in the busbar voltage information to determine whether or not a low current state is in effect in step S07 of the control process shown in Figure 2. In this case, the battery control device 12 determines that a low current state is in effect when the voltage value at the busbar is less than a predetermined value VT3 that is set in advance in accordance with the low current determination value. Regardless of its orientation, if the voltage value at the busbar is less than the predetermined value VT3, it falls within the fourth determination range corresponding to Embodiment 4. 【0061】At timing T33 shown in Figure 6, the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state because the voltage value at the busbar is within a fourth determination range, such as being less than a predetermined value VT3. From timing T33 to timing T36 in Figure 6, the same control is performed as from timing T03 to timing T06 in Embodiment 1 shown in Figure 3. 【0062】 In the high-voltage battery 13, the voltage value at the busbar decreases in response to a decrease in input and output current, based on Ohm's law (V = IR). Therefore, when the voltage value at the busbar is within a fourth determination range, such as less than a predetermined value VT3, it can be determined that the input and output current of the high-voltage battery 13 is in a low-current state. 【0063】 As described above, in the battery control device 12 of Embodiment 4, if there is an abnormality in the current measurement using the current sensor, and the busbar voltage value indicated by the busbar voltage information included in the acquired state information is within a fourth determination range such as less than a predetermined value VT3, then the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 can control the switchgear 16 to electrically open. As a result, even if there is an abnormality in the current measurement of the high-voltage battery 13, the connection to the high-voltage battery 13 can be safely disconnected while preventing melting of the various relays included in the switchgear 16, and furthermore, the system can be stopped without causing inconvenience to the user due to the burden of replacing parts. Similar to Embodiment 1, a warning output is continuously issued in response to the abnormal state of FT1, so that the user can be appropriately informed of the occurrence of an abnormality before the system is stopped. 【0064】 (Example 5) The energization control method in Example 5 of the present invention will be described with reference to the timing chart in Figure 7. In Figure 7, the battery control device 12 uses the amount of change over time in the total voltage of the high-voltage battery 13 to control the electrical opening of the various relays included in the switchgear 16. 【0065】From timing T41 to timing T42 shown in Figure 7, the same control is performed as from timing T01 to timing T02 in Embodiment 1 shown in Figure 3. In Embodiment 5 shown in Figure 7, if the period D01, which is the unreceived diagnosis period, has elapsed at timing T42, the battery control device 12 determines that there is an abnormality in the current sensor by step S04 of the control process shown in Figure 2. In response to this determination result, the battery control device 12 acquires state information other than the current value by step S06 of the control process shown in Figure 2. The battery control device 12 only needs to have a function to acquire the amount of change over time in the total voltage of the high-voltage battery 13 by calculation based on detection signals from various sensors. The battery control device 12 in Embodiment 5 acquires the amount of change over time in the total voltage of the high-voltage battery 13 as time change information. 【0066】 The time change in the total voltage of the high-voltage battery 13 can be obtained, for example, by differentiating the sum of voltage values ​​detected for each cell group, which is a combination of multiple battery cells contained in the high-voltage battery 13, or by differentiating the voltage value between the two electrodes of the high-voltage battery 13. The battery control device 12 uses the time change in the total voltage of the high-voltage battery 13 shown in the time change information to determine whether or not it is in a low-current state in step S07 of the control processing shown in Figure 2. In this case, the battery control device 12 determines that it is in a low-current state when the absolute value of the time change in the total voltage of the high-voltage battery 13 is less than a predetermined value DT1 which is set in advance in correspondence with the low-current determination value. When the absolute value of the time change in the total voltage of the high-voltage battery 13 is less than the predetermined value DT1, it becomes a time change within the fifth determination range corresponding to Example 5. 【0067】At timing T43 shown in Figure 7, the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state because the amount of change over time in the total voltage of the high-voltage battery 13 is within a fifth determination range, such as being less than a predetermined value DT1. From timing T43 to timing T46 shown in Figure 7, the same control is performed as from timing T01 to timing T06 in Embodiment 1 shown in Figure 3. 【0068】 The state of charge (SOC) of the high-voltage battery 13 changes with charging and discharging. Due to the characteristics of lithium-ion batteries, the voltage change between the two electrodes based on the state of charge (SOC) decreases in response to the decrease in input and output current in the high-voltage battery 13, so the amount of change in the total voltage over time becomes small. Therefore, if the amount of change in the total voltage of the high-voltage battery 13 over time is within a fifth determination range, such as less than a predetermined value DT1, it can be determined that the input and output current of the high-voltage battery 13 is in a low-current state. 【0069】 As described above, in the battery control device 12 of Embodiment 5, if there is an abnormality in the current measurement using the current sensor, and the amount of change in the total voltage of the high-voltage battery 13 over time, as indicated by the time change information included in the acquired state information, falls within a fifth determination range such as less than a predetermined value DT1, then the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 becomes capable of electrically opening the switchgear 16. As a result, even if there is an abnormality in the current measurement of the high-voltage battery 13, the connection to the high-voltage battery 13 can be safely disconnected while preventing melting of the various relays included in the switchgear 16, and furthermore, the system can be stopped without causing inconvenience to the user due to the burden of replacing parts. Similar to Embodiment 1, a warning output is continuously issued in response to the abnormal FT1 state, so that the user can be appropriately informed of the occurrence of an abnormality before the system is shut down. 【0070】(Example 6) The energization control method in Example 6 of the present invention will be described with reference to the timing chart in Figure 8. In Figure 8, the battery control device 12 uses the temperature of the high-voltage battery 13 and the temperature of the high-voltage components to control the electrical opening of the various relays included in the switchgear 16. 【0071】 From timing T51 to timing T52 shown in Figure 8, the same control is performed as from timing T01 to timing T02 in Embodiment 1 shown in Figure 3. In Embodiment 6 shown in Figure 8, if the period D01, which is the period of non-received diagnosis, has elapsed at timing T52, the battery control device 12 determines that there is an abnormality in the current sensor by step S04 of the control process shown in Figure 2. In response to this determination result, the battery control device 12 acquires state information other than the current value by step S06 of the control process shown in Figure 2. The state information in Embodiment 6 only needs to include the temperature detected in the high-voltage battery 13 and the temperature detected in a high-voltage component other than the high-voltage battery 13. 【0072】 The battery control device 12 acquires the temperature detected by a temperature sensor provided on the high-voltage battery 13 as battery temperature information indicating the temperature of the high-voltage battery 13. In addition, the battery control device 12 acquires the temperature detected by a temperature sensor provided on a high-voltage component other than the high-voltage battery 13, such as a relay or contactor included in the switchgear 16, as component temperature information indicating the temperature of the high-voltage component. 【0073】 The battery control device 12 uses the battery temperature indicated in the battery temperature information and the high-voltage component temperature indicated in the component temperature information to determine whether or not a low current state is in effect in step S07 of the control process shown in Figure 2. In this case, the battery control device 12 determines that a low current state is in effect if the absolute value of the difference between the battery temperature and the high-voltage component temperature is less than a predetermined value TT1 that is set in advance and corresponds to the low current determination value. The difference between the battery temperature and the high-voltage component temperature falls within the sixth determination range corresponding to Embodiment 6 when its absolute value is less than the predetermined value TT1. 【0074】At timing T53 shown in Figure 8, the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state because the difference between the battery temperature and the high-voltage component temperature is within a sixth determination range, such as less than a predetermined value TT1 corresponding to the low-current determination value. From timing T53 to timing T56 shown in Figure 8, the same control is performed as from timing T03 to timing T06 in Embodiment 1 shown in Figure 3. 【0075】 When the input and output currents are high, the high-voltage battery 13 and high-voltage components experience a temperature increase due to heat generation corresponding to their respective temperature coefficients. In this case, due to the difference in temperature coefficients, for example, the high-voltage components become hotter than the high-voltage battery 13. Conversely, if the temperature difference between the high-voltage battery 13 and the high-voltage components is within a sixth determination range, such as less than a predetermined value TT1, then the input and output currents of each are in a low-current state, and therefore it can be determined that the input and output currents of the high-voltage battery 13 are in a low-current state. 【0076】 As described above, in the battery control device 12 of Embodiment 6, if there is an abnormality in the current measurement using the current sensor, and the difference between the battery temperature indicated by the battery temperature information included in the acquired state information and the high-voltage component temperature indicated by the component temperature information is within a sixth determination range such as less than a predetermined value TT1, then the battery control device 12 determines that the input / output current of the high-voltage battery 13 is in a low-current state. Based on this determination result, the battery control device 12 becomes capable of electrically opening the switchgear 16. As a result, even if there is an abnormality in the current measurement of the high-voltage battery 13, the connection to the high-voltage battery 13 can be safely disconnected while preventing melting of the various relays included in the switchgear 16, and furthermore, the system can be stopped without causing inconvenience to the user due to the burden of replacing parts. Similar to Embodiment 1, a warning output is continuously issued in response to the abnormal FT1 state, so that the user can be appropriately informed of the occurrence of an abnormality before the system is shut down. 【0077】(Modifications) This invention does not necessarily have to possess all the technical features shown in the above embodiments. Some parts of the embodiments can be omitted, replaced, or arbitrary configurations added so as to solve at least one problem in the prior art. The hardware configuration, flowchart, timing chart, etc. shown in the above embodiments are examples and can be modified as appropriate. 【0078】 For example, in the above embodiment, when there is no abnormality in the current measurement using the current sensor, the current value indicated by the battery current information is used to determine whether or not the input / output current of the high-voltage battery 13 is in a low-current state. On the other hand, when there is an abnormality in the current measurement using the current sensor, the system determines whether or not the input / output current of the high-voltage battery 13 is in a low-current state based on state information other than the current value. However, even when there is no abnormality in the current measurement using the current sensor, the system may also determine whether or not the input / output current of the high-voltage battery 13 is in a low-current state based on state information other than the current value. 【0079】 The priority given to implementing any of the above embodiments 1 to 6 can be arbitrarily set based on the specifications of the in-vehicle system 10, etc. The battery control device 12 may perform a low-current state determination using another embodiment if it is not possible to perform a low-current state determination using any one of the above embodiments 1 to 6. Thus, the above embodiments 1 to 6 can be combined as appropriate. For example, by combining embodiment 2 and embodiment 4, even if the software area of ​​the battery control device 12 fails and the calculations in the software area stop, it is possible to determine that the input / output current of the high-voltage battery 13 is in a low-current state. 【0080】 The present invention is also applicable to control systems other than the in-vehicle system 10 mounted on a vehicle. For example, the present invention is applicable to control systems such as any power system, electrical equipment, or electric machinery that involves charging and discharging batteries. 【0081】A control program for realizing the operation of the above embodiment may be stored on a computer-readable recording medium such as a CD-ROM (Compact Disc Read-Only Memory), DVD (Digital Versatile Disc), MO (Magneto Optical Disc), memory card, or semiconductor memory and distributed. By installing this program on any computer, a control system including a battery control device 12 capable of executing the control processing shown in Figure 2 may be configured. If the functions of the battery control device 12 are realized through a division of labor between the OS (Operating System) and the application, or through cooperation between the OS and the application, only the parts other than the OS may be stored on the recording medium. 【0082】 Various embodiments and modifications of the present invention include those that can be made possible by the exercise of ordinary creative ability without departing from the broad spirit and scope of the present invention. The embodiments described above are for illustrative purposes only and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of disclosure are considered to be within the scope of the present invention. 【0083】 10 In-vehicle system, 11 Vehicle control device, 12 Battery control device, 13 High-voltage battery, 14 Low-voltage battery, 15 Charge / discharge circuit, 16 Switchgear, 21 Communication line.

Claims

1. A power supply control method by a second control device that controls a battery, which is a second control device capable of electrical communication via a communication line with a first control device capable of controlling the operation of a vehicle, the second control device being capable of controlling a battery, the second control device being capable of electrical communication with a first control device capable of electrical communication with a charge / discharge circuit via a switchgear, the second control device being capable of electrical communication with a first control device, the second control 2. The energization control method according to claim 1, wherein the second control device acquires the state information including battery current information, which indicates the current value detected by a current sensor for the input and output current of the battery, and determines that the low current state is present when the current value indicated in the battery current information is within the first determination range.

3. The energization control method according to claim 1 or 2, wherein the second control device, when there is an abnormality in current measurement using a current sensor that detects the input and output current of the battery, acquires state information including charge state information that can estimate the open-circuit voltage value of the battery and closed-circuit voltage information that indicates the closed-circuit voltage value of the battery, and determines that the low current state is present when the difference between the open-circuit voltage value estimated from the charge state information and the closed-circuit voltage value indicated in the closed-circuit voltage information is within the second determination range.

4. The energization control method according to any one of claims 1 to 3, wherein the second control device, when there is an abnormality in current measurement using a current sensor that detects the input and output current of the battery, acquires state information including corrected voltage information that shows the corrected voltage value after correcting the amount of voltage drop due to the resistance of the busbars that electrically connect the electrode terminals of a plurality of battery cells contained in the battery, and pre-correction voltage information that shows the pre-correction voltage value before correcting the amount of voltage drop due to the resistance of the busbars, and determines that the low current state is in place when the difference between the corrected voltage value shown in the corrected voltage information and the pre-correction voltage value shown in the pre-correction voltage information is within the third determination range.

5. The energization control method according to any one of claims 1 to 4, wherein the second control device, when there is an abnormality in current measurement using a current sensor that detects the input and output current of the battery, acquires state information including busbar voltage information that indicates the voltage value at the busbars that electrically connect the electrode terminals of a plurality of battery cells contained in the battery, and determines that the low current state is present when the voltage value at the busbars indicated in the busbar voltage information is within the fourth determination range.

6. The energization control method according to any one of claims 1 to 5, wherein the second control device acquires state information including time change information indicating the amount of change over time in the total voltage of the battery when there is an abnormality in the current measurement using a current sensor that detects the input and output current of the battery, and determines that the low current state is present when the amount of change over time in the total voltage of the battery indicated in the time change information is within the fifth determination range.

7. The energization control method according to any one of claims 1 to 6, wherein the second control device, when there is an abnormality in current measurement using a current sensor that detects the input / output current of the battery, acquires state information including battery temperature information indicating the temperature of the battery and component temperature information indicating the temperature of a high-voltage component other than the battery, and determines that the low current state is present when the difference between the temperature indicated in the battery temperature information and the temperature indicated in the component temperature information is within the sixth determination range.

8. A power supply control system comprising: a battery electrically connectable to a charge / discharge circuit via a switchgear; a first control device capable of controlling the operation of a vehicle; and a second control device capable of electrical communication via a communication line with the first control device and performing control related to the battery, wherein the second control device acquires state information based on the results of monitoring the state of the battery, and when an abnormality occurs in the reception of a start signal transmitted from the first control device, it determines whether the input / output current of the battery is in a low current state based on the state information, and performs control to electrically open the switchgear based on the determination that it is in a low current state.

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