JP2013099167A - Control device and control method for vehicle mounted with electric storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit a circulation current from running among electric storage devices connected in parallel during maintenance.SOLUTION: A control device is provided, including: a control unit 51 that carries out a charge-discharge control of an electric storage system including a plurality of electric storage devices 20A, 20B connected in parallel; and an abnormality detection unit 52 that detects abnormality in components disposed in each of the electric storage devices and relating to charge-discharge processes. When abnormality of a component is detected in a part of the plurality of electric storage devices connected in parallel, the control device controls in such a manner that power of electric storage devices other than the electric storage device having the abnormal component is output to a motor 33 for traveling while prohibiting charging/discharging of the electric storage device having the abnormal component. Further, when a difference in the charging capacity between the electric storage device having the abnormal component and other electric storage devices excluding the electric storage device having the abnormal component decreases to a predetermined value or less, the control device controls to terminate the power supply from the electric storage system to the motor 33 for traveling.

Description

  The present invention relates to control of a vehicle equipped with a power storage system in which a plurality of power storage devices are connected in parallel.

  In Patent Document 1, when an abnormality occurs in a part of the batteries connected in parallel, vehicle control using the power of the normal battery is allowed while disconnecting the abnormal battery, and the normal battery is guided to a high SOC and after stopping. It is controlled so that it can respond to high power output such as restart.

JP 2007-282375 A

  When abnormality occurs in some of the batteries connected in parallel, if the control is performed so that the SOC of the normal battery is led to a high SOC as in Patent Document 1, the abnormal battery is replaced with a normal battery after replacement. There is a risk that the voltage difference (SOC difference) with the battery for use will increase. When the voltage difference becomes large, it flows in a large circulating current corresponding to the voltage difference flowing between the batteries connected in parallel after replacement, and it is difficult to appropriately protect the battery components such as the battery or the current sensor.

  For this reason, it is necessary to carry out replacement work including charging / discharging work to eliminate the voltage difference between the normal battery and the replacement battery, but there is an abnormality in the battery itself as compared with the case where the battery itself is replaced like a battery abnormality. If there is an abnormality in the battery components such as the system main relay and current sensor that are connected to the battery without being seen, the battery that has an abnormality in the battery components connected in parallel even though it is not necessary to replace the battery itself There is a problem that the cost for replacing the battery parts is increased because a charge / discharge operation for eliminating the voltage difference between the battery and other batteries must be performed.

  The vehicle control device according to the first invention of the present application includes a control unit that performs charge / discharge control of a power storage system having a plurality of power storage devices connected in parallel, and parts related to charge / discharge processing provided in each power storage device. And an abnormality detection unit for detecting an abnormality. When a part abnormality is detected in some of the power storage devices, the charging / discharging of the power storage device in which the part is abnormal is prohibited, and the power of the power storage devices other than the power storage device in which the part is abnormal is output to the traveling motor The power storage device other than the power storage device having an abnormality in the component until the charge capacity difference between the power storage device having the abnormality in the component and the power storage device other than the power storage device having the abnormality in the component becomes equal to or less than a predetermined value. The power is controlled to be output to the traveling motor, and the power supply from the power storage system to the traveling motor is controlled to end when the charge capacity difference becomes a predetermined value or less.

  According to the first invention of this application, when abnormality of a component is detected in a part of a plurality of power storage devices connected in parallel, charge / discharge control of a normal power storage device other than the power storage device having an abnormality in the component is performed. Control based on the charge capacity of the power storage device that is abnormal, and when the charge capacity difference is less than or equal to a predetermined value, control is performed so that the power supply from the power storage system to the driving motor is terminated. It is possible to suppress a circulating current from flowing between power storage devices connected in parallel. Furthermore, the cost of replacing parts can be reduced compared to the case where the power storage device itself is replaced.

  The abnormality detection unit can detect a state abnormality of each power storage device, and the control unit can charge / discharge the power storage device in which the state abnormality is detected when a state abnormality is detected in a part of the plurality of power storage devices. The charging capacity of the power storage device other than the power storage device in which the state abnormality is detected is less than or equal to a predetermined value while controlling the power of the power storage device other than the power storage device in which the state abnormality is detected to be output to the traveling motor. In this case, the power supply from the power storage system to the traveling motor can be controlled to end.

  When a state abnormality is detected on the premise that the power storage device itself is replaced, power storage other than the power storage device having the state abnormality is performed until the charge capacity of the power storage device other than the power storage device in which the state abnormality is detected becomes a predetermined value or less. By controlling the power of the device to be output to the traveling motor, the vehicle can be traveled efficiently using the power of the power storage device other than the power storage device having a state abnormality.

  A vehicle in which electric power is supplied from the power storage system in a state where the component abnormality or state abnormality has occurred to the traveling motor by performing charge / discharge control that prohibits charging of the power storage system when a component abnormality or state abnormality is detected The continuation of travel can be reduced.

  When a component abnormality is detected, by performing charge / discharge control in which the power output value from the power storage device other than the power storage device in which the component abnormality is detected to the traveling motor is limited to a predetermined upper limit value, the component abnormality is detected. The vehicle can be traveled efficiently using the power of a power storage device other than a certain power storage device.

  The vehicle control method according to the second aspect of the present invention is a vehicle control method in which a plurality of power storage devices are connected in parallel and a power storage system for supplying power to a vehicle driving motor is mounted. A step of detecting an abnormality of a component related to a charge / discharge process provided in each of the power storage devices, and a charge of the power storage device in which the abnormality of the component is detected when a component abnormality is detected in a part of the plurality of power storage devices. A step of controlling the power of the power storage device other than the power storage device in which the discharge is prohibited and the abnormality of the component is detected to be output to the traveling motor; and the abnormality of the power storage device in which the abnormality of the component is detected and the component are detected. And controlling to end the power supply from the power storage system to the traveling motor when the difference in charge capacity with power storage devices other than the power storage device becomes a predetermined value or less.

  According to the second invention of the present application, even when a component abnormality is detected in a part of the plurality of power storage devices connected in parallel, charging / discharging of a normal power storage device other than the power storage device having the component abnormality is permitted. On the other hand, it is possible to suppress the circulating current from flowing between the power storage devices connected in parallel after the component replacement, and it is possible to reduce the part replacement cost compared to the case where the power storage device itself is replaced.

  Further, in the second invention of the present application, when a state abnormality based on the replacement of the power storage device itself is detected, until the charge capacity of the power storage device other than the power storage device in which the state abnormality is detected becomes equal to or less than a predetermined value, By controlling the power of the power storage device other than the power storage device having the abnormal state to be output to the traveling motor, the vehicle can be traveled efficiently using the power of the power storage device other than the power storage device having the abnormal state. .

It is a figure which shows the structure of the battery system which concerns on Example 1. FIG. 4 is a flowchart showing vehicle control by one assembled battery of the assembled batteries connected in parallel according to the first embodiment. It is a figure which shows an example of the voltage behavior of the assembled battery which concerns on Example 1. FIG. It is the figure which showed the relationship between SOC of the assembled battery which concerns on Example 1, and OCV. It is a figure which shows the processing flow of the assembled battery exchange method which concerns on Example 2. FIG.

  Examples of the present invention will be described below.

Example 1
A battery system (corresponding to a power storage system) that is Embodiment 1 of the present invention will be described. FIG. 1 is a diagram showing the configuration of the battery system of this example. The battery system of the present embodiment can be mounted on a vehicle. Vehicles include hybrid cars and electric cars. The hybrid vehicle includes an engine or a fuel cell as a power source for running the vehicle, in addition to a battery pack described later. An electric vehicle includes only a battery pack as a power source for the vehicle.

  The battery pack of this embodiment is composed of a plurality of battery stacks. As shown in FIG. 1, the battery pack includes four battery stacks 11 to 14, and each battery stack has a plurality of single cells. As the single battery, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. Moreover, an electric double layer capacitor (capacitor) can be used instead of the secondary battery. As the unit cell, a rectangular or cylindrical unit cell can be used.

  The inside of the unit cell includes power generation elements (for example, a positive electrode element, a negative electrode element, a separator (including an electrolytic solution) disposed between the positive electrode element and the negative electrode element can be stacked), and are adjacent to each other. Two unit cells are electrically connected by a bus bar. For example, a pair of end plates are disposed at both ends of the battery stack 11, and the pair of end plates are restrained by a restraining member, thereby restraining a plurality of cells arranged in one direction. The same applies to the battery stacks 12 to 14.

  The four battery stacks 11 to 14 are electrically connected via a wire harness. Moreover, the electric current circuit breaker 22 mentioned later is being fixed. The current breaker 22 is used to cut off the current paths of the battery stacks 11 to 14. The current breaker 22 can be composed of a plug and a grip inserted into the plug, and the current path can be blocked by removing the grip from the plug.

  In this embodiment, two battery packs 20A and 20B (each corresponding to a power storage device) are configured using four battery stacks 11 to 14, and the battery packs 20A and 20B are electrically connected in parallel. Has been. The number of unit cells constituting the assembled batteries 20A and 20B is equal to each other, and the assembled batteries 20A and 20B include a plurality of battery stacks.

  The assembled battery 20A is composed of two battery stacks 11 and 12, and the battery stacks 11 and 12 are electrically connected in series. The assembled battery 20B includes two battery stacks 13 and 14, and the battery stacks 13 and 14 are electrically connected in series.

  In the present embodiment, one assembled battery is constituted by two battery stacks, but the present invention is not limited to this, and one assembled battery can be constituted by one battery stack or three or more battery stacks. . Moreover, you may comprise the assembled battery contained in a battery pack so that three or more assembled batteries connected in parallel may be included.

  Each assembled battery 20A, 20B is provided with a fuse 21. A current breaker 22 is provided between the battery stack 11 and the battery stack 12, and a current breaker 22 is provided between the battery stack 13 and the battery stack 14. The two current breakers 22 can be configured integrally, and by pulling out the grip of the current breaker 22, the current paths of the assembled batteries 30 and 31 can be simultaneously cut off.

  System main relay SMR_B1 is connected to the positive terminal of assembled battery 20A, and system main relay SMR_B2 is connected to the positive terminal of assembled battery 20B. The system main relay SMR_G1 is connected to the negative terminal of the assembled battery 20A, and the system main relay SMR_G2 is connected to the negative terminal of the assembled battery 20B. The system main relays SMR_B 1, B 2, G 1 and G 2 are controlled to be turned on / off by the controller 50. System main relay SMR_B1 etc. are relay switches, for example.

  In order to electrically connect the assembled batteries 20A, 20B and a boost converter 31 described later, the system main relays SMR_B1, B2, SMR_G1, G2 are switched from OFF to ON. Thereby, charging / discharging of assembled battery 20A, 20B can be performed.

  The assembled batteries 20A and 20B are provided with a current sensor 23, a voltage monitoring IC 24, and a temperature sensor 25, respectively. The battery pack of the present embodiment includes parts connected to the battery such as system main relays SMR_B1, B2, G1, G2, fuse 21, current breaker 22, current sensor 23, voltage monitoring IC 24, temperature sensor 25, etc. The battery parts are provided in each of the assembled batteries 20 </ b> A and 20 </ b> B and are controlled and monitored by the controller 50.

  The current sensor 23, the voltage monitoring IC 24, and the temperature sensor 25 are sensor components that detect physical quantities representing the states of the assembled batteries 20A and 20B. System main relays SMR_B1, G1 and system main relays SMR_B2, G2 are switch parts that allow connection between corresponding assembled batteries 20A, 20B and boost converter 31 and switch between an on state and an off state. The fuse 21 and the current breaker 22 are current interrupting parts that interrupt the current paths of the assembled batteries 20A and 20B.

  These sensor parts, switch parts, current interruption parts, etc. are battery parts connected to each of the assembled batteries 20A and 20B in relation to the charge / discharge process, and an abnormality of the battery part is detected in the abnormality detection process described later. The The battery parts can include an electronic control IC (ECU) that processes detection results output from the sensor parts of the assembled batteries 20A and 20B and monitors the battery parts.

  The current sensor 23 of the assembled battery 20A is provided between the system main relay SMR_B1 and the boost converter 31, and detects the charge / discharge current of the assembled battery 20A. The current sensor 23 of the assembled battery 20B is provided between the system main relay SMR_B2 and the boost converter 31, and detects the charge / discharge current of the assembled battery 20B. Each current sensor 23 outputs a detection result to the controller 50.

  Each voltage monitoring IC 24 detects the voltage of each of the assembled batteries 20 </ b> A and 20 </ b> B and outputs the detection result to the controller 50. The voltage monitoring IC 24 includes the voltage of the assembled battery 20A (20B), the voltage of the unit cell, and the voltage when the plurality of unit cells constituting the assembled battery 20A (20B) are divided into a plurality of arbitrary blocks. Each block includes two or more single cells.

  Each temperature sensor 25 detects the temperature of each of the assembled batteries 20 </ b> A and 20 </ b> B and outputs the detection result to the controller 50. The temperature sensor 25 can be provided in one place or a plurality of places of the assembled batteries 20A and 20B.

  A battery pack including the assembled batteries 20 </ b> A and 20 </ b> B connected in parallel is connected to the boost converter 31. Boost converter 31 boosts the output voltage of the battery pack and outputs the boosted power to inverter 32. Boost converter 31 steps down the output voltage of inverter 32 and outputs the reduced power to the battery pack. The step-up converter 31 can be composed of, for example, a chopper circuit. Boost converter 31 operates in response to a control signal from controller 50. Further, a current sensor 26 is provided between the battery pack and the boost converter 31 for detecting a current input from the battery pack to the boost converter 31 or a current output from the boost converter 31 to the battery pack. The current sensor 26 is provided separately from the battery parts of the battery pack.

  The inverter 32 converts the DC power output from the boost converter 31 into AC power, and outputs the AC power to the motor generator (MG) 33. As the motor generator 33, for example, a three-phase AC motor can be used. The inverter 32 converts AC power output from the motor / generator 33 into DC power and outputs the DC power to the boost converter 31.

  The motor / generator 33 receives the AC power from the inverter 32 and generates kinetic energy for running the vehicle. The motor / generator 33 is connected to wheels, and the kinetic energy generated by the motor / generator 33 is transmitted to the wheels. When the vehicle is decelerated or stopped, the motor / generator 33 converts kinetic energy generated during braking of the vehicle into electric energy (AC power). The AC power generated by the motor / generator 33 is output to the inverter 33. Thereby, regenerative electric power can be stored in a battery pack (assembled battery 20A, 20B).

  In the battery system of this embodiment, the motor / generator 33 can be used as a load that operates by receiving electric power from the battery pack. Further, although the boost converter 31 is used, the boost converter 31 can be omitted. That is, the battery pack can be connected to the inverter 32.

  Further, the battery pack is connected to an auxiliary device or a charger 60. An auxiliary machine is a device (power consuming device) that operates by consuming electric power output from a battery pack, and is, for example, an air conditioner, an AV device, a lighting device, or the like mounted on a vehicle.

  The controller 50 is a control device that calculates the required vehicle output required for the entire vehicle and performs charge / discharge control of the assembled batteries 20A and 20B connected in parallel with the output control of the battery pack based on the required vehicle output. is there. The controller 50 uses the discharge control to output the electric power of the assembled batteries 20A and 20B to the motor / generator 33 based on the vehicle output request, and the regenerative electric power at the time of vehicle braking when the vehicle decelerates or stops. , 20B is charged. In the case of a hybrid vehicle, the controller 50 is configured as a control device that calculates a required vehicle output required for the entire vehicle and performs output control of the engine and / or battery pack based on the required vehicle output.

  The SOC (State of Charge) indicates the ratio of the current charge capacity to the full charge capacity of the assembled battery, and the controller 50 detects the result of detection by the voltage monitoring IC 24 in order to manage the SOC of each of the assembled batteries 20A and 20B. Can be used to calculate and identify the SOC of the assembled batteries 20A and 20B, and to store and manage the charge / discharge history and the SOC information.

  The SOCs of the assembled batteries 20A and 20B can be specified from the OCV (Open Circuit Voltage) of the assembled batteries 20A and 20B. Since SOC and OCV are in a correspondence relationship, if this correspondence relationship is obtained in advance, the SOC can be specified from the OCV. The OCV of the assembled batteries 20A, 20B can be calculated from the voltage (CCV: Closed Circuit Voltage) detected by the voltage monitoring IC 24. The SOC of each of the battery stacks 11 to 14 constituting the assembled battery 10 can be calculated together with the SOC of the assembled batteries 20A and 20B. The SOC can be calculated by integrating the charge / discharge current values of the assembled batteries 20A and 20B detected by the current sensor 24.

  The charger 60 is an AC / DC converter that converts AC power supplied from an external power source (for example, commercial power source) (not shown) into DC power, or an external charging current (DC power) that is output from the external power source or AC / DC converter. A DC / DC converter that boosts the current) and outputs it to the assembled batteries 20A and 20B can be included. Note that the charger 60 can also be configured to output the power supplied from the assembled batteries 20A and 20B to an externally connectable device that is not mounted on the vehicle.

  Next, charge / discharge control associated with vehicle control will be described in detail. In this embodiment, when an abnormality occurs in a part of a plurality of battery packs connected in parallel constituting the battery pack, the battery pack (abnormal battery) in which the abnormality has occurred is disconnected from the input / output control of the battery pack. The vehicle control using the power of a normal assembled battery (normal battery) connected in parallel to the abnormal battery is allowed.

  In the present embodiment, the abnormality detected in each of the assembled batteries 20A and 20B is classified into a case where the battery component is abnormal and a case where the battery itself is abnormal, and vehicle control using only a normal assembled battery is performed. The charge / discharge control is controlled so as to be different depending on whether the battery component is abnormal or the battery itself is abnormal.

  As shown in FIG. 1, the controller 50 can include a vehicle control unit 51 and an abnormality detection unit 52. The vehicle control unit 51 performs charge / discharge control of the assembled batteries 20 </ b> A and 20 </ b> B connected in parallel to the vehicle request output required for the entire vehicle. In addition, the controller 50 can also be comprised including the memory | storage part which memorize | stores the SOC information of each assembled battery 20A, 20B, charging history, various calculation results, information used for calculation, etc.

  The abnormality detection unit 52 detects an abnormality (failure) in the battery component of the battery pack composed of the assembled batteries 20A and 20B connected in parallel.

  The abnormality detection unit 52 monitors, for example, each of the system main relays SMR_B1, B2, G1, and G2, and monitors the presence / absence of a response to the control signal output from the vehicle control unit 51 to each system main relay and the operation of the control signal. Thus, the abnormality of the system main relays SMR_B1, B2, G1, and G2 can be detected. Specifically, after the control signal for switching the system main relay from the off state to the on state is output, the control signal for switching the system main relay from the on state to the off state is displayed when the detection value of the current sensor 23 is 0. When the current value is detected by the current sensor 23 after the output, the abnormality detection unit 52 can detect the abnormality of the system main relay.

  The abnormality of the current sensor 23 is detected by, for example, the current value detected by the current sensor 23 of each of the assembled batteries 20A and 20B connected in parallel and the current sensor 26 provided between the battery pack and the boost converter 31. The abnormality of each current sensor 23 can be detected using the current value to be used. For example, when the current values A1 and A2 detected by each current sensor 23 exceed a predetermined threshold with respect to the output current A of the battery pack detected by the current sensor 26 (the output of the battery pack detected by the current sensor 26) When the current A / 2 is compared with the current values A1 and A2 and the difference exceeds a predetermined threshold value), the abnormality of the current sensors 23 of the assembled batteries 20A and 20B can be detected.

  The abnormality of the voltage monitoring IC 24 is, for example, that the voltage monitoring IC 24 of the assembled battery 20 </ b> A detects the voltage between the single cells of the battery stack 11 and detects the voltage between the terminals of the battery stack 11. Is compared with the voltage between the terminals of the battery stack 11, an abnormality of the voltage monitoring IC 24 can be detected. For example, in a battery stack in which four unit cells are connected in series, the voltage detection value of one unit cell shows an abnormal value, but is calculated based on the voltage detected by each of the other three unit cells. If the difference between the total voltage value for four cells and the voltage across the terminals of the battery stack is less than or equal to a predetermined value, the voltage detection value of a single cell is incorrect, that is, the voltage monitoring IC 24 has failed. Can be determined.

  The abnormality of the temperature sensor 25 is detected, for example, by a separate temperature sensor (not shown) provided in an intake duct or the like connected to the battery pack, and the temperature of the cooling air flowing into the battery pack is detected. By detecting the temperature of the cooling air flowing into each of 20B and comparing the two, the abnormality of the temperature sensor 25 can be detected when the difference exceeds a predetermined value. Further, a plurality of temperature sensors 25 are provided in each of the assembled batteries 20A and 20B, and the temperature detected by the other temperature sensors 25 is compared between the plurality of temperature sensors 25 to determine whether or not the difference exceeds a predetermined value. Thus, the abnormality of each of the temperature sensors 25 of the assembled batteries 20A and 20B can be detected.

  An abnormality (disconnection) of the fuse 21 can be detected, for example, by connecting a diagnostic circuit to the fuse 21 to detect the resistance value of the fuse 21 and monitoring whether the fuse 21 is disconnected. The same applies to the current breaker 22. For example, by connecting a diagnostic circuit to the current breaker 22 and monitoring the resistance value of the current breaker 22, a resistance abnormality due to poor contact or the like is detected as an abnormality in the current breaker 22. can do. In addition, abnormalities in the electronic control IC (ECU) that monitors battery components can be determined by outputting a predetermined control signal to the electronic control IC in a predetermined diagnosis mode and diagnosing the contents of the input response signal, the presence or absence, etc. An abnormality of the electronic control IC can be detected.

  The abnormality detection unit 52 can detect battery abnormality (state abnormality) of the assembled batteries 20A and 20B along with abnormality detection of battery parts. For example, it is possible to detect an abnormality for each battery stack or each single cell constituting the assembled batteries 20A, 20 and detect each battery abnormality of the assembled batteries 20A, 20B. When an assembled battery is composed of a plurality of battery stacks, if an abnormal state is detected in any one of the battery stacks, it is detected that the entire assembled battery including the battery stack in which the abnormal state is detected is abnormal. can do.

  Specifically, the abnormality detection unit 52 determines whether the voltage value detected by the voltage monitoring IC 24 exceeds a predetermined value with respect to the current value detected by the current sensor 23 or a voltage difference between battery stacks or between single cells. Can be determined that battery abnormality has occurred in the assembled batteries 20A, 20B. Further, for example, when each of the battery temperature, resistance, and SOC shows a predetermined behavior associated with battery abnormality, it can be detected that the battery pack 20A, 20B has battery abnormality.

  When the ignition switch of the vehicle is switched from OFF to ON, the vehicle control unit 51 switches the system main relays SMR-B1, B2, G1, and G2 from OFF to ON, and the abnormality detection unit is started as charge / discharge control starts. A control signal is output so as to start the abnormality detection process for 52. When an abnormality is detected in the battery pack by the abnormality detection process, the vehicle control unit 51 performs charge / discharge control of the battery pack according to each abnormality of the battery component abnormality and the state abnormality.

  The abnormality detection unit 52 detects battery component abnormality or battery abnormality for each of the plurality of assembled batteries 20A and 20B constituting the battery pack. The vehicle control unit 51 performs different charge / discharge control on a normal battery in which no abnormality is detected, depending on whether the detected abnormality is a battery component abnormality or a battery abnormality. FIG. 2 is a flowchart showing an operation flow of discharge control when an abnormality occurs in a part of the plurality of assembled batteries connected in parallel according to the present embodiment.

  In step S101, the abnormality detection unit 52 performs battery component abnormality detection for each of the assembled batteries 20A and 20B. If no battery component abnormality is detected, the abnormality detection unit 52 proceeds to step S106 and performs battery abnormality detection for each of the assembled batteries 20A and 20B. If no battery abnormality is detected after battery part abnormality detection, the process returns to step S101.

  In step S102, when a battery part abnormality is detected in one of the assembled batteries 20A and 20B, the vehicle control unit 51 disconnects the assembled battery in which the battery part abnormality is detected from the charge / discharge control of the battery pack. For example, when a battery component abnormality is detected in the assembled battery 20B, the vehicle control unit 51 prohibits charging / discharging of the assembled battery 20B in which the abnormality of the battery component is detected, and the assembled battery 20B in which the abnormality of the battery component is detected. The system main relays SMR_B2 and G2 are switched from on to off while the system main relays SMR_B1 and G1 are kept on in order to allow the travel motor to output the electric power of the assembled battery 20A other than the above.

  The vehicle control unit 51 performs output restriction for limiting the power output value supplied from the assembled battery 20A to the motor generator 33 to a predetermined upper limit value, and performs charge / discharge control of the assembled battery 20A that is a normal battery ( S103). By charging / discharging control of the assembled battery 20A with output restriction, the vehicle travel distance using the power of the assembled battery 20A can be made longer than when the output restriction is not performed, and the vehicle travel distance using power can be increased. On the other hand, the power of the assembled battery 20A can be used efficiently.

  Further, the vehicle control unit 51 performs output control only for power supply (discharge) to the load without charging the regenerative power in the charge / discharge control for the battery pack 20A after detecting the abnormality of the battery pack 20B. Charge / discharge control that prohibits charging the entire battery system. The same applies to the case where an abnormal state of the assembled battery described later is detected. It is possible to reduce the chance that the vehicle continues to travel when electric power is supplied to the motor / generator 33 from the battery system in which a battery component abnormality or a state abnormality has occurred. In other words, when the abnormality is detected, the power stored in the assembled battery 20A is efficiently used to limit the output so that the vehicle travel distance using the power of the battery system is as long as possible. By prohibiting, it is possible to control so that the vehicle travels unnecessarily by supplying power from the battery system to the motor / generator 33 in a state where a battery component abnormality or a state abnormality has occurred.

  In step S104, the vehicle control unit 51 performs charge / discharge control of the assembled battery 20A based on the charge capacity of the assembled battery 20B having an abnormality in battery components. The vehicle control unit 51 uses the SOC with respect to the charging capacity of the assembled battery, and the assembled battery until the SOC difference between the SOC of the assembled battery 20B in which the abnormality of the battery component is detected and the SOC of the normal assembled battery 20A becomes equal to or less than a predetermined value. Discharge control using 20A is performed. That is, the discharge of the assembled battery 20A is permitted until the difference between the SOC of the assembled battery 20B in which an abnormality is detected in the assembled batteries 20A and 20B connected in parallel and the SOC of the normal assembled battery 20A is equal to or less than a predetermined value. Carry out vehicle control.

  In this embodiment, in the case of a battery part abnormality, it is assumed that the battery part is repaired and replaced instead of replacing the assembled battery itself in which an abnormality is detected like a battery abnormality described later, Discharge control using the assembled battery 20A is performed until the SOC difference between the assembled batteries 20A and 20B becomes a predetermined value or less. For this reason, when the battery parts are replaced, the voltage difference between the assembled batteries 20A and 20B connected in parallel is reduced to a predetermined value, so that the circulating current flowing between the assembled batteries 20A and 20B is suppressed by the voltage difference. The battery parts after repair and replacement of the battery parts and the assembled batteries 20A and 20B can be appropriately protected.

  When the difference between the SOC of the assembled battery 20B in which an abnormality is detected in step S104 and the SOC of the normal assembled battery 20A is equal to or less than a predetermined value, the vehicle control unit 51 proceeds to step S105 and charges / discharges the assembled battery 20A. In order to prohibit the control, the system main relays SMR_B1, G1 are switched from on to off, and the charge / discharge control of the assembled battery 20A is terminated. That is, the vehicle control unit 51 performs control so as to end the charge / discharge control of the battery system. When the charge / discharge control of the battery system is terminated after an abnormality is detected in the battery pack, the controller 50 does not end the charge / discharge control in a normal state with no abnormality. For example, a flag indicating abnormal termination is set. Thus, it can be distinguished from the end of charge / discharge control in a normal state.

  Note that, when the charge / discharge control is terminated while the vehicle is traveling, the vehicle control unit 51 performs a predetermined process before the difference between the SOC of the assembled battery 20B in which an abnormality is detected and the SOC of the normal assembled battery 20A is equal to or less than a predetermined value. At the point of time, control (for example, lighting of a lamp to end the charge / discharge control) that informs the user that the charge / discharge control of the battery system is ended in advance is performed, and then the charge / discharge control of the battery system is ended. Can be controlled. Further, without prohibiting charge / discharge control of the assembled battery 20A until a predetermined time elapses after the difference between the SOC of the assembled battery 20B in which the abnormality is detected and the SOC of the normal assembled battery 20A becomes equal to or less than a predetermined value, Thereafter, the charge / discharge control of the battery system may be terminated.

  The vehicle control unit 51 uses the current value and the voltage value detected by the current sensor 23 and the voltage monitoring IC 24 immediately before the abnormality of the battery component is detected in the determination process of step S104, so that the abnormality of the battery component is detected. A set in which an abnormality of the battery component is detected using the current value and voltage value detected by the current sensor 23 and the voltage monitoring IC 24 after calculating the SOC of the detected assembled battery 20B or detecting the abnormality of the battery component. The SOC of the battery 20B can be calculated. The vehicle control unit 51 calculates the SOC of the assembled battery 20A after the abnormality of the battery part is detected using the detection value detected by the current sensor 23 or the voltage monitoring IC 24, and when the abnormality of the battery part is detected Compared with the SOC of the assembled battery 20B (when charge / discharge control of the assembled battery 20B is disconnected), the SOC difference between the assembled batteries 20A and 20B can be obtained.

  Note that the vehicle control unit 51 can perform the determination process in step S104 using the OCV of each of the assembled batteries 20A and 20B, in addition to the case where the SOC difference between the assembled batteries 20A and 20B is equal to or less than a predetermined value. .

  As described above, since the SOC and the OCV are in a correspondence relationship, the vehicle that detects and calculates the OCV between the assembled batteries 20A and 20B, and permits the discharging of the assembled battery 20A until the OCV difference becomes a predetermined value or less. Control can be carried out. The vehicle control unit 51 can detect the voltage value of the assembled battery 20B with the voltage monitoring IC 24 and obtain the OCV of the assembled battery 20B in a state disconnected from the charge / discharge control after the abnormality of the battery is detected. . The OCV of the assembled battery 20A can be obtained by calculating the OCV based on the voltage value detected by the voltage monitoring IC 24 as described above. Since the relationship between the OCV and the SOC changes as the capacity of the assembled batteries 20A and 20B deteriorates, the capacity is deteriorated by performing vehicle control that permits discharging of the assembled battery 20A until the OCV difference becomes a predetermined value or less. The output can be limited with high accuracy by suppressing the influence of the above.

  Further, the vehicle control unit 51 integrates the charging / discharging current of the assembled battery 20A detected by the current sensor 23, and permits the discharging of the assembled battery 20A until the current accumulated value becomes equal to or less than the dischargeable capacity of the assembled battery 20A. Vehicle control can be performed.

  FIG. 3 is a diagram illustrating an example of the voltage behavior of the OCV of the assembled battery 20A (normal battery). As shown in FIG. 3, the behavior of the voltage (CCV) of the assembled battery 20 </ b> A detected by the voltage monitoring IC 24 from the time t <b> 1 when the abnormality of the battery component occurs is indicated by a dotted line. Further, the behavior of the voltage of the assembled battery 20A indicated by the solid line is an OCV calculated from the voltage (CCV) of the assembled battery 20A detected by the voltage monitoring IC 24.

The voltage value of the assembled battery 20B in which the assembled battery 20B in which the abnormality of the battery component is detected is disconnected from the charge / discharge load and cannot be charged / discharged can be acquired as OCV (Vn). On the other hand, by determining the allowable voltage difference (Va) between the assembled battery 20A and the assembled battery 20B that is allowed until the SOC difference between the assembled batteries 20A and 20B becomes a predetermined value or less, the assembled battery is determined in advance. An OCV lower limit value (Vo = Vn−Va) of 20A can be calculated. Therefore, SOC_n corresponding to Vn of the assembled battery 20B and SOC_o corresponding to Vo of the assembled battery 20A can be obtained based on the relationship map between the SOC and OCV of the assembled battery shown in FIG. As shown in Expression 1, the dischargeable capacity [Ah] corresponding to the difference between SOC_n and SOC_o can be calculated from the full charge capacity [Ah] of the assembled battery 20A.
(Formula 1)
Dischargeable capacity = full charge capacity × (SOC_n−SOC_o) / 100

  The full charge capacity of the assembled battery 20A can be calculated in advance from, for example, an external charge current integrated value during external charging using an external power source. Further, the full charge capacity can be calculated by taking into account the deterioration capacity from the full charge capacity in the initial state at the time of manufacture of the assembled battery 20A to the present time.

  The vehicle control unit 51 calculates the allowable dischargeable capacity of the assembled battery 20A from the time t1 when the abnormality of the battery component is detected until the SOC difference between the assembled batteries 20A and 20B becomes a predetermined value or less. It is possible to perform vehicle control that permits discharge of the assembled battery 20A until the integrated current value detected by the current sensor 23 of 20A becomes equal to or less than the dischargeable capacity.

  The OCV of each of the assembled batteries 20A and 20B at the time when the abnormality of the battery component is detected differs depending on charging / discharging in the vehicle control. Therefore, the assembled battery for the OCV of the assembled battery 20B at the time of detecting the abnormality of the battery component From the OCV lower limit value of 20A, the dischargeable capacity of the assembled battery 20A allowed until the SOC difference between the assembled batteries 20A and 20B becomes a predetermined value or less is calculated, and the current of the assembled battery 20A detected by the current sensor 23 By comparing with the integrated value, it is possible to control the output with high accuracy while suppressing the influence of capacity deterioration, temperature, etc. of the assembled batteries 20A and 20B.

  Returning to the description of FIG. 2, when no battery component abnormality is detected in each of the assembled batteries 20A and 20B in step S102, the vehicle control unit 51 subsequently performs battery abnormality detection for each of the assembled batteries 20A and 20B (S106). .

  In step 106, the vehicle control part 51 returns to step S101, when the abnormality detection part 52 has not detected battery abnormality in each assembled battery 20A, 20B. On the other hand, when a battery abnormality is detected in a part of the assembled batteries 20A and 20B by the abnormality detection unit 52, the vehicle control unit 51 detects the battery abnormality detected in the same manner as when an abnormality is detected in the battery component. Disconnect the battery from the charge / discharge control of the battery pack.

  Unlike the case where an abnormality is detected in the battery component, the vehicle control unit 51 sets the power output value supplied from the assembled battery 20B other than the assembled battery 20A in which the battery abnormality is detected to the motor / generator 33 to a predetermined upper limit value. Without limiting to the above, charge / discharge control of the assembled battery 20B which is a normal battery is performed (S107).

  In step S108, the vehicle control unit 51 performs discharge control using the assembled battery 20B until the SOC of the assembled battery 20B becomes a predetermined value or less. That is, when a battery component abnormality is detected, normal battery charge / discharge control is performed based on the relative SOC difference from the other battery assembly in which the battery component abnormality is detected. Is detected, the SOC of the normal assembled battery 20B is equal to or lower than a predetermined value in the assembled batteries 20A and 20B connected in parallel on the assumption that the assembled battery itself that is abnormal is replaced with a replacement assembled battery. Until then, the vehicle control that permits the discharge of the assembled battery 20B is performed.

  As described above, when a state abnormality based on replacement of the assembled battery 20A itself is detected, the vehicle control unit 51 determines that the charge capacity of the assembled battery 20B other than the assembled battery 20A in which the state abnormality is detected is equal to or less than a predetermined value. Until then, by controlling the electric power of the assembled battery 20B to be output to the motor / generator 33, vehicle control using the electric power stored in the normal assembled battery 20B efficiently can be performed.

  When the SOC of the normal assembled battery 20B becomes equal to or lower than the predetermined value in step S108, the vehicle control unit 51 proceeds to step S105 and turns on the system main relays SMR_B2, G2 to prohibit charging / discharging of the assembled battery 20B. Is switched to OFF, the charge / discharge control of the assembled battery 20B is terminated, and the charge / discharge control of the battery system is terminated.

  Even in the determination process of step S108, the vehicle control unit 51 uses the OCV of the assembled battery 20B or detects the assembled battery detected by the current sensor 23 in addition to the case where the SOC of the assembled battery 20B is equal to or lower than the predetermined value. Using the current integrated value obtained by integrating the charging / discharging current of 20B, it is possible to perform vehicle control that permits discharging of the assembled battery 20B.

  In addition, when the assembled battery is composed of a plurality of battery stacks, when an abnormal state is detected in any one of the battery stacks, the entire assembled battery including the battery stack in which the abnormal state is detected is abnormal. Can be detected. For this reason, the replacement of the assembled battery includes replacing one or more battery stacks in which a state abnormality is detected among the plurality of battery stacks included in the assembled battery.

  In this way, in this embodiment, the abnormality that occurs in the battery is distinguished from the battery abnormality that presupposes the replacement of the battery itself and the abnormality of the battery component that does not require replacement of the battery itself, and is connected in parallel. Even if a battery component abnormality is detected in some of the battery packs, the battery packs that are connected in parallel after replacement of the battery parts are allowed while charging / discharging normal battery packs other than battery packs with abnormal battery components. The circulation current can be prevented from flowing between the batteries, and the replacement cost of the battery parts can be reduced as compared with the case where the assembled battery itself is replaced.

  That is, when the vehicle running with the abnormal battery disconnected and allowing charging / discharging of the normal battery as in the battery system of the present embodiment is performed, when the abnormal battery is replaced with a replacement pack, the batteries connected in parallel are connected. If there is a voltage difference, a circulating current will be generated, which may cause capacity degradation due to high-rate degradation, lithium metal deposition, etc., or a blown fuse, etc., making it difficult to properly protect the battery or battery parts. .

  For this reason, when replacing an abnormal battery with a healthy replacement battery, it is necessary to perform charge / discharge work to eliminate the voltage difference and to carry out replacement work to suppress excessive circulating current flow. In the example, the abnormality that occurs in the battery is distinguished from the battery abnormality that assumes that the battery itself is replaced and the abnormality of the battery component that does not require the battery itself to be replaced, and the battery itself is replaced like a battery abnormality. When there is an abnormality in the battery parts without any abnormalities in the battery itself, and when the battery pack is replaced, it is possible to suppress the circulating current from flowing between the battery packs connected in parallel after replacing the battery parts. Compared to the above, it is possible to reduce the replacement cost of the battery parts.

(Example 2)
FIG. 5 is a diagram illustrating the second embodiment. In this embodiment, after the assembled battery in which the battery abnormality is detected is replaced with the replacement assembled battery, the voltage between the assembled batteries including the replacement assembled battery connected in parallel is adjusted, so that the battery system can be used. .

  FIG. 5 is a diagram showing a processing flow of the assembled battery replacement method of the present embodiment. For example, when there is a battery abnormality in one of the assembled batteries 20A and 20B connected in parallel in the first embodiment, it is necessary to perform replacement maintenance of the assembled battery in which the battery abnormality is detected.

  The controller 50 of this embodiment can have a maintenance mode, and performs the maintenance mode based on a predetermined control signal. The controller 50 executes a battery replacement mode in which the battery pack to be replaced (or the battery stack 11 constituting the battery pack) is replaced in the maintenance mode, and the SOC between the battery packs electrically connected in parallel after the replacement Perform equalization control.

  An operator who replaces the assembled battery connects the information processing apparatus to the controller 50 via a predetermined connection adapter provided in the vehicle. The worker inputs a maintenance mode instruction signal (input control signal) from the information processing apparatus. The controller 50 that has received the maintenance instruction signal shifts to the maintenance mode (battery replacement mode) (S301). At this time, system main relays SMR_B1, G1, B2, and G2 are off.

  The controller 50 identifies an assembled battery in which battery abnormality is detected among the assembled batteries 20A and 20B connected in parallel. When the battery abnormality is detected, the controller 50 can previously store information for identifying the assembled battery in which the battery abnormality is detected in a storage unit (not illustrated) with respect to the assembled battery in which the battery abnormality is detected. . In other words. The controller 50 can identify a normal assembled battery, for example, the assembled battery 20B, using information for identifying the assembled battery in which the battery abnormality is detected.

  When the controller 50 identifies the assembled battery 20B as a normal assembled battery in which no battery abnormality is detected, the controller 50 extracts the SOC of the assembled battery 20B from a storage unit (not shown), and determines whether or not the assembled battery 20B is a predetermined SOC. Is discriminated (S302). As the predetermined SOC, the SOC of the replacement assembled battery can be used.

  When it is determined that the assembled battery 20B is not the predetermined SOC, the controller 50 keeps the system main relays SMR_B1, G1 off (the assembled battery in which the battery abnormality is detected) in order to charge the assembled battery 20B to the predetermined SOC. The system main relays SMR_B2 and G2 are switched from OFF to ON while the connection of 20A is prohibited. The controller 50 performs charge control for charging the assembled battery 20B with electric energy from the external power source via the charger 60 (S303). The external power supply and the vehicle can be connected using a charging cable or the like that can be connected to a charging adapter on which the vehicle is mounted.

  In step S303, the operator who replaces the assembled battery can input a charge permission signal from the information processing apparatus connected to the controller 50, and can perform mode switching for returning the controller 50 to the charge permission mode. When the battery abnormality for replacing the assembled battery occurs, the controller 50 shifts to the charge permission mode by the charge permission signal in the charge / discharge mode (abnormal end mode) for prohibiting the charge / discharge of the battery system.

  In the charging control from the external power source in step S303, the controller 50 monitors the SOC of the battery pack 20B being charged. For example, when the battery 50 is charged up to a predetermined SOC, the controller 50 stops charging the battery pack 20B. The relays SMR_B2 and G2 are switched from on to off. The controller 50 detects whether or not the voltage of the assembled battery 20B being charged is detected by the voltage monitoring IC 24, so that whether or not the battery has been charged up to a predetermined SOC, that is, whether or not a reference voltage corresponding to the predetermined SOC has been reached. Can be determined. At this time, it is determined whether or not the assembled battery 20B has been charged up to a predetermined SOC using a reference voltage corresponding to a predetermined SOC that varies depending on the amount of charging current output from the charger 60 via the external power supply. It can be constituted as follows.

  The controller 50 can control the worker who performs the replacement work to output a message indicating that the assembled battery 20B has been charged up to a predetermined SOC, for example, that the replacement preparation has been completed. The operator replaces the assembled battery 20A in which the battery abnormality to be replaced is detected with the assembled battery for replacement (S304).

  The controller 50 determines whether or not the battery is replaced with a replacement battery pack (S305). The operator inputs a control signal indicating completion of replacement from the information processing apparatus to the controller 50 after the replacement work is completed, and the controller 50 determines whether or not the replacement assembled battery has been replaced based on the input signal. be able to.

  After replacement with the replacement assembled battery, the controller 50 determines whether or not an SOC difference (voltage difference) has occurred in the SOC between the normal assembled battery 20B and the replacement assembled battery (S306). When there is no SOC difference between the normal assembled battery 20B and the replacement assembled battery, the process proceeds to step S307, and the controller 50 returns the charge / discharge control of the battery system after the assembled battery replacement (the battery abnormality is detected). Then, the abnormal termination mode of the battery system is shifted to a normal mode in which charge / discharge control is permitted), and the battery system can be used.

  On the other hand, if it is determined in step S306 that there is an SOC difference between the normal assembled battery 20B and the replacement assembled battery, the controller 50 proceeds to step S308, and the replaced normal assembled battery 20B and A process of equalizing the SOC with the replacement assembled battery is performed.

  In step S308, when it is determined that the SOC of the replacement assembled battery is higher than the SOC of the normal assembled battery 20B, the controller 50 proceeds to step S309 and switches the system main relays SMR_B2 and G2 from off to on. Then, the normal assembled battery 20B is charged. On the other hand, when it is determined that the SOC of the replacement assembled battery is lower than the SOC of the normal assembled battery 20B, the process proceeds to step S310, the system main relays SMR_B2, G2 are switched from OFF to ON, and the normal assembled battery is Discharge 20B of power. The controller 50 discharges a normal assembled battery 20B by outputting the power of the assembled battery 20B to a power consuming device that can be externally connected via the charger 60, an air conditioner, an AV device, a lighting device, etc. mounted on the vehicle. Can be made.

  After charging / discharging the normal assembled battery 20B in steps S309 and S310, the controller 50 returns to step S306, and the SOC between the normal assembled battery 20B and the replacement assembled battery after being replaced with the replacement assembled battery. It is determined whether or not the difference (voltage difference) has been eliminated. If the SOC difference between the normal assembled battery 20B and the replacement assembled battery has been eliminated, the process proceeds to step S307.

  Even if an SOC difference occurs between the assembled batteries connected in parallel after the replacement (for example, natural discharge), the normal assembled battery 20B after being replaced with the replacement assembled battery is replaced with the replacement assembled battery. Since the battery system is returned to the normal mode in which charge and discharge can be performed after equalizing the SOC, the battery system can be used in a suitable state.

11-14 Battery stack 20A, 20B Battery pack (power storage device)
21 Fuse 22 Current breaker 23, 26 Current sensor 24 Voltage monitoring IC
25 Temperature Sensor 31 Boost Converter 32 Inverter 33 Motor / Generator 50 Controller 51 Vehicle Control Unit 52 Abnormality Detection Unit 60 Charger

Claims (6)

A control device for a vehicle equipped with a power storage system in which a plurality of power storage devices are connected in parallel and supplies power to a traveling motor,
A controller that performs charge / discharge control of the power storage system;
An abnormality detection unit that detects an abnormality of a component related to charge / discharge processing provided in each of the power storage devices, and
When the abnormality of the component is detected in a part of the plurality of power storage devices, the control unit prohibits charging / discharging of the power storage device in which the abnormality of the component is detected, and the power storage in which the abnormality of the component is detected And controlling the power of the power storage device other than the device to be output to the traveling motor, and charging capacity between the power storage device in which the abnormality of the component is detected and the power storage device other than the power storage device in which the abnormality of the component is detected A control device that performs control so that power supply from the power storage system to the traveling motor is terminated when the difference is equal to or less than a predetermined value. The abnormality detection unit detects a state abnormality of each of the power storage devices,
When the state abnormality is detected in a part of the plurality of power storage devices, the control unit prohibits charging / discharging of the power storage device in which the state abnormality is detected, and other than the power storage device in which the state abnormality is detected Control is performed so that the power of the power storage device is output to the traveling motor, and when the charge capacity of a power storage device other than the power storage device in which the state abnormality is detected becomes equal to or less than a predetermined value, the travel from the power storage system The control device according to claim 1, wherein control is performed so as to end power supply to the motor for use.   The control device according to claim 1, wherein the control unit performs charge / discharge control in which charging of the power storage system is prohibited when an abnormality of the component or the state abnormality is detected.   When the abnormality of the component is detected, the control unit limits the power output value from the power storage device other than the power storage device in which the abnormality of the component is detected to the traveling motor to a predetermined upper limit value. The control device according to any one of claims 1 to 3. A control method for a vehicle equipped with a power storage system in which a plurality of power storage devices are connected in parallel and supplies power to a vehicle driving motor,
Detecting an abnormality of a component related to a charge / discharge process provided in each of the power storage devices;
Power storage other than the power storage device in which the abnormality of the component is detected by prohibiting charging / discharging of the power storage device in which the abnormality of the component is detected when abnormality of the component is detected in a part of the plurality of power storage devices Controlling the power of the apparatus to be output to the traveling motor;
When a charge capacity difference between the power storage device in which the abnormality of the component is detected and a power storage device other than the power storage device in which the abnormality of the component is detected is equal to or less than a predetermined value, the power storage system is connected to the travel motor. Controlling to terminate the power supply;
The control method characterized by including. Detecting an abnormal state of the power storage device;
When the state abnormality is detected in a part of the plurality of power storage devices, charging / discharging of the power storage device in which the state abnormality is detected is prohibited, and power of power storage devices other than the power storage device in which the state abnormality is detected is Controlling to output to the motor for traveling,
Controlling the power supply from the power storage system to the traveling motor to be terminated when a charge capacity of a power storage device other than the power storage device in which the state abnormality is detected is equal to or less than a predetermined value;
The control method according to claim 5, further comprising:

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