Battery control device

Abstract

To provide a battery control device capable of easily switching control of a storage battery according to use.SOLUTION: A battery control device includes a control unit that controls charging and discharging of a storage battery, and a communication unit that communicates with an ECU provided in a vehicle on which the storage battery is mounted. When abnormality occurs in communication between the communication unit and the ECU, the control unit determines that use of the storage battery is stationary, and switches control of charging and discharging from vehicle control corresponding to the vehicle to control in which limitation of a voltage of the storage battery is relaxed compared to the vehicle control or control in which charging and discharging speed of the storage battery is lowered than that in the vehicle control.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a battery control device.

Background Art

[0002] Regarding battery control, for example, Patent Document 1 describes that an operator operates a changeover switch outside the battery case to switch the control rules of a storage battery (secondary battery) according to its use.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when an in-vehicle storage battery is reused for stationary use, according to the above method, it is troublesome to operate the changeover switch, and there is a risk that the operator may make a mistake or forget to operate the changeover switch. In this case, since the control of the storage battery is used in the in-vehicle specification, there is a risk that it may not conform to the stationary specification.

[0005] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a battery control device capable of easily switching the control of a storage battery according to its use.

Means for Solving the Problems

[0006] The battery control device of the present invention includes a control unit that controls charging and discharging of a storage battery, and a communication unit that communicates with an ECU provided in a vehicle on which the storage battery is mounted. When an abnormality occurs in communication between the communication unit and the ECU, the control unit determines that the use of the storage battery is for stationary use, and switches the control of charging and discharging from vehicle control corresponding to the vehicle to control in which the voltage limit of the storage battery is relaxed compared to the vehicle control, or control in which the charging and discharging speed of the storage battery is reduced compared to the vehicle control.

Advantages of the Invention

[0007] According to the present invention, the control of the storage battery can be easily switched according to the use.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0009] (Vehicle System) FIG. 1 is a configuration diagram showing an example of a vehicle system 9a. The vehicle system 9a is mounted on a vehicle such as a hybrid vehicle or an electric vehicle. The vehicle system 9a includes a battery device 3, a differential gear 6, a drive shaft 60, a vehicle ECU (Electronic Control Unit) 91, an air conditioner ECU (air conditioner ECU) 92, a meter ECU 93, a motor generator (MG) 80, and an inverter 81. The battery device 3 includes a battery ECU 1, a storage battery 2 such as a lithium-ion battery, a temperature sensor 20, a current sensor 21, and a voltage sensor 22. The battery device 3 is, for example, a reusable battery pack.

[0010] The positive terminal 23a and the negative terminal 23b of the storage battery 2 are connected to the inverter 81, and the inverter 81 is connected to the motor generator 80. The storage battery 2 supplies power to the motor generator 80 during motor operation, and the power generated by the motor generator during generator operation is charged into the storage battery 2. The inverter 81 converts the DC current input from the storage battery 2 into a three-phase AC current and outputs it to the motor generator 80, and also converts the three-phase AC current input from the motor generator 80 into a DC current and outputs it to the storage battery 2.

[0011] The rotating shaft of the motor generator 80 is connected to the drive shaft 60 via the differential gear 6. Thereby, the motor generator 80 operates as a motor for driving the vehicle. Also, the motor generator 80 operates as a generator by means of regenerative braking.

[0012] The temperature sensor 20 detects the temperature of the storage battery 2. The current sensor 21 detects the input / output current of the storage battery 2. The voltage sensor 22 is connected between the positive terminal 23a and the negative terminal 23b and detects the voltage of the storage battery 2. The temperature sensor 20, the current sensor 21, and the voltage sensor 22 respectively output the detected values to the battery ECU 1.

[0013] The battery ECU 1 is an example of a battery control device. The battery ECU 1 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), etc. The battery ECU 1 operates the CPU according to a program stored in the ROM.

[0014] The battery ECU 1 has a control unit 10, a communication port 11, and a non-volatile memory 13 such as a flash memory. The control unit 10 is formed, for example, as a software function by a program, but may be hardware such as an electronic circuit. In the non-volatile memory 13, in-vehicle setting data 130 and stationary setting data 131 are stored. Note that, instead of the non-volatile memory 13, other storage devices such as a hard disk drive may be used.

[0015] Communication port 11 is an example of a communication unit. The communication port 11 is hardware such as an electronic circuit, for example. The communication port 11 communicates with a vehicle ECU 91, an air conditioner ECU 92, and a meter ECU 93 provided in the vehicle via a communication bus 90 in accordance with the CAN (Controller Area Network) standard. The vehicle ECU 91 controls an inverter 81 and the like. The air conditioner ECU 92 controls an air conditioner (not shown) of the vehicle. The meter ECU 93 controls various meters (not shown) of the vehicle. The communication port 11, the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 transmit and receive a frame FR, respectively. The frame FR includes a synchronization header HD and a plurality of data areas #1 to #n (n: an integer of 2 or more).

[0016] The communication port 11, the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 detect the head position of the frame FR on the time axis by the synchronization header HD, and detect the positions on the time axis of the plurality of time-division data areas #1 to #n based on the head position. The communication port 11, the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 insert communication data into a predetermined data area assigned in advance among the plurality of data areas #1 to #n, and acquire communication data from the area assigned to the communication partner. In this way, the communication port 11, the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 transmit and receive communication data such as commands and responses to each other.

[0017] The control unit 10 controls the charge and discharge of the storage battery 2. The control unit 10 acquires detection values of a temperature sensor 20, a current sensor 21, and a voltage sensor 22. The control unit 10 calculates the state of charge (SOC) of the storage battery 2 from each detection value. The control unit 10 transmits the SOC and control parameters regarding the charge and discharge of the storage battery 2 to the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93. The control parameters include an upper limit and a lower limit of the use voltage of the storage battery 2 (hereinafter, use voltage range) and an upper limit of the amount of electric power (Win, Wout) input to and output from the storage battery 2.

[0018] The vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 respectively control the inverter 81, the air conditioner, and the meter so that the storage battery 2 operates based on the control parameters received from the control unit 10. Thereby, the control unit 10 performs charge and discharge control of the storage battery 2.

[0019] When the battery device 3 is mounted on the vehicle, the control unit 10 reads out in-vehicle setting data 130 generated in advance based on the specifications of the vehicle from the non-volatile memory 13. The control unit 10 sets the usage voltage range of the in-vehicle storage battery 2 and the upper limits of Win and Wout based on the in-vehicle setting data 130. On the other hand, the stationary setting data 131 indicates the usage voltage range and the upper limits of Win and Wout generated in advance based on the specifications of the stationary power storage system, but is not used when the storage battery 2 is mounted on the vehicle.

[0020] Reference symbol G indicates an example of the in-vehicle setting data 130 and the stationary setting data 131. The in-vehicle setting data 130 used by the control unit 10 is indicated by a solid line, and the unused stationary setting data 131 is indicated by a dotted line. The in-vehicle setting data 130 is a set value corresponding to the specifications of the vehicle, and the stationary setting data 131 is a set value corresponding to the specifications of the stationary power storage system.

[0021] The usage voltage range Ea (V1a to V2a (V)) of the in-vehicle setting data 130 is narrower than the usage voltage range Eb (V1b to V2b (V)) of the stationary setting data 131. The in-vehicle usage voltage range Ea is set narrower than the stationary usage voltage range Eb so that, considering the regenerative power to the storage battery 2 due to sudden braking of the vehicle, the usage voltage of the storage battery 2 does not increase rapidly and exceed its limit value. Note that the usage voltage ranges Ea and Eb of the in-vehicle setting data 130 and the stationary setting data 131 may be defined by the SOC ranges corresponding to the usage voltage ranges Ea and Eb.

[0022] The upper limits P1a, P2a, P1b, and P2b of Wout and Win are set corresponding to the SOC. The upper limits P1a and P2a of Wout and Win in the in-vehicle setting data 130 are larger than the upper limits P1b and P2b of Wout and Win in the stationary setting data 131. Here, the upper limits P1a, P2a, P1b, and P2b are treated as absolute values of power (kW). The upper limits P1a and P2a of Wout and Win for in-vehicle use are set to higher values than the upper limits P1b and P2b of Wout and Win for stationary use because a large amount of power is required for driving the vehicle, etc. Thereby, when the storage battery 2 is for in-vehicle use, the control unit 10 can charge and discharge the storage battery 2 in a shorter time than when it is for stationary use.

[0023] In the range on the lower side of the SOC including 0 (%), the smaller the SOC, the smaller the upper limits P1a, P2a, P1b, and P2b. Also, in the range on the higher side of the SOC including 100 (%), the larger the SOC, the smaller the upper limits P1a, P2a, P1b, and P2b. Therefore, the progress of deterioration in the ranges on the lower and higher sides of the SOC where the storage battery 2 is likely to deteriorate is suppressed. Also, in other ranges of the SOC, the upper limits P1a, P2a, P1b, and P2b are substantially constant.

[0024] The control unit 10 performs vehicle-specific control corresponding to the vehicle on the storage battery 2 based on the in-vehicle setting data 130. However, when the battery device 3 is reused from the vehicle system 9a to the stationary power storage system, the storage battery 2 cannot be fully utilized due to differences in specifications if the vehicle-specific control is maintained. Therefore, when an abnormality occurs in the communication between the communication port 11 and the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93, the control unit 10 determines that the use of the storage battery 2 is for stationary use and switches the charge / discharge control from vehicle-specific control to stationary control. The configuration of the stationary power storage system is described below.

[0025] (Stationary Power Storage System) FIG. 2 is a configuration diagram showing an example of the stationary power storage system 9b. In FIG. 2, the components common to FIG. 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0026] The stationary power storage system 9b, as an example, charges the battery 2 with electric power from wind power generation, solar power generation, etc., and supplies power to household electrical appliances. The stationary power storage system 9b includes a reused battery device 3, a power conditioner ECU (power conditioner ECU) 95, and an inverter 82. The positive terminal 23a and the negative terminal 23b of the battery 2 are connected to the inverter 82, and the inverter 82 is connected to a power system 83 including a power generation system, electrical appliances, etc. The inverter 82 converts the DC current input from the battery 2 into a three-phase AC current and outputs it to the power system 83, and also converts the three-phase AC current input from the power system 83 into a DC current and outputs it to the battery 2.

[0027] The power conditioner ECU 95 controls the inverter 82, etc. The communication port 11 communicates with the power conditioner ECU 95 via a communication bus 94 according to the CAN standard. The communication between the communication port 11 and the power conditioner ECU 95 is performed by a frame FR in the same manner as in the case of the stationary power storage system 9b. The stationary power storage system 9b is not provided with a vehicle ECU 91, an air conditioner ECU 92, and a meter ECU 93 provided in the vehicle system 9a. Therefore, the communication port 11 detects communication errors with the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93. The communication error is an example of an abnormality in the communication of the communication port 11.

[0028] For example, when there is no data in the data areas respectively assigned to the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 in the frame FR, the communication port 11 detects a communication error. The communication port 11 notifies the control unit 10 of the communication error. Note that the communication port 11 does not detect a communication error for the power conditioner ECU 95.

[0029] When the control unit 10 receives a communication error notification for the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93, it switches the charge and discharge control of the storage battery 2 from vehicle control based on the in-vehicle setting data 130 to stationary control based on the stationary setting data 131. That is, the control unit 10 switches the setting data used for control from the in-vehicle setting data 130 to the stationary setting data 131 in response to a communication error of the communication port 11. The control unit 10 transmits the SOC and control parameters based on the stationary setting data 131 to the power converter ECU 95 via the communication port 11. The power converter ECU 95 controls the inverter 85 so that the storage battery 2 operates based on the control parameters received from the control unit 10. Thereby, the control unit 10 performs charge and discharge control of the storage battery 2.

[0030] Within the frame of the symbol G, the in-vehicle setting data 130 not used by the control unit 10 is indicated by a dotted line, and the used stationary setting data 131 is indicated by a solid line. The operating voltage range Eb of the stationary setting data 131 is wider than the operating voltage range Ea of the in-vehicle setting data 130. Specifically, the upper limit V2b of the operating voltage range for in-vehicle use is larger than the upper limit V2a of the operating voltage range for stationary use, and the lower limit V1b of the operating voltage range for in-vehicle use is smaller than the lower limit V1a of the operating voltage range for stationary use. For this reason, the battery device 3 can correspond to a wide range of voltages according to various generators and electrical devices in the power system 83.

[0031] Also, the upper limits P1b and P2b of Wout and Win of the stationary setting data 131 are smaller than the upper limits P1a and P2a of Wout and Win of the in-vehicle setting data 130. For this reason, over the entire range of the SOC, it is possible to suppress deterioration of the storage battery 2 by reducing the charge and discharge rate compared to the in-vehicle case.

[0032] In this way, the control unit 10 relaxes the limitation of the operating voltage of the storage battery 2 more than vehicle control according to the operating voltage range Eb, and reduces the charge and discharge rate of the storage battery 2 more than vehicle control according to the upper limits P1b and P2b of Wout and Win. For this reason, stationary control corresponding to the stationary power storage system 9b becomes possible.

[0033] Further, when an abnormality occurs in the communication between the communication port 11 and the PC ECU 95, the control unit 10 determines that the use of the storage battery 2 is for stationary use, and switches the charge / discharge control of the storage battery 2 from in-vehicle control to stationary control. For this reason, the battery ECU 1 does not require a changeover switch as described in the above Patent Document 1, and after the battery device 3 is reused in the stationary power storage system 9b, the charge / discharge control can be switched immediately and automatically. Therefore, the battery ECU 1 can easily switch the control of the storage battery 2 according to the use.

[0034] (Operation of Battery ECU) FIG. 3 is a flowchart showing an example of the operation of the battery ECU 1. After the battery ECU 1 is activated, the communication port 11 determines whether or not it has received the frame FR (step St1). If the frame has not been received (No in step St1), the process of step St1 is executed again.

[0035] Also, when the frame has been received (Yes in step St1), the communication port 11 determines the presence or absence of a communication error based on each data area assigned to the vehicle ECU 91, the air conditioner ECU 92, and the meter ECU 93 in the frame FR (step St2). When a communication error has occurred (Yes in step St2), the control unit 10 selects a stationary operation mode corresponding to the stationary power storage system 9b (step St3). Next, the control unit 10 reads the stationary setting data 131 from the nonvolatile memory 13 (step St4).

[0036] Also, when no communication error has occurred (No in step St2), the control unit 10 selects an in-vehicle operation mode corresponding to the vehicle system 9a (step St5). Next, the control unit 10 reads the in-vehicle setting data 130 from the nonvolatile memory 13 (step St6).

[0037] Next, the control unit 10 acquires the detection values of the temperature sensor 20, current sensor 21, and voltage sensor 22 (step St7). Next, the control unit 10 calculates the SOC of the storage battery 2 from the detection values (step St8). Next, the control unit 10 calculates the upper limits P1a, P2a, P1b, and P2b of Wout and Win corresponding to the SOC (step St9).

[0038] Next, the communication port 11 transmits the SOC and the control parameters (operating voltage range, upper limits P1a, P2a, P1b, and P2b of Wout and Win) (step St10). The transmission destinations are the power conditioner ECU 95 in the case of the stationary power storage system 9b, and the vehicle ECU 91, air conditioner ECU 92, and meter ECU 93 in the case of the vehicle system 9a. The communication port 11 inserts the SOC and the control parameters into the data area allocated within the frame FR. Note that, as the control parameters to be transmitted, the operating voltage range and the upper limits P1a, P2a, P1b, and P2b of Wout and Win are listed, but only one of them may be sufficient.

[0039] Next, the control unit 10 determines whether to stop the control, for example, according to a command from a higher-level system (step St11). If the control continues (No in step St11), the processes from step St7 and subsequent steps are executed again. If the control stops (Yes in step St11), this operation ends.

[0040] The above-described embodiments are preferred examples of the present invention. However, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0041] 1 Battery ECU (battery control device), 2 Storage battery, 3 Battery device, 9a Vehicle system, 9b Stationary power storage system, 10 Control unit, 11 Communication port, 13 Non-volatile memory, 91 Vehicle ECU, 92 Air conditioner ECU, 93 Meter ECU, 95 Power conditioner ECU, 130 In-vehicle setting data, 131 Stationary setting data

Claims

【Claim 1】 A control unit that controls charging and discharging of a storage battery, and a communication unit that communicates with an ECU provided in a vehicle on which the storage battery is mounted, and when an abnormality occurs in communication between the communication unit and the ECU, the control unit determines that the use of the storage battery is for stationary use, and switches the control of charging and discharging from vehicle control corresponding to the vehicle to control in which the voltage limit of the storage battery is relaxed from the vehicle control, or control in which the charging and discharging speed of the storage battery is reduced from the vehicle control. A battery control device.

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