JP7236787B2 - battery controller - Google Patents

Description

The present disclosure relates to battery control devices.

BACKGROUND ART Conventionally, an invention related to technology for controlling a battery is known (see Patent Document 1 below). The battery control device according to the conventional invention includes an internal resistance table in which the internal resistance value corresponding to the temperature and state of charge of the cell is described for each charge or discharge duration time of the cell. The battery control device calculates the maximum permissible charging current or maximum permissible discharging current of the cell using the internal resistance value described in the internal resistance table, and calculates the maximum permissible charging power or maximum permissible discharging power calculated according to the calculated value. By using it, the charging or discharging of the single cell is controlled (see Ibid., paragraph 0009, etc.).

According to the above-described conventional battery control device, even if the internal resistance of the unit battery changes as charging and discharging continues, the internal resistance value acquired from the internal resistance table is switched in accordance with the change, so that the change in internal resistance can be controlled. can follow. As a result, the allowable charge/discharge power can be obtained with high accuracy (see the same document, paragraph 0010, etc.).

Japanese Patent No. 5715694

The above-described conventional battery control device is capable of calculating the maximum power value during charging and discharging of the battery corresponding to the internal resistance value by setting an appropriate internal resistance value according to the conduction time of the current flowing through the battery. It is possible.

Here, it is assumed that the maximum power value during charge/discharge is defined as the power that can be continuously input to the battery for a predetermined number of seconds from the current time. In this case, the current value that can be continuously applied to the battery from the current time is calculated, the voltage when the battery is energized is calculated based on the current value, and the voltage and the calculated current that can be continuously applied to the battery are calculated. The maximum power value during charging and discharging is calculated by multiplying the value by

However, the calculated value and the measured value of the voltage of the battery at the time of energization may not match. In this case, when a secondary load corresponding to the maximum power value during charge/discharge calculated as described above is input to the battery, the calculated maximum current value that can be continuously applied to the battery will be excessively large. There is a risk that the current value will be energized to the battery.

The present disclosure provides a battery control device capable of calculating a maximum power value that does not allow excessive current to flow through the battery.

In one aspect of the present disclosure, the maximum current value of the battery and the calculated voltage value of the battery when the maximum current value is applied are calculated based on the internal resistance value of the battery, and the maximum current value and the calculated voltage value are calculated. and a first internal resistance value of the battery used for calculating the maximum current value and a first internal resistance value of the battery used for calculating the calculated voltage value The battery control device is characterized in that the two internal resistance values are different.

According to the above aspect of the present disclosure, it is possible to provide a battery control device capable of calculating a maximum power value that does not allow an excessive current to flow through the battery.

1 is a schematic diagram showing a configuration example of a power storage device of a hybrid vehicle according to Embodiment 1; FIG. FIG. 2 is an example of a circuit configuration of a cell control unit that configures the power storage device shown in FIG. 1; FIG. FIG. 2 is a functional block diagram of an assembled battery control unit that constitutes the power storage device shown in FIG. 1 ; FIG. 4 is a functional block diagram of a function for calculating a maximum power value during charging shown in FIG. 3; FIG. 4 is a functional block diagram of a function for calculating a maximum electric power value during discharging shown in FIG. 3; Graph showing an example of changes over time in battery voltage and internal resistance during a discharge test. 4 is a graph showing changes in internal resistance characteristics depending on the energization time of the battery; FIG. 5 is a graph showing an example of the maximum power value during charging calculated in FIGS. 3 and 4; FIG. The graph which shows an example of the maximum electric power value at the time of discharge calculated by FIG.3 and FIG.4. The graph explaining the problem of the battery control apparatus of a comparative example. The graph explaining the problem of the battery control apparatus of a comparative example. The graph explaining the problem of the battery control apparatus of a comparative example. 5 is a graph for explaining the operation of the assembled battery control unit shown in FIG. 4; 5 is a graph for explaining the operation of the assembled battery control unit shown in FIG. 4; FIG. 5 is a block diagram corresponding to FIG. 4 of an assembled battery control unit according to the second embodiment; FIG. 6 is a block diagram corresponding to FIG. 5 of an assembled battery control unit according to the second embodiment; An example of a voltage equivalent circuit model that reproduces the voltage behavior of a battery. A graph when a load equivalent to the maximum power during charging is continuously input to the battery. A graph when a load equivalent to the maximum power during charging is continuously input to the battery. A graph when a load equivalent to the maximum power during discharge is continuously input to the battery. A graph when a load equivalent to the maximum power during discharge is continuously input to the battery. Waveform when power equivalent to the maximum power during charging is input to the battery. Waveform when power equivalent to the maximum power during charging is input to the battery. Waveform when power equivalent to the maximum power during discharge is input to the battery. Waveform when power equivalent to the maximum power during discharge is input to the battery. FIG. 11 is a map loaded in a storage device in an assembled battery control unit according to the third embodiment; FIG. FIG. 16 is a block diagram corresponding to FIG. 15 of the assembled battery control unit according to the fourth embodiment;

Hereinafter, embodiments of a battery control device according to the present disclosure will be described with reference to the drawings.

As an example, an embodiment in which a battery control device according to the present disclosure is applied to a power storage device constituting a power source of a hybrid electric vehicle (HEV) will be described below. The configuration of the battery control device according to the following embodiments can also be applied to a power storage device control circuit of a power storage device that constitutes the power source of passenger cars such as HEVs and EVs and industrial vehicles such as hybrid railway vehicles.

In the following description, an example in which a lithium ion battery is applied to an electric storage device that constitutes an electric storage device will be described. Nickel-metal hydride batteries, lead batteries, electric double layer capacitors, hybrid capacitors, and the like can also be used as electric storage devices.

[Embodiment 1]
FIG. 1 is a schematic diagram showing a configuration example of a power storage device 100 for an HEV. Power storage device 100 is, for example, an HEV battery connected to inverter 300 via relay 200 . In addition, assembled battery control unit 150 and inverter 300 of power storage device 100 are connected to vehicle control unit 400 via signal lines. Further, inverter 300 is connected to motor generator 500 as an external load.

The power storage device 100 includes, for example, an assembled battery 110, a cell management unit 120, a current detection unit 130, a voltage detection unit 140, an assembled battery control unit 150, a communication path 160, an insulating element 170, and a storage device. 180 and a central processing unit 190 . Further, power storage device 100 configures a battery system including relay 200, for example.

The assembled battery 110 includes a plurality of cells 1 that are secondary batteries. The assembled battery 110 has, for example, a configuration in which a plurality of single cells 1 capable of storing and releasing electrical energy by charging and discharging of direct current are connected in series. Although the specifications of the individual cells 1 are not particularly limited, for example, the output voltage is approximately 3.0 [V] to approximately 4.2 [V], and the average output voltage is approximately 3.6 [V].

In the example shown in FIG. 1, the assembled battery 110 has a configuration in which a plurality of unit cells 1 are connected in series to form a battery group 111, and the plurality of battery groups 111 are connected in series. For convenience of illustration, FIG. 1 shows an example in which the assembled battery 110 includes two battery groups 111 connected in series, and each battery group 111 includes four cells 1 connected in series. there is However, the number of battery groups 111 included in the assembled battery 110, the method of connecting the battery groups 111 in series or parallel, and the number of cells 1 included in each battery group 111 are not particularly limited.

Each individual battery group 111 serves as a unit for state management and control of the cell 1, for example. Note that the plurality of battery groups 111 may be connected in parallel. Moreover, the number of cells 1 constituting the battery groups 111 may be the same in all the battery groups 111 or may be different in each battery group 111 .

In the example shown in FIG. 1, an assembled battery 110 includes a battery group 111 in which a plurality of single cells 1 are connected in series via bus bars, for example, and a plurality of battery groups 111 are connected in series via bus bars, for example. configuration. For convenience of illustration, FIG. 1 shows an example in which the assembled battery 110 includes two battery groups 111 connected in series, and each battery group 111 includes four cells 1 connected in series. there is However, the number of battery groups 111 included in the assembled battery 110, the method of connecting the battery groups 111 in series or parallel, and the number of cells 1 included in each battery group 111 are not particularly limited.

Each individual battery group 111 serves as a unit for state management and control of the cell 1, for example. Note that the plurality of battery groups 111 may be connected in parallel. Moreover, the number of cells 1 constituting the battery groups 111 may be the same in all the battery groups 111 or may be different in each battery group 111 .

The cell management unit 120 monitors and manages the states of the cells 1 that make up the assembled battery 110 . The unit cell management unit 120 has, for example, a function of determining or diagnosing overcharge or overdischarge of the unit cell 1, and a function of outputting an abnormality signal when a communication error or the like occurs. to the assembled battery control unit 150 . The cell management unit 120 includes, for example, multiple cell control units 121 .

The cell control unit 121 is provided for each cell control unit 121, for example. The cell control unit 121 monitors the state of each cell 1 forming the battery group 111 and controls each cell 1 . The cell control unit 121 operates by receiving power supply from the battery group 111 to be controlled, for example.

FIG. 2 is an example of a circuit configuration of the cell control unit 121 that constitutes the power storage device 100 shown in FIG. The cell control unit 121 includes, for example, a voltage detection circuit 121a, a temperature detection unit 121b, a control circuit 121c, and a signal input/output circuit 121d. Although not shown, the cell control unit 121 includes a circuit that equalizes variations in voltage among the cells 1 that occur due to self-discharge of the cells 1 and variations in current consumption. there is

The voltage detection circuit 121 a is a voltage sensor that measures the voltage of the cell 1 , and measures the voltage between the positive and negative external terminals of each cell 1 that constitutes the battery group 111 . Temperature detection unit 121b is a temperature detection circuit connected to a temperature sensor that measures the surface temperature of cell 1, for example. The surface temperature of the cell 1 measured by the temperature sensor can also be detected by the voltage detection circuit 121a.

Temperature detection unit 121b measures, for example, at least one temperature of battery group 111 as a whole, and outputs the temperature as a representative value of the temperature of unit cells 1 forming battery group 111 . Therefore, in the example shown in FIG. 2, the cell control unit 121 includes one temperature detection unit 121b. Note that the cell control unit 121 may have one temperature detection unit 121b for each cell 1 . However, in this case, the configuration of the cell control unit 121 becomes more complicated than when the single cell control unit 121 is provided with one temperature detection unit 121b.

The surface temperature of the cell 1 output from the temperature detection unit 121b is, for example, detected by the cell control unit 121 and the assembled battery control unit 150 as the cell 1, the battery group 111, or the assembled battery 110 (hereinafter simply referred to as "battery"). ) is used for various calculations to determine the state of Also, the surface temperature of the cell 1 output from the temperature detection unit 121b is used for various calculations by the central processing unit 190, for example.

The control circuit 121c receives the voltage value between the external terminals of the cell 1 output from the voltage detection circuit 121a and the measured value of the surface temperature of the cell 1 output from the temperature detection section 121b. The control circuit 121c outputs the input voltage value of each unit cell 1 and the measured value of the surface temperature of the unit cell 1 for each battery group 111 to the signal input/output circuit 121d. The signal input/output circuit 121d combines the voltage value of the cell 1 output from the control circuit 121c and the measured value of the surface temperature of the cell 1 for each battery group 111 via the communication path 160 and the insulating element 170. Output to battery control unit 150 .

As shown in FIG. 1, the current detection unit 130 is, for example, an ammeter or a current sensor that detects current flowing through the assembled battery 110 and measures the current value. Voltage detection unit 140 is, for example, a voltmeter or a voltage sensor that detects the overall voltage of assembled battery 110 and measures the voltage value.

The assembled battery control unit 150 is an embodiment of the battery control device according to the present disclosure, and calculates the maximum power value during charging and discharging of the battery to control the battery. The assembled battery control unit 150, for example, detects the state of the battery, manages the state of the battery, and controls the battery. More specifically, the assembled battery control unit 150 stores, for example, the voltage and temperature of the unit cells 1 output from the unit cell management unit 120, the current value flowing through the assembled battery 110 output from the current detection unit 130, the voltage Information such as the overall voltage value of the assembled battery 110 output from the detection unit 140 is input.

The assembled battery control unit 150 includes, for example, a central processing unit 190, and determines and detects the state of the battery based on the input information. The assembled battery control unit 150 outputs the determination result or the detection result of the battery state to the cell management unit 120 and the vehicle control unit 400 via the signal line.

Also, assembled battery control unit 150 uses information input by central processing unit 190 and information stored in storage device 180, for example, to appropriately control assembled battery 110, battery group 111, and unit cell 1. perform various calculations. Furthermore, the assembled battery control unit 150 outputs a calculation result and a command based on the calculation result to the cell management unit 120 and the relay 200 .

In addition, assembled battery control unit 150 is connected to cell management unit 120 via communication path 160 and insulating element 170 such as a photocoupler, for example, and transmits and receives signals to and from cell management unit 120 . The assembled battery control unit 150 receives, for example, determination results, diagnosis results, and abnormal signals output from the cell management unit 120 . Also, a signal from the storage device 180 and a signal from the vehicle control unit 400 are input to the assembled battery control unit 150, for example.

The battery pack control unit 150 and the cell management unit 120 have different operating power sources, for example. Specifically, assembled battery control unit 150 uses, for example, a 14 [V] system power supply for in-vehicle accessories, and cell management unit 120 uses, for example, assembled battery 110 as a power supply. Therefore, the assembled battery control unit 150 and the unit cell management unit 120 mutually transmit and receive signals via the insulating element 170 . Note that the insulating element 170 may be mounted on the circuit board that constitutes the cell management unit 120 or may be mounted on the circuit board that constitutes the assembled battery control unit 150 . Further, depending on the configuration of power storage device 100, insulating element 170 may be omitted.

Communication between the assembled battery control unit 150 and the plurality of cell control units 121 constituting the cell management unit 120 will be described in more detail. A plurality of cell control units 121 are connected in series, for example, like each battery group 111 . That is, the plurality of unit cell control units 121 are arranged from the unit cell control unit 121 having the highest potential of the battery group 111 to be monitored to the unit cell control unit 121 having the lowest potential of the battery group 111 to be monitored. They are connected in series in descending order of potential of the battery group 111 .

The information output from the battery pack control unit 150 is input to the unit cell control unit 121 in which the monitored battery group 111 has the highest potential via the communication path 160 and the insulating element 170 . Furthermore, the information output from the assembled battery control unit 150 and input to the unit cell control unit 121 having the highest potential of the monitored battery group 111 and the output of the unit cell control unit 121 are the next monitored batteries. It is input to the cell control unit 121 in which the potential of the group 111 is high.

By sequentially repeating this, information including information on all battery groups 111 is finally output from the cell control unit 121 with the lowest potential of the battery group 111 to be monitored, and is output via the communication path 160 and the insulating element 170. is input to the assembled battery control unit 150 . Communication between adjacent unit cell control units 121 can be performed, for example, via an insulating element 170 arranged between them.

In this manner, the assembled battery control unit 150 and the plurality of unit cell control units 121 are connected in a loop by the communication path 160, for example. This looped connection is sometimes called, for example, a daisy chain connection, a daisy chain connection, or a string connection.

The storage device 180 is configured by, for example, a memory such as a RAM or a ROM, a hard disk, or the like, and is provided outside the assembled battery control unit 150 in the example shown in FIG. Note that the storage device 180 may be mounted on a circuit board that constitutes the assembled battery control section 150 to constitute a part of the assembled battery control section 150 . Further, the storage device 180 may be mounted, for example, on each of the circuit boards that constitute the assembled battery control section 150 and the cell control section 121 .

Storage device 180 stores, for example, information on assembled battery 110 , each battery group 111 , and each single cell 1 . Specifically, for example, a limit value such as a current limit value of the assembled battery 110, and information on battery characteristics of the assembled battery 110, each battery group 111, and each unit cell 1 are stored.

Storage device 180 stores, for example, an arithmetic expression, a table, a graph, or a map for determining the state of charge (SOC) of the battery from the voltage value, current value, and temperature of cell 1 . In addition, the storage device 180, for example, from the voltage value, the current value and the temperature of the unit cell 1, arithmetic expression, table, graph or A map is stored. The calculation formulas and the like for obtaining these SOC and SOHR are well known, and therefore the description thereof is omitted.

Further, the storage device 180 stores, for example, various arithmetic expressions, maps, programs, and data used for arithmetic operations by the central processing unit 190 in various arithmetic functions of the assembled battery control unit 150, which will be described later. Various arithmetic expressions stored in the storage device 180 will be described in detail in the explanation of various arithmetic functions of the assembled battery control unit 150, which will be described later.

Central processing unit 190, as shown in FIG. 1, is mounted on, for example, a circuit board that constitutes assembled battery control unit 150, constitutes a part of assembled battery control unit 150, and is capable of information communication with storage device 180. It is connected. It should be noted that central processing unit 190 may be mounted, for example, on a circuit board that constitutes cell management unit 120 .

In addition, central processing unit 190 is connected, for example, via a signal line to current detection unit 130 , which is a current sensor that measures the current flowing through unit cell 1 , and obtains a current measurement value by current detection unit 130 . The central processing unit 190 is also connected to, for example, a voltage detection unit 140 that measures the voltage of the assembled battery 110 via a signal line, and acquires a voltage measurement value by the voltage detection unit 140 . The central processing unit 190 is also connected to, for example, an environmental temperature sensor (not shown) via a signal line, and acquires the environmental temperature around the cell 1 from the environmental temperature sensor.

Central processing unit 190 is also connected to cell control unit 121 via communication path 160 and insulating element 170, for example. Thereby, the central processing unit 190 acquires the voltage of each unit cell 1 constituting the battery group 111 measured by the voltage sensor provided in the unit cell control unit 121 . In addition, the central processing unit 190 acquires, for example, the measured value of the surface temperature of at least one unit cell 1 of each battery group 111 measured by a temperature sensor. The central processing unit 190 executes various calculations based on the information stored in the storage device 180 and the information obtained from the sensors and the like.

FIG. 3 is a functional block diagram of the assembled battery control section 150 shown in FIG. The assembled battery control unit 150 has, for example, a function F1 for detecting the battery state, a function F2 for calculating the maximum electric power value during charging, and a function F3 for calculating the maximum electric power value during discharging. Each functional block shown in FIG. 3 includes, for example, information input to assembled battery control unit 150, information and programs stored in storage device 180, central processing unit 190 that reads them and executes various processes, It can be realized by

As shown in FIG. 3, in the function F1 for detecting the battery state, the central processing unit 190 receives, for example, the voltage value, the current value, and the temperature of the cell 1, and calculates the arithmetic expression stored in the storage device 180. is used to calculate and output the SOC and SOHR of the battery. In the function F2 for calculating the maximum electric power value during charging and the function F3 for calculating the maximum electric power value during discharging, the central processing unit 190, for example, outputs SOC and SOHR output from the function F1 for detecting the battery state, and the unit The temperature of battery 1 is used as an input. Then, the central processing unit 190 calculates and outputs the maximum electric power value W _max,chg during charging in the function F2 for calculating the maximum electric power value during charging using the arithmetic expression or the like stored in the storage device 180, The function F3 for calculating the maximum electric power value during discharge calculates and outputs the maximum electric power value W _max,dis during discharge.

FIG. 4 is a functional block diagram of the function F2 for calculating the maximum power value during charging shown in FIG. The function F2 includes, for example, a function F21 for calculating the charging resistance for current calculation, a function F22 for calculating the charging resistance for voltage calculation, a function F23 for calculating the maximum current value during charging, and a function F23 for calculating the maximum current value during charging. It has a function F24 for calculating the voltage and a function F25 for calculating the maximum power value during charging.

In the function F21 that calculates the charging resistance for current calculation, the central processing unit 190 receives the SOC, temperature, and SOHR of the battery as inputs, and uses the following formula (1) and map stored in the storage device 180: , calculates and outputs the internal resistance value R _{chg_i} used to calculate the maximum current value during charging.

In addition, in the function F22 for calculating the charging resistance for voltage calculation, the central processing unit 190 receives the SOC, temperature, and SOHR of the battery as inputs, and uses the following formula (2), map, etc., stored in the storage device 180. is used to calculate and output the internal resistance value R _{chg_v} . This internal resistance value R _{chg_v} is used to calculate a predicted voltage value of the battery when a chargeable current is applied to the battery.

In addition, in the function F23 for calculating the maximum current value during charging, the central processing unit 190 receives the SOC of the battery and the internal resistance value R _{chg_i} that is the output of the function F21 for calculating the charging resistance for current calculation. . In addition, in this function F23, the central processing unit 190 receives an upper limit current value I _limit,chg , an upper limit voltage value V _max , and an open circuit voltage (OCV), which are not shown.

In this function F23, the central processing unit 190 receives the above information and uses the following formula (3) stored in the storage device 180 to calculate the maximum current value I _max.chg during charging. output. Upper limit current value Ilimit _,chg and upper limit voltage value _Vmax , which are inputs to function F23, are determined, for example, by materials of members constituting the battery system including power storage device 100 and relay 200, and the like. Also, OCV is the voltage observed when the battery is placed in a static state.

In addition, in the function F24 that calculates the calculated voltage value during charging, the central processing unit 190 calculates SOC, the internal resistance value R _{chg_v} for voltage calculation that is the output of the function F22, and the output of the function F23 during charging: Input the maximum current value I _max.chg . Then, in this function F24, the central processing unit 190 uses these inputs to calculate the calculated voltage value V _max,chg during charging based on the following formula (4) stored in the storage device 180. Output.

Further, in the function F25 for calculating the maximum power value during charging, the central processing unit 190 calculates the maximum current value I _max.chg during charging, which is the output of the function F23, and the calculated voltage during charging, which is the output of the function F24. Take the value V _max,chg as input. Then, in this function F25, the central processing unit 190 uses these inputs to calculate and output the maximum electric power value W _max,chg during charging based on the following formula (5). Note that in Expression (5), N is the number of cells 1 that constitute the assembled battery 110 .

As described above, in the function F2 for calculating the maximum power value during charging, the central processing unit 190 receives the SOC and SOHR output from the function F1 for detecting the battery state and the temperature of the single battery 1 as inputs and stores them. Using an arithmetic expression or the like stored in the device 180, the maximum electric power value Wmax _,chg during charging is calculated and output.

FIG. 5 is a functional block diagram of the function F3 for calculating the maximum power value during discharge shown in FIG. The function F3 for calculating the maximum power value during discharge includes, for example, a function F31 for calculating a discharge resistance for current calculation, a function F32 for calculating a discharge resistance for voltage calculation, and a function F32 for calculating a maximum current value during discharge. It has a function F33, a function F34 for calculating the calculated voltage value during discharge, and a function F35 for calculating the maximum power value during discharge.

In the function F31 that calculates the discharge resistance for current calculation, the central processing unit 190 inputs the SOC, temperature, and SOHR of the battery, and based on the following formula (6) and maps stored in the storage device 180, Calculates and outputs the internal resistance value R _{dis_i} used to calculate the maximum current value during discharge.

In addition, in the function F32 for calculating the discharge resistance for voltage calculation, the central processing unit 190 receives the SOC, temperature, and SOHR of the battery as inputs, and based on the following formula (7) and maps stored in the storage device 180, to calculate and output the internal resistance value _{Rdis_v} . This internal resistance value _{Rdis_v} is used to calculate a calculated voltage value, which is a voltage prediction value of the battery when the maximum current value during discharge is applied.

Also, in the function F33 for calculating the maximum current value during discharge, the central processing unit 190 stores the SOC of the battery, the internal resistance value R _{dis_i} that is the output of the function F31, and the values stored in the storage device 180 (not shown). Input the upper limit current value I _limit,dis and the lower limit voltage value V _min . Here, upper limit current value I _limit,dis and lower limit voltage value V _min are determined by materials of members constituting the battery system including power storage device 100 and relay 200 . Based on these inputs and the following formula (8) stored in the storage device 180, the central processing unit 190 calculates and outputs the maximum current value I _max.dis during discharge.

In addition, in the function F34 for calculating the calculated voltage value during discharge, the central processing unit 190 calculates the SOC of the battery, the internal resistance value R _{dis_v} that is the output of the function F32, and the maximum current during discharge that is the output of the function F33. Take the value I _max.dis as input. Based on these inputs and the following formula (9) stored in the storage device 180, the central processing unit 190 calculates and outputs the calculated voltage value V _max,dis during discharge.

Further, in the function F35 for calculating the maximum power value during discharge, the central processing unit 190 calculates the maximum current value I _max.dis output from the function F33 and the calculated voltage value V _max,dis output from the function F34. As an input, the maximum electric power value W _max,dis during discharge is calculated and output based on the following formula (10) stored in the storage device 180 . Note that in Expression (10), N is the number of cells 1 that constitute the assembled battery 110 .

As described above, in the function F3 for calculating the maximum electric power value during discharge, the central processing unit 190 receives the SOC and SOHR output from the function F1 for detecting the battery state and the temperature of the single battery 1 as inputs, and stores them. Using an arithmetic expression or the like stored in the device 180, the maximum electric power value W _max,dis during discharge is calculated and output.

Next, the map (ChgDCR_iMap) included in the formula (1), the map (ChgDCR_vMap) included in the formula (2), the map (DisDCR_iMap) included in the formula (6), and the formula (7) Describes the map (DisDCR_vMap) included in the . These maps of the internal resistance values of batteries are used for charging and discharging by varying conditions such as battery SOC and temperature, and inputting or outputting a pulse-shaped or step-shaped current to or from the battery for each condition. It can be created by conducting tests and acquiring data.

FIG. 6 is a graph showing an example of temporal changes in battery voltage and internal resistance during a discharge test in which the battery is discharged to output a step current. In FIG. 6, graph (a) is the time waveform of current, graph (b) is the time waveform of voltage, and graph (c) is the time waveform of internal resistance.

As shown in graph (a) of FIG. 6, when the current changes stepwise from a resting state of zero and the battery starts to discharge, the voltage drops stepwise as shown in graph (b) of FIG. As shown in graph (c) of FIG. 6, the internal resistance of the battery increases with the lapse of time after the battery starts to discharge. In this way, the internal resistance of the battery changes according to the time the battery is energized.

Therefore, when creating a map of the internal resistance of the battery, it is determined in advance whether to adopt the relationship between the voltage and the internal resistance when how much time has passed since the start of energization of the battery. Then, a map of the internal resistance value of the battery is created using the relationship between the plurality of voltages and the internal resistance value after a predetermined time has elapsed from the start of the energization of the battery.

FIG. 7 is a graph showing changes in internal resistance characteristics according to the energization time of the battery. In graphs (a) and (b) of FIG. 7, the horizontal axis is SOC and the vertical axis is internal resistance. , and the dotted line indicates the internal resistance characteristic for the temperature between them. Graph (a) in FIG. 7 shows internal resistance characteristics when the battery is energized for a relatively long time, and graph (b) in FIG. 7 shows the battery for a relatively short time. It shows the internal resistance characteristics when energized over a period of time.

As shown in FIG. 7, the lower the temperature of the battery, the higher the internal resistance of the battery. Also, the longer the energization time, the higher the internal resistance tends to be. Therefore, for the internal resistance values R _{chg_i} , R _{chg_v} , R _{dis_i} , and R _{dis_v} used in the process of power calculation in the above formulas (1) to (10), the internal resistance values corresponding to any one or more energization times , a map corresponding to the SOC and the temperature as shown in FIG.

In addition, since the OCV included in the above formulas (3), (4), (8), and (9) generally changes according to the SOC, data should be obtained in advance by experiment as in the case of the internal resistance characteristic map. to create a map corresponding to the SOC and store it in the storage device 180 .

FIG. 8 is a graph showing an example of the maximum electric power value W _max,chg during charging calculated by the function F2 shown in FIGS. 3 and 4 based on the formulas (1) to (5). The upper limit current value I _limit,chg , which is the input of the above equation (3), that is, the input of the function F23 that calculates the maximum current value during charging, is determined by the materials of the members constituting the battery system, etc., as described above. . When this upper limit current value I _limit,chg is a fixed value such as 200 [A], the tendency of the maximum power value W _max,chg during charging depends on which of the minimum values is selected in the above formula (3). It depends on whether

That is, in the first case where the maximum current value _Imax.chg during charging in Equation (3) is the upper limit current value _Ilimit,chg determined by the materials of the members constituting the battery system, the maximum current value during charging The tendency of the power value W _max,chg is shown in graph (a) of FIG. On the other hand, in the second case where the maximum current value I _max.chg during charging in Equation (3) is a current value defined by the upper limit voltage value V _max , the maximum power value W _max,chg during charging The trend is shown in graph (b) of FIG.

In the first case where the maximum current value _Imax.chg during charging is limited by the upper limit current value Ilimit _,chg, since the upper limit current value _Ilimit,chg is a fixed value, the maximum power value W during charging The magnitude of _max,chg is determined by the voltage when the upper limit current value _Ilimit,chg flows through the battery, that is, the magnitude of the calculated voltage value Vmax _,chg during charging calculated by the above equation (4). In the above formula (4), the higher the battery SOC, the higher the OCV, and the lower the battery temperature, the _higher the internal resistance value R _{chg_v} . increases as the temperature rises, and increases as the battery temperature decreases. Therefore, the maximum power value W _max,chg during charging calculated by the above formula (5) also increases as the SOC of the battery increases, as shown in the graph (a) of FIG. 8, and the battery temperature decreases. It tends to get bigger.

On the other hand, in the second case where the maximum current value I _max.chg during charging is limited by the upper limit voltage value V _max , the maximum current value I _max.chg during charging changes according to the SOC and temperature of the battery. Therefore, the maximum power value W max,chg during charging is determined by the maximum current value I _{max ,chg} during charging. Specifically, the higher the SOC, the higher the OCV and the smaller the maximum charging current value _{Imax.chg . .chg} tends to be smaller. Therefore, the maximum power value W _max,chg during charging calculated by the above formula (5) also decreases as the SOC of the battery increases, as shown in the graph (b) of FIG. 8, and the battery temperature decreases. It tends to get smaller.

FIG. 9 is a graph showing an example of the maximum electric power value W _max,dis during discharge calculated in FIGS. 3 and 4 based on the formulas (6) to (10). The maximum electric power value W _max,dis during discharge decreases as the SOC decreases. Further, as the temperature of the battery decreases, the internal resistance of the battery tends to increase and the maximum electric power value W _max,dis during discharge tends to decrease.

As described above, the assembled battery control unit 150 of the power storage device 100 controls the charging/discharging time for appropriately controlling the charging/discharging of the battery based on the input information and the information stored in the storage device 180 in advance. , SOC and SOHR calculations, and calculations for voltage equalization control. The assembled battery control unit 150 outputs these calculation results and commands based on the calculation results to the cell management unit 120 and the vehicle control unit 400 .

Inverter 300 is connected to power storage device 100 via relay 200, for example, as shown in FIG. Inverter 300 is also connected to vehicle control unit 400 . Vehicle control unit 400 controls inverter 300 based on the information output from assembled battery control unit 150 . In a vehicle equipped with power storage device 100 , power storage device 100 is connected to inverter 300 via relay 200 under the control of vehicle control unit 400 , for example. As a result, the motor generator 500 is driven by the electric energy stored in the cells 1 forming the assembled battery 110, and the vehicle runs. Further, regenerated electric power generated by motor generator 500 during braking of the vehicle is supplied to power storage device 1000 via inverter 300 and relay 200, and unit cells 1 forming assembled battery 110 are charged.

Hereinafter, the operation of the assembled battery control unit 150, which is one embodiment of the battery control device according to the present disclosure, will be described based on comparison with the conventional technology and a comparative example.

Conventionally, battery systems installed in electric vehicles (EV), plug-in hybrid vehicles (PHEV), hybrid vehicles (HEV), etc. consist of secondary batteries connected in series or in parallel, and the secondary batteries and a load. It has electrical components such as relays and current sensors for controlling the on/off of electrical connections. The battery system is equipped with a battery control device that limits the power or current applied from the secondary battery to the load, such as the motor, in the event that excessive use of the battery system is detected, in order to suppress a decrease in output due to deterioration of the secondary battery. ing.

In the battery system, limits are set on the voltage of the battery and the current flowing through the battery in order to use the secondary battery within an appropriate range. The limit values for the voltage of the battery, that is, the upper and lower voltage limits, and the limit value for the current, that is, the upper limit current value are set for the purpose of preventing overcharging of the secondary battery and suppressing the progress of deterioration. . These are important parameters for defining the maximum power value that can be charged to the secondary battery or the maximum power value that can be discharged from the secondary battery, that is, the maximum power value during charging and the maximum power value during discharging.

In addition to the above-described upper limit voltage value, lower limit voltage value, and upper limit current value of the secondary battery, the internal resistance of the secondary battery is used to calculate the maximum power value during charging and discharging of the secondary battery. The internal resistance of the secondary battery changes according to the time during which the current flows, that is, the energization time. Therefore, when specifying the real-time maximum power value during charge/discharge of a secondary battery, it is necessary to set an appropriate internal resistance that takes into account the charge/discharge pattern while the secondary battery is actually in operation. It is necessary to calculate the maximum power value at that time.

According to the conventional battery control device described in Patent Document 1, even if the internal resistance of the unit battery changes as charging and discharging continues, the internal resistance value obtained from the internal resistance table is switched according to the change. Therefore, changes in internal resistance can be followed. (See Id., paragraph 0010, etc.). In this conventional battery control device, by setting an appropriate internal resistance value according to the conduction time of the current flowing in the secondary battery, the maximum power value during charging and discharging of the secondary battery corresponding to the internal resistance value is controlled. It is possible to calculate

Here, the maximum power value during charging and discharging is defined as the power that can be continuously input to the secondary battery over a predetermined period of time from the current time. In this case, the current value that can be continuously applied to the secondary battery from the current time is calculated, the voltage when the secondary battery is energized is calculated based on the current value, and the voltage and the calculated continuous secondary battery are calculated. By multiplying by the current value that can be applied to the battery, the maximum power value during charging and discharging is calculated.

However, the calculated value and the measured value of the voltage of the secondary battery during energization may not match. In this case, when a load corresponding to the maximum power value during charging and discharging calculated as described above is input to the secondary battery, an excessively large current is applied to the calculated current that can be continuously applied to the secondary battery. A current value or an excessively small current value may flow to the secondary battery.

Here, for comparison with the assembled battery control unit 150 of the present embodiment, a battery control device of a comparative example corresponding to the prior art is assumed. In the battery control device of the comparative example, the internal resistance value R _{chg_i} for calculating the maximum current value I _max.chg during charging and the internal resistance value for calculating the calculated voltage value V _max,chg during charging shown in FIG. R _{chg_v} is the same internal resistance value, and the internal resistance value R _{dis_i} for calculating the maximum current value I _max.dis during discharging shown in FIG. 5 and the calculated voltage value V _{max, dis} during discharging is the same internal resistance value as the internal resistance value R _{dis_v} of . Problems of the battery control device of this comparative example will be described with reference to FIGS. 10 to 12. FIG.

FIG. 10 is a graph showing an example of temporal changes in power, current, internal resistance, and voltage during charging of a power storage device provided with a battery control device of a comparative example. In FIG. 10, graph (a) shows changes in power over time during charging of the battery, graph (b) shows changes over time in current flowing through the battery during charging, and graph (c) shows internal resistance of the battery during charging. , and graph (d) shows the time change of the voltage of the battery during charging.

In the power storage device provided with the battery control device of the comparative example, when charging is started from the battery resting state, the SOC of the battery changes, so that the maximum power value during charging changes over time. Therefore, in FIG. 10, it is assumed that the calculated power value that changes with the passage of time is directly input to the battery. Also, as shown in FIG. 8, the behavior of the maximum power value during charging changes depending on which current value is selected as the minimum value in the above formula (3). Therefore, in _FIG . 10, the power _, current, Behavior of internal resistance value and voltage is shown.

In the first case where the maximum current value _Imax.chg during charging is limited by the upper limit current value Ilimit _,chg , the maximum power value during charging increases as the SOC rises. As the SOC rises, the maximum power value during charging also tends to increase, as shown in graph (a) of FIG. At this time, since the upper limit current value I _limit,chg during charging determined by the components of the battery system is a fixed value, the calculated maximum current value I _{max during charging indicated by the dotted line in the graph (b) of FIG. chg} becomes a fixed value.

However, as indicated by the solid line in the graph (b) of FIG. 10, the value of the current actually flowing through the battery, when energization is started from the resting state, is the calculated maximum current value _Imax during charging indicated by the dotted line. It greatly exceeds _.chg , decreases with the lapse of time, and converges to the calculated maximum current value _Imax.chg during charging. The reason why such a phenomenon occurs is as follows.

The actual internal resistance value of the battery indicated by the solid line in the graph (c) of FIG. 10 is the minimum value at the start of energization of the battery, and increases with the lapse of time. Therefore, the actual battery voltage value indicated by the solid line in the graph (d) of FIG. 10 is also the minimum value at the start of energization of the battery, and increases with the lapse of time.

In the battery control device of the comparative example, the internal resistance value of the battery used for voltage calculation is the actual battery resistance at the time when a predetermined time has passed since the start of charging, as indicated by the dotted line in the graph (c) of FIG. Fixed to the internal resistance value. Therefore, the actual internal resistance value of the battery indicated by the solid line in the graph (c) of FIG. be smaller than

Therefore, when the charging of the battery is started at the maximum power value during charging calculated based on the internal resistance value for calculation indicated by the dotted line in graph (c) of FIG. 10, the solid line in graph (b) of FIG. The actual current value indicated by , greatly exceeds the maximum current value I _max.chg indicated by the dotted line. The maximum power value during charging based on the value of the current flowing at this time is given by the following formula (11).

In Equation (11), the right side of the upper row is the maximum power value during charging calculated by the battery control device of the comparative example, and the maximum current value I _max.chg indicated by the dotted line in the graph (b) of FIG. 10 includes an internal resistance value R _{chg_v} for voltage calculation indicated by a dashed line. The right side of the lower row, which is equal to the right side of the upper row, shows the actual current value I _max.chg′ indicated by the solid line in the graph (b) of FIG. 10 and the actual internal resistance indicated by the solid line in the graph (c) of FIG. It contains the value R _{chg_v'} .

According to this formula (11), when the internal resistance value R _{chg_v} for voltage calculation indicated by the dashed line in the graph (c) of FIG. 10 is greater than the actual internal resistance value R _{chg_v′} indicated by the solid line, the graph (b) of FIG. , the current value I _max.chg′ indicated by the solid line is greater than the maximum current value I _max.chg indicated by the dotted line. However, after a predetermined period of time has elapsed, the actual internal resistance value R _{chg_v′} indicated by the solid line converges to the internal resistance value R _{chg_v} for voltage calculation indicated by the dashed line in the graph (c) of FIG. In b), the current value I _max.chg′ indicated by the solid line coincides with the maximum current value I _max.chg indicated by the dotted line.

FIG. 11 is a graph showing an example of temporal changes in power, current, internal resistance, and voltage during charging of a power storage device provided with a battery control device of a comparative example. In FIG. 11, graph (a) shows the time change of the electric power during charging of the battery, graph (b) shows the time change of the current flowing through the battery during charging, and graph (c) shows the internal resistance of the battery during charging. , and graph (d) shows the time change of the voltage of the battery during charging.

FIG. 10 shows the _first case in which the maximum current value I _max.chg during charging is limited by the upper limit current value I _limit,chg. is limited by the upper limit voltage value V _max , the behavior of power, current, internal resistance value, and voltage. As described above, in the power storage device including the battery control device of the comparative example, when the battery starts to be energized from the resting state, the SOC of the battery changes, so that the maximum power value during charging changes from moment to moment. . Therefore, also in FIG. 11, it is assumed that the calculated power value that changes with the passage of time is directly input to the battery.

In the second case where the maximum current value _Imax.chg during charging is limited by the upper limit voltage value _Vmax , as shown in the graph (a) of FIG. , the maximum power value during charging decreases. Similarly, as shown in graph (b) of FIG. 11, the current value decreases as the SOC of the battery increases during charging. Even in the second case where the maximum current value _Imax.chg during charging is limited by the upper limit voltage value _Vmax , as shown in the graph (c) of FIG. The internal resistance of the actual battery indicated by is smaller than the internal resistance of the calculation battery indicated by the dotted line. Therefore, in the graph (b) of FIG. 11, the current value that actually flows through the battery indicated by the solid line is higher than the maximum current value I _max.chg during charging indicated by the dotted line in the graph (b) of FIG. growing.

As described above, in the power storage device including the battery control device according to the comparative example, if the internal resistance value used for calculating the voltage of the battery differs from the actual internal resistance value of the battery, the current flowing through the battery is The maximum current value I _max.chg during charging may be exceeded. In particular, in the first case, the phenomenon of exceeding the upper limit current value I _limit,chg during charging, which is determined by the constraints of the components of the battery system, may affect the safety and durability of the battery system. .

Next, the behavior of the power storage device provided with the battery control device of the comparative example when power corresponding to the maximum power value during discharge is output will be described with reference to FIG. 12 . In FIG. 12 as well, similarly to FIGS. 10 and 11, a description will be made on the assumption that the calculated value of the maximum electric power value during discharge, which changes with the passage of time, is directly output from the battery. Also, during discharging, the actual internal resistance of the battery at the time when a predetermined time has passed since the start of discharge is used as a fixed value as the internal resistance for calculating the current and voltage, and calculation is performed based on this internal resistance for calculation. It is assumed that the maximum electric power value is discharged at the time of discharge.

During discharge, the maximum power value during discharge decreases as the SOC decreases. At this time, as indicated by the solid line in the graph (b) of FIG. 11, the value of current actually flowing through the battery decreases over time. During discharging, unlike during charging, in the graph (b) of FIG. 12, the absolute value of the current actually flowing through the battery indicated by the solid line is smaller than the absolute value of the maximum current value during discharging indicated by the dotted line. . Since the current value during discharge is a negative value, the current values are compared here according to the magnitude of the absolute value of the current value. In this way, in the graph (b) of FIG. 12, the absolute value of the current actually flowing through the battery indicated by the solid line is smaller than the absolute value of the maximum current value during discharge indicated by the dotted line for the following reason. for a reason.

In the battery control device of the comparative example, the internal resistance value for calculation indicated by the dotted line in the graph (c) of FIG. 12 is fixed to the actual internal resistance of the battery after a predetermined period of time has elapsed. Therefore, the internal resistance value for calculation indicated by the dotted line becomes larger than the actual internal resistance value of the battery indicated by the solid line until a predetermined time elapses from the start of discharging of the battery. In this case, as shown in the graph (b) of FIG. 12, when the battery is discharged at the maximum power value during discharge calculated using the internal resistance value for voltage calculation, the actual power flowing to the battery indicated by the solid line is The absolute value of the current value is smaller than the absolute value of the maximum current value during the calculation indicated by the dotted line. The maximum power value at the time of discharge based on the value of the current flowing at this time is given by the following formula (12).

In equation (12), the right side of the upper row is the maximum power value during discharge calculated by the battery control device of the comparative example, and the current value I _max.dis for calculation indicated by the dotted line in the graph (b) of FIG. , the graph (c) of FIG. 12 includes an internal resistance value R _{dis_v} for calculation indicated by a dashed line. In addition, on the right side of the lower row, which is equal to the right side of the upper row, the current value I _max.dis' indicated by the solid line in the graph (b) of FIG. 12 and the actual internal resistance value R indicated by the solid line in the graph (c) of FIG. _{dis_v'} is included.

According to this formula (12), when the internal resistance value R _{dis_v} for calculation indicated by the broken line in the graph (c) of FIG. 12 is greater than the actual internal resistance value R _{dis_v} indicated by the solid line, the solid line It can be seen that the absolute value of the current value I _max.dis′ indicated by is smaller than the absolute value of the current value I _max.dis for calculation indicated by the dotted line. However, after a predetermined time has passed, the internal resistance value R _{dis_v} for voltage calculation indicated by the broken line in the graph (c) _of FIG. In b), the current value I _max.dis′ indicated by the solid line matches the current value I _max.dis for calculation indicated by the dotted line.

Thus, in the battery control device of the comparative example, the current value actually flowing through the battery during discharging is smaller than the absolute value of the maximum current value during discharging, unlike during charging described above. Therefore, in the battery control device of the comparative example, the internal resistance value for calculation is fixed to the actual internal resistance of the battery at the time when the predetermined time has elapsed during discharge, thereby increasing safety. there is Therefore, in the following, in the battery control device of the comparative example, the assembled battery control unit, which is an embodiment of the battery control device according to the present disclosure, will be focused on the charging of the battery in which the current value flowing through the battery exceeds the maximum current value. 150 will be explained.

As described above, the assembled battery control unit 150 _{of the} present embodiment controls the maximum current _value I _max.chg ( _or I _max.dis ) and the calculated voltage value V _max,chg (or V _max,dis ) of the battery when the maximum current value is applied, and the maximum power value W _max of the battery based on the maximum current value and the calculated voltage value _,chg (or Wmax _,dis ). Then, the assembled battery control unit 150 calculates the first internal resistance value R _{chg_i} (or R _{dis_i} ) of the battery and _the calculated voltage _value V _max,chg (or V _max,dis ) is different from the second internal resistance value R _{chg_v} (or R _{dis_v} ) used for calculation.

13 and 14 are graphs for explaining the action of the assembled battery control unit 150 of this embodiment. In FIG. 13, graph (a) shows the change in power over time during charging of the battery, graph (b) shows change over time in the current flowing through the battery during charging, and graph (c) shows the internal resistance of the battery during charging. , and graph (d) shows the time change of the voltage of the battery during charging. The graph of FIG. 13 will be described below, focusing on differences from the graph of the battery control device of the comparative example shown in FIG. 11 .

First, as indicated by the dotted line in the graph (c) of _{FIG .} For example, it is set to the internal resistance value at or immediately after the start of energization of the battery indicated by the solid line. Therefore, in the graph (b) of FIG. 13, the current value that actually flows through the battery at the moment power is input to the battery indicated by the solid line matches the maximum current value I _max.chg indicated by the broken line. That is, in the graph (c) of FIG. 13, the internal resistance value R _{chg_v} for voltage calculation indicated by the dotted line coincides with the actual internal resistance value R _{chg_v′} indicated by the solid line when the battery starts to be energized. The current value actually flowing through the battery indicated by the solid line in (b) coincides with the maximum current value I _max.chg indicated by the dotted line.

After the maximum current value I _max.chg flows through the battery at the moment power is input to the battery, the internal resistance of the battery indicated by the solid line in graph (c) of FIG. It becomes larger than the internal resistance value R _{chg_v} for calculation. That is, in the above formula (11), the actual internal resistance value R _{chg_v′} is greater than the internal resistance value R _{chg_v} for voltage calculation, so the current flowing through the battery is , is smaller than the maximum current value I _max.chg .

As described above, according to the assembled battery control unit 150 of the present embodiment, the first internal resistance value R chg_i of the battery used to calculate the maximum current value I _max.chg and the first internal resistance value R _{chg_i} used to calculate the calculated voltage value V _max,chg By making the second internal resistance value R _{chg_v} different and setting the second internal resistance value R _{chg_v} to the internal resistance value of the battery at the moment power is input to the battery or immediately after that, an excessive current in the battery can be prevented. It is possible to calculate the maximum power value W _max,chg that is not energized. Here, immediately after is a sampling period of a sensor that measures voltage, current, and the like, for example.

Next, with reference to FIG. 14, the action of the assembled battery control unit 150 of the present embodiment in the second case where the maximum current value _Imax.chg during charging is limited by the upper limit voltage value _Vmax will be described. . In FIG. 14, graph (a) shows the time change of the electric power during charging of the battery, graph (b) shows the time change of the current flowing through the battery during charging, and graph (c) shows the internal resistance of the battery during charging. , and graph (d) shows the time change of the voltage of the battery during charging.

This second case is basically the same as the first case, and in the graph (c) of _FIG . Matches the resistance value R _{chg_v'} . Therefore, the current value actually flowing through the battery indicated by the solid line in the graph (b) of FIG. 14 becomes equal to the maximum current value I _max.chg indicated by the dotted line at the start of energization of the battery and immediately thereafter. After that, as shown in the graph (c) of FIG. 14, the actual internal resistance value R _{chg_v′} indicated by the solid line becomes larger than the internal resistance value R _{chg_v} for voltage calculation indicated by the dotted line.

Therefore, the current value actually flowing through the battery indicated by the solid line in the graph (b) of FIG. 14 is smaller than the maximum current value I _max.chg indicated by the dotted line. Therefore, according to the assembled battery control unit 150 of the present embodiment, the first internal resistance value R chg_i of the battery used to calculate the maximum current value I _max.chg and the second internal resistance value R _{chg_i} used to calculate the calculated voltage value V _max,chg By setting the second internal resistance value R _{chg_v} to the internal resistance value of the battery at the moment power is input to the battery or _immediately after that, an excessive current is passed through the battery. It is possible to calculate the maximum power value W _max,chg that is not used.

In the assembled battery control unit 150 of the present embodiment, by setting the second internal resistance value R _{chg_v} to the internal resistance value of the battery at the moment power is input to the battery or immediately after that, the maximum current value I _{max.chg and the second internal resistance value R chg_v used} for calculating the calculated voltage value V _max,chg were made different from each other. As a result, as shown in FIGS. 13 and 14, it is possible to calculate the maximum power value W _max,chg at which an excessive current does not flow through the battery.

Also, in the assembled battery control unit 150 of the present embodiment, data such as current and voltage are sampled at a control cycle ranging from about 100 [msec] to about 10 [msec], for example. Therefore, the internal resistance value of the battery that appears at the moment power is input to the battery is determined by the acquired data of the current and voltage one control cycle, that is, one sampling cycle, and the current acquired data. The internal resistance seen at this time is equal to the internal resistance value seen one sampling period after the pulse or step power is input to the battery. Therefore, in actual operation, the internal resistance value corresponding to the sampling period, for example, the internal resistance visible 100 [msec] after the power input can be used as the internal resistance value R _{chg_v} for voltage calculation.

Note that in the assembled battery control unit 150 of the present embodiment, the first internal resistance value R _{chg_i} is the internal resistance value of the battery when the first time elapses from the start of energization of the maximum current value I _max.chg to the battery. and the second internal resistance value R _{chg_v} is set to the internal resistance value of the battery when a second period of time shorter than the first period of time has elapsed from the start of energization. Specifically, for example, the second time can be the sampling cycle, and the first time can be a predetermined time longer than the sampling cycle.

As described above, according to the present embodiment, it is possible to provide the assembled battery control unit 150, which is a battery control device, capable of calculating the maximum power value W _max,chg that does not allow an excessive current to flow through the battery. can.

[Embodiment 2]
Embodiment 2 of the battery control device according to the present disclosure will be described below with reference to FIGS. 1 to 3 and FIGS. 15 to 25 .

In the assembled battery control unit 150 of Embodiment 1 described above, the first internal resistance values R _{chg_i} and R _{dis_i} of the battery used to calculate the maximum current values I _max.chg and I _max.dis and the maximum current value I _max The second internal resistance values R _{chg_v} and R _{dis_v} used for calculating the calculated voltage values _{V max,chg} and V _max,dis of the battery when .chg and I _max.dis are energized are set to different values, and continuously The maximum current values I _max.chg and I _max.dis during charging and discharging calculated during normal charging are not exceeded. In the assembled battery control unit 150 of the present embodiment, in addition to the above-described Embodiment 1, an arithmetic expression that considers the history of charging and discharging up to the current time (polarization voltage generated by charging and discharging up to the previous time) is applied. do.

More specifically, the assembled battery control unit 150 of the present embodiment differs from that of the first embodiment in the arithmetic functions of the storage device 180 and the central processing unit 190 . Other points of the assembled battery control unit 150 of the present embodiment are the same as those of the above-described embodiment, so the same parts are given the same reference numerals and the description thereof is omitted.

FIG. 15 is a block diagram of the function F2' for calculating the allowable power during charging of the assembled battery control unit 150 of the present embodiment, which corresponds to FIG. 4 of the first embodiment. In place of the functions F21 and F22 shown in FIG. 4, the assembled battery control unit 150 of the present embodiment has a function F21′ for calculating the parameters of the charge equivalent circuit for current calculation, and a function F21′ for calculating the parameters of the charge equivalent circuit for voltage calculation. is provided with a function F22' for calculating

As shown in FIG. 15, the function F21' for calculating the parameters of the charging equivalent circuit for current calculation receives the battery SOC, SOHR, temperature, and continuous conduction time t_cur for current calculation as inputs, and calculates the maximum current value. output the internal resistance value R _{chg_i} and the polarization voltage V _{p_i} . The function F22' for calculating the parameters of the charge equivalent circuit for voltage calculation receives the battery SOC, SOHR, temperature, and the continuous conduction time t_vol for voltage calculation, and calculates the internal resistance value R _{chg_v} for calculation of the calculated voltage value. , the polarization voltage V _{p_v} is output.

Furthermore, the function F23' for calculating the maximum current value during charging receives the internal resistance value R _{chg_i} output from the function F21' and the polarization voltage V _{p_i} as inputs, and outputs the maximum current value I _max,chg during charging. do. A function F24' for calculating the calculated voltage during charging receives the internal resistance value R _{chg_v} output from the function F22' and the polarization voltage V _{p_v} , and outputs the calculated voltage value V _max,chg during charging. The function F25′ for calculating the maximum power during charging receives the maximum current value I _max,chg output from the function F23′ and the calculated voltage value V _max,chg output from the function F24′, Output the maximum power value W _max,chg .

First, referring to FIG. 17, the charge/discharge history of the battery, that is, the method of calculating the polarization voltage will be described. FIG. 17 is an example of a voltage equivalent circuit model, that is, a voltage model M that reproduces the voltage behavior of the battery. Voltage model M is stored in storage device 180, for example. In the voltage model M, the electromotive force component simulating the OCV of the battery is represented by Ro, which is the ohmic resistance component of the battery material that does not depend on time, and the polarization resistance Rp, which simulates the polarization voltage _Vp that changes with time. and capacitor C are connected in series. 17, τ is the polarization time constant component in the parallel circuit of the polarization resistor Rp and the capacitor C. In FIG.

The battery voltage (Closed Circuit Voltage: CCV) based on the voltage model M shown in FIG. 17 is represented by the following formulas (13) and (14).

OCV, Ro, Rp, and τ included in formulas (13) and (14) are extracted in advance from charge/discharge test results using batteries as maps corresponding to SOC and temperature, and stored in storage device 180, for example. Implement. This makes it possible to compute the real-time voltage behavior during charging and discharging of the battery based on equations (13) and (14). In Expression (14), _{Vp_z} indicates the polarization voltage one control cycle before, and ts indicates the control cycle.

The polarization voltage V _p in FIG. 17 and equation (14) indicates a voltage component that can be generated by charging and discharging the battery up to this point. By using this polarization voltage _Vp to calculate the maximum power during charging and discharging, which will be described later, the maximum power during charging and discharging is calculated in consideration of the voltage history up to the present time. Hereinafter, an example of calculating the maximum electric power during charging will be described based on FIG. 17 and Equations (13) and (14).

In the function F21′ for calculating the parameters of the charge equivalent circuit for current calculation, the central processing unit 190 receives the battery SOC, SOHR, temperature, and continuous energization time t_cur for current calculation, as described above, and stores them. Based on the following formulas (15) to (17) stored in the device 180, the internal resistance value R _{chg_i} and the polarization voltage V _{p_i} are calculated. Here, the polarization voltage V _{p_i} is the polarization voltage after the elapse of time corresponding to the continuous energization time t_cur of the polarization voltage V _p generated up to the present time.

Here, Rp(SOC,T) and τ(SOC,T) included in Equation (16) are represented by Equations (18) and (19) below.

In the function F22' for calculating the parameters of the charge equivalent circuit for voltage calculation, the central processing unit 190 receives SOC, temperature, SOHR, and energizable time t_vol for voltage calculation. Then, the central processing unit 190 outputs the internal resistance value R _{chg_v} and the polarization voltage V _{p_v} based on the above inputs and the following formulas (20) and (21). Here, the central processing unit 190 calculates the polarization voltage _{Vp_v} after the elapse of time corresponding to t_vol of the polarization voltage Vp generated up to the present time calculated by the above formula (16) stored in the storage device 180.

In the function F23' that calculates the maximum current value during charging, the central processing unit 190 receives the internal resistance value R _{chg_i} and the polarization voltage V _{p_i} output from the function F21', and the SOC. Further, the central processing unit 190 receives as input the upper limit current value I _limit,chg and the upper limit voltage value V _max that are determined from the components of the battery system (not shown). Also, the central processing unit 190 calculates the maximum current value I _max,chg during charging based on these inputs and the following equation (22) stored in the storage device 180 .

In the function F24′ that calculates the calculated voltage during charging, the central processing unit 190 calculates the SOC, the internal resistance value R _{chg_v} and the polarization voltage V _{p_v} that are the outputs of the function F22′, and the maximum current value that is the output of the function F23′. Let I _max,chg be the input. Then, the central processing unit 190 calculates the calculated voltage value V _max,chg during charging based on these inputs and the following formula (23) stored in the storage device 180 .

In the function F25′ for calculating the maximum electric power during charging, the central processing unit 190 calculates the maximum current value I _max,chg during charging, which is the output of the function F23′, and the calculated voltage value during charging, which is the output of the function F24′. Let V _max,chg be the input. Then, the central processing unit 190 outputs the maximum electric power value W _max,chg during charging based on these inputs and the following formula (24) stored in the storage device 180 . In Expression (24), N indicates the number of unit cells 1 that constitute power storage device 100 .

FIG. 16 is a block diagram of a function F3' for calculating the maximum electric power during discharge of the assembled battery control unit 150 of the present embodiment, which corresponds to FIG. 5 of the first embodiment. Instead of the functions F31 and F32 shown in FIG. 5, the assembled battery control unit 150 of the present embodiment has a function F31′ for calculating the parameters of the discharge equivalent circuit for current calculation and the parameters of the discharge equivalent circuit for voltage calculation. is provided with a function F32' for calculating

As shown in FIG. 16, the function F31' for calculating the parameters of the discharge equivalent circuit for current calculation receives the battery SOC, SOHR, temperature, and continuous conduction time t_cur for current calculation as inputs, and calculates the maximum current value. output the internal resistance value R _{dis_i} and the polarization voltage V _{p_i} . The function F32' for calculating the parameters of the discharge equivalent circuit for voltage calculation receives the SOC, SOHR, temperature of the battery, and the continuous conduction time t_vol for voltage calculation, and calculates the internal resistance value R _{dis_v} for calculation of the calculated voltage value. , the polarization voltage V _{p_v} is output.

Furthermore, the function F33' for calculating the maximum current value during discharge receives the internal resistance value _{Rdis_i} , which is the output of the function F31', and the polarization voltage _{Vp_i} , and outputs the maximum current value _Imax,dis during discharge. do. A function F34' for calculating the calculated voltage during discharge receives the internal resistance value _{Rdis_v} and the polarization voltage _{Vp_v} output from the function F32', and outputs the calculated voltage value Vmax _,dis during discharge.

In the function F31' for calculating the parameters of the discharge equivalent circuit for current calculation, the central processing unit 190 receives the battery SOC, SOHR, temperature, and continuous conduction time t_cur for current calculation as described above. Furthermore, the central processing unit 190 calculates an internal resistance value R _{dis_i} based on these inputs and the following formula (25) stored in the storage device 180 . Further, the central processing unit 190 calculates the polarization voltage V _{p_i} after the elapse of time corresponding to t_cur of the polarization voltage V _p generated up to the present time based on the above equation (17).

In the function F32' for calculating the parameters of the discharge equivalent circuit for voltage calculation, the central processing unit 190 receives the SOC, the temperature, the SOHR, and the energization time t_vol for voltage calculation. Then, the central processing unit 190 outputs the internal resistance value R _{dis_v} based on the above input and the following formula (26) stored in the storage device 180 . Here, the central processing unit 190 calculates the polarization voltage V _{p_v} after the elapse of time corresponding to t_vol of the polarization voltage Vp generated up to the present time calculated by the above equation (16) based on the above equation (21). .

In the function F33' that calculates the maximum current value during discharge, the central processing unit 190 receives the internal resistance value _{Rdis_i} , the polarization voltage _{Vp_i} , and SOC output from the function F31'. In addition, the central processing unit 190 receives as input the upper limit current value I _limit,dis and the lower limit voltage value V _min determined from the components of the battery system (not shown). Further, the central processing unit 190 calculates the maximum current value I _max,dis during discharge based on these inputs and the following equation (27) stored in the storage device 180 .

In the function F34′ for calculating the calculated voltage during discharge, the central processing unit 190 calculates the internal resistance value R _{dis_v} and the polarization voltage V _{p_v} that are the outputs of the function F32′, the maximum current value I _{max that is the output of the function F23′,} Let _dis be the input. Then, the central processing unit 190 calculates the calculated voltage value V _max,dis during discharge based on these inputs and the following formula (28) stored in the storage device 180 .

In the function F35′ for calculating the maximum power during discharge, the central processing unit 190 calculates the maximum current value I _max,dis during discharge, which is the output of the function F33′, and the calculated voltage value during discharge, which is the output of the function F34′. Let V _max,dis be the input. Then, the central processing unit 190 outputs the maximum electric power value W _max,dis during discharge based on these inputs and the following formula (29) stored in the storage device 180 . In Expression (29), N indicates the number of unit cells 1 that constitute power storage device 100 .

Next, regarding the maximum power during charging or discharging calculated based on the above formula (24) or (29), problems of the battery control device according to the comparative example and effects of the assembled battery control unit 150 of the present embodiment are shown. 18 to 25 for explanation.

As described in the above embodiment, the battery control device according to the comparative example energizes the battery with a pulse current or step current, and measures the internal resistance of the battery when a predetermined time elapses as an internal resistance for current calculation. Used as an internal resistance for resistance and voltage calculations. This corresponds to setting the energization time t_cur for current calculation and the energization time t_vol for voltage calculation to the same value in the present embodiment.

18 to 21 show graphs when the load corresponding to the maximum power during charging and the maximum power during discharging, which are sequentially calculated, are continuously input to the battery in the same manner as in the first embodiment described above. show. In each figure, graph (a) shows time change of power, graph (b) shows time change of current, and graph (c) shows time change of voltage.

FIG. 18 shows the first case in which the maximum current value I _max.chg during charging is limited by the upper limit current value I _{limit,chg, and} FIG. 19 shows the maximum current value I _max.chg during charging. is limited by the upper limit voltage value V _max . FIG. 20 shows the first case in which the maximum current value I _max.dis during discharge is limited by the upper limit current value I _{limit,dis, and FIG} . This is the second case limited by the voltage value _Vmin .

The calculation formula for electric power by the assembled battery control unit 150 of the present embodiment is a calculation formula that applies the equivalent circuit model shown in FIG. 17 . Assuming that the assumed equivalent circuit model can perfectly reproduce the voltage behavior of the battery, in the test of inputting power equivalent to the maximum power during charging shown in FIGS. , there is a discrepancy between the voltage value when the maximum charging current is applied and the actual battery voltage calculated by the above equation (23).

That is, as shown in graphs (c) of FIGS. 18 and 19, the calculated battery voltage indicated by the dotted line is greater than the measured voltage indicated by the solid line. An excessively calculated maximum power during charging is entered. Therefore, as shown in graphs (b) of FIGS. 18 and 19, the actual current indicated by the solid line flows excessively through the battery compared to the maximum current value during charging indicated by the broken line.

On the other hand, in the test of outputting power equivalent to the maximum power during discharge, as indicated by the dotted line in the graphs (c) of FIGS. The voltage value of the battery during this period is lower than the actual voltage value indicated by the solid line. As a result, as shown in graph (a), the maximum electric power at the time of discharge, which is calculated to be too small, is output. Therefore, in the graphs (b) of FIGS. 20 and 21, the absolute value of the actual current value shown by the solid line flows too small compared to the absolute value of the maximum current value during discharge shown by the dotted line.

Next, the operation of the assembled battery control unit 150 of this embodiment will be described with reference to FIGS. 22 to 25. FIG. As in the assembled battery control unit 150 of the first embodiment, the voltage calculation energization time t_vol, which is used to calculate the battery voltage when the maximum current is applied during charging or discharging, is set at the moment power is input. In order to reproduce the voltage of 22 and 23 show the waveforms when power corresponding to the maximum power during charging when t_vol is 0, and FIGS. 24 and 25 show the maximum power during discharging when t_vol is 0. It shows the waveform when a considerable amount of power is input.

As shown in FIGS. 22 and 23, by setting t_Vol to 0, the calculated voltage calculated by the above formula (23) matches the actual battery voltage, so the current value that flows corresponds to the maximum current during charging. It can be seen that a current of That is, according to the assembled battery control unit 150 of the present embodiment, the battery can be charged without an excessive current flowing through the battery as in the case of applying the battery control device of the comparative example or the conventional technology.

Also, as shown in graphs (c) of FIGS. 24 and 25, by setting t_Vol to 0, the calculated voltage value of the battery when the maximum current during discharge calculated by the above formula (28) is applied corresponds to the actual voltage value of the battery. Therefore, as shown in the graphs (b) of FIGS. 24 and 25, it can be seen that the current flowing through the battery is equivalent to the maximum current during discharge. In other words, according to the assembled battery control unit 150 of the present embodiment, discharging can be performed without imposing excessive restrictions as in the case of applying the battery control device of the comparative example or the conventional technology.

As described above, the assembled battery control unit 150 of the present embodiment includes a voltage model M capable of estimating temporal changes in battery voltage, including the battery polarization voltage, based on the current flowing through the battery. _Then , based on _the voltage model M, the assembled battery control unit 150 determines the first polarization voltage V Estimate _{p_i} . The assembled battery control unit 150 also estimates the second polarization voltage V _{p_v} when the second internal resistance value R _{chg_v} and the energization time t_vol corresponding to the second internal resistance value R _{chg_v} have elapsed. Furthermore, the assembled battery control unit 150 calculates the maximum current value I _max,chg of the battery based on the first internal resistance value R _{chg_i} and the first polarization voltage V _{p_i} , and calculates the second internal resistance value R _{chg_v} and A calculated voltage value V max, _chg of the battery is calculated based on the second polarization voltage V _{p_v} and the maximum current value I max, _chg (or I _max,dis ). Then, the assembled battery control unit 150 calculates the maximum power value W _{max,chg by multiplying the maximum current value I max,chg} and the calculated voltage value V _{max ,chg} .

Therefore, according to the assembled battery control unit 150 of the present embodiment, it is possible to suppress the flow of excessive current during charging, and to maximize the discharging performance of the battery without excessively restricting during discharging. becomes possible.

[Embodiment 3]
Embodiment 3 of the battery control device according to the present disclosure will be described below with reference to FIGS. 1 to 3 and FIG. 26 .

In the assembled battery control unit 150 of the present embodiment, the internal resistance value included in the map of the formula (2), ChgR_vMap(SOC,T), stored in the storage device 180 is the assembled battery control according to the first embodiment described above. Different from part 150 . Other points of the assembled battery control unit 150 of the present embodiment are the same as those of the above-described embodiment, so the same parts are given the same reference numerals and the description thereof is omitted.

In the assembled battery control unit 150 of Embodiment 1, the internal resistance value that is visible at the moment power is input in all SOC and all temperature ranges is stored in the storage device 180 as the charging internal resistance for voltage calculation, and is implemented. I gave an example of how to use it. Since the upper limit current value I _limit,chg in the above formula (3) is a value that takes into account not only the battery but also the restrictions imposed by the components that make up the battery system, operation of the battery system beyond this value should be avoided. .

Therefore, under the condition of the first case where the maximum current value _Imax.chg during charging is limited by the upper limit current value _Ilimit,chg , as in the first embodiment, the internal resistance value for voltage calculation is set to the electric power It is necessary to set the resistance value at the moment when is input. However, in the second case where the maximum current value _Imax.chg during charging is limited by the upper limit voltage value _{Vmax , the maximum current during charging is calculated with a value smaller than the upper limit current value Ilimit,chg.} there is Since the maximum current during charging uses the battery resistance value at the time when the predetermined time has passed, it is calculated as the current value that reaches the upper limit voltage after the predetermined time has passed. Therefore, the voltage does not deviate from the upper limit voltage at the moment power is turned on.

In addition, even if a current exceeding the chargeable current smaller than the upper limit current value I _limit,chg flows, if the value is smaller than the upper limit current value I _limit,chg , the operation of the power storage device 100 No problem. In other words, in the second case, it is considered not necessary to use the resistance value visible at the moment power is input as the internal resistance value for voltage calculation. Since the same internal resistance value was used in , the maximum power during charging was excessively limited.

Therefore, in the present embodiment, in the SOC and temperature regions that correspond to the first case limited by the upper limit current value I _limit,chg , the internal resistance value that appears at the moment power is input is the same as in the first embodiment. In other SOC and temperature regions that correspond to the second case, the internal resistance value (for example, the same internal resistance value for current calculation as value). That is, the resistance value used as the internal resistance value for voltage calculation is changed between the regions of the first case and the second case.

FIG. 26 shows the configuration of the map loaded in the storage device 180 as ChgR_vMap(SOC,T) of the above-described formula (2) in the battery pack control unit 150 of the present embodiment. A map (a) in FIG. 26 is a table in which the maximum current value during charging calculated using the internal resistance value for current calculation is organized as a table according to SOC and temperature. In the map (a) of FIG. 26, when the upper limit current value I _limit,chg is set to 200 [A], there is an area limited to 200 [A] on the high temperature and low SOC side (the area surrounded by the dotted line ).

For the reason described above, in order to ensure that the area limited by 200 [A] does not exceed 200 [A], the internal resistance value at the moment power is input is stored in the storage device as in the first embodiment. 180 and installed. For other areas, the internal resistance value is different from the internal resistance value at the time 10 [sec] has passed after the start of energization, or the internal resistance value that appears at the moment power is applied, such as 2 [sec] or 5 [sec]. set.

A specific example is shown in the map (b) of FIG. In the area limited by 200 [A] extracted from the map (a) of FIG. A value is set (a value greater than the resistance value in the area limited by 200 [A] is set). As a result, in a region where the calculated maximum current during charging exceeds, for example, 200 [A], it is possible to calculate the maximum power during charging such that deviation of 200 [A] does not occur.

In addition, in areas other than this region, it is possible to define the maximum power during charging with power that is greater than the power calculated from the internal resistance value at the moment the power is turned on. Considering the influence of linear interpolation, the area for setting the resistance value that can be seen at the moment power is input will also appear at the moment power is input, even for the nearest grid point adjacent to the 200 [A] limit area. internal resistance may be set. Further, since the areas in the first case and the second case differ depending on the state of deterioration of the battery, a map corresponding to the deterioration is prepared in advance, and an appropriate internal resistance value corresponding to the deterioration is determined. You may make it calculate.

According to the assembled battery control unit 150 of the present embodiment, only the region restricted by the upper limit current value I _limit,chg that the power storage device 100 must not exceed, the internal resistance at the moment power is input is maintained. A value can be set as an internal resistance value for voltage calculation. This makes it possible to control the battery so that it is not subject to an excessive maximum power limit, especially during charging.

[Embodiment 4]
Embodiment 4 of the battery control device according to the present disclosure will be described below with reference to FIGS. 1 to 3 and FIG. 27 .

In the third embodiment, the maximum current value _Imax.chg during charging is limited by the upper limit current value _Ilimit,chg, and the maximum current value _Imax.chg during charging is limited by the upper limit voltage value _Vmax . In the second limited case, an example is shown in which the internal resistance values to be loaded in the internal resistance maps used for calculation are selectively used. However, as in the second embodiment, when the power is calculated without mounting the internal resistance value when the predetermined time has passed in the storage device 180, that is, when a time such as seconds is specified and the time is In the case of having a function of calculating the corresponding internal resistance value, the technique of the third embodiment cannot be adopted. Therefore, in the present embodiment, when the upper limit current value of the formulas (3) and (22) is limited, a flag indicating that the limit is applied is output. An example of switching the resistance value will be described.

The assembled battery control unit 150 of the present embodiment differs from the assembled battery control unit 150 according to the first embodiment described above in the functional block composed of the storage device 180 and the central processing unit 190 . Other points of the assembled battery control unit 150 of the present embodiment are the same as those of the above-described first embodiment, so that the same parts are denoted by the same reference numerals and the description thereof is omitted.

FIG. 27 is a block diagram of the assembled battery control unit 150 of the present embodiment, which corresponds to FIG. 15 of the second embodiment. The assembled battery control unit 150 of the present embodiment outputs a flag to notify that the output of the function F23' for calculating the maximum current during charging is limited by the upper limit current value. The output flag is input to the function F22' that calculates the parameters of the charge equivalent circuit for voltage calculation. Upon receiving the flag, the function F22' sets the energization time t_vol for voltage calculation to "0" in the region limited by the upper limit current value based on the input flag. Set 5 [sec] and 10 [sec].

With the configuration as described above, charging can be performed without deviating from the upper limit current value of 200 [A], for example. Furthermore, in a region where the upper limit current value is not exceeded, by changing the internal resistance value used for voltage calculation to an arbitrary value, it is possible to avoid excessive limitation of the chargeable power. An arbitrary value of the internal resistance value used for voltage calculation may be, for example, the same value as the energization time t_cur for current calculation, or may be a value other than this.

According to the assembled battery control unit 150 of the present embodiment, as in the third embodiment, only the region restricted by the upper limit current value that should not be exceeded as a power storage device can be reliably observed at the moment power is input. The internal resistance value can be set as the internal resistance value for voltage calculation. This makes it possible to control the battery so that the maximum power is not excessively limited, especially during charging.

The embodiment of the battery control device according to the present disclosure has been described in detail above with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes within the scope of the present disclosure are possible. etc., are intended to be included in this disclosure.

1: single cell (battery),
100: power storage device (battery system)
110: assembled battery (battery),
111: battery group (battery),
150: Assembled battery control unit (battery control device)
200: relay (battery system),
500: motor generator (external load),
I _max.chg : maximum current value,
I _max.dis : Maximum current value,
I _limit,chg : Upper limit current value,
I _limit,dis : Upper limit current value,
M: voltage model
R _{chg_i} : internal resistance value (first internal resistance value),
R _{chg_v} : internal resistance value (second internal resistance value),
R _{dis_i} : internal resistance value (first internal resistance value),
R _{dis_v} : internal resistance value (second internal resistance value),
V _max,chg : Calculated voltage value,
V _max,dis : Calculated voltage value,
W _max,chg : Maximum power value,
W _max,dis : Maximum power value,
V _{p_i} : polarization voltage,
V _{p_v} : polarization voltage,
V _max : Upper limit voltage,
V _min : Lower limit voltage,
SOC: rate of charge.

Claims (5)

A maximum current value of the battery and a calculated voltage value of the battery when the maximum current value is applied are calculated based on the internal resistance value of the battery, and the battery is operated based on the maximum current value and the calculated voltage value. A battery control device that calculates a maximum power value,
The first internal resistance value of the battery used for calculating the maximum current value and the second internal resistance value of the battery used for calculating the calculated voltage value are different,
The first internal resistance value is set to the internal resistance value of the battery when a first period of time has elapsed from the start of energization of the maximum current value to the battery,
The battery control device, wherein the second internal resistance value is set to the internal resistance value of the battery when a second time period shorter than the first time period has elapsed from the start of the energization. A voltage model capable of estimating the time change of the voltage of the battery including the polarization voltage of the battery based on the current flowing in the battery;
Based on the voltage model, the first polarization voltage is calculated when the energization time corresponding to the first internal resistance value and the first internal resistance value has elapsed, and the second internal resistance value and the Calculate the second polarization voltage when the energization time corresponding to the second internal resistance value has elapsed,
calculating the maximum current value of the battery based on the first internal resistance value and the first polarization voltage, and calculating the maximum current value based on the second internal resistance value, the second polarization voltage and the maximum current value calculating the calculated voltage value of the battery;
2. The battery control device according to claim 1, wherein the maximum power value is calculated by multiplying the maximum current value and the calculated voltage value. The first internal resistance value, or the maximum current value during charging or the maximum current value during discharging that does not deviate from the upper limit voltage or lower limit voltage of the battery based on the first internal resistance value and the first polarization voltage Calculate the maximum current value,
An upper limit current value that is determined in consideration of the characteristics of the battery system including a battery assembly that connects a plurality of the batteries and a relay that controls connection with an external load, and the characteristics of the battery, and the maximum current during charging. Calculate the smaller one of the values as the maximum current value during charging,
3. The battery control device according to claim 2 , wherein the smaller one of the upper limit current value and the maximum current value during discharging is calculated as the maximum current value during discharging. The second internal resistance value is used as the internal resistance used to calculate the calculated voltage value only for the charging rate or temperature condition of the battery for which the maximum current value during charging is determined by the upper limit current value. 4. The battery control device according to claim 3 . The second internal resistance value and the 4. The battery control device according to claim 3 , wherein a second polarization voltage is used.

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