JP7274368B2 - battery control system - Google Patents

Description

The present disclosure relates to battery control systems.

2. Description of the Related Art Conventionally, an invention related to a battery pack input/output control device that limits input/output based on the surface temperature of a battery pack configured by combining a plurality of unit batteries is known (see Patent Document 1 below). This conventional control device includes an inside/outside temperature difference estimation module for estimating the temperature difference between the surface temperature and the inside temperature of the battery pack as a maximum temperature estimation unit for estimating the maximum temperature inside the battery pack, an R-caused temperature difference estimation module for estimating the temperature difference due to the resistance difference. Here, the intake air temperature, current load, and cooling air volume are taken into consideration in estimating the inside/outside temperature difference and the R-caused temperature difference. It also includes a controller and an input/output limiter that limits the input/output power of the battery pack based on the estimated maximum temperature (see the same document, abstract, etc.).

The above conventional control device estimates the maximum temperature inside the battery pack and limits the input/output of the battery pack based on the estimated maximum temperature. Here, the estimation of the maximum temperature of the battery pack is performed by estimating the temperature difference between the inside and outside of the battery, which is the difference between the battery inside temperature and the battery surface temperature, according to at least one of the intake air temperature, the current load, and the cooling air flow rate. Then, the internal resistance of each unit battery is estimated from each battery voltage and current value at a plurality of placement positions, and the temperature difference in the battery pack due to the difference in internal resistance of each unit battery is estimated. Then, the total value of the temperature differences estimated by these is added to the maximum value of the battery surface temperature to estimate the maximum temperature of the battery pack. In this way, the maximum temperature of the battery pack is estimated by reflecting the influence of the intake air temperature, current load, cooling airflow, and the influence of the variation in the internal resistance of the unit battery, so that the input/output limit of the battery pack is more sufficiently restricted. (See Ibid., paragraph 0018, etc.).

Also known is a method for estimating the core temperature of a module of a traction battery of an electric or hybrid vehicle in which a plurality of charge storage elements are packaged (see US Pat. This conventional method is characterized by measuring the temperature at the outer wall of the battery module and establishing a diffusion model of the heat generated within the charge storage element of the battery module (ibid., claim 1, etc.). ).

This conventional method provides as output an estimate of the temperature of the outer wall of the battery module as a function of the core temperature of the module which the model receives as input. Also, an estimate of the core temperature of the battery module is obtained by determining a temperature value supplied as an input to the model such that a temperature value substantially equal to the measured temperature is obtained as the output from the model. calculate.

This conventional method requires that the temperature values supplied as input to the model be such that the difference between the temperature measured at the outer wall and the output temperature of the model is substantially zero. The temperature of the ambient air and the current at the terminals of the battery module are also measured, and the diffusion model takes these measurements as inputs. Also, the diffusion model of the heat generated within the charge storage element of the battery module is established by applying a heat equation at each node of the one-dimensional spatial mesh of the battery module (ibid., claim 2- 4, etc.).

JP 2011-222133 A Japanese Patent Publication No. 2014-531711

In the conventional control device described in Patent Document 1, the maximum internal temperature of the battery pack estimated by the maximum temperature estimator is different from the true internal temperature of the battery pack due to the accuracy limit of the temperature model of the battery pack. An error occurs between them.

In the conventional method described in Patent Document 2, the difference between the temperature measured at the outer wall of the battery module and the output temperature of the diffusion model of the heat generated inside the charge storage element of the battery module is substantially zero. The temperature values supplied as inputs to the model are determined such that In order to realize this, for example, the following two methods are conceivable.

One is a method of substituting the measured temperature into the formula representing the model and solving simultaneous equations. The other is to adjust the core temperature of the battery module little by little and use a function to derive the temperature at the outer wall of the battery module from this core temperature. It is a method of performing calculations until it becomes zero. However, all of these methods have the problem that the calculation load is high.

The present disclosure provides a battery control system capable of reducing the calculation load more than conventionally while suppressing the error between the true internal temperature of the battery and its calculated value.

One aspect of the present disclosure is a battery control system comprising a current sensor that measures the magnitude of current flowing through a battery, a temperature sensor that measures the surface temperature of the battery, a storage device, and a central processing unit, wherein the storage device is a battery temperature estimation formula that defines the relationship between the surface temperature and internal temperature of the battery and the magnitude of the current, and the difference between the measured value of the surface temperature and the calculated value of the surface temperature. A calculation formula, a correction coefficient map that defines the relationship between the magnitude and duration of the current and the correction coefficient, and the sum of the surface temperature error multiplied by the correction coefficient and the calculated value of the internal temperature is corrected for internal temperature. and an internal temperature correction formula for the value, and the central processing unit uses the magnitude of the current measured by the current sensor to calculate the surface temperature and the internal temperature based on the battery temperature estimation formula. calculating the surface temperature error based on the error calculation formula using the calculated value of the surface temperature and the measured value of the surface temperature measured by the temperature sensor; calculating the correction factor based on the correction factor map using the magnitude and duration measurements; using the correction factor, the surface temperature error, and the calculated internal temperature based on the internal temperature correction formula The battery control system is characterized in that the internal temperature correction value is calculated by using the internal temperature correction value, and the battery is controlled based on the internal temperature correction value.

According to the above aspect of the present disclosure, it is possible to provide a battery control system that can reduce the calculation load more than conventionally while suppressing the error between the true internal temperature of the battery and its calculated value.

1 is a schematic configuration diagram showing Embodiment 1 of a battery control system according to the present disclosure; FIG. FIG. 2 is a schematic perspective view of a battery pack that constitutes the battery control system shown in FIG. 1; FIG. 2B is a graph showing the relationship between the positions of the single cells in the battery pack shown in FIG. 2A and the internal temperature; Typical sectional drawing of the battery pack shown to FIG. 2A. FIG. 2B is a graph showing the relationship between allowable power and temperature of the cells of the battery pack shown in FIG. 2A; FIG. FIG. 2 is an example of a circuit configuration of a cell control unit that constitutes the battery control system shown in FIG. 1; FIG. FIG. 2 is a flowchart showing an example of the operation of the battery control system shown in FIG. 1; FIG. 2 is a functional block diagram of the battery control system shown in FIG. 1; 8 is a graph of the internal temperature correction value, which is the output of the error correction function shown in FIG. 7; 4 is a graph for explaining the effect of the internal temperature correction value of the battery control system shown in FIG. 1; 4 is a graph for explaining the effect of the internal temperature correction value of the battery control system shown in FIG. 1; 4 is a graph for explaining the effect of the battery control system shown in FIG. 1 on allowable power; 4 is a graph for explaining the effect of the battery control system shown in FIG. 1 on allowable power; FIG. 2 is a functional block diagram of Embodiment 2 of the battery control system according to the present disclosure; 9 is a graph for explaining the effect of the internal temperature correction value of the battery control system of the second embodiment; 3 is a functional block diagram of Embodiment 3 of a battery control system according to the present disclosure; FIG. FIG. 4 is a functional block diagram of Embodiment 4 of the battery control system according to the present disclosure; FIG. 5 is a functional block diagram of Embodiment 5 of a battery control system according to the present disclosure;

Embodiments of a battery control system according to the present disclosure will be described below with reference to the drawings.

Batteries are used in a wide range of fields, from mobile terminals to stabilization of power grid connections. In recent years, automobiles using batteries as a power source, such as electric cars and hybrid cars, have been attracting attention as a countermeasure against the _CO2 problem, exhaust gas, and fossil fuel depletion. The battery systems installed in these vehicles detect battery voltage, temperature, and current, calculate state quantities such as battery charging rate based on these, and determine control values for battery current and voltage. It has a controller.

In the following embodiments, an example in which the battery control system according to the present disclosure is applied to a battery system that constitutes a power source of a plug-in hybrid electric vehicle (PHEV) will be described. In addition, the battery control system according to the present disclosure is not only a PHEV battery system, but also a power storage device that constitutes a power supply for industrial vehicles including passenger cars such as hybrid vehicles (HEV) and electric vehicles (EV) and hybrid railway vehicles. It is applicable to capacitor control circuits.

Further, in the following embodiments, an example in which a lithium ion secondary battery is adopted as a battery to be controlled by the battery control system according to the present disclosure will be described. The battery is not limited to a lithium ion secondary battery, and a nickel hydrogen battery, a lead battery, an electric double layer capacitor, a hybrid capacitor, or the like can be used. Further, a plurality of cells may be connected in series to form an assembled battery, a plurality of cells may be connected in parallel to form an assembled battery, or a plurality of cells may be connected in series to form an assembled battery. A battery group may be formed, and a plurality of battery groups may be connected in parallel to form an assembled battery.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram showing Embodiment 1 of a battery control system according to the present disclosure. In the example shown in FIG. 1 , battery control system 100 is connected to charger 300 and inverter 400 via relay 200 . In addition, assembled battery control unit 150, charger 300, and inverter 400 of battery control system 100 are connected to vehicle control unit 500 via signal lines. Further, inverter 400 is connected to motor generator 600 .

The battery control system 100 according to the present embodiment 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 insulation It comprises an element 170 , a storage device 180 and a central processing unit 190 . 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. Also, although illustration is omitted, the assembled battery 110 includes, for example, an environmental temperature sensor that acquires the environmental temperature around the cells 1 .

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 .

FIG. 2A is a schematic perspective view showing an example of a battery pack 100P configuring battery control system 100 shown in FIG. FIG. 2B is a graph showing the relationship between the positions of the single cells 1 forming the battery pack 100P shown in FIG. 2A and the internal temperature. FIG. 3 is a schematic cross-sectional view of battery pack 100P shown in FIG. 2A. In FIG. 2A, in order to describe the main configuration of the assembled battery 110, the housing 101 and the junction box 102 of the battery pack 100P are indicated by imaginary lines (two-dot chain lines). Illustration of the configuration is omitted. In FIG. 2B, the horizontal axis is the position of the cell 1 in the height direction Z of the battery pack 100P, and the vertical axis is the internal temperature of the cell 1. In FIG.

The battery pack 100P includes, for example, a housing 101, an assembled battery 110 housed inside the housing 101, and a junction box 102 housed in the housing 101 together with the assembled battery 110. The housing 101 is, for example, a rectangular box-shaped container made of metal or resin. The assembled battery 110 is, for example, fixed to the bottom wall and side walls of the housing 101 via fastening members such as bolts.

A junction box 102 disposed in front of the assembled battery 110 inside the housing 101 is, for example, a structure 112 such as a metal plate or a metal block constituting the assembled battery 110 or a fastening member such as a bolt is attached to the housing 101. fixed directly or indirectly through The structures 112 are arranged, for example, on both sides of a battery group 111 in which a plurality of unit cells 1 are integrated, and serve as a heat dissipation member that protects the assembled battery 110 when an external force acts and promotes heat dissipation of the assembled battery 110. also works. Note that the structure 112 may be omitted depending on the application of the assembled battery 110 .

The assembled battery 110 is configured by integrating a plurality of batteries, that is, a plurality of unit cells 1 and connecting them in series, for example. The assembled battery 110 includes, for example, multiple battery groups 111 . One battery group 111 includes, for example, multiple cells 1 managed by a common cell management unit 120 . A plurality of unit cells 1 constituting assembled battery 110 and battery group 111 are connected in series or in parallel by connecting external terminals of two adjacent unit cells 1 with a conductive member such as a bus bar.

The unit cell 1 is, for example, a flat prismatic lithium ion secondary battery, and includes a wound body 1a, a pair of current collector plates 1b, a container 1c, and a pair of external terminals 1d. The wound body 1a has a structure in which a long belt-shaped positive electrode and a negative electrode are laminated with a long belt-shaped separator interposed therebetween and wound. In the wound body 1a, the negative electrode current collector is exposed from the separator at one end in the winding axial direction, and the positive electrode current collector is exposed from the separator at the other end in the winding axial direction.

Of the pair of current collector plates 1b, one current collector plate 1b is a positive electrode current collector plate joined to the positive electrode current collector exposed at one end of the wound body 1a, and the other current collector plate 1b is wound. This is a negative electrode current collector plate joined to the negative electrode current collector exposed at the other end of the winding body 1a. The container 1c is made of, for example, aluminum or its alloy, and accommodates the wound body 1a, the current collector plate 1b, and the electrolytic solution, and electrically connects the wound body 1a, the current collector plate 1b, and the external terminal 1d. insulated to

A pair of external terminals 1d are arranged on the end face of the container 1c via an insulating member. Of the pair of external terminals 1d, one external terminal 1d is a positive electrode external terminal connected to one current collector 1b, which is a positive electrode current collector, inside the container 1c, and the other external terminal 1d is connected to the container. This is a negative external terminal connected to the other external terminal 1d, which is a negative current collecting plate, inside 1c. The unit cell 1 has, for example, a temperature sensor 2 arranged on the end face of a container 1c provided with a pair of external terminals 1d.

In battery pack 100P shown in FIG. 2A, cell 1 has, for example, a flat rectangular shape. A plurality of flat prismatic cells 1 are stacked in the thickness direction of each cell 1 so that the width direction of each cell 1 is parallel to the bottom wall of the housing 101, and the bottom of the housing 101 is formed. placed on the wall. In the example shown in FIG. 2A, a battery group 111 in which six cells 1 are integrated in the height direction Z of the assembled battery 110 perpendicular to the bottom wall of the housing 101 is arranged in two rows in the width direction of the cells 1. placed side by side. In addition, the number of cells 1 constituting the battery group 111 and the number of the battery groups 111 are not particularly limited.

With such an arrangement of the cells 1, the temperature distribution of the cells 1 has the following tendency. For example, as shown in FIG. 2B, in the height direction Z of a battery pack 100P in which a plurality of cells 1 are integrated, the internal temperature of the cells 1 at both ends is the lowest, and the temperature of the cells 1 placed in the center is the lowest. The internal temperature tends to be the highest. This is because, in the direction in which the plurality of cells 1 are stacked, heat dissipation from the cells 1 at both ends is easier than that from the cells 1 arranged in the center. Also, in each unit cell 1, for example, heat dissipation is accelerated in the portions that are in contact with the coolant, the heat radiating member, the structure 112, etc., and the temperature tends to be lower than the other portions.

FIG. 4 is a graph showing the relationship between the allowable power of the cell 1 and the temperature of the cell 1. As shown in FIG. Many of the control parameters for the single cell 1 depend on the temperature of the single cell 1 . One such control parameter is Direct Current Resistance (DCR). DCR increases as the temperature of the cell 1 decreases. Therefore, as shown in FIG. 4, the allowable power of the cell 1 decreases as the temperature of the cell 1 decreases. Here, the allowable power is the maximum power value that the cell 1 can output, which is set to protect the cell 1 .

A temperature sensor 2 for measuring the surface temperature of at least one cell 1 among the plurality of cells 1 constituting each battery group 111 shown in FIG. 1 is provided on the outer surface of the cell 1. . The allowable power of the assembled battery 110 is the power that reaches the upper limit voltage or lower limit voltage of the cell 1 when the cell 1 is charged or discharged. The internal resistance of the cell 1 tends to increase as the internal temperature of the cell 1 decreases. Therefore, among the plurality of cells 1 connected in series and through which the same amount of current flows, the cell 1 with the lowest temperature reaches the upper limit voltage or the lower limit voltage in the shortest time.

That is, the allowable power of the assembled battery 110 is the output when the maximum current is flowing through the assembled battery 110, and the maximum current that can be passed through the assembled battery 110 is , is limited by the lower and upper currents of the cell 1 at the lowest temperature. Therefore, in order to calculate the allowable power of the assembled battery 110, it is necessary to use the internal temperature of the cell 1 having the lowest temperature among the plurality of cells 1 forming the battery group 111. FIG.

Therefore, the temperature sensor 2, for example, considers the tendency of the temperature distribution of the unit cells 1 as described above, and determines the unit cell 1 having the lowest temperature among the plurality of unit cells 1 constituting each battery group 111. Provided on the outer surface. Moreover, the temperature sensors 2 may be installed on the outer surface of the cell 1 that has the lowest temperature and the cell 1 that has the highest temperature among the plurality of cells 1 forming each battery group 111 . Also, the temperature sensor 2 may be installed on the outer surface of all the single cells 1 constituting each battery group 111 .

Junction box 102 accommodates, for example, control units such as cell management unit 120 and assembled battery control unit 150 including central processing unit 190 and electronic components such as relays, and is connected to assembled battery 110 . Also, the junction box 102 is connected to, for example, a voltage detection circuit 121a (see FIG. 5) as a voltage sensor for measuring the voltage of the cell 1, the temperature sensor 2, the current detection unit 130, the voltage detection unit 140, and the like. .

The cell management unit 120 includes a cell control unit 121 provided for each battery group 111, as shown in FIG. 1, for example. The cell control unit 121 monitors the state of each cell 1 forming the battery group 111 and controls each cell 1 .

FIG. 5 is an example of a circuit configuration of the cell control section 121 that constitutes the cell management section 120 of the battery control system 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 and SOC among the cells 1 that occur due to self-discharge of the cells 1 and variations in current consumption. I have.

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 1 d of each cell 1 that constitutes the battery group 111 . Temperature detection unit 121b is a temperature detection circuit connected to temperature sensor 2 that measures the surface temperature of cell 1, for example. The surface temperature of the cell 1 measured by the temperature sensor 2 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. 5, 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 used, for example, by the cell control unit 121 and the assembled battery control unit 150 to determine the state of the cell 1, the battery group 111, or the assembled battery 110. Used for various calculations. 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 1d 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 , for example, detects the state of the assembled battery 110 and manages the state of the assembled battery 110 . 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 voltage value of the entire battery group 111 output from the detection unit 140 is input.

Assembled battery control unit 150 includes, for example, a central processing unit 190, and determines and detects the state of assembled battery 110 based on input information. The assembled battery control unit 150 outputs the determination result or the detection result of the state of the assembled battery 110 to the cell management unit 120 and the vehicle control unit 500 via the signal line. In addition, assembled battery control unit 150 is connected to cell management unit 120 via, for example, communication path 160 and insulation element 170 such as a photocoupler. Send and receive signals through

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 . Also, depending on the configuration of the battery control system 100, the 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.

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 unit 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, internal resistance characteristics, capacity at full charge, polarization characteristics, deterioration characteristics, individual difference information, state of charge (SOC), open circuit voltage (Open circuit voltage: OCV) is stored in storage device 180 . Storage device 180 also stores, for example, a battery temperature estimation formula, an error calculation formula, a correction coefficient map, and an internal temperature correction formula. The arithmetic expressions stored in the storage device 180 will be described in more detail below.

The battery temperature estimation formula is a formula that defines the relationship between the surface temperature and internal temperature of the cell 1 and the magnitude of the current flowing through the cell 1 . The battery temperature estimation formula is, for example, a temperature model of the cell 1, and is represented by the following formulas (1) and (2).

In the above formula (1), T(t) _seq is the calculated value of the temperature of the unit cell 1, and f is a function defined by the thermal network method, for example. The thermal network method is a method of expressing a thermal system to be modeled by the transfer of heat quantity between a plurality of simplified mass points. The amount of heat transfer is determined by the temperature difference and thermal resistance between two points, and the amount of heat transferred and generated is stored as the amount of heat used to raise the temperature of the mass point in the entire system.

In the above formula (1), t is the time of the current calculation, Δt is the time interval between the time of the previous calculation and the time of the current calculation, and T(t-Δt) _seq is the previous calculation. A calculated value of the temperature of the cell 1 at the time, Q _gen (t) is the amount of heat generated by the cell 1 , and _Tamb (t) is the environmental temperature around the cell 1 . Note that T(t) _seq and T(t−Δt) _seq include the internal temperature T _in (t) of the cell 1, the surface temperature T _sur (t), and the temperature T _oth (t) of other parts. 2 is a sequence of temperatures of portions of the cell 1;

Note that the function f is not limited to the above formula (1). Specifically, for example, using the previous calculated value T(t-Δt) _seq of the temperature of the cell 1, the heat generation amount Q _gen (t), and the ambient temperature T _amb , the temperature T(t) of the cell 1 _seq may be a formula that takes the previous calculated value T(t−Δt) _seq of the temperature of the cell 1 as the starting temperature and approaches the ambient temperature T _amb with a time constant τ determined by the battery design.

In addition, the relationship between the previous calculated value T(t-Δt) _seq of the temperature of the single cell 1, the amount of heat generation Q _gen (t), the environmental temperature _Tamb , and the current internal temperature _Tin of the single cell 1 is defined. The resulting map may be stored in storage device 180 . In this case, the previous calculation value T(t-Δt) _seq of the temperature of the single cell 1, the heat generation amount Q _gen (t), and the ambient temperature T _amb are input, and the current internal temperature T _in of the single cell 1 is mapped. You may make it search from.

In the above formula (2), R is the calculated value of the resistance of the single cell 1, SOC(t) is the calculated value of the SOC of the single cell 1 at time t during the calculation, and T' _in (t-Δt) is The previous cell 1 internal temperature correction value, I(t), is the measured value of the current flowing through the cell 1 . The resistance value of the single cell 1 can be obtained, for example, from the relationship between the resistance value of the single cell 1, the SOC, and the temperature. That is, storage device 180 stores, for example, the above equations (1) and (2) as battery temperature estimation equations that define the relationship with the magnitude of the current flowing through unit cell 1 .

Note that the heat generation amount Q _gen (t) of the single cell 1 can also be calculated without using the previous internal temperature correction value T′ _in (t−Δt) of the single cell 1 . That is, the storage device 180 experimentally acquires the relationship between the current value, SOC, and environmental temperature of the single cell 1 and the internal temperature and surface temperature of the single cell 1, instead of using the above formula (2). A created map of experimental results may be stored. Also, the SOC of the cell 1 can be calculated by the central processing unit 190 based on the relationship between the current value and the voltage value flowing through the cell 1 stored in the storage device 180, for example.

Also, the heat generation amount Q _gen (t) of the cell 1 can be calculated by the following formula (3). That is, the storage device 180 may store the following formula (3).

In the above formula (3), Q _gen (t) is the amount of heat generated by the cell 1, CCV(t) is the measured voltage of the cell 1, and OCV(t) is the open-circuit voltage of the cell 1. The value, I, is the measured value of the current flowing through the cell 1 . Note that the relationship between the charging rate SOC and the measured voltage CCV of the single cell 1 is experimentally acquired in advance, and a map or graph representing the correspondence relationship between the charging rate SOC and the measured voltage CCV is stored in the storage device 180. can be done. As a result, the central processing unit 190 calculates the open-circuit voltage OCV(t) of the cell 1 based on the calculated value of the charging rate SOC(t) and the map or graph showing the correspondence relationship between the charging rate SOC and the measured voltage CCV. can be calculated.

Further, the storage device 180 stores the error calculation formula as described above. The error calculation formula is a formula in which the difference between the measured value of the surface temperature of the unit cell 1 and the calculated value of the surface temperature of the unit cell 1 is the surface temperature error. .

In the above formula (4), T _sur,mes (t) is the measured value of the surface temperature of the cell 1 and T _sur,cal (t) is the calculated value of the surface temperature of the cell 1 . In the above formula (4), ΔT _sur (t) is the measured value T _{sur,mes (t) and the calculated value T sur,mes} (t) of the surface temperature of the unit cell 1 between the time intervals Δt It is the difference from _sur,cal (t), that is, the time rate of change of the surface temperature error of the cell 1 . For simplicity, the time rate of change of the surface temperature error will be simply referred to as the "surface temperature error".

Further, the storage device 180 stores a correction coefficient map as described above. The correction coefficient map is a map that defines the relationship between the magnitude and duration of the current flowing through the cell 1 and the correction coefficient. More specifically, storage device 180 stores, for example, current-time index arithmetic expressions represented by the following equations (5a), (5b), or (5c).

In the above formulas (5a), (5b), and (5c), CTa, CTb, and CTc are respectively determined based on the magnitude of the current flowing through the cell 1 and the duration of the current, and is the current time index used for In the above formulas (5a), (5b), and (5c), I is the measured value of the current flowing through the cell 1, t is the duration of the current flowing through the cell 1, and R is the This is the calculated value of the internal resistance.

Further, the correction coefficient map stored in the storage device 180 is, for example, a map that defines the relationship between the current time index CTa, CTb or CTc and the correction coefficient α. More specifically, the correction coefficient map is, for example, a graph or table showing the relationship between the current time index CTa, CTb or CTc and the correction coefficient α. The correction coefficient α is used to correct the calculated value of the internal temperature of the cell 1 to calculate a more accurate corrected value of the internal temperature of the cell 1 .

In the correction coefficient map, the correction coefficient α is a value of 0 or more, and the current time index CTa, CTb or CTc and the correction coefficient α are in one-to-one correspondence. In the correction coefficient map, the correction coefficient α is determined to increase, for example, as the current time index CTa, CTb or CTc increases. That is, in the correction coefficient map stored in the storage device 180, the relationship between the magnitude and duration of the current and the correction coefficient α is as follows. is stored as a relationship in which the correction coefficient α increases as the current time index CTa, CTb, or CTc expressed by the above equations (5a), (5b), or (5c) increases.

Also, the correction coefficient map can be experimentally created and stored in the storage device 180, for example. Specifically, for example, an experimental battery equivalent to the cell 1 is prepared, and a thermometer capable of measuring the internal temperature and a thermometer capable of measuring the surface temperature are installed in the experimental battery. Then, the experimental battery is repeatedly charged and discharged, and the internal temperature and surface temperature of the experimental battery are actually measured. Also, the current flowing through the experimental battery and the voltage of the experimental battery are measured, and the internal temperature and the surface temperature of the experimental battery are calculated based on the measured current and voltage values. Then, an internal temperature error between the measured value and the calculated value of the internal temperature of the experimental battery and a surface temperature error between the measured value and the calculated value of the surface temperature of the experimental battery are obtained.

Then, the larger the internal temperature error with respect to the surface temperature error of the experimental battery, the larger the correction coefficient α, and the smaller the internal temperature error with respect to the surface temperature error of the experimental battery, the smaller the correction coefficient α. Create a coefficient map. In other words, the correction coefficient map is created so that the larger the error in the amount of heat generated in the experimental battery, the larger the correction factor α, and the smaller the error in the amount of heat generated in the experimental battery, the smaller the correction factor α. In this manner, the experimentally created correction coefficient map can be stored in the storage device 180 .

The storage device 180 also stores the internal temperature correction formula as described above. The internal temperature correction formula is expressed by the following formula (6), the surface temperature error ΔT _sur (t) of the cell 1 multiplied by the correction coefficient α and the calculated value T _in ( t) to be the internal temperature correction value T' _in (t).

Further, the storage device 180 stores the surface temperature measurement value T _sur,mes (t) of the cell 1 as the surface temperature correction value T′ _sur,cal (t), as represented by the following formula (7). A surface temperature correction formula may be stored.

As described above, the storage device 180 of the present embodiment includes, for example, the battery temperature estimation formulas represented by the formulas (1) and (2), the error calculation formula represented by the formula (4), and the formula The current time index calculation formula represented by (5a), (5b) or (5c), the correction coefficient map showing the relationship between the current time index CTa, CTb or CTc and the correction coefficient α, and the above formula (6) are stored.

Central processing unit 190, as shown in FIG. 1, is mounted on, for example, a circuit board that constitutes assembled battery control unit 150, and is connected to storage device 180 so as to be able to communicate information therewith. 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 . Also, the central processing unit 190 acquires the measured value of the surface temperature of at least one unit cell 1 of each battery group 111 measured by the temperature sensor 2, for example. 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.

Charger 300 is connected to battery control system 100 via relay 200, for example. Charger 300 is connected to a power source installed at home or a charging station, for example, when charging battery control system 100 . Charger 300 is connected to vehicle control unit 500 via, for example, a signal line, and controls charging voltage, charging current, and the like based on commands from vehicle control unit 500 . Note that charger 300 may be connected to assembled battery control section 150 via a signal line, for example, and may control charging voltage, charging current, and the like based on commands from assembled battery control section 150 . Charger 300 is installed inside or outside the vehicle depending on, for example, its performance, purpose of use, installation conditions of an external power source, configuration of the vehicle, and the like.

Inverter 400 is connected to battery control system 100 via relay 200, for example. Inverter 400 is also connected to motor generator 600 . Vehicle control unit 500 controls inverter 400 based on the information output from assembled battery control unit 150 . Vehicle control unit 500 also controls charger 300 connected to battery control system 100 via relay 200 .

In a vehicle equipped with battery control system 100 , battery control system 100 is connected to inverter 400 via relay 200 under the control of vehicle control unit 500 , for example. As a result, the motor generator 600 is driven by the electric energy stored in the cells 1 forming the assembled battery 110, and the vehicle runs. In addition, regenerative electric power generated by motor generator 600 during braking of the vehicle is supplied to battery control system 100 via inverter 400 and relay 200, and unit cells 1 forming assembled battery 110 are charged.

Further, when the charger 300 is connected to an external power supply installed at home or at a charging station, the charger 300 and the battery control system 100 are connected via the relay 200 based on a command from the vehicle control unit 500. be done. As a result, power is supplied from an external power supply to battery control system 100 via charger 300 and relay 200, and unit cells 1 constituting assembled battery 110 are charged until a predetermined condition is satisfied.

The electrical energy stored in the single cell 1 that constitutes the assembled battery 110 of the battery control system 100 is used for the next run of the vehicle and for operating electrical components inside and outside the vehicle. In addition, the electric energy stored in the unit cells 1 forming the assembled battery 110 of the battery control system 100 may be supplied to the outside of the vehicle, such as a household power supply, if necessary.

Next, the operation of the battery control system 100 of this embodiment will be described.

FIG. 6 is a flow chart showing an example of the operation of the battery control system 100. As shown in FIG. The battery control system 100 first executes an activation determination process P1 for determining whether to turn on the system. More specifically, battery control system 100 determines, for example, by means of central processing unit 190 whether the start switch of the vehicle is on or off. When the central processing unit 190 determines that the start switch of the vehicle is off (NO), it repeatedly executes the start determination process P1, and when it determines that the start switch of the vehicle is on (YES), it turns on the system. It is activated, and the history reading process P2 is executed.

In the history reading process P2, the battery control system 100, for example, by the central processing unit 190, stores the last time the system stopped in the storage device 180 immediately before the system stopped, the temperature of the unit cell 1 at that time, and Read the SOC of cell 1 when the system is stopped. Next, the battery control system 100 executes the initial condition determination process P3.

In the initial condition determination process P3, the battery control system 100 acquires the elapsed time from the previous system stop point to the current system startup point by using the central processing unit 190, for example, and stores the elapsed time in the storage device 180. compared to the specified threshold time. If the elapsed time is longer than the threshold time, central processing unit 190 sets the surface temperature of cell 1 measured by temperature sensor 2 as the initial value of the internal temperature of cell 1 . Further, if the elapsed time is equal to or less than the threshold time, the central processing unit 190 sets the heat generation amount Q _gen (t) of the unit cell 1 to zero in the above formula (1), and Using the time interval Δt from the time of calculation of , as the elapsed time, a calculated value T(t) _seq of the temperature of the unit cell 1 is output.

Next, the battery control system 100 executes a temperature calculation process P4, an error correction process P5, and a stop determination process P6. These processes are executed by the central processing unit 190 at each calculation time interval Δt.

FIG. 7 is a functional block diagram of the battery control system 100 of this embodiment. The battery control system 100 includes, for example, a temperature calculation function F1, a correction coefficient calculation function F2, and an error correction function F3. Each of these functions is realized, for example, by various information and programs stored in the storage device 180 and the central processing unit 190 that performs calculations using them.

The central processing unit 190 first acquires or calculates information to be input to the temperature calculation function F1, the correction coefficient calculation function F2, and the error correction function F3. Specifically, the central processing unit 190 acquires, for example, the environmental temperature T _amb (t) around the unit cell 1 from the environmental temperature sensor, and the current value I(t) flowing through the unit cell 1 from the current detection unit 130. is acquired, and the measured value T _sur,mes (t) of the surface temperature of the cell 1 is acquired from the temperature sensor 2 . In addition, the central processing unit 190, for example, based on the acquired current value flowing through the cell 1, the voltage of the cell 1, the information stored in the storage device 180, etc., determines the state of health of the cell 1. SOH), SOC(t), OCV(t), etc.

Battery control system 100, for example, executes temperature calculation processing P4 shown in FIG. 6 by temperature calculation function F1 shown in FIG. In the temperature calculation function F1, the central processing unit 190 uses, for example, the measured value I(t) of the magnitude of the current measured by the current detection unit 130 as a current sensor as an input. Then, the central processing unit 190 calculates the calculated value T _sur,cal (t) of the surface temperature of the unit cell 1 and the internal temperature A temperature calculation value T(t) _seq including the calculation value T _in (t) is calculated.

In the example shown in FIG. 7, the central processing unit 190, in addition to the current measurement value I(t), for example, the environmental temperature _Tamb (t) around the cell 1 and the unit SOC(t) of battery 1 is used as input. Then, the central processing unit 190 outputs a calculated value T _sur,cal (t) of the surface temperature of the unit cell 1 and a calculated value T _in (t) of the internal temperature at each time interval Δt of calculation as the output of the temperature calculation function F1. Output the computed value T(t) _seq containing

That is, in the temperature calculation function F1, the central processing unit 190 first calculates the SOC(t) of the cell 1 and the previous temperature calculation value T(t- Δt) _seq and the current measurement value I(t) are input to calculate the heat generation amount Q _gen (t) of the unit cell 1 from time t−Δt to time t. Next, the central processing unit 190 calculates the previous calculated value T(t−Δt) _seq of the temperature of the unit cell 1 and the unit cell 1 and the ambient temperature T _amb (t) are input, and the calculated value T(t) _seq of the temperature of the cell 1 this _time is calculated and output.

Next, the battery control system 100 executes the error correction process P5 shown in FIG. 6 by the correction coefficient calculation function F2 and the error correction function F3 shown in FIG. In the correction factor calculation function F2, the central processing unit 190 uses the current sensor measured value I(t) of the magnitude of the current and the measured value of the duration of the current based on the correction factor map stored in the storage device 180. to calculate the correction coefficient α.

More specifically, in the correction coefficient calculation function F2, the central processing unit 190, for example, calculates the magnitude and duration of the current corresponding to the correction coefficient α on a one-to-one basis in the correction coefficient map in the above formula (5a), ( 5b) or calculate the current time index CTa, CTb or CTc represented by (5c). Then, using the obtained current-time index CTa, CTb or CTc, based on the correction coefficient map stored in the storage device 180, the correction coefficient α is calculated and output.

Next, in the error correction function F3, the central processing unit 190 calculates, for example, the calculated value T _sur,cal (t) of the surface temperature of the unit cell 1 and the calculated value T _in (t) of the internal temperature output from the temperature calculation function F1. t), the correction coefficient α output from the correction coefficient calculation function F2, and the measured value T _sur,mes (t) of the surface temperature of the cell 1 by the temperature sensor 2 are input. Then, the central processing unit 190 uses the calculated value T _sur,mes (t) of the surface temperature and the measured value T sur,mes (t) of the surface temperature measured by the temperature sensor 2 to obtain the above equation (4). A surface temperature error ΔT _sur (t) is calculated based on the expressed error calculation formula.

Furthermore, in the error correction function F3, the central processing unit 190 uses the correction coefficient α output by the correction coefficient calculation function F2, the surface temperature error ΔT _sur (t), and the calculated value T _in (t) of the internal temperature to obtain the above-mentioned An internal temperature correction value T' _in (t) is calculated and output based on the internal temperature correction formula represented by Equation (6). In addition, in the error correction function F3, the central processing unit 190 calculates the measured value T _sur,mes (t) of the surface temperature of the unit cell 1 based on the surface temperature correction formula represented by the above-described formula (7), for example. Output as surface temperature correction value T' _sur,cal (t).

As described above, the battery control system 100 converts the internal temperature correction value T' _in (t) output from the error correction function F3 shown in FIG. The assembled battery 110 , the battery group 111 and the single cell 1 are controlled by the assembled battery control unit 150 and the single cell management unit 120 .

Next, the battery control system 100 executes stop determination processing P6 shown in FIG. More specifically, battery control system 100, for example, by central processing unit 190, determines whether or not the activation switch of the vehicle is off. When the central processing unit 190 determines that the start switch of the vehicle is not off (NO), it returns to the temperature calculation process P4, and when it determines that the start switch of the vehicle is off (YES), it executes the history writing process P7.

In the history writing process P7, the battery control system 100, for example, by the central processing unit 190, determines the time when the start switch of the vehicle is turned off, the temperature of the cell 1 at the time of the stop, the SOC of the cell 1 at the time of the stop, and the temperature of the cell 1 at the time of the stop. is overwritten and stored in the storage device 180 . As described above, the operation of the battery control system 100 is completed, and the activation determination process P1 is started again.

For example, in the battery control system 100 of the present embodiment, all the cells 1 forming the assembled battery 110 are usually controlled to have substantially the same SOC and have substantially the same open circuit voltage. The open-circuit voltage of the cell 1 is the voltage value of the cell 1 when no current flows through the cell 1, that is, when the magnitude of the current flowing through the cell 1 is zero.

The voltage of the single cell 1 is determined by the internal resistance that depends on the internal temperature of the single cell 1 . The internal resistance of the cell 1 mainly depends on the temperature of the wound body 1a, that is, the internal temperature of the cell 1. The lower the internal temperature of the cell 1, the higher the internal resistance of the cell 1 tends to be. . Therefore, among the plurality of cells 1 connected in series and through which the same amount of current flows, the cell 1 with the lowest temperature reaches the upper limit voltage or the lower limit voltage in the shortest time.

The allowable power of the assembled battery 110 is the power at which any single cell 1 constituting the assembled battery 110 reaches the upper limit voltage or lower limit voltage during charging or discharging. Therefore, as the internal temperature of the cell 1 decreases, the allowable power of the assembled battery 110 decreases. Therefore, in order to calculate the allowable power of the assembled battery 110, it is necessary to use at least the lowest internal temperature of the cell 1. FIG. However, the wound body 1a is accommodated inside the container 1c. Therefore, the temperature of the wound body 1a, that is, the internal temperature of the cell 1 cannot be directly measured by a temperature sensor or the like.

The surface temperature of the single cell 1 directly measured by the temperature sensor 2 is lower than the temperature of the wound body 1a of the single cell 1, that is, the internal temperature of the single cell 1. Therefore, if the surface temperature of the cell 1 measured by the temperature sensor 2 is used as the internal temperature of the cell 1 as it is to calculate the internal resistance of the cell 1, the calculated value of the internal resistance of the cell 1 will be the actual value. It becomes higher than the internal resistance, and the allowable power of the assembled battery 110 is excessively limited. This causes the performance of assembled battery 110 to deteriorate, for example, in a low-temperature environment such as a cold region.

The conventional control device described in Patent Document 1 estimates the maximum temperature inside the battery group and limits the input/output of the battery group based on the estimated maximum temperature. The maximum temperature of the battery group is estimated by estimating the temperature difference between the inside and outside of the battery, which is the difference between the temperature inside the battery and the temperature on the surface of the battery, according to at least one of the intake air temperature, the current load, and the cooling air volume. The internal resistance of each unit battery is estimated from each battery voltage and current value at the arrangement position of , and the temperature difference within the battery group due to the difference in internal resistance of each unit battery is estimated.

Then, the total value of the temperature differences estimated by these is added to the maximum value of the battery surface temperature to estimate the maximum temperature of the battery group. However, the maximum internal temperature of the battery group estimated by the maximum temperature estimator has an error with the true internal temperature of the battery group due to the accuracy limit of the temperature model of the battery group.

In the conventional method described in Patent Document 2, the difference between the temperature measured at the outer wall of the battery module and the output temperature of the diffusion model of the heat generated inside the charge storage element of the battery module is substantially zero. The temperature values supplied as inputs to the model are determined such that However, all of the methods for realizing this have the problem that the computational load is high.

In contrast, as described above, the battery control system 100 of the present embodiment is characterized by the following configuration. The battery control system 100 includes a current detection unit 130 as a current sensor that measures the magnitude of the current flowing through the cell 1, a temperature sensor 2 that measures the surface temperature of the cell 1, a storage device 180, and a central processing unit 190. . The storage device 180 stores the battery temperature estimation formula, the error calculation formula, the correction coefficient map, and the internal temperature correction formula of formula (6). The battery temperature estimation formula is a formula that defines the relationship between the surface temperature T _sur and the internal temperature T _in of the unit cell 1 and the current magnitude I(t), like the formulas (1) and (2). . As shown in Equation (4) above _, the error calculation formula is the surface temperature error ΔT _sur ( _t ). The correction coefficient map is, for example, a table or graph that defines the relationship between the magnitude and duration of the current represented by (5a), (5b) or (5c) and the correction coefficient α. The internal temperature correction formula is the internal temperature correction value T', which is the sum of the surface temperature error ΔT _sur (t) multiplied by the correction coefficient α and the calculated value T _in (t) of the internal temperature, as shown in Equation (6) above. It is a formula for _in (t). In addition, central processing unit 190 uses the magnitude of the current measured by the current sensor to calculate the surface temperature and internal temperature of unit cell 1 based on the battery temperature estimation formula. Further, the central processing unit 190 uses the calculated surface temperature value T _sur,cal (t) and the measured surface temperature value T _sur,mes (t) measured by the temperature sensor 2, based on the error calculation formula. to calculate the surface temperature error ΔT _sur (t). In addition, the central processing unit 190 uses the magnitude and duration of the current measured by the current sensor to calculate the correction coefficient α based on the correction coefficient map. Further, the central processing unit 190 uses the correction coefficient α, the surface temperature error ΔT _sur (t), and the calculated value T _in of the internal temperature to calculate the internal temperature correction value T′ _in (t) based on the internal temperature correction formula. do. Then, the central processing unit 190 controls the cell 1, the battery group 111 and the assembled battery 110 based on the internal temperature correction value _T'in (t).

With such a configuration, the battery control system 100 of the present embodiment suppresses the error between the true internal temperature of the cell 1 and its calculated value T _in (t), while reducing the calculation load more than before. can do. For example, consider a case where the heat generation amount Q _gen (t) of cell 1 calculated by central processing unit 190 is less than the true heat generation amount of cell 1 . In this case, the calculated value T _in (t) of the internal temperature of the cell 1 is lower than the true internal temperature of the cell 1 . Since the calculated value T _sur,cal (t) of the surface temperature of the cell 1 depends on the amount of heat transfer from the inside of the cell 1, similarly, the calculated value T _sur,cal (t ) is also lower than the true surface temperature. Here, the true surface temperature of cell 1 can be measured by temperature sensor 2 .

FIG. 8 is a graph of the internal temperature correction value _T'in (t), which is the output of the error correction function F3 shown in FIG. As shown in FIG. 8, according to the battery control system 100 of the present embodiment, the measured value T _sur,mes (t), which is the true surface temperature of the cell 1 measured by the temperature sensor 2, and the A surface temperature error ΔT _sur (t), which is a difference from the calculated value T _sur,cal (t) of the surface temperature, can be obtained. Then, the calculated surface temperature error ΔT _sur (t) is multiplied by the correction coefficient α and added to the calculated value T _in (t) of the internal temperature of the unit cell 1 to obtain the internal temperature correction value T′ _in (t). can ask. Therefore, it is possible to reduce the calculation load more than before while suppressing the error between the true internal temperature of the cell 1 and its calculated value T _in (t).

9 and 10 are graphs illustrating the effect of the internal temperature correction value _T'in (t) calculated in the battery control system 100 of this embodiment. 9 and 10, the true internal temperature T _in,real (t) of the cell 1 is indicated by a solid line, and the internal temperature correction value T' _{in ,var} (t) is shown with a dotted line. 9 and 10, the true surface temperature of the unit cell 1, that is, the measured value T _sur,mes (t) of the surface temperature of the unit cell 1 is indicated by a chain double-dashed line.

Furthermore, as comparative examples 1 and 2 with respect to the present embodiment, the internal temperature correction values T'in _,fix,S (t) _{and T'in,fix,L} (t) of the cell 1 when the correction coefficient α is fixed are indicated by a dashed-dotted line and a dashed line, respectively. Note that the internal temperature correction value T' _in,fix,L (t) of Comparative Example 1 indicated by a dashed line is a case where the correction coefficient α is fixed to a value larger than that of Comparative Example 2, and is indicated by a dashed line. The internal temperature correction value T′ _in,fix,S (t) of Comparative Example 2 is obtained by fixing the correction coefficient α to a value smaller than that of Comparative Example 1. In the examples shown in FIGS. 9 and 10, the true internal temperature T _in,real (t) of the unit cell 1 and the internal temperature correction value T′ _in,var (t) of the present embodiment differ from each other over all time. It is higher than the measured value T _sur,mes (t) of the surface temperature of the battery 1 .

9 and 10, in the section up to time t1, the true calorific value Q _gen,real (t) of the cell 1 and the calculated value Q _gen,cal (t) of the calorific value of the cell 1 are almost equal. Assume the case. In this case, in the section up to time t1, the error between the true heat generation amount Q _gen,real (t) of the cell 1 and the calculated value Q _gen,cal (t) of the heat generation amount of the cell 1 is small. , the error between the calculated value T _in (t) of the internal temperature before correction and the true internal temperature T _in,real (t) is small, and the calculated value T _in (t) of the internal temperature does not require a large correction.

Therefore, in the interval up to this time t1, the internal temperature correction value T' _in,fix,S (t) of Comparative Example 2 in which the correction coefficient α is fixed at a relatively small value and the true internal temperature T _in,real (t) becomes smaller. On the other hand, in the internal temperature correction value T′ _in,fix,L (t) of Comparative Example 1 in which the correction coefficient α is fixed at a relatively large value, the correction amount of the calculated value T _in (t) of the internal temperature is excessive. , and oscillates around the true internal temperature T _in,real (t). That is, when the error between the true calorific value Q _gen,real (t) of the cell 1 and the calculated calorific value Q _gen,cal (t) is small, the correction coefficient α is fixed at a value larger than necessary. Then, like the internal temperature correction value T'in _,fix,L (t) of Comparative Example 1, the error from the true internal temperature _Tin,real (t) increases.

In addition, in FIG. 9, in the section after time t1, the true heat generation amount Q _gen,real (t) of the cell 1 becomes larger than the calculated value Q _gen,cal (t) of the heat generation amount of the cell 1. ing. In this case, the calculated value T _in (t) of the internal temperature before correction becomes smaller than the true internal temperature T _in,real (t), requiring a relatively large correction. Therefore, in the section after time t1, the internal temperature correction value T′ _in,fix,L (t) of Comparative Example 1, in which the correction coefficient α is fixed at a relatively large value, and the true internal temperature T _in,real (t) becomes smaller. On the other hand, in the internal temperature correction value T′ _in,fix,S (t) of Comparative Example 2 in which the correction coefficient α is fixed at a relatively small value, the correction amount of the calculated value T _in (t) of the internal temperature is too small. , and the error from the true internal temperature T _in,real (t) increases. That is, when the error between the true calorific value Q _gen,real (t) of the cell 1 and the calculated calorific value Q _gen,cal (t) is large, the correction coefficient α is fixed at a value smaller than necessary. Then, the error from the true internal temperature T in, _{real (t) increases like the internal temperature correction value T′ in, fix,S} (t) of Comparative Example 2 shown in FIG.

In addition, in FIG. 10, in the section after time t1, the true heat generation amount Q _gen,real (t) of the cell 1 becomes smaller than the calculated value Q _gen,cal (t) of the heat generation amount of the cell 1. ing. Therefore, the calculated value T _in (t) of the internal temperature before correction is higher than the true internal temperature T _in,real (t) and requires a relatively large correction. Therefore, in the section after time t1, the internal temperature correction value T′ _in,fix,L (t) of Comparative Example 1, in which the correction coefficient α is fixed at a relatively large value, and the true internal temperature T _in,real (t) becomes smaller. On the other hand, in the internal temperature correction value T′ _in,fix,S (t) of Comparative Example 2 in which the correction coefficient α is fixed at a relatively small value, the correction amount of the calculated value T _in (t) of the internal temperature is too small. , and the error from the true internal temperature T _in,real (t) increases. That is, when the error between the true calorific value Q _gen,real (t) of the cell 1 and the calculated calorific value Q _gen,cal (t) is large, the correction coefficient α is fixed at a value smaller than necessary. Then, the error from the true internal temperature T in, _{real (t) increases like the internal temperature correction value T′ in, fix,S} (t) of Comparative Example 2 shown in FIG.

In this way, the internal temperature correction values T'in _,fix,S (t) and T'in _,fix,L (t) of Comparative Examples 1 and 2 with the correction coefficient α fixed are shown in FIGS. In both the interval up to time t1 and the interval after time t1, the error from the true internal temperature T _in,real (t) cannot be reduced. On the other hand, according to the battery control system 100 of the present embodiment, by increasing or decreasing the correction coefficient α according to the magnitude and duration of the current flowing through the cell 1, In both intervals, the error between the internal temperature correction value T' _in,var (t) and the true internal temperature T _in,real (t) can be reduced. Further, the battery control system 100 of the present embodiment can calculate the internal temperature correction value T'in _,var (t) by simple calculation using the correction coefficient α. Therefore, according to the battery control system 100 of the present embodiment, while suppressing the error between the true internal temperature T _in,real (t) of the cell 1 and its calculated value T _in (t), can also reduce the computational load.

FIG. 11 is a graph illustrating the effect of the battery control system 100 on allowable power in the section after time t1 shown in FIG. In the interval after time t1 shown in FIG. 9, the true heat generation amount Q _gen,real (t) of the cell 1 is larger than the calculated value Q _gen,cal (t) of the heat generation amount of the cell 1. . The error between the true internal temperature T _in,real (t) of the cell 1 and the measured value T _sur,mes (t) of the surface temperature of the cell 1 is the largest. The correction value T' _in,fix,S (t) is the second largest, and the internal temperature correction value T' _in,var (t) of this embodiment and the internal temperature correction value T' _in,fix,L (t) is equivalent and smallest. Therefore, if the measured value T _sur,mes (t) of the surface temperature of the cell 1 or the internal temperature correction value T′ _in,fix,S (t) of Comparative Example 1 is used to calculate the allowable power, the calculation of the allowable power Compared to the case where the true internal temperature T _in,real (t) of the cell 1 is used for , the calculated value P(T) of the allowable power becomes smaller. In this case, the single cell 1 cannot be fully utilized up to the true allowable power.

On the other hand, if the internal temperature correction value T' _in,var (t) of the present embodiment is used to calculate the allowable power, the true internal temperature T _in,real (t) of the cell 1 is used to calculate the allowable power. A calculated value P(T) of the allowable power equivalent to the case of using is obtained. It should be noted that in the interval after time t1 shown in FIG. 9, the same effect can be obtained even when the internal temperature correction value T'in _,fix,L (t) of Comparative Example 2 is used to calculate the allowable power. However, in the section up to time t1 shown in FIG _. may be calculated, the life and safety of the unit cell 1 may be reduced.

FIG. 12 is a graph illustrating the effect of the battery control system 100 on allowable power in the section after time t1 shown in FIG. In the section after time t1 shown in FIG. 10, the true heat generation amount Q _gen,real (t) of the cell 1 is smaller than the calculated value Q _gen,cal (t) of the heat generation amount of the cell 1. . The error between the true internal temperature T _in,real (t) of the cell 1 and the measured value T _sur,mes (t) of the surface temperature of the cell 1 is the largest. The correction value T' _in,fix,S (t) is the second largest, and the internal temperature correction value T' _in,var (t) of this embodiment and the internal temperature correction value T' _in,fix,L (t) is equivalent and smallest.

Therefore, if the measured value T _sur,mes (t) of the surface temperature of the cell 1 is used to calculate the allowable power, the true internal temperature T _in,real (t) of the cell 1 is used to calculate the allowable power. Compared to the case, the calculated value P(T) of the allowable power becomes smaller. In this case, the single cell 1 cannot be fully utilized up to the true allowable power. Further, if the internal temperature correction value T' _in,fix,S (t) of Comparative Example 1 is used for calculation of the allowable power, the true internal temperature T _in,real (t) of the cell 1 is used for the calculation of the allowable power. The calculation value P(T) of the allowable power becomes larger than when it is used. In this case, the life and safety of the cell 1 may be reduced.

On the other hand, if the internal temperature correction value T' _in,var (t) of the present embodiment is used to calculate the allowable power, the true internal temperature T _in,real (t) of the cell 1 is used to calculate the allowable power. A calculated value P(T) of the allowable power equivalent to the case of using is obtained. It should be noted that in the section after time t1 shown in FIG. 10, similar effects can be obtained when the internal temperature correction value T'in _,fix,L (t) of Comparative Example 2 is used to calculate the allowable power. However, in the interval up to the time t1 _shown in FIG. may be calculated, the life and safety of the unit cell 1 may be reduced.

As described above, according to the present embodiment, it is possible to provide the battery control system 100 that can reduce the calculation load more than the conventional one while suppressing the error between the true internal temperature of the battery and its calculated value. can be done. In addition, by using the internal temperature correction value T'in _,var (t), the single cell 1, the battery group 111, and the assembled battery 110 can be safely and fully utilized up to the allowable power.

[Embodiment 2]
Next, Embodiment 2 of the battery control system according to the present disclosure will be described with reference to FIGS. 13 and 14 with reference to FIGS. The battery control system of this embodiment differs from the battery control system 100 according to the first embodiment in the information stored in the storage device 180 and the processing by the central processing unit 190 . Other points of the battery control system of the present embodiment are the same as those of the battery control system 100 of the first embodiment described above, so the same parts are denoted by the same reference numerals and the description thereof is omitted.

In the battery control system of the present embodiment, the battery temperature estimation formula stored in the storage device 180 defines the relationship between the temperature of a plurality of parts of the cell 1 and the magnitude of current. Further, the correction coefficient map stored in the storage device 180 defines the relationship between the magnitude and duration of the current and the correction coefficient α _i for each portion of the cell 1 . Further, the storage device 180 stores the surface temperature error ΔT _sur (t) multiplied by the correction coefficient α _i of each portion of the cell 1 and each A partial temperature correction formula is stored that sets a partial temperature correction value T′ _i (t) to the sum of the calculated value T _i (t) of the temperature of the part.

FIG. 13 is a functional block diagram of the battery control system of this embodiment. As shown in FIG. 13, in the temperature calculation function F1, the central processing unit 190 uses the measured value I(t) of the magnitude of the current measured by the current detection unit 130, which is a current sensor, to calculate the battery temperature estimation formula , the calculated value T _i (t) of the temperature of each portion of the cell 1 is output. Then, the central processing unit 190 adds the calculated surface temperature value T _sur,cal (t) and the internal temperature value T _in (t) of the cell 1 output from the temperature calculation function F1 to the cell 1 to the _error correction function F3.

In addition, in the correction coefficient calculation function F2, the central processing unit 190 uses the measured value I(t) of the magnitude of the current and the measured value of the duration of the current by the current sensor, and uses the correction coefficient map stored in the storage device 180. A sequence α _seq of correction coefficients α _i for each portion of the cell 1 is calculated based on . Here, α _in is a correction coefficient for the inside of the cell 1 . In this case, similarly to the first embodiment described above, in the correction coefficient map, the correction coefficient α _in is determined so as to increase as the current time index CTa, CTb or CTc increases, for example.

Therefore, in the correction coefficient _calculation function F2, the central processing unit 190 performs α _in /Σα _i is relatively large and the error in the heat generation amount Q _gen (t) of the cell 1 is relatively small, α _in /Σα _i is relatively small and the sequence α _seq of the correction coefficient α _i is output.

Further, in the error correction function F3, the central processing unit 190 uses the correction coefficient α _i , the surface temperature error ΔT _sur (t), and the calculated value T _i (t) of the temperature of each portion of the unit cell 1 to obtain the above formula A partial temperature correction value T′ _i (t), which is a temperature correction value for each portion of the cell 1, is calculated based on the partial temperature correction formula (8). Then, the central processing unit 190 controls the cell 1 based on this partial temperature correction value T' _i (t).

In Embodiment 1 described above, the error correction function F3 corrects only the calculated value T _in (t) of the internal temperature of the cell 1 . This method is a method of reflecting all of the surface temperature error ΔT _sur (t) of the single cell 1 in the internal temperature correction value T′ _in (t) of the single cell 1 . However, in the actual cell 1, heat conduction occurs not only between the surface and the inside, but also between the surface of the cell 1 and portions other than the inside of the cell 1.

For example, when a current flows through the single cell 1 and the single cell 1 generates heat from the inside, most of the heat transfer to the surface of the single cell 1 is from the inside of the single cell 1 . In this case, just by correcting the calculated value T _in (t) of the internal temperature of the cell 1 as in the first embodiment described above, the internal temperature correction value T′ _in (t) close to the true internal temperature can be obtained. is obtained.

However, when the current flowing through the cell 1 is zero and the inside of the cell 1 does not generate heat, the heat transfer to the surface of the cell 1 is The ratio of heat transfer from portions other than the inside of the cell 1 increases. In addition, it is conceivable that the model of heat conduction between the surface of the single cell 1 and portions other than the inside of the single cell 1 is inaccurate. In this case, in the method of reflecting all the surface temperature error ΔT _sur (t) of the single cell 1 in the internal temperature correction value T′ _in (t) of the single cell 1 as in the first embodiment, the internal temperature correction value T′ There is a possibility that the error between _in (t) and the true internal temperature of the cell 1 cannot be made sufficiently small.

FIG. 14 is a graph explaining the effect of the internal temperature correction value of the battery control system of this embodiment. In FIG. 14, the true internal temperature T _in,real (t) of the cell 1 is indicated by a solid line, and the internal temperature correction value T′ _in,var,1 (t) by the battery control system 100 of Embodiment 1 is indicated by a single point. It is indicated by a dashed line, and the internal temperature correction value T'in _,var,2 (t) by the battery control system of the second embodiment is indicated by a dotted line. In the section up to time t2, a current flows through the cell 1 and the cell 1 generates heat. In the section after time t2, no current flows through the cell 1 and the cell 1 does not generate heat.

In the interval up to time t2, the internal temperature correction value T′ _in,var,1 (t) by the battery control system 100 of Embodiment 1 and the internal temperature correction value T′ _in,var,2 by the battery control system of Embodiment 2 (t) has a small error from the true internal temperature T _in,real (t) of the cell 1 .

However, in the battery control system 100 of Embodiment 1, the surface temperature error ΔT _sur (t) of the cell 1 is reflected only in the internal temperature correction value T′ _in,var,1 (t). Therefore, in the section after time t2, if the thermal conduction model of the cell 1 is inaccurate, the internal temperature correction value T' _in,var,1 (t) and the true internal temperature T _in,real The error with (t) is expanding.

On the other hand, the internal temperature correction value T' _in,var,2 (t) by the battery control system of the present embodiment is such that the surface temperature error ΔT _sur (t) of the cell 1 is the internal temperature correction value T' _in, It is reflected not only in _var,1 (t) but also in partial temperature correction values _T'i (t) of other parts. As a result, even if the heat conduction model of the unit cell 1 is inaccurate, the error in the calculated value T _in (t) of the internal temperature due to heat conduction can be corrected, and the internal temperature correction value T′ _{in,var, 2} (t) and the true internal temperature T _in,real (t) of the cell 1 can be reduced.

As described above, in the battery control system of the present embodiment, the storage device 180 includes a battery temperature estimation formula that defines the relationship between the temperature of a plurality of parts of the cell 1 and the magnitude of the current, and A surface temperature error ΔT _sur (t) multiplied by a correction coefficient map that defines the relationship between the magnitude and duration of the current and the correction coefficient for the portion of the unit cell 1 and the correction coefficient α _i for each portion of the cell 1 and a partial temperature correction formula that sets the partial temperature correction value T′ _i (t) to the sum of the calculated value T _i (t) of the temperature of each portion of the cell 1 . In addition, the central processing unit 190 uses the magnitude of the current measured by the current sensor to calculate the temperature of each portion of the cell 1 based on the battery temperature estimation formula, and the magnitude and duration of the current measured by the current sensor. Using the time measurements, calculate the correction factor α _i for each portion of the cell 1 based on the correction factor map, and calculate the correction factor α _i , the surface temperature error ΔT _sur (t) and each portion of the cell 1 Using the calculated value T _i (t) of the temperature, the partial temperature correction value T′ _i (t) is calculated based on the partial temperature correction _formula , and the unit cell 1 , the battery group 111 and the assembled battery 110 are controlled.

With this configuration, according to the battery control system of the present embodiment, not only can the same effect as the battery control system 100 of the first embodiment described above be obtained, but current does not flow through the single cell 1, causing the single cell 1 to generate heat. Even if not, the error between the internal temperature correction value T' _in,var,2 (t) and the true internal temperature T _in,real (t) of the cell 1 can be reduced.

[Embodiment 3]
Next, Embodiment 3 of the battery control system according to the present disclosure will be described with reference to FIGS. 1 to 6 and FIG. 15 . FIG. 15 is a functional block diagram of the battery control system of this embodiment. The battery control system of this embodiment differs from the battery control system 100 according to the first embodiment in the information stored in the storage device 180 and the processing by the central processing unit 190 . Other points of the battery control system of the present embodiment are the same as those of the battery control system 100 of the first embodiment described above, so the same parts are denoted by the same reference numerals and the description thereof is omitted.

As with the battery control system 100 of Embodiment 1, the battery control system of this embodiment includes a voltage detection circuit 121a shown in FIG. The storage device 180 also stores state-of-charge-open-circuit voltage data indicating the relationship between the state-of-charge (SOC) of the single cell 1 and the open-circuit voltage (OCV) of the single cell 1, and the SOC of one single cell 1 and one single cell. State-of-charge-temperature coefficient data for which one state-of-charge-temperature coefficient is determined in combination with the internal temperature of the battery 1 is stored. In addition, the central processing unit 190 uses the OCV of the cell 1 measured by the voltage sensor, calculates the SOC of the cell 1 based on the state of charge-open circuit voltage data, and calculates the SOC value and the internal temperature value. Using T _in (t), calculate the state of charge-temperature coefficient based on the state of charge-temperature coefficient data, multiply the calculation result by the internal temperature correction formula by the state of charge-temperature coefficient, and obtain the internal temperature correction value T' Compute _in (t).

In the battery control system 100 of Embodiment 1 described above, the correction coefficient calculation function F2 receives only the current measurement value I(t) and its duration. On the other hand, in the battery control system of the present embodiment, as shown in FIG. 15, in addition to the measured current value I(t), the calculated values _Tin (t) and SOC(t) of the internal temperature of the cell 1 are also calculated. It is used as an input for the correction coefficient calculation function F2. The amount of heat generated by the single cell 1 is affected not only by the current measurement value I(t) and its duration, but also by the internal temperature and SOC of the single cell 1 .

With the configuration described above, the battery control system of the present embodiment can achieve the same effects as the battery control system 100 of the first embodiment described above. Further, in the correction coefficient calculation function F2, the central processing unit 190 calculates the internal temperature when SOC(t) is higher than the upper limit threshold, when SOC(t) is lower than the lower limit threshold, and when SOC(t) is lower than the lower limit threshold. The lower the value T _in (t), the higher the state of charge-temperature coefficient can be. Therefore, it is possible to calculate the internal temperature correction value T' _{in (} t) by classifying the cases in which an error occurs in the amount of heat generated by the cell 1 in more detail. The error with the internal temperature can be reduced more effectively.

[Embodiment 4]
Next, Embodiment 4 of the battery control system according to the present disclosure will be described with reference to FIGS. 1 to 6 and FIG. 16 . FIG. 16 is a functional block diagram of the battery control system of this embodiment. The battery control system of this embodiment differs from the battery control system 100 according to the first embodiment in the information stored in the storage device 180 and the processing by the central processing unit 190 . Other points of the battery control system of the present embodiment are the same as those of the battery control system 100 of the first embodiment described above, so the same parts are denoted by the same reference numerals and the description thereof is omitted.

As with the battery control system 100 of Embodiment 1, the battery control system of this embodiment includes a voltage detection circuit 121a shown in FIG. The storage device 180 stores the state-of-charge-open-circuit voltage data that defines the relationship between the state of charge (SOC) of the cell 1 and the open-circuit voltage (OCV) of the cell 1, the SOC of the cell 1, and the data that flows through the cell 1. a calorific value calculation formula that defines the relationship between the magnitude of current, the calculated value of the internal temperature of the cell 1 or the measured value of the voltage of the battery by a voltage sensor, and the calorific value of the cell 1; and calorific value-correction coefficient data defining the relationship between the calorific value and the correction coefficient α. The central processing unit 190 uses the OCV of the single battery 1 measured by the voltage sensor to calculate the SOC of the single battery 1 based on the state-of-charge - open-circuit voltage data. Using the size and the calculated value _Tin (t) of the internal temperature or the measured value of the voltage of the cell 1 by the voltage sensor, the heat generation amount of the cell 1 is calculated based on the heat generation calculation formula, Using the calculated calorific value of 1, α is calculated based on the calorific value-correction coefficient data.

In the battery control system 100 of Embodiment 1 described above, the correction coefficient calculation function F2 receives the current measurement value I(t) as an input. However, in the battery control system of the present embodiment, the heat generation amount Q _gen (t) of the unit cell 1, which is the output of the temperature calculation function F1, is used as the input of the correction coefficient calculation function F2, instead of the measured current value I(t). and

That is, in the battery control system of the present embodiment, in the temperature calculation function F1, the central processing unit 190 calculates the SOC(t) and the current measurement value I(t), and the internal temperature calculation value T _in (t) or Using the measured value of the voltage of the single cell 1 by the voltage sensor, the heat generation amount Q _gen (t) of the single cell 1 is calculated based on the heat generation calculation formula, and is output to the correction coefficient calculation function F2.

Further, in the battery control system of the present embodiment, in the correction coefficient calculation function F2, the central processing unit 190 uses the calculated value Q _gen (t) of the calorific value of the unit cell 1, based on the calorific value-correction coefficient data. Calculate the correction coefficient α. Thereby, the central processing unit 190 outputs the correction coefficient α as a function proportional to the calculated value Q _gen (t) of the heat generation amount of the unit cell 1, for example.

Therefore, according to the battery control system of the present embodiment, for example, an error proportional to the heat generation amount of the cell 1 occurs between the calculated value T _in (t) of the internal temperature of the cell 1 and the true internal temperature. , the calculated value T _in (t) of the internal temperature of the cell 1 can be corrected by a correction amount proportional to the amount of heat generated by the cell 1 . As a result, according to the present embodiment, as in the first embodiment described above, it is possible not only to suppress the error between the true internal temperature of the unit cell 1 and its calculated value T _in (t), It is possible to provide a battery control system that can reduce the calculation load more than the battery control system 100 of the first embodiment.

[Embodiment 5]
Next, Embodiment 5 of the battery control system according to the present disclosure will be described with reference to FIGS. 1 to 6 and FIG. 17 . FIG. 17 is a functional block diagram of the battery control system of this embodiment. The battery control system of this embodiment differs from the battery control system 100 according to the first embodiment in the information stored in the storage device 180 and the processing by the central processing unit 190 . Other points of the battery control system of the present embodiment are the same as those of the battery control system 100 of the first embodiment described above, so the same parts are denoted by the same reference numerals and the description thereof is omitted.

In the battery control system 100 of Embodiment 1, the temperature calculation function F1 receives the measured value I(t) of the current flowing through the cell 1, and calculates the heat generation of the cell 1 using the above formula (2) or (3). We were calculating the quantity Q _gen (t). On the other hand, the battery control system of the present embodiment does not calculate the heat generation amount Q _gen (t) of the cell 1, but uses the surface temperature error ΔT _sur (t) of the cell 1 to calculate the internal temperature of the cell 1. Correct the value T _in (t).

In the battery control system of the present embodiment, the storage device 180 stores a heat transfer amount calculation formula that defines the relationship between the surface temperature and internal temperature of the cell 1 and the heat transfer amount of the cell 1 . The central processing unit 190 uses the calculated value T _sur,cal (t) of the surface temperature of the unit cell 1 and the calculated value T _in (t) of the internal temperature of the unit cell 1, and calculates the heat transfer of the unit cell 1 using the heat transfer amount calculation formula. Calculate quantity.

More specifically, as shown in FIG. 17, in the battery control system of the present embodiment, the temperature calculation function F1 does not use the current measurement value I(t) as an input, and the unit cell 1's Only the amount of heat transfer is calculated using a calculation formula in which the amount of heat generated Q _gen (t)=0, that is, the calculation formula for the amount of heat transfer. Further, in the battery control system of the present embodiment, in the correction coefficient calculation function F2, the current measurement value I(t) is input, and a correction coefficient map that defines the relationship between the magnitude and duration of the current and the correction coefficient α Based on, the correction coefficient α is calculated and output.

In the battery control system of the present embodiment, in order to reflect the heat generation amount of the cell 1, only the error from the heat generation amount of the cell 1 is corrected under each condition of the current flowing through the cell 1. The correction coefficient α becomes larger than that of the control system 100 . However, according to the battery control system of the present embodiment, the calculation of the calorific value Q _gen (t) of the cell 1 can be omitted, and the calculation load can be reduced more than the battery control system 100 of the first embodiment. can.

The embodiment of the battery control system 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 cell (battery)
2 temperature sensor 100 battery control system 121a voltage detection circuit (voltage sensor)
130 current detector (current sensor)
140 voltage detection unit (voltage sensor)
180 storage device 190 central processing unit
I(t) current measurement
Q _gen (t) Heat generation of single cell
SOC(t) Battery state of charge
T _amb (t) Ambient temperature
T _in (t) Calculated cell internal temperature
T' _in (t) Internal temperature correction value
T _oth (t) Computed temperature of other part of cell
T' _i (t) Partial temperature correction value
T _sur,mes (t) Measured cell surface temperature
T _sur,cal (t) Calculated cell surface temperature
T' _sur,cal (t) Surface temperature correction value ΔT _sur (t) Surface temperature error α Correction coefficient α Sequence of _seq correction coefficients

Claims (3)

A battery control system comprising a current sensor for measuring the magnitude of the current flowing through the battery, a temperature sensor for measuring the surface temperature of the battery, a storage device, and a central processing unit,
The storage device stores a battery temperature estimation formula that defines the relationship between the surface temperature and internal temperature of the battery and the magnitude of the current, and the difference between the measured value of the surface temperature and the calculated value of the surface temperature as a surface temperature error. , a correction coefficient map that defines the relationship between the magnitude and duration of the current and the correction coefficient, and the sum of the surface temperature error multiplied by the correction coefficient and the calculated value of the internal temperature An internal temperature correction formula as an internal temperature correction value is stored,
The central processing unit calculates the surface temperature and the internal temperature based on the battery temperature estimation formula using the magnitude of the current measured by the current sensor, and calculates the surface temperature and the temperature The surface temperature error is calculated based on the error calculation formula using the surface temperature measured by the sensor, and the correction is performed using the current magnitude and duration measured by the current sensor. calculating the correction coefficient based on the coefficient map; using the correction coefficient, the surface temperature error, and the calculated value of the internal temperature; calculating the internal temperature correction value based on the internal temperature correction formula; A battery control system that controls the battery based on a correction value. The storage device stores the battery temperature estimation formula defining the relationship between the temperature of a plurality of parts of the battery and the magnitude of the current, and the magnitude of the current and the continuity for each of the parts of the battery. the correction coefficient map in which the relationship between time and the correction coefficient is defined; the surface temperature error multiplied by the correction coefficient of each of the portions of the battery; and a calculated value of the temperature of each of the portions of the battery. and a partial temperature correction formula having a partial temperature correction value that is the sum of
The central processing unit uses the magnitude of the current measured by the current sensor to calculate the temperature of each of the portions based on the battery temperature estimation formula, and the magnitude and continuity of the current by the current sensor. calculating said correction factor for each said part based on said correction factor map using said measurements of time; calculating said part temperature using said correction factor, said surface temperature error and said calculated values of temperature of each said part; calculating the partial temperature correction value based on a correction formula, and controlling the battery based on the partial temperature correction value;
The battery control system according to claim 1. In the correction coefficient map stored in the storage device,
The relationship between the magnitude of the current and the duration and the correction factor is
An increase in the current time index CTa, CTb or CTc represented by the formula (5a), (5b) or (5c), where I is the measured value of the magnitude of the current, R is the internal resistance of the battery, and t is the time. is stored as a relationship in which the correction coefficient increases with
The battery control system according to claim 1.

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