Battery control device and vehicle control device

Abstract

A computing device 130 of a battery control device calculates a first resistance value R1 of a secondary battery on the basis of an amount of change in a voltage value between a first time c1 and a second time c2, and an amount of change in a current value between the first time and the second time. Next, an amount of change β in surface temperature is calculated on the basis of a first surface temperature Ts1 within a range from the first time to the second time and a second surface temperature Ts2 at a third time at which a predetermined time n has elapsed from the second time. Next, the amount of current flowing through the secondary battery from the time at which the first surface temperature was measured to the third time c3 at which the second surface temperature was measured is calculated. Next, the internal temperature of the secondary battery is estimated on the basis of the amount of change in the surface temperature and the amount of current. Next, with reference to a map, a second resistance value R2 reflecting the difference between the internal temperature and the surface temperature of the secondary battery is estimated on the basis of the estimated internal temperature. A deterioration rate is calculated on the basis of the first resistance value and the second resistance value.

Description

Battery control device and vehicle control device

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

[0002] 2. Description of the Related Art Conventionally, a technique for determining deterioration of a secondary battery has been known (see Patent Document 1).

[0003] JP 2016-215836 A

[0004] In battery control and vehicle control, there is a demand for improved accuracy in calculating the deterioration rate of secondary batteries.

[0005] A battery control device according to one aspect of the present invention includes a map containing data indicating the relationship between the surface temperature, internal temperature, and resistance of a secondary battery, and a calculation device that calculates a deterioration rate of the secondary battery based on the amount of change in the voltage, current, and surface temperature of the secondary battery. The calculation device calculates a first resistance value of the secondary battery based on the amount of change in the voltage between a first time and a second time and the amount of change in the current between the first time and the second time. The calculation device calculates the amount of change in the surface temperature based on a first surface temperature within the range from the first time to the second time and a second surface temperature at a third time a predetermined time after the second time. The calculation device calculates the amount of current of the secondary battery from the time the first surface temperature is measured to the third time when the second surface temperature is measured. The calculation device estimates the internal temperature of the secondary battery based on the amount of change in the surface temperature and the amount of current. The calculation device estimates a second resistance value that reflects a difference between the internal temperature and the surface temperature of the secondary battery based on the estimated internal temperature while referring to the relationship between the surface temperature, the internal temperature, and the resistance value stored in the map. The calculation device calculates the deterioration rate based on the first resistance value and the second resistance value.

[0006] A vehicle control device according to one aspect of the present invention is a vehicle control device including the battery control device, and controls a vehicle having the secondary battery and electrical equipment that operates using power from the secondary battery.

[0007] According to the present invention, it is possible to improve the accuracy of calculating the deterioration rate of a secondary battery in battery control or vehicle control.

[0008] 1 is a graph showing the temperature characteristics of the secondary battery 310, superimposing an example of the relationship between the current supply time of the secondary battery 310 and the internal temperature Ti, and the relationship between the current supply time of the secondary battery 310 and the surface temperature Ts. 2 is a graph showing the temperature characteristics of the secondary battery 310, superimposing an example of the relationship between the temperature T and resistance of the secondary battery 310 before deterioration, and the relationship between the temperature T and resistance of the secondary battery 310 after deterioration. 3 is a block diagram showing a vehicle 1 provided with a vehicle control device 10 including a battery control device 100 of an embodiment. 4 is a block diagram showing the battery control device 100. 5 is data included in a map 120, showing the relationship between the squared current value of the secondary battery 310 for a predetermined current supply time n and the amount of temperature change β in the surface temperature Ts of the secondary battery 310 for the predetermined current supply time n, for each of a plurality of SOCs of the secondary battery 310.

[0009] (Temperature Characteristics of Secondary Battery 310 in the Embodiment) The temperature characteristics of the secondary battery 310 will be described with reference to FIGS. 1 and 2. FIG.

[0010] FIG. 1 is a graph showing the temperature characteristics of the secondary battery 310, and is a graph showing an example of the relationship between a predetermined current-carrying time n of the secondary battery 310 and the internal temperature Ti, and the relationship between a predetermined current-carrying time n of the secondary battery 310 and the surface temperature Ts.

[0011] When a current is applied to the secondary battery 310, the charging / discharging body included in the secondary battery 310 generates heat due to an electrochemical reaction. The charging / discharging body is, for example, a wound body in which a positive electrode and a negative electrode are wound with a separator interposed therebetween. The charging / discharging body may also be a laminated body in which multiple positive electrodes and negative electrodes are stacked with a separator interposed therebetween. In the secondary battery 310, the charging / discharging body is housed in an exterior body. The exterior body is, for example, a can and a lid. The exterior body may also be a laminate film. Heat generated in the charging / discharging body moves from the inside of the secondary battery 310 toward the surface of the secondary battery 310. The surface of the secondary battery 310 is the surface of the lid or can. Heat is dissipated from the charging / discharging body from the inside of the secondary battery 310 toward the surface of the secondary battery 310.

[0012] Therefore, when the secondary battery 310 is energized, a difference occurs between the internal and external temperatures of the secondary battery 310 until the secondary battery 310 reaches a thermal equilibrium state. Therefore, as shown in Fig. 1, an internal temperature curve L1 indicating the internal temperature Ti of the secondary battery 310 and a surface temperature curve L2 indicating the surface temperature Ts of the secondary battery 310 do not overlap with each other in the region where the secondary battery 310 is not in a thermal equilibrium state. At any time in the region where the secondary battery 310 is not in a thermal equilibrium state, the internal temperature Ti of the secondary battery 310 indicated by the internal temperature curve L1 is higher than the surface temperature Ts of the secondary battery 310 indicated by the surface temperature curve L2.

[0013] In the secondary battery 310, when the time shown in FIG. 1 is 0, the internal temperature curve L1 and the surface temperature curve L2 overlap. That is, when the time is 0, the secondary battery 310 is in a state of thermal equilibrium. When the time is 0, the secondary battery 310 is not energized, and therefore the charging / discharging elements contained in the secondary battery 310 do not generate heat. Therefore, when the time is 0, the internal temperature Ti and the surface temperature Ts of the secondary battery 310 match. The fact that the internal temperature Ti and the surface temperature Ts of the secondary battery 310 match is based on the assumption that the thermal influence on the secondary battery 310 by the surrounding environment is sufficiently small.

[0014] The surface temperature Ts of the secondary battery 310 at any time within the range from the first time c1 to the second time c2 shown in FIG. 1 is defined as a first surface temperature Ts1. The first surface temperature Ts1 is, for example, the surface temperature Ts of the secondary battery 310 at the second time c2. The first surface temperature Ts1 may be the first time c1 or an intermediate time between the first time c1 and the second time c2. The time from the first time c1 to the second time c2 is, for example, several tens of milliseconds. As described below, the battery control device 100 calculates a first resistance value R1 of the secondary battery 310 during the period from the first time c1 to the second time c2. At any time within the range from the first time c1 to the second time c2, the internal temperature Ti of the secondary battery 310 indicated by the internal temperature curve L1 is higher than the surface temperature Ts of the secondary battery 310 indicated by the surface temperature curve L2.

[0015] In the secondary battery 310, the surface temperature Ts at a third time c3, which is a predetermined time n after the second time c2 shown in FIG. 1 , is defined as a second surface temperature Ts2. The predetermined time n is, for example, several seconds to several tens of seconds. As will be described later, the battery control device 100 calculates the current amount SI of the secondary battery 310 during the predetermined time n from the time when the first surface temperature Ts1 of the secondary battery 310 is measured (any time within the range from the first time c1 to the second time c2) to the third time c3. The current amount SI of the secondary battery 310 is an integrated current amount, and is calculated by squaring the current and multiplying it by the predetermined time n (I ２ ×n). At the third time c3, the internal temperature Ti of the secondary battery 310 indicated by the internal temperature curve L1 is higher than the surface temperature Ts of the secondary battery 310 indicated by the surface temperature curve L2.

[0016] For the secondary battery 310, the value obtained by subtracting the first surface temperature Ts1 from the second surface temperature Ts2 shown in FIG. 1 is defined as the amount of change β. Because the secondary battery 310 is energized for the predetermined time n, the second surface temperature Ts2 is higher than the first surface temperature Ts1. In other words, the amount of change β is the amount of increase in the surface temperature Ts of the secondary battery 310 for the predetermined time n, and corresponds to the surface temperature difference of the secondary battery 310. As will be described later, the battery control device 100 calculates a correction value α for the surface temperature Ts of the secondary battery 310 based on the amount of change β in the surface temperature Ts of the secondary battery 310 and the amount of current SI.

[0017] 1, the internal temperature curve L1 and the surface temperature curve L2 of the secondary battery 310 overlap with each other at the fourth time c4. That is, at the fourth time c4, the secondary battery 310 is in a thermal equilibrium state.

[0018] FIG. 2 is a graph showing the temperature characteristics of the secondary battery 310, and is a graph showing an example of the relationship between the temperature T and resistance of the secondary battery 310 before deterioration and the relationship between the temperature T and resistance of the secondary battery 310 after deterioration, superimposed on one another.

[0019] FIG. 2 shows a pre-deterioration resistance curve L3 representing the relationship between the temperature T and resistance value R of the pre-deterioration secondary battery 310 at a given time. The pre-deterioration secondary battery 310 corresponds to, for example, a new secondary battery 310. FIG. 2 also shows a deteriorating resistance curve L4 representing the relationship between the temperature T and resistance value R of the pre-deterioration secondary battery 310 at a predetermined time. The resistance of the secondary battery 310 increases as it deteriorates. The resistance is, for example, the internal resistance of the secondary battery 310. The internal resistance is, for example, DCR (Direct Current Resistance). Even when the secondary battery 310 is energized under the same conditions, the resistance value R of the deteriorating secondary battery 310 is greater than that of the pre-deterioration secondary battery 310. The temperature of the secondary battery 310 is assumed to be the temperature of a charging / discharging element provided inside the secondary battery 310. Therefore, in order to calculate the resistance value R of the secondary battery 310, it is preferable to perform calculation based on the internal temperature Ti estimated from the surface temperature Ts of the secondary battery 310 rather than on the surface temperature Ts of the secondary battery 310.

[0020] The SOH of the secondary battery 310 depends on the temperature of the charging / discharging body. The SOH (State of Health) is the deterioration rate of the secondary battery 310. The temperature of the charging / discharging body is closer to the internal temperature Ti of the secondary battery 310, rather than the surface temperature Ts of the secondary battery 310. As will be described later, in an embodiment, in order to improve the calculation accuracy of the SOH of the secondary battery 310, the internal temperature Ti of the secondary battery 310 is accurately estimated based on the measured surface temperature Ts of the secondary battery 310.

[0021] (Configuration of Vehicle 1 According to the Embodiment) The battery control device 100 and the vehicle control device 10 according to the embodiment will be described with reference to FIGS. 1 to 5 based on the configuration of the vehicle 1 provided with the vehicle control device 10 including the battery control device 100. FIG.

[0022] Fig. 3 is a block diagram showing a vehicle 1 equipped with a vehicle control device 10 including a battery control device 100 according to an embodiment. Fig. 4 is a block diagram showing the battery control device 100. Fig. 5 is data included in the map 120, which shows the relationship between the squared current value of the secondary battery 310 for a predetermined current-carrying time n and the temperature difference between the surface temperature Ts of the secondary battery 310 for the predetermined current-carrying time n, for each of a plurality of SOCs of the secondary battery 310.

[0023] (Configuration of Vehicle 1) Vehicle 1 is, for example, a hybrid electric vehicle. A hybrid electric vehicle is, for example, a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV). Hybrid electric vehicles include strong hybrid electric vehicles with an output voltage of, for example, several hundred volts, and mild hybrid electric vehicles with an output voltage of, for example, 48 volts. Vehicle 1 may also be an electric vehicle (EV).

[0024] If the vehicle 1 is an HEV, the vehicle 1 is provided with a motor 600, which is an electric device used to drive the vehicle 1, and an engine 700, which is an internal combustion engine. In an HEV, the power generated by the motor 600 and the engine 700 is transmitted to tires. The motor 600 is operated by power supplied from the battery pack 20. The HEV is provided with a generator for charging the battery pack 300 of the battery pack 20. If the vehicle 1 is an EV, the vehicle 1 is not provided with the engine 700. In an EV, the power generated by the motor 600 is transmitted to tires.

[0025] The vehicle 1 has a battery control device 100, a vehicle equipment control device 200, a battery pack 300, a relay 400, a power converter 500, a motor 600, and an engine 700. In the vehicle 1, the configuration including the battery control device 100 and the vehicle equipment control device 200 is referred to as the vehicle control device 10. The vehicle control device 10 is equipped with the battery control device 100. The vehicle control device 10 controls the vehicle 1, which has a secondary battery 310 and electrical devices that operate using power from the secondary battery 310. In the vehicle 1, the configuration including the battery control device 100 and the battery pack 300 is referred to as the battery pack 20. Below, each configuration of the vehicle 1, from the battery control device 100 to the engine 700, will be described.

[0026] (Configuration of Battery Control Device 100) The configuration of the battery control device 100 will be described with reference to Figs. 1 to 5 .

[0027] The battery control device 100 is referred to as, for example, a battery management system (BMS). As shown in Fig. 4, the battery control device 100 includes a sensor unit 110, a map 120, and a calculation device 130. The configurations of the sensor unit 110, the map 120, and the calculation device 130 of the battery control device 100 will be described below.

[0028] (Configuration of Sensor Unit 110) The sensor unit 110 measures the voltage value V, current value I, and temperature T of the secondary battery 310 included in the battery pack 300. As shown in Fig. 4, the sensor unit 110 includes a voltage measurement unit 111, a current measurement unit 112, and a temperature measurement unit 113. The configurations of the voltage measurement unit 111, the current measurement unit 112, and the temperature measurement unit 113 of the sensor unit 110 will be described below.

[0029] (Configuration of Voltage Measurement Unit 111) The voltage measurement unit 111 measures the voltage value V of the secondary battery 310. The voltage measurement unit 111 is configured by, for example, a circuit combining cell voltage detection terminals, electric wires, resistors, capacitors, etc. The voltage measurement unit 111 measures the voltage value of the secondary battery 310 via a bus bar that electrically connects one secondary battery 310 to another secondary battery 310. A cell voltage detection terminal is attached to the bus bar. Therefore, the voltage measurement unit 111 measures the potential of the negative external terminal of one secondary battery 310 and the potential of the positive external terminal of the other secondary battery 310. The voltage measurement unit 111 measures the voltage value of the secondary battery 310 based on the difference between the potential of the positive external terminal and the negative external terminal of the secondary battery 310. The voltage value V of the secondary battery 310 corresponds to the open circuit voltage (OCV) of the secondary battery 310.

[0030] (Configuration of current measurement unit 112) The current measurement unit 112 measures the current value I of the secondary battery 310. The current measurement unit 112 is configured in combination with the circuit of the voltage measurement unit 111. The voltage measurement unit 111 calculates the current value I of the secondary battery 310 based on the value of the current flowing through the resistor of the voltage measurement unit 111.

[0031] (Configuration of Temperature Measurement Unit 113) The temperature measurement unit 113 measures the surface temperature Ts of the secondary battery 310. The temperature measurement unit 113 is attached to the surface of the secondary battery 310. The surface of the secondary battery 310 is, for example, the surface of the lid of the secondary battery 310, and is the surface of a portion where a tear-off valve or the like is not formed. The temperature measurement unit 113 is pressed against the surface of the secondary battery 310 by a support member and is in contact with the surface. The temperature measurement unit 113 may be bonded to the surface of the secondary battery 310 with an adhesive. The temperature measurement unit 113 is attached to all of the multiple secondary batteries 310. The temperature measurement unit 113 may also be attached to some of the secondary batteries 310. When the temperature measurement unit 113 is attached to some of the multiple secondary batteries 310, for example, the average value of the surface temperatures Ts of some of the secondary batteries 310 is set as the surface temperature Ts of the secondary battery 310.

[0032] (Configuration of Map 120) The configuration of the map 120 will be described with reference to FIG. 5 and other figures.

[0033] Figure 5 shows data included in map 120, which shows the relationship between the squared current value of secondary battery 310 during a predetermined current-carrying time n and the temperature change β of surface temperature Ts of secondary battery 310 during the predetermined current-carrying time n, for each of multiple SOCs of secondary battery 310.

[0034] The map 120 includes an OCV-SOC correlation table 121, a temperature correction table 122 shown in FIG.

[0035] The OCV-SOC correlation table 121 is referenced by an SOC estimation unit 131 of the calculation device 130, which will be described later. The OCV-SOC correlation table 121 is a table showing the relationship between the OCV and the SOC. The OCV (Open Circuit Voltage) is the open circuit voltage of the secondary battery 310. The SOC (States of Charge) is the charging rate of the secondary battery 310. For example, the secondary battery 310, such as a lithium-ion secondary battery, has a correlation between the OCV and the SOC. For such a secondary battery 310, there is a predetermined SOC corresponding to a predetermined OCV. That is, the secondary battery 310 has a relationship between the OCV and the SOC that is represented by a curve. Therefore, by calculating the OCV, the secondary battery 310 can estimate the corresponding SOC.

[0036] The temperature correction table 122 is referenced by an internal temperature calculation unit 133 of the calculation device 130, which will be described later. The temperature correction table 122 stores, for each of a plurality of SOCs of the secondary battery 310, a squared current value (I ２×n) and the change β in the surface temperature Ts of the secondary battery 310 over a predetermined current-carrying time n. The temperature correction table 122 cancels the effects of discharging and charging the secondary battery 310 by using the square of the current value I of the secondary battery 310. The temperature correction table 122 also shows a correction value α for the surface temperature Ts of the secondary battery 310 at the second time c2, which corresponds to the change β in the surface temperature Ts of the secondary battery 310. The internal temperature Ti of the secondary battery 310 at the second time c2 is estimated by adding the correction value α to the surface temperature Ts of the secondary battery 310 at the second time c2.

[0037] The resistance value correlation table 123 is referenced by a second resistance calculation unit 135 of the calculation device 130, which will be described later. The resistance value correlation table 123 is a table showing the relationship between the SOC of the secondary battery 310 and the resistance value (second resistance value R2) of the secondary battery 310 before deterioration, which corresponds to the internal temperature Ti of the secondary battery 310. The resistance value correlation table 123 shows the relationship between the internal resistance and SOC of the secondary battery 310 before deterioration, i.e., the internal resistance and SOC of the secondary battery 310 when it is new.

[0038] (Configuration of Calculation Device 130) The calculation device 130 calculates the SOH of the secondary battery 310 based on the amount of change in the voltage value V, the current value I, and the surface temperature Ts of the secondary battery 310.

[0039] The arithmetic device 130 includes information processing devices such as a CPU (Central Processing Unit), an ECU (Electronic Control Unit), an MPU (Micro Processing Unit), and a DSP (Digital Signal Processor). The arithmetic device 130 also includes storage devices (memories) such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The information processing devices included in the arithmetic device 130 perform calculations based on programs and data stored in a recording device.

[0040] 4, the arithmetic device 130 includes an SOC estimation unit 131, a delay block 132, an internal temperature calculation unit 133, a first resistance calculation unit 134, a second resistance calculation unit 135, an SOHR calculation unit 136, and a life prediction unit 137. Below, the configuration of each of the SOC estimation unit 131 to the life prediction unit 137 of the arithmetic device 130 will be described.

[0041] (Configuration of SOC estimation unit 131 of arithmetic device 130) The SOC estimation unit 131 of the arithmetic device 130 estimates the SOC of the secondary battery 310 based on the voltage value V of the secondary battery 310 measured by the voltage measurement unit 111 of the sensor unit 110 and the OCV-SOC correlation table 121 of the map 120. When the voltage value V of the secondary battery 310 measured by the voltage measurement unit 111 is defined as a predetermined voltage value, the SOC estimation unit 131 first extracts an OCV equivalent to the predetermined voltage value from the OCV-SOC correlation table 121, and then derives an SOC from the OCV-SOC correlation table 121 that corresponds to the extracted OCV. The SOC estimation unit 131 estimates the SOC derived from the OCV-SOC correlation table 121 as the SOC of the secondary battery 310.

[0042] (Configuration of delay block 132 of calculation device 130) The delay block 132 of the calculation device 130 inputs the second surface temperature Ts2 of the secondary battery 310 measured by the temperature measurement unit 113 at the third time c3 shown in Figure 1 to the internal temperature calculation unit 133.

[0043] (Configuration of Internal Temperature Calculation Unit 133 of Calculation Device 130) The internal temperature calculation unit 133 of the calculation device 130 calculates the internal temperature Ti of the secondary battery 310 at the second time c2. The internal temperature calculation unit 133 receives the first surface temperature Ts1 shown in FIG. 1 from the temperature measurement unit 113. The first surface temperature Ts1 is, for example, the surface temperature Ts of the secondary battery 310 at the second time c2. The internal temperature calculation unit 133 receives the second surface temperature Ts2 shown in FIG. 1 from the temperature measurement unit 113 via the delay block 132. The second surface temperature Ts2 is the surface temperature Ts of the secondary battery 310 at the third time c3. The internal temperature calculation unit 133 calculates the amount of change β in the surface temperature Ts of the secondary battery 310 based on the first surface temperature Ts1 and the second surface temperature Ts2. The change amount β is the value obtained by subtracting the first surface temperature Ts1 from the second surface temperature Ts2.

[0044] The current value I is input to the internal temperature calculation unit 133 from the current measurement unit 112. The internal temperature calculation unit 133 calculates the square of the current value I during the current application time n of the secondary battery 310 (I ２ That is, the internal temperature calculation unit 133 calculates the amount of current SI(I ２ The internal temperature calculation unit 133 calculates the change amount β of the surface temperature Ts of the secondary battery 310 and the amount of current SI(I ２ ×n), a correction value α for the first surface temperature Ts1 of the secondary battery 310 is calculated. As shown in FIG. 1 , the value obtained by adding the correction value α to the first surface temperature Ts1 at the second time c2 corresponds to the internal temperature Ti of the secondary battery 310 at the second time c2. Instead of using the correction value α, a configuration may be adopted in which the surface temperature Ts of the secondary battery 310 is multiplied, divided, or added by a predetermined coefficient based on the amount of change β in the surface temperature Ts of the secondary battery 310.

[0045] (Configuration of first resistance calculation unit 134 of calculation device 130) The first resistance calculation unit 134 of the calculation device 130 calculates a first resistance value R1 of the secondary battery 310 based on the voltage value V and current value I of the secondary battery 310 input from the sensor unit 110. The first resistance value R1 corresponds to the internal resistance of the secondary battery 310 at the time of calculation. The internal resistance of the secondary battery 310 corresponds to, for example, DCR (Direct Current Resistance), which is the DC resistance of the secondary battery 310.

[0046] The first resistance calculation unit 134 calculates a first resistance value R1 of the secondary battery 310 based on a change dV in the voltage value V of the secondary battery 310 between the first time c1 and the second time c2 shown in FIG. 1 and a change dI in the current value I between the first time c1 and the second time c2. The change dV in the voltage value V of the secondary battery 310 is the value obtained by subtracting the voltage value V of the secondary battery 310 at the first time c1 from the voltage value V of the secondary battery 310 at the second time c2. The change dI in the current value I of the secondary battery 310 is the value obtained by subtracting the current value I of the secondary battery 310 at the first time c1 from the current value I of the secondary battery 310 at the second time c2. The time from the first time c1 to the second time c2 is set to, for example, several tens of milliseconds. The time from the first time c1 to the second time c2 may be set to a few milliseconds to a few hundred milliseconds, or may be set to one second or more.

[0047] (Configuration of Second Resistance Calculation Unit 135 of Computing Device 130) The second resistance calculation unit 135 of the computing device 130 calculates the resistance value (second resistance value R2) of the secondary battery 310 before deterioration. The second resistance value R2 corresponds to the internal resistance of the secondary battery 310 when new. The second resistance calculation unit 135 of the computing device 130 calculates the second resistance value R2 of the secondary battery 310 based on the SOC of the secondary battery 310 input from the SOC estimation unit 131, the surface temperature Ts (corresponding to the internal temperature Ti) of the secondary battery 310 input from the internal temperature calculation unit 133 and corrected by the correction value α, and the resistance value correlation table 123. The resistance value correlation table 123 shows the relationship between the SOC of the secondary battery 310, the surface temperature Ts (corrected to the internal temperature Ti by the correction value α) of the secondary battery 310, and the resistance value (second resistance value R2) of the secondary battery 310 before deterioration. That is, the second resistance calculation unit 135 refers to the relationship between the surface temperature Ts, internal temperature Ti, and resistance value R of the secondary battery 310, and estimates the second resistance value R2 of the secondary battery 310 that reflects the difference between the internal temperature Ti and surface temperature Ts of the secondary battery 310 based on the estimated internal temperature Ti of the secondary battery 310.

[0048] (Configuration of SOHR Calculation Unit 136 of Calculation Device 130) The SOHR calculation unit 136 of the calculation device 130 calculates the deterioration rate of the secondary battery 310 based on the amount of change in the voltage value V, current value I, and surface temperature Ts of the secondary battery 310. Specifically, the SOHR calculation unit 136 calculates the deterioration rate of the secondary battery 310 based on the first resistance value R1 of the secondary battery 310 calculated by the first resistance calculation unit 134 and the second resistance value R2 of the secondary battery 310 calculated by the second resistance calculation unit 135. As described above, the first resistance calculation unit 134 refers to the amount of change in the voltage value V and current value I of the secondary battery 310 when calculating the first resistance value R1. Also, as described above, the second resistance calculation unit 135 refers to the amount of change β in the surface temperature Ts of the secondary battery 310 when calculating the second resistance value R2.

[0049] The SOHR calculation unit 136 calculates the deterioration rate of the secondary battery 310, for example, by dividing the first resistance value R1 by the second resistance value R2. The deterioration rate of the secondary battery 310 corresponds to the SOH (State of Health). The SOH is expressed, for example, by the deterioration rate of the resistance of the secondary battery 310. That is, the SOH is expressed, for example, by the SOHR (State of Health based on Resistance). The resistance of the secondary battery 310 is the internal resistance of the secondary battery 310. Therefore, the SOHR calculation unit 136 calculates the SOH as the rate of increase in resistance of the secondary battery 310, i.e., the SOHR, based on the first resistance value R1 of the secondary battery 310 and the second resistance value R2 of the secondary battery 310.

[0050] The SOHR calculation unit 136 of the calculation device 130 may be configured to calculate SOHC instead of SOH. SOHC (State of Health based on Capacity) is the rate of deterioration of the capacity of the secondary battery 310. In such a configuration, the first resistance calculation unit 134 and the second resistance calculation unit 135 are each changed to a configuration that calculates the capacity of the secondary battery 310.

[0051] (Configuration of lifespan prediction unit 137 of calculation device 130) The lifespan prediction unit 137 of the calculation device 130 predicts the lifespan of the secondary battery 310 based on the SOH. The lifespan prediction unit 137 predicts the lifespan of the secondary battery 310 based on the SOHR of the secondary battery 310 calculated by the SOHR calculation unit 136. The lifespan prediction unit 137 predicts the lifespan of the secondary battery 310 based on, for example, the amount of change in the SOHR of the secondary battery 310 calculated by the SOHR calculation unit 136. Furthermore, the lifespan prediction unit 137 predicts the lifespan of the secondary battery 310 based on the SOHR of the secondary battery 310 calculated by the SOHR calculation unit 136 and the usage history of the secondary battery 310. Furthermore, assuming that the battery pack 300 includes multiple secondary batteries 310, the lifespan prediction unit 137 predicts the lifespan of the battery pack 300 based on the SOHR of each secondary battery 310 and the usage history of the battery pack 300.

[0052] (Configuration of the vehicle equipment control device 200) The configuration of the vehicle equipment control device 200 will be described with reference to Figure 3. The vehicle equipment control device 200 controls the drive equipment of the vehicle 1. The vehicle equipment control device 200 includes information processing devices such as a CPU, ECU, MPU, and DSP. The vehicle equipment control device 200 includes storage devices such as a ROM and RAM. The information processing devices included in the vehicle equipment control device 200 perform control based on programs and data stored in recording devices. The information processing devices and recording devices of the vehicle equipment control device 200 may also be used as the information processing devices and recording devices of the battery control device 100. The drive equipment of the vehicle 1 includes a relay 400, a power converter 500, a motor 600, and an engine 700. The vehicle equipment control device 200 references information on the power of the battery pack 300 output from the battery control device 100.

[0053] (Configuration of Battery Pack 300) The configuration of the battery pack 300 will be described with reference to FIG. 3 . The battery pack 300 includes a plurality of secondary batteries 310. The plurality of secondary batteries 310 are connected in series, in parallel, or in series and parallel by bus bars. The secondary batteries 310 are, for example, lithium-ion batteries. Power from the battery pack 300 is supplied to the motor 600 via a relay 400 and a power converter 500. The secondary batteries 310 may be configured by devices with power storage capabilities, such as nickel-metal hydride batteries, all-solid-state batteries, lead batteries, and electric double-layer capacitors. The battery pack 300 may also be configured by a single secondary battery 310.

[0054] (Configuration of relay 400) The configuration of the relay 400 will be described with reference to Fig. 3. The relay 400 is connected between the battery pack 300 and the power converter 500. The relay 400 passes current from the battery pack 300 to the motor 600 via the power converter 500. The relay 400 also cuts off current from the battery pack 300 to the motor 600 via the power converter 500.

[0055] (Configuration of power converter 500) The configuration of the power converter 500 will be described with reference to Fig. 3. The power converter 500 is connected between the relay 400 and the motor 600. The power converter 500 transforms at least the power of the battery pack 300 while converting it from direct current (DC) to alternating current (AC). The power converter 500 includes an inverter circuit and a converter circuit.

[0056] (Configuration of motor 600) The configuration of motor 600 will be described with reference to FIG. 3. Motor 600 performs a power running operation to generate driving force and a regenerative operation to recover energy, depending on the running state of vehicle 1. In the power running operation of motor 600, power converter 500 converts the power output from battery pack 300 from direct current to alternating current, transforms the voltage, and supplies the power to motor 600. This causes motor 600 to generate power, and vehicle 1 runs. In the regenerative operation of motor 600, power converter 500 converts the power generated by motor 600 from alternating current to direct current, transforms the voltage, and supplies the power to battery pack 300. This charges battery pack 300.

[0057] (Configuration of engine 700) The configuration of engine 700 will be described with reference to Fig. 3. Engine 700 is an internal combustion engine. Engine 700 drives vehicle 1. Engine 700 is used, for example, as a drive source for tires of vehicle 1. If vehicle 1 is an EV (electric vehicle), engine 700 is not used.

[0058] (Effects of the embodiment) Effects of the battery control device 100 and the vehicle control device 10 of the embodiment will be described with reference to FIGS. 1 to 5. FIG.

[0059] (1) The battery control device 100 includes a map and a calculation device 130. The map includes data showing the relationship between the surface temperature Ts, internal temperature Ti, and resistance value R of the secondary battery 310. The calculation device 130 calculates the SOH of the secondary battery 310 based on the amount of change in the voltage value, current value, and surface temperature Ts of the secondary battery 310. The calculation device 130 calculates the first resistance value R1 of the secondary battery 310 based on the amount of change dV in the voltage value V of the secondary battery 310 between the first time c1 and the second time c2 and the amount of change dI in the current value I between the first time c1 and the second time c2. The arithmetic device 130 calculates a change amount β in the surface temperature Ts of the secondary battery 310 based on a first surface temperature Ts1 of the secondary battery 310 within a range from a first time c1 to a second time c2 and a second surface temperature Ts2 of the secondary battery 310 at a third time c3 when a predetermined time n has elapsed since the second time c2. The arithmetic device 130 calculates an amount of current SI of the secondary battery 310 from the time when the first surface temperature Ts1 of the secondary battery 310 is measured to the third time c3 when the second surface temperature Ts2 of the secondary battery 310 is measured. The arithmetic device 130 estimates an internal temperature Ti of the secondary battery 310 based on the change amount β in the surface temperature of the secondary battery 310 and the amount of current SI. The arithmetic device 130 estimates a second resistance value R2 of the secondary battery 310 that reflects the difference between the internal temperature Ti and the surface temperature Ts of the secondary battery 310, based on the estimated internal temperature Ti of the secondary battery 310, while referring to the relationship between the surface temperature Ts, internal temperature Ti, and resistance value R of the secondary battery 310 stored in the map. The arithmetic device 130 calculates the SOH of the secondary battery 310 based on the first resistance value R1 of the secondary battery 310 and the second resistance value R2 of the secondary battery 310.

[0060] The battery control device 100 configured as described above estimates the resistance value of the secondary battery 310 by reflecting the difference between the internal temperature Ti and the surface temperature Ts of the secondary battery 310. The calculation device 130 calculates the SOH of the secondary battery 310 based on the resistance value of the secondary battery 310. Therefore, the battery control device 100 can improve the accuracy of calculating the SOH of the secondary battery 310. In other words, the battery control device 100 can improve the reliability of the secondary battery 310.

[0061] (2) The calculation device 130 calculates a correction value α for the surface temperature Ts of the secondary battery 310 based on the amount of change β in the surface temperature Ts of the secondary battery 310 and the amount of current SI. The calculation device 130 estimates the internal temperature Ti of the secondary battery 310 corresponding to the surface temperature Ts of the secondary battery 310 that reflects the correction value α.

[0062] The battery control device 100 configured as described above can estimate the internal temperature Ti of the secondary battery 310 using a relatively versatile and simple method that uses the correction value α. Therefore, the battery control device 100 can improve the accuracy of calculating the SOH of the secondary battery 310.

[0063] (3) The calculation device 130 calculates the SOH as the resistance increase rate (SOHR) of the secondary battery 310 based on the first resistance value R1 and the second resistance value R2.

[0064] According to the battery control device 100 configured as described above, in order to improve the calculation accuracy of the SOH of the secondary battery 310, it is possible to apply the battery control device 100 to the calculation of the SOHR, which is relatively versatile.

[0065] (4) The data included in the map indicates at least the relationship between the surface temperature Ts, the internal temperature Ti, and the resistance value R of the secondary battery 310, as well as the SOC.

[0066] According to the battery control device 100 configured as described above, when there is a correlation between the resistance value R and the SOC of the secondary battery 310, the accuracy of calculating the SOH of the secondary battery 310 can be further improved by also taking into account the SOC value of the secondary battery 310. Similarly, according to the battery control device 100 configured as described above, when there is a correlation between the internal temperature Ti and the resistance value R of the secondary battery 310 and the SOC, the accuracy of calculating the SOH of the secondary battery 310 can be further improved by also taking into account the SOC value of the secondary battery 310.

[0067] (5) The computing device 130 predicts the life of the secondary battery 310 based on the SOH.

[0068] The battery control device 100 configured as described above can improve the accuracy of calculating the SOH of the secondary battery 310, thereby improving the accuracy of predicting the life of the secondary battery 310. Therefore, the battery control device 100 can supply power from the secondary battery 310 to electrical equipment such as the motor 600 until just before the secondary battery 310 reaches the end of its life. In other words, the battery control device 100 can fully use up the secondary battery 310. Furthermore, the battery control device 100 can prevent the secondary battery 310 from supplying power to electrical equipment such as the motor 600 after the secondary battery 310 has reached the end of its life.

[0069] (6) The battery control device 100 further includes a voltage measurement unit 111 that measures the voltage value V of the secondary battery 310, a current measurement unit 112 that measures the current value I of the secondary battery 310, and a temperature measurement unit 113 that measures the surface temperature Ts of the secondary battery 310.

[0070] The battery control device 100 configured as described above can calculate the SOH of the secondary battery 310 even when the voltage measurement unit 111, the current measurement unit 112, and the temperature measurement unit 113 are not provided on the secondary battery 310 side. When the voltage measurement unit 111, the current measurement unit 112, and the temperature measurement unit 113 are not provided on the secondary battery 310 side, this also includes when the voltage measurement unit 111, the current measurement unit 112, and the temperature measurement unit 113 are not provided on the battery pack 300 side.

[0071] (7) The vehicle control device 10 includes a battery control device 100. The vehicle control device 10 controls the vehicle 1 having a secondary battery 310 and a motor 600 (electrical equipment) that operates using power from the secondary battery 310.

[0072] According to the vehicle control device 10 configured as described above, the accuracy of calculation of the SOH of the secondary battery 310 is improved, thereby enabling the motor 600 of the vehicle 1 to operate more effectively. The electrical device is not limited to the motor 600. The electrical device may be, for example, an air conditioner of the vehicle 1.

[0073] (8) The vehicle 1 has an engine 700 (internal combustion engine) that drives the vehicle 1 .

[0074] The vehicle control device 10 configured as described above can improve the calculation accuracy of the SOH of the secondary battery 310, thereby enabling the engine 700 to be operated appropriately. That is, the vehicle control device 10 is suitable for application to, for example, an HEV. Operating the engine 700 appropriately means, for example, suppressing operation of the engine 700 as much as possible when it is desired to suppress operation of the engine 700 in order to operate the vehicle 1.

[0075] (Other Embodiments) Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0076] For example, the battery control device 100 of the present invention is not limited to a configuration that controls the secondary battery 310 used in the vehicle 1. The battery control device 100 of the present invention may also be configured to control the secondary battery 310 used in machine tools, aircraft, ships, etc.

[0077] 1 Vehicle, 10 Vehicle control device, 20 Battery pack, 100 Battery control device, 110 Sensor unit, 111 Voltage measurement unit, 112 Current measurement unit, 113 Temperature measurement unit, 120 Map, 121 OCV-SOC correlation table, 122 Temperature correction table, 123 Resistance value correlation table, 130 Calculation device, 131 SOC estimation unit, 132 Delay block, 133 Internal temperature calculation unit, 134 First resistance calculation unit, 135 Second resistance calculation unit, 136 SOHR calculation unit, 137 Life prediction unit, 200 Vehicle equipment control device, 300 Assembled battery, 310 Secondary battery, 400 Relay, 500 Power converter, 600 Motor (electrical equipment), 700 Engine (internal combustion engine), Ti Internal temperature, Ts surface temperature, Ts1 first surface temperature, Ts2 second surface temperature, c1 first time, c2 second time, c3 third time, c4 fourth time, L1 internal temperature curve, L2 surface temperature curve, L3 resistance curve before deterioration, L4 resistance curve when deteriorated, R1 first resistance value, R2 second resistance value, SI current amount, α correction value, β change amount.

Claims

1. A system comprising: a map including data showing the relationship between the surface temperature, internal temperature, and resistance value of a secondary battery; and a calculation device that calculates a deterioration rate of the secondary battery based on the amount of change in the voltage value, current value, and surface temperature of the secondary battery, wherein the calculation device calculates a first resistance value of the secondary battery based on the amount of change in the voltage value between a first time and a second time and the amount of change in the current value between the first time and the second time; calculates the amount of change in the surface temperature based on a first surface temperature within the range from the first time to the second time and a second surface temperature at a third time a predetermined time after the second time; calculates the amount of current of the secondary battery from the time when the first surface temperature is measured to the third time when the second surface temperature is measured; and estimates the internal temperature of the secondary battery based on the amount of change in the surface temperature and the amount of current. a second resistance value that reflects a difference between the internal temperature and the surface temperature of the secondary battery based on the estimated internal temperature while referring to the relationship between the surface temperature, the internal temperature, and the resistance value stored in the map; and a battery control device that calculates the deterioration rate based on the first resistance value and the second resistance value.

2. A battery control device according to claim 1, wherein the calculation device calculates a correction value for the surface temperature based on the amount of change in the surface temperature and the amount of current, and estimates the internal temperature corresponding to the surface temperature reflecting the correction value.

3. A battery control device according to claim 1, wherein the calculation device calculates the deterioration rate as a resistance increase rate of the secondary battery based on the first resistance value and the second resistance value.

4. A battery control device according to claim 1, wherein the data indicates the relationship between the internal temperature, the resistance value and the charging rate of the secondary battery.

5. A battery control device according to claim 1, wherein the arithmetic unit predicts the life of the secondary battery based on the deterioration rate.

6. A battery control device according to claim 1, further comprising: a voltage measuring unit that measures the voltage value of the secondary battery; a current measuring unit that measures the current value of the secondary battery; and a temperature measuring unit that measures the surface temperature of the secondary battery.

7. A vehicle control device comprising the battery control device according to claim 1, which controls a vehicle having the secondary battery and electrical equipment that operates on the power of the secondary battery.

8. A vehicle control device according to claim 7, wherein the vehicle has an internal combustion engine that drives the vehicle.

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