Battery control device, battery control method, and vehicle control device

Abstract

The present application provides a battery control device (200) comprising: a degradation calculation unit 232 that calculates the degree of degradation of a battery 101; a degradation prediction unit 502 that predicts the degree of degradation of the battery; and a battery pack control management unit 230 that restricts charging and discharging of the battery on the basis of a comparison between a temporal change in the degree of degradation of the battery obtained from the calculation performed by the calculation unit and a temporal change in the degree of degradation of the battery obtained from the prediction performed by the prediction unit.

Description

Battery control device, battery control method, and vehicle control device

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

[0002] To prevent global warming, there is a need to reduce carbon dioxide emissions. To address this issue, for example, automobiles powered solely by conventional gasoline engines are increasingly being replaced with hybrid electric vehicles (HEVs) that combine gasoline engines with electric motors, or electric vehicles that use only electric motors. To prevent a decline in vehicle performance due to this replacement, large secondary batteries used as power sources for HEVs and electric vehicles must have high output and large capacity. A storage battery module that constitutes a large secondary battery is composed of multiple secondary battery cells (batteries) connected in series and parallel to achieve high output and large capacity. Secondary batteries such as lithium-ion batteries are generally used.

[0003] It is known that secondary batteries, such as lithium-ion batteries, experience a specific increase in internal resistance when continuously used at a high current, accelerating their degradation. This specific increase in resistance gradually decreases if the current supply is stopped promptly after the resistance increase is detected, and recovery can be achieved over a long period of time, such as several days. However, if the detection of the resistance increase is delayed and the secondary battery is continuously subjected to a high load, the secondary battery's degradation is accelerated and fixed. Even if the resistance is reduced by resting the secondary battery for a long period of time, the resistance will rise rapidly when the current supply is resumed.

[0004] A control method for a secondary battery has been proposed with the aim of suppressing such an increase in internal resistance (for example, see Patent Document 1). The method described in Patent Document 1 sets multiple periods and corresponding thresholds for the charge / discharge current of the rechargeable battery, and limits the charge / discharge current of the rechargeable battery so that the sum of the currents during those periods or the sum of the squares of the currents is equal to or less than the corresponding thresholds.

[0005] JP 2011-79447 A

[0006] The method of Patent Document 1 lowers the current limit value after the resistance rises due to continuous high loads. This accelerates the deterioration of the secondary battery, and even if the current supply to the load is stopped, the resistance may not recover to the value before the specific rise. Furthermore, if the limit value is returned and the current is increased after the resistance has recovered to a certain extent, the resistance may rise rapidly in a short period of time and exceed the threshold again, as mentioned above. In this state, the limit is applied frequently, which ultimately leads to greater battery deterioration. Therefore, a performance margin that anticipates this is necessary to effectively utilize the battery until its expected lifespan.

[0007] From the perspective of optimizing performance, a smaller margin is better, and minimizing the margin requires preventing the occurrence of the above-mentioned phenomena. These phenomena occur in conventional methods because it is difficult to detect and prevent early occurrence of a specific increase in battery resistance caused by continuous operation of the battery under high load. In other words, to minimize the margin and effectively utilize the battery to its expected lifespan, it is necessary to detect and prevent early occurrence of a specific increase in battery resistance caused by continuous operation of the battery under high load.

[0008] The present invention aims to provide a battery control device, a battery control method, and a vehicle control device that can ensure stable load output while suppressing unexpected abnormal increases in resistance due to continuous operation of the battery under high load or other reasons, and that can effectively use the battery until its expected lifespan.

[0009] In order to achieve the above object, the present invention provides a battery control device including a calculation unit that calculates a deterioration level of a battery, a prediction unit that predicts the deterioration level of the battery, a determination unit that determines the state of the battery based on a comparison between the calculated deterioration level of the battery over time and the predicted deterioration level of the battery over time, and a limiting unit that limits charging and discharging of the battery based on the determined state of the battery.The present invention also provides a battery control method and a vehicle control device as described in the claims.

[0010] According to the present invention, it is possible to ensure stable output of the load while suppressing unexpected specific increases in resistance value, and to effectively utilize the battery until the expected end of its life.

[0011] 1 is a block diagram showing a partial configuration of a vehicle equipped with an embodiment of a battery control device according to the present invention. FIG. 2 is a block diagram showing the configuration of a battery pack control management unit of the battery control device of the embodiment. FIG. 3 is a block diagram showing the configuration of a power limit calculation unit of the embodiment. FIG. 4 is an error map of the model predicted value SOHRest. FIG. 5 is a graph of the error of the model predicted value SOHRest. FIG. 6 is an error map of the detected value SOHRcalc. FIG. 7 is a graph of the error of the detected value SOHRcalc. FIG. 8 is a graph showing the relationship between the number of cycles and SOHR in a secondary battery. FIG. 9 is a graph showing the current value of the battery. FIG. 10 is a graph showing the fluctuations of the model predicted value SOHRest and the detected value SOHRcalc of the battery. FIG. 11 is a graph showing the fluctuations per hour of the detected value SOHRcalc and the model predicted value SOHRest of the battery. FIG. 12 is a graph showing the time changes in the OCV and CCV of the battery. 1 is a graph showing the relationship between the fluctuation per hour of the detected value SOHRcalc and the fluctuation per hour of the model predicted value SOHRest in a battery control method that reflects an increase in the battery resistance value. FIG. 2 is a graph showing the relationship between the detected value SOHRcalc and the model predicted value SOHRest. FIG. 3 is a graph showing the timing of SOHR calculation. FIG. 4 is a graph showing the time fluctuation of the current detected by the current detection unit regarding the recovery of the increase in the battery resistance value. FIG. 5 is a graph showing the time change of the detected value SOHRcalc. FIG. 6 is a graph explaining the time change of the difference (dSOHRcalc / dt-dSOHRest / dt) in a second example of a method for determining an increase in the battery resistance value. FIG. 7 is an example of a flowchart of a control method executed by a battery control device. FIG. 8 is a graph showing the time change of the detected value SOHRcalc and the model predicted value SOHRest to explain the effect of the battery control method by the battery control device. FIG. 9 is a graph showing the time change of the power limit value. 10 is a graph showing the change over time of difference 1 (dSOHRcalc / dt-dSOHRest / dt).

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description, to clarify dimensions such as voltage V, current I, power W, resistance R, temperature T, and time t, symbols for each dimension are used even if not shown. Furthermore, if necessary, subscripts are added to the dimension symbols. For example, battery voltage Vu, effective current Ie, temperature T, ambient temperature Ts, maximum temperature Tmax, average temperature Ta, temperature Tu of each secondary battery cell (battery), and minimum temperature Tmin are listed. Note that the units of each dimension are generally omitted throughout the text and figures.

[0013] 1 is a block diagram showing the partial configuration of a vehicle 1 equipped with an embodiment of a battery control device according to the present invention. The vehicle 1 is equipped with a battery pack 100 that supplies power to the vehicle 1, a battery control device 200 that controls battery operation such as charging and / or discharging of the battery pack 100, a vehicle drive device 300 that drives the vehicle 1, and a vehicle control device 400 that controls the battery control device 200 and the vehicle drive device 300.

[0014] The vehicle 1 is configured as a hybrid electric vehicle (HEV), an electric vehicle (EV), or a plug-in hybrid electric vehicle (PHEV).

[0015] (Configuration of vehicle drive device 300) The vehicle drive device 300 drives the vehicle 1. The vehicle drive device 300 includes a relay 310 that passes or cuts off power, a power conversion unit 320 that transforms power while converting it between direct current and alternating current, a motor 330 used as a power source for the vehicle 1, and an engine 340 used as a power source for the vehicle 1.

[0016] The relay 310 is electrically connected between the battery pack 100 and the power conversion unit 320. This allows power to be passed or cut off between the battery pack 100 and the motor 330 via the power conversion unit 320. In this embodiment, the relay 310 is incorporated into the vehicle drive device 300, but it may also be incorporated into the battery control device 200. By incorporating the relay 310 into the battery control device 200, it becomes possible to cut the output voltage from the battery pack 100 by the relay 310 when the battery pack 100 and the battery control device 200 are assembled into or removed from the vehicle 1. This makes it possible to prevent accidents such as electric shock or short circuit.

[0017] The power conversion unit 320 is electrically connected between the relay 310 and the motor 330. The power conversion unit 320 includes an inverter circuit and a converter circuit, thereby realizing AC / DC conversion and voltage transformation required for power exchange between the battery pack 100 and the motor 330.

[0018] The motor 330 is a motor for driving the vehicle or generating electricity, and together with the engine 340, is a power source for the vehicle 1. When the vehicle is driving, the vehicle driving motor rotates the tires of the vehicle 1 using power from the battery pack 100. On the other hand, when generating electricity, the generator motor charges the battery pack 100 using regenerative energy generated during deceleration. The vehicle driving motor and the generator motor may be integrated to reduce costs and space, or may be provided separately to optimize performance.

[0019] The engine 340 is used together with the motor 330 as a power source for the vehicle 1. The power of the engine 340 rotates the tires of the vehicle 1 and the motor 330.

[0020] With the above configuration, when the vehicle 1 is driven by the motor 330, or when the vehicle 1 is driven by the engine 340 and rapidly accelerates, the power discharged from the battery pack 100 is converted into AC by the power conversion unit 320, transformed, and supplied to the motor 330, thereby reducing the fuel consumption of the engine and improving fuel efficiency. Furthermore, when the vehicle 1 decelerates, the motor 330 is operated as a regenerative brake to recover kinetic energy as electric power, and this electric power is converted into DC by the power conversion unit 320 and transformed, while being charged into the battery 101, thereby making it possible to prepare for the next discharge due to driving or acceleration.

[0021] (Configuration of vehicle control device 400) The vehicle control device 400 controls the operation of the entire vehicle 1 while controlling the battery control device 200 and the vehicle drive device 300. The vehicle control device 400 includes a vehicle control management unit 410 that controls the battery control device 200 and the vehicle drive device 300, and a vehicle memory unit 420 that stores information about the vehicle 1.

[0022] The vehicle control management unit 410 controls the relay 310, the power conversion unit 320, the motor 330, the engine 340, etc. The vehicle control management unit 410 controls a wide range of components, one example of which is determining the allocation of driving power between the motor 330 and the engine 340 based on predetermined information. Here, the predetermined information includes information on the battery 101 input from the battery control device 200, information input from the power conversion unit 320, information input from the motor 330, information input from the engine 340, etc. The information on the battery 101 is, for example, the state of charge (SOC).

[0023] The vehicle control management unit 410 formulates an energy management plan for the distribution of driving force between the engine 340 and the motor 330 and the charging and discharging of the battery pack 100 by referring to information such as the power limit value and SOC from the battery pack control management unit 230, and outputs control commands calculated based on this to the power conversion unit 320 to control the load or the amount of power generation. Through these calculations, the vehicle control management unit 410 can prevent energy loss associated with acceleration and deceleration of the vehicle, i.e., energy waste such as engine startup due to insufficient SOC and regeneration failure due to excessive SOC, thereby improving fuel efficiency and reducing carbon dioxide emissions.

[0024] The vehicle storage unit 420 stores information about the vehicle 1. The stored information is data used to control the vehicle control device 400. This information includes data about the distribution of driving force between the motor 330 and the engine 340, etc.

[0025] (Configuration of battery pack 100) The battery pack 100 supplies power to the motor 330 via a relay 310 and a power conversion unit 320. One or more battery packs 100 are provided in the vehicle 1. The multiple battery packs 100 are electrically connected in series with each other. The battery pack 100 includes one or more batteries 101. The multiple batteries 101 are electrically connected in series with each other. A lithium-ion secondary battery is used as the battery 101. The battery 101 may also be a nickel-metal hydride battery, a lead battery, an all-solid-state battery, or the like.

[0026] (Configuration of battery control device 200) The battery control device 200 controls the batteries 101 etc. of the battery pack 100. The battery control device 200 includes a battery management unit 210 that manages the states of the batteries 101 etc., a detection unit 220 that detects the states of the batteries 101 etc., a battery pack storage unit 240 that stores information about the batteries 101 etc., and a battery pack control management unit 230 that controls and manages the battery pack 100.

[0027] The battery control device 200 is configured as a Battery Management System (BMS). The multiple functional blocks of the battery control device 200 (such as the assembled battery control management unit 230) are realized by, for example, a microcomputer, controller, processor, or the like mounted on an integrated circuit board executing a program stored in a memory. Note that the functional blocks may also be realized by dedicated hardware.

[0028] The battery control device 200 appropriately calculates the SOC of the battery 101 and a power limit value, which is a limit value for charging and discharging. If the resistance value of the battery 101 increases abnormally, the power limit value is further appropriately limited. If the resistance value of the battery 101 recovers, the limit on the power limit value is relaxed. Here, an abnormal increase in the resistance value of the battery 101 refers to a case where the resistance value of the battery 101 temporarily increases, such as when the battery is continuously used under a high load, and the resistance value can then recover after a long rest of several days or so.

[0029] The battery control device 200 outputs the calculated power limit value to the vehicle control device 400. The vehicle control device 400 controls the input / output of the motor 330 based on this information, thereby realizing safe charging and discharging of the battery pack 100 and preventing an abnormal increase in the resistance value of the battery 101.

[0030] (Battery management unit 210) The battery management unit 210 manages the states of the batteries 101, etc. The battery management unit 210 includes one or more battery control units 211. One battery control unit 211 corresponds to one or more assembled batteries 100. Each battery control unit 211 performs state control such as measurement of the voltage, balancing, etc. of the batteries 101 included in the corresponding assembled battery 100.

[0031] (Detection Unit 220) The detection unit 220 detects the current, voltage, temperature, and other conditions of the battery 101, etc. The detection unit 220 includes a current detection unit 221, a voltage detection unit 222, and a temperature detection unit 223.

[0032] The current detection unit 221 detects the current value of each battery 101 and the current value of multiple batteries 101 connected in series, etc. When the batteries 101 are connected in series, the current value of one current detection unit 221 provided for each battery 101 may be used as the current value of each battery 101. The current detection unit 221 includes a current sensor and an electric wire. The current sensor is electrically connected to a component of the battery pack 100 so as to detect the current flowing through the battery 101. The component of the battery pack 100 is, for example, a bus bar. The current detection unit 221 outputs the detected current value to the battery pack control management unit 230. This enables the battery pack control management unit 230 to calculate the SOC, deterioration state, power limit value, etc. of the battery 101 and detect overcurrent, etc.

[0033] The voltage detection unit 222 detects the voltage value of multiple battery packs 100 connected in series or the like. The voltage detection unit 222 includes a voltage sensor and an electric wire. The voltage sensor is electrically connected to a component such as a bus bar so as to be able to detect the voltage of one or multiple battery packs 100 connected in series. The voltage detection unit 222 outputs the detected voltage value to the battery pack control management unit 230. This enables the battery pack control management unit 230 to protect the battery pack 100 and calculate the SOC, etc.

[0034] The temperature detection unit 223 detects the temperature of the battery 101, the ambient temperature of the battery pack 100, etc. The temperature detection unit 223 includes a temperature sensor and an electric wire. The temperature sensor is attached to the battery 101 and the battery pack 100. The temperature detection unit 223 outputs the detected temperature to the battery pack control management unit 230. This enables the battery pack control management unit 230 to calculate the maximum temperature, average temperature, and minimum temperature of the battery 101 and detect excessive temperature rise, etc. Furthermore, by correcting the battery characteristics used in the calculation of the SOC, etc. based on the temperature, the calculation accuracy of the SOC, etc. can be improved.

[0035] The detection unit 220 is not limited to the above configuration. The detection unit 220 may be configured to include a communication detection unit that detects the communication state of the battery management unit 210. In such a configuration, when a communication error occurs in the battery management unit 210, the communication detection unit notifies the assembled battery control management unit 230 of the communication failure of the battery management unit 210. A part or all of the detection unit 220 may be configured by the battery control unit 211 of the battery management unit 210.

[0036] Alternatively, the current detection unit 221, voltage detection unit 222, and temperature detection unit 223 may be configured to diagnose the battery 101 and the battery pack 100, and output the results and detected values ​​to the battery pack control management unit 230 and the vehicle control management unit 410. With this configuration, even if the battery pack control management unit 230 fails, it becomes possible to output the measured values ​​and diagnostic results to the vehicle control management unit 410. The detection unit 220 of the battery control device 200 may be provided in the battery pack 100.

[0037] (Battery Pack Control Management Unit 230) The battery pack control management unit 230 will be described with reference to FIG. 2 . The battery pack control management unit 230 performs calculations for appropriately controlling the charging and discharging of the battery pack 100 and for diagnosing and protecting the battery pack 100 based on information input from the detection unit 220 and the battery management unit 210, as well as current limit values ​​and battery characteristics of the batteries 101 pre-stored in the battery pack storage unit 240. Examples of calculations for appropriate control include calculations of the state of charge (SOC) and state of health (SOHR: State of Health based on Resistance) of the batteries 101, and calculations of limit values ​​for charging and discharging power for each battery 101. Examples of calculations for diagnosis and protection include calculations for voltage equalization control of each battery 101, overcharge diagnosis, overdischarge diagnosis, and health diagnosis of the detection unit 220. To achieve this, the battery pack control management unit 230 has an SOC calculation unit 231, a deterioration calculation unit 232, a power limit calculation unit 233, a voltage equalization calculation unit 234, a diagnosis unit 235, etc. Then, based on the measurement values ​​and characteristics of the battery pack 100 and the battery 101 acquired from the detection unit 220, the battery pack storage unit 240, and the battery control unit 211, the battery pack control management unit 230 outputs the calculation results and commands based on the calculation results to the battery management unit 210, the battery control unit 211, and the vehicle control management unit 410.

[0038] The SOHR calculated by the deterioration calculation unit 232 is calculated as the ratio of the current resistance value to the initial resistance value based on at least one of the data input from the detection unit 220 and the battery management unit 210 and the battery characteristics of the battery pre-stored in the battery pack storage unit 240. Because the current flowing through the battery 101 is inversely proportional to the resistance value, such a ratio is suitable as an index representing the deterioration state of the battery.

[0039] The power limit value calculated by the power limit calculation unit 233 is calculated as an upper limit of the power value at which each battery 101 and the battery pack 100 can be appropriately charged and discharged, based on data input from the detection unit 220 and the battery management unit 210, the SOC calculated by the SOC calculation unit 231, the SOHR calculated by the degradation calculation unit 232, input from the battery pack storage unit 240, etc. Conditions for the power value at which appropriate charging and discharging can be performed include, for example, not exceeding an upper limit current value set for each component, not exceeding upper or lower limit voltages of the battery 101 due to charging and discharging, not exceeding upper or lower limit temperatures of the battery 101 or components, the SOC being within a predetermined range, the life of the battery 101 being guaranteed, and quickly becoming 0 if an abnormality is found in the battery 101. The calculated power limit value is output to the vehicle control management unit 410 and used for charge and discharge control, energy management, etc.

[0040] In this way, by adopting a hierarchical structure in which data from multiple batteries 101 is aggregated in the battery management unit 210 and then aggregated in the battery pack control management unit 230, it is possible to shorten the signal lines required for aggregation, simplify the structure, and ensure flexibility in the number of batteries 101, thereby realizing a large secondary battery consisting of a large number of batteries.

[0041] (Battery Pack Storage Unit 240) The battery pack storage unit 240 stores the history, state, statistics, characteristics, etc. of the battery 101. The history is, for example, the history of the current value, voltage value, temperature, etc. of the battery 101. The state is, for example, the SOC, current value, voltage value, internal resistance value, and temperature of the battery 101. The statistics are, for example, the integrated value or average value of the current, and the number of times an abnormal value has been detected. The characteristics are, for example, the internal resistance characteristic, full charge capacity, polarization resistance characteristic, degradation characteristic, individual difference, and SOC table of the battery 101. The SOC table records the correspondence between the SOC and the OCV. In this embodiment, the battery pack storage unit 240 is provided separately from the battery pack control management unit 230. However, it may be configured to be provided inside the battery management unit 210 or inside the battery pack control management unit 230. The history, statistics, etc. may also be stored in the vehicle control management unit 410, the vehicle storage unit 420, or the like, which are external to the battery control device 200.

[0042] 3 shows the configuration of the power limit calculation unit 233. The power limit calculation unit 233 includes a limit value calculation unit 501, a deterioration prediction unit 502, a resistance increase determination unit 503, and a limit value correction unit 504. In addition to these, the power limit calculation unit 233 may include a prediction calculation error information output unit 505, a detection calculation error information output unit 506, and a resistance increase threshold calculation unit 507.

[0043] (Limit Value Calculation Unit 501) The limit value calculation unit 501 calculates the upper limit of the power value at which each battery 101 and the battery pack 100 can be safely charged and discharged based on data input from the detection unit 220 and the battery management unit 210, the SOC calculated by the SOC calculation unit 231, the SOHR calculated by the degradation calculation unit 232, input from the battery pack storage unit 240, etc., and outputs the calculated limit value. Conditions for the power value at which each battery 101 and the battery pack 100 can be safely charged and discharged include, for example, not exceeding an upper limit current value set for each component, not exceeding upper or lower limit voltages of the battery 101 due to charging or discharging, not exceeding upper or lower limit temperatures of the battery 101 or components, keeping the SOC within a predetermined range, and quickly returning to zero if an abnormality is found in the battery 101. The characteristics of the limit value may differ depending on the purpose of use of the limit value. Therefore, multiple types of limit values ​​may be output as necessary. Different limit values ​​may be used for charging and discharging.

[0044] (Deterioration prediction unit 502) The deterioration prediction unit 502 predicts the deterioration state of the battery 101 based on a deterioration model of the battery 101. The deterioration model of the battery 101 simulates the deterioration of the battery 101 based on data such as the current used, voltage range, temperature, current supply frequency, and amount of electricity used of the battery 101. The deterioration model is, for example, a mathematical model (such as a multivariate deterioration prediction formula) or a map related to deterioration conditions.

[0045] The degradation model is constructed based on data of the battery 101 acquired on a weekly or monthly basis, and estimates the degradation fluctuations of the battery applied to a vehicle until the required life span is reached. This degradation model assumes that a sudden increase in resistance of the battery 101 does not occur. In other words, the degradation model models the progression of relatively gradual degradation of the battery 101.

[0046] The deterioration prediction unit 502 converts information about the battery 101 into internal deterioration parameters, which are predetermined parameters for deterioration prediction. The deterioration prediction unit 502 calculates a predicted value of the deterioration level of the battery 101 based on these parameters and a deterioration model. The deterioration prediction unit 502 outputs a model predicted value SOHRest as a predicted value of the deterioration state of the battery 101. Because the model predicted value SOHRest is calculated based on the deterioration model, fluctuations in the model predicted value SOHRest are relatively gradual, similar to fluctuations in the deterioration model.

[0047] (Calculation of internal deterioration parameters) The deterioration prediction unit 502 selects a predetermined range of data from the data of the battery 101 stored in the battery pack storage unit 240. Based on the selected data, the deterioration prediction unit 502 calculates the capacity of the battery 101 and an internal deterioration parameter corresponding to the deterioration state of the internal resistance as the parameter described above.

[0048] Based on the voltage of the battery 101 included in the selected data, the deterioration prediction unit 502 calculates a charge / discharge end voltage curve representing the relationship between the SOC of the battery 101 and the charge / discharge end voltage, and an OCV curve representing the relationship between the SOC of the battery 101 and the OCV, for each of a plurality of usage times.

[0049] The deterioration prediction unit 502 calculates a resistance curve representing the relationship between the SOC and internal resistance of the battery 101 for multiple periods of use based on the charge / discharge end voltage curve, the OCV curve, and the current of the secondary battery represented in the selected data.

[0050] The deterioration prediction unit 502 calculates internal deterioration parameters of the battery 101 based on the end-of-charge / discharge voltage curve, the OCV curve, and the resistance curve. The internal deterioration parameters of the battery 101 include parameters related to the capacity of the positive electrode, the capacity of the negative electrode, the resistance of the positive electrode, and the resistance of the negative electrode. The deterioration model may be configured to reflect the deterioration state of the battery 101 based on the physical properties of the positive electrode and the negative electrode of the battery 101.

[0051] (Deterioration Model) The deterioration model calculates the amount of change in the utilization rate and resistance deterioration rate of the active material of the positive and negative electrodes of the battery 101 based on conditions such as the current, voltage, temperature, and current conduction ratio of the battery 101, as well as the calculated internal deterioration parameters. Then, from these, the SOHR of the battery 101 is predicted in chronological order. The deterioration prediction unit 502 can calculate a predicted value of deterioration of the battery 101 while reflecting the state of the battery 101 in the deterioration model with relatively high accuracy.

[0052] The degradation model may be configured to extract the usage conditions of the battery 101 based on calculated values ​​based on information on the degradation states of the positive electrode, negative electrode, and other components of the battery 101, and on detected values ​​of the battery 101. This degradation model makes it possible to predict the capacity degradation and resistance change of the battery 101 based on the usage conditions of the battery 101. By using various information in this way, the prediction accuracy of the SOHR based on the degradation model is improved, and the accuracy of detecting specific increases in resistance is improved, thereby allowing the battery life to approach the expected life. As a result, the battery performance can be maintained and the energy loss of the vehicle can be reduced.

[0053] (Resistance Increase Determination Unit 503) The resistance increase determination unit 503 differentiates the model predicted value SOHRest output from the deterioration prediction unit 502 and the deterioration calculation value SOHRcalc output from the deterioration calculation unit 232 to calculate (dSOHRest / dt) and (dSOHRcalc / dt), which are fluctuations per unit time. (dSOHRcalc / dt) corresponds to the deterioration rate (change over time) of the battery 101. On the other hand, (dSOHRest / dt) corresponds to the deterioration rate of the battery 101 in the absence of a specific resistance increase.

[0054] When an idiosyncratic resistance increase occurs, the actual measured value (dSOHRcalc / dt) becomes larger than the model predicted value (dSOHRest / dt). Therefore, the resistance increase determination unit 503 calculates the difference 1 [(dSOHRcalc / dt) - (dSOHRest / dt)] between (dSOHRcalc / dt) and (dSOHRest / d), and compares this with the threshold A to determine whether an idiosyncratic resistance increase has occurred in the battery 101. That is, when the difference 1 [(dSOHRcalc / dt) - (dSOHRest / dt)] becomes a value outside the threshold A as an allowable range, the resistance increase determination unit 503 can determine this as the timing when an idiosyncratic resistance increase in the battery 101 has started.

[0055] The threshold value A is determined taking into consideration the calculation error of the battery pack control management unit 230, the estimation range of the deterioration model, and other sensor errors. By setting the threshold value A in this manner, the battery pack control management unit 230 can suppress a specific increase in resistance of the battery 101 while suppressing instability in the load output.

[0056] (Limit value correction unit 504) The limit value correction unit 504 corrects the limit value of the charge / discharge power of the battery 101 based on the determination result of the resistance increase determination unit 503. When the resistance increase determination unit 503 determines that a specific resistance increase has occurred in the battery 101, the limit value correction unit 504 corrects the limit value in a direction that reduces the charge / discharge power of the battery 101.

[0057] The limit value correction unit 504 outputs the corrected limit value to the vehicle control management unit 410. The vehicle control management unit 410 controls the load (power conversion unit 320) based on the corrected limit value to limit the charging and discharging power of the battery 101.

[0058] In this way, when the measured value and the model predicted value of the resistance increase rate deviate by more than the threshold value A and it is determined that an idiosyncratic increase in resistance has occurred, the limit value correction unit 504 reduces the power limit value, thereby reducing the power flowing to the load (= the power flowing to the battery 101) and making it possible to suppress the idiosyncratic increase in resistance of the battery 101 early on.

[0059] (Prediction Calculation Error Information Output Unit 505) The prediction calculation error information output unit 505 outputs an error that may be included in the calculation result of the model predicted value SOHRest, i.e., SOHRest_error, based on the current, voltage, and temperature. When outputting the error, the prediction calculation error information output unit 505 references the error information shown in Figures 3A and 3B. Figure 3A is a map of prediction calculation error information when the battery 101 is under low load, and includes SOHRest error information for each integrated capacity under each of a plurality of battery conditions. Figure 3B is a graph of this map.

[0060] 3A and 3B show error information in a degradation prediction model in a region where the load on the battery 101 is low, i.e., a region where a resistance increase specific to the battery 101 does not occur. The characteristics of the error information shown in FIGS. 3A and 3B are configured so that the error of the model predicted value SOHRest changes as the integrated usage of the battery 101 increases. The change in the error of the model predicted value SOHRest is also configured to correlate with conditions such as the operating range (ΔSOC), current value, and temperature of the battery 101. As described above, even in a degradation model in which the error of the degradation estimation value fluctuates with an increase in the integrated usage of the battery 101, i.e., an increase in the degradation of the battery 101, it is possible to estimate the error that may be included in the model output.

[0061] (Detection Calculation Error Information Output Unit 506) The detection calculation error information output unit 506 outputs an error, i.e., SOHRcalc_error, that may be included in the detection value SOHRcalc output by the degradation calculation unit 232 based on the temperature and SOC. The error includes, for example, an error in the calculation algorithm, a detection error of current, voltage, and temperature, and / or a conversion error. When outputting the error, the detection calculation error information output unit 506 references the error information shown in FIGS. 4A and 4B. FIG. 4A is a map of detection value error information when the battery 101 is under low load, and includes detection value error information for each SOC at each of multiple battery temperatures. FIG. 4B is a graph of this map. If the error in SOHRcalc depends on the current, voltage, etc., a multidimensional map may be created by adding dimensions such as current and voltage values ​​to the map of FIG. 4A.

[0062] The calculation error of the detected value SOHRcalc increases or decreases depending on the SOC dependency of SOHR, the temperature dependency of various sensors, etc. In this configuration, the SOC, temperature, etc. are input to the error information map, so even if the detected value SOHRcalc has the above-mentioned characteristics, it is possible to estimate the error that may be included in the detected value.

[0063] (Resistance Increase Threshold Calculation Unit 507) One form of the resistance increase threshold calculation unit 507 is configured to output a large threshold A when the error is large and a small threshold A when the error is small, based on the model prediction error SOHRest_error and the detection error SOHRcalc_error, to the resistance increase determination unit 503. With this configuration, it is possible to output the threshold A according to the error in the detection value SOHRcalc and the model prediction value SOHRest, and it is possible to more precisely determine the occurrence of an unusual resistance increase.

[0064] In another embodiment of the resistance increase threshold calculation unit 507 , a threshold A calculated from the detected SOHR using equation (1) is output to the resistance increase determination unit 503 .

[0065] A∝SOHR(t,T,I)...(1)

[0066] The SOHR increases due to factors such as the current integration capacity. Many of these factors are common to prediction calculation errors and detection calculation errors, and the SOHR can be used as an alternative to calculating these errors. By calculating the threshold A using the SOHR in this way, the maps, memory, and calculation time required for calculation can be reduced.

[0067] (Operation of Battery Control Device 200) Next, the operation of the battery control device 200 will be described.

[0068] (Increase in Resistance Value of Battery 101) The manner in which the resistance value of battery 101 increases will now be described. FIG. 5 is a graph showing a phenomenon in which a specific resistance increase occurs when a secondary battery such as a lithium-ion battery is continuously used under high load. FIG. 5 shows how much the resistance increases with respect to the number of cycles when a lithium-ion battery is cycle-tested under a high-load pattern. As an index for determining whether a specific resistance increase has occurred, SOHR, which indicates the percentage increase in resistance value relative to the initial state (increase rate), was used.

[0069] As shown in Figure 5, if the indicator rises (a) and power is halted for a long period of time, the SOHR will decrease (b). However, if high-load charge / discharge cycles are resumed, the resistance (SOHR) will rise again, accelerating battery degradation. If the rise in the indicator is discovered late and high-load use continues, the battery degradation cannot be recovered. Even if the battery is halted, the resistance will rise as soon as high-load cycle operation begins, accelerating cumulative battery degradation (c). To avoid this, the battery control device 200 reduces the load by using a power limit value, etc.

[0070] (Determining Specific Resistance Increase) A first example of a method for determining specific resistance increase in the battery 101 will be described with reference to FIGS. 6A, 6B, and 6C. FIG. 6A is a graph showing the current value of a certain battery 101 among the multiple batteries 101. FIG. 6B is a graph showing the time-dependent fluctuations of the model-predicted value SOHRest and the detected value SOHRcalc of the battery 101. FIG. 6C is a graph showing the time-dependent fluctuations of the model-predicted value SOHRest (dSOHRest / dt) and the time-dependent fluctuations of the detected value SOHRcalc (dSOHRcalc / dt), as well as the difference 1 ((dSOHRcalc / dt) - (dSOHRest / dt)). Note that the time-dependent change rate of SOHRcalc and the difference 1 are almost the same value and therefore overlap. The horizontal axes of FIGS. 6A, 6B, and 6C are time axes on the same scale. Hereafter, the horizontal axis of related figures is the time axis of the same scale.

[0071] The current value of the battery 101 is the current value when multiple batteries 101 are connected in series. The current value of the battery 101 varies over time. In the following description, the current value of the battery 101 is defined as positive in the direction in which the battery 101 is charged.

[0072] 6B , the detected value SOHRcalc increases due to a specific increase in the resistance value of the battery 101. On the other hand, the degree of deterioration in the deterioration model does not fluctuate much when the battery 101 is energized for a short period of time, such as several hours, and therefore the model predicted value SOHRest is shown as an approximately flat line.

[0073] 6B , when the detected value SOHRcalc and the model predicted value SOHRest are compared in magnitude, the degree of deterioration of the battery 101 can be determined to some extent. However, even if the detected value SOHRcalc and the model predicted value SOHRest are directly compared, it is not easy to determine whether an unusual increase in the resistance value of the battery 101 is occurring due to continuous use of the battery 101 under a high load. Therefore, the resistance increase determination unit 503 determines whether an unusual increase in the resistance value of the battery 101 is occurring based on the method shown in FIG. 6C .

[0074] 6C shows the rate of change per unit time of the detected value SOHRcalc and the model predicted value SOHRest of the battery 101. The degradation calculation unit 232 calculates the rate of change of the detected value SOHRcalc. The rate of change of the detected value SOHRcalc is calculated as (dSOHRcalc / dt) by differentiating the detected value SOHRcalc with respect to time.

[0075] The degradation prediction unit 502 calculates the rate of change of the model predicted value SOHRest. The rate of change of the model predicted value SOHRest is calculated as (dSOHRest / dt) by time-differentiating the model predicted value SOHRest. The resistance increase determination unit 503 determines that an unusual increase in resistance has occurred when (dSOHRcalc / dt) significantly deviates from (dSOHRest / dt) (high-load resistance increase determination). That is, as shown in FIG. 6C , when the difference 1 [(dSOHRcalc / dt) - (dSOHRest / dt)], which is the difference in time derivatives, is positive and exceeds threshold A, the resistance increase determination unit 503 determines that an unusual increase in resistance has occurred in the battery 101.

[0076] In response to this determination, the limit value correction unit 504 updates, corrects, or changes the limit value so as to reduce the charge / discharge power of the battery 101 in order to suppress an increase in the resistance of the battery 101. The limit value correction unit 504 may change the limit value gradually rather than suddenly lowering it. By gradually changing the limit value, it is possible to prevent the control of the load or the amount of power generation from becoming unstable, thereby improving the ride comfort of the vehicle.

[0077] The resistance increase threshold calculation unit 507 determines the threshold A taking into consideration the allowable error range, calculation error in the deterioration calculation, calculation error in the model prediction value calculation, estimation range of the deterioration model, sensor error, etc., in order to prevent erroneous determination of a high load resistance increase. It is desirable for the resistance increase threshold calculation unit 507 to set the threshold A within a range that does not cause the high load resistance to be switched on and off too frequently. Multiple thresholds A may be set depending on the conditions and the power limit value. As a first example of the threshold A, the threshold A may be set relatively large.

[0078] When the resistance increase determination unit 503 determines that the difference 1 exceeds the threshold A, the limit value correction unit 504 corrects the limit value of the charge / discharge power of the battery 101 so that a relatively strict power limit is applied to the battery 101. As a result, the current limit of the battery 101 is realized according to the resistance value characteristics of the battery 101.

[0079] As a second example of threshold value A, threshold value A may be set to a relatively small value. In the second example, when resistance increase determination unit 503 determines that difference 1 exceeds threshold value A, limit value correction unit 504 corrects the limit value so that a power limit that is relatively more lenient than that in the first example is applied to battery 101.

[0080] As a third example of the threshold value A, the threshold value A may be changed depending on the degree of deterioration of the battery 101. The third example is useful when the rate of increase in the resistance value of the battery 101 is affected by the SOHR. The threshold value A may be determined as a function of the SOHR with respect to time, temperature, and current, for example, as shown in the above-described formula (1).

[0081] By setting a threshold value in this way, it becomes possible to control the battery so as to suppress an increase in the resistance of the battery 101 while suppressing the load output from becoming unstable.

[0082] (Correction of Limit Value) As shown in Figures 7A and 7B, the limit value correction unit 504 can correct the limit value of the current or power of the battery 101, for example, based on a ΔV limiting method. The ΔV limiting method is a method of setting a limit value so that ΔV is within a certain threshold Vth. ΔV is the difference between an OCV (open circuit voltage) and a CCV (closed circuit voltage). The OCV is the voltage when no load is applied to the battery 101. In other words, the OCV is the voltage (open circuit voltage) when no current is flowing from the battery 101 to an electrical device.

[0083] CCV is the actual terminal voltage of the battery 101. If the battery 101 is left for a long period of time without current flowing through it, the CCV and OCV will match. On the other hand, if current is passed through the battery 101, the CCV will change due to the voltage generated by the internal resistance of the battery 101 and the polarization voltage generated by the current, and will no longer match the OCV. The CCV increases when the battery 101 is charged and decreases when the battery 101 is discharged.

[0084] As described above, the amount of change in CCV increases with an increase in resistance, and therefore ΔV increases with an increase in resistance. Therefore, when an unusual increase in resistance occurs, ΔV also tends to become an unusually large value. The ΔV limiting method limits charging and discharging so that this ΔV is equal to or less than a predetermined value. Therefore, when such a large ΔV occurs, a strict power limit value is set, reducing the load and enabling battery recovery. In this embodiment, when the resistance increase determination unit 503 determines an unusual increase in resistance, the limit value correction unit 504 reduces the value of the threshold Vth. This allows the limit value correction unit 504 to quickly reduce the limit value, eliminating the unusual increase in resistance at an early stage and preventing rapid battery degradation.

[0085] (Control Method of Battery 101) With reference to FIGS. 8A to 8C , a control method of the battery 101 by the battery control device 200 that reflects an increase in the resistance value of the battery 101 will be described. The degradation calculation unit 232 calculates the detected value SOHRcalc at a predetermined time point, for example, the timing when conditions suitable for calculating degradation are met ( FIG. 8C ), for the arbitrarily switched current flow. An example of such a timing is a timing when the current flow changes significantly instantaneously. At this time, the detected value SOHRcalc fluctuates stepwise according to the timing, as shown in FIG. 8B . Calculating the detected value SOHRcalc at the timing when the current flow changes significantly instantaneously improves the calculation accuracy. Note that the calculation timing may be uniform and regular. This improves the real-time nature of the detected value SOHRcalc.

[0086] The resistance increase determination unit 503 calculates (dSOHRcalc / dt) and (dSOHRest / dt) in a time series manner, as shown in Fig. 8A. As described above, the deterioration model used as the basis for calculating the model predicted value SOHRest models the progression of deterioration under conditions in which a sudden increase in resistance does not occur, so the model predicted value SOHRest fluctuates slowly. In contrast, the detected value SOHRcalc fluctuates noticeably at each calculation timing in accordance with the charging and discharging of the battery.

[0087] In (c) of Figure 8A, the sudden rise in (dSOHRcalc / dt) is due to the fact that a high load has been applied for a while, resulting in an unusual rise in resistance and a short-term increase in the detected value SOHRcalc. On the other hand, in (d) of Figure 8A, the sudden drop in (dSOHRcalc / dt) is due to the fact that the battery had just been suspended or suppressed from power supply, resulting in the battery recovering from the unusual rise in resistance and a sudden drop in the detected value SOHRcalc.

[0088] 9A and 9B , the recovery of the battery 101 from an increase in resistance will be described by the battery control device 200, comparing the detected value SOHRcalc ( FIG. 9B ) with the change in current of the battery 101 ( FIG. 9A ). When the resistance increase determination unit 503 determines that a specific increase in resistance has occurred in the battery 101, the limit value correction unit 504 corrects the limit value to eliminate the specific increase in resistance. As a result, a period of suspension of charging and discharging occurs between the two charging and discharging periods.

[0089] Therefore, even if the detected value SOHRcalc increases significantly during high-load operation of the battery control device 200, the detected value SOHRcalc quickly returns to the value before the increase (e).Then, the battery pack control management unit 230 suspends charging and discharging at an early stage after the detected value SOHRcalc begins to increase, thereby preventing irreversible deterioration and causing the detected value SOHRcalc to return to approximately the same value as before the peculiar increase in resistance occurred (f).

[0090] (Second Example of Method for Determining Increase in Resistance Value of Battery 101) A second example of a method for determining a specific increase in resistance of the battery 101 by the battery control device 200 will be described with reference to Figure 10. After the aforementioned limiting process (Figure 9A), the rate of change of SOHRcalc (dSOHRcalc / dt) suddenly drops (Figure 10, 600). Utilizing this, auxiliary determination of a high-load resistance increase can be realized.

[0091] The resistance increase determination unit 503 determines that an idiosyncratic resistance increase has begun when the difference 1 [(dSOHRcalc / dt) - (dSOHRest / dt)] exceeds the threshold A and reaches the region X in Figure 10 (700). On the other hand, when the charge / discharge power of the battery 101 is limited and the battery recovers from the idiosyncratic resistance increase, in the early stage, the difference 1 exceeds the allowable error (threshold A) from X and suddenly reaches the region Y (600). As a result, the resistance increase determination unit 503 can reconfirm that the battery was in a state of idiosyncratic resistance increase. In other words, the battery pack control management unit 230 can realize auxiliary determination of high-load resistance increase.

[0092] This auxiliary determination can also be used to determine whether the peculiar resistance increase has been resolved. That is, if the difference 1 returns to within the allowable error range after this auxiliary determination is once established (700), the assembled battery control management unit 230 can determine that the battery has recovered from the peculiar resistance increase. This enables the assembled battery control management unit 230 to determine whether it is acceptable to increase the power limit value to the value before the high-load resistance increase determination. This determination may also be made when the difference 1 returns to a value equal to or greater than 0 and less than a predetermined threshold. By using such a determination condition, it is possible to more reliably determine that the battery has recovered.

[0093] (Flowchart of a control method executed by the battery control device 200) The processor of the microcomputer repeatedly executes the flowchart shown in Figure 11 at predetermined intervals based on a program recorded in memory. The flowchart will be explained using the block diagrams of Figures 1, 2 and 3.

[0094] In step S11, the detection unit 220 detects the current value, voltage value, and temperature of the battery 101, and then proceeds to steps S12 and S15. In step S12, the deterioration prediction unit 502 converts the detected values ​​of the voltage V, current I, and temperature T of the battery 101 into parameters for a deterioration model, and then proceeds to step S13.

[0095] In step S13, the deterioration prediction unit 502 inputs the parameters converted in step S12 into the deterioration model, and then proceeds to step S14. In step S14, the deterioration prediction unit 502 calculates a model predicted value SOHRest based on the deterioration model of step S13, and then proceeds to step S16. In step S15, the deterioration calculation unit 232 calculates a detected value SOHRcalc, and then proceeds to step S16.

[0096] In step S16, the resistance increase determination unit 503 differentiates the detected value SOHRcalc to calculate dSOHRcalc / dt. Also, the resistance increase determination unit 503 differentiates the model predicted value SOHRest to calculate dSOHRest / dt. Next, the resistance increase determination unit 503 proceeds to step S17.

[0097] In step S17, the resistance increase determination unit 503 compares the difference 1 [(dSOHRcalc / dt)-(dSOHRest / dt)] with the threshold value A. If the difference 1 is greater than the threshold value A (step S17: Yes), the resistance increase determination unit 503 determines that a specific resistance increase has occurred in the battery 101, and the resistance increase determination unit 503 proceeds to step S18.

[0098] On the other hand, in step S17, if the difference 1 is the same as the threshold value A (NO), or if the difference is less than or equal to the threshold value A (NO), the resistance increase determination unit 503 determines that no specific resistance increase has occurred in the battery 101, and the resistance increase determination unit 503 proceeds to step S21.

[0099] In step S18, the limit value corrector 504 corrects downward the correction amount used to change the limit value of the current or power of the battery 101, and then proceeds to step S19. By reducing this correction amount, the load can be reduced and an unusual increase in the resistance value can be suppressed.

[0100] In step S19, the resistance increase determination unit 503 compares difference 1 with threshold value A. Furthermore, the resistance increase determination unit 503 compares difference 2 [(detected value SOCRcalc) - (model predicted value SOCRest)] with threshold value B. If difference 1 is smaller than threshold value A and difference 2 is equal to or greater than 0 and smaller than threshold value B (step S19: Yes), the resistance increase determination unit 503 determines that the peculiar resistance increase of the battery 101 has been resolved in step S18, and the resistance increase determination unit 503 proceeds to step S20.

[0101] On the other hand, in step S19, if difference 1 is equal to or greater than threshold A, or difference 2 is less than 0 or equal to or greater than threshold B, it is determined that the peculiar resistance increase of battery 101 has not yet been resolved, and the limit value of the current or power of battery 101 remains limited, and the process proceeds to step S21. That is, after limiting battery 101 (step S18), resistance increase determination unit 503 and limit value correction unit 504 continue the limit until the battery recovers from the peculiar resistance increase state and approaches the model predicted value SOHRest, which is the original value.

[0102] In step S20, the limit value corrector 504 corrects the correction amount upward (in the direction of easing), and then proceeds to step S21. By correcting the correction amount upward, the current value and voltage value of the battery 101 approach their normal values ​​when the battery 101 recovers from the peculiar resistance increase state.

[0103] In step S21, a limit is implemented to reduce the current and power based on the correction amount. Such limits include direct limits on the current and power, as well as effective current limits and ΔV limits. At this time, the current and power resulting from the limit are set so that they do not exceed the limit value output from the limit value calculation unit 501 at maximum. Similarly, they are set so that they do not become less than 0.

[0104] By using this flow, the battery pack control management unit 230 can drive the load more efficiently by shortening the output suppression period while suppressing battery degradation, thereby making it possible to make effective use of energy.

[0105] (Effects of the method for controlling the battery 101 by the battery control device 200) The effects of the method for controlling the battery 101 by the battery control device 200 will be described with reference to Figures 12A to 12C, etc. In this figure, the model predicted value SOHRest(n) is a curve that gradually increases as the battery 101 is used over a long period of time. To use the battery to its expected lifespan, it is important that the detected value SOHRcalc(m, o) does not deviate significantly from this model predicted value SOHRest(n), that is, that the difference between the two does not exceed threshold B.

[0106] In this embodiment, when the resistance increase determination unit 503 determines that difference 1 [(dSOHRcalc / dt) - (dSOHRest / dt)] exceeds threshold A (g), the limit value correction unit 504 corrects the power limit value in a decreasing direction in synchronization with this or without delay (h). This reduces the load on the battery 101, alleviating the idiosyncratic resistance increase and reducing difference 1. The amount of reduction continues to increase until difference 1 becomes equal to or less than threshold A. This creates a low-load state necessary to alleviate the idiosyncratic resistance increase.

[0107] When the difference 1 becomes equal to or less than the threshold value A, the correction amount of the power limit value is maintained until the SOHRcalc becomes equal to or less than the threshold value B. This creates a state in which the resistance value is reduced by mitigating the specific increase in resistance.

[0108] When SOHRcalc falls below threshold B, the correction amount of the power limit value is reduced, and the power limit is relaxed. Then, when the correction amount reaches 0, the reduction of the correction amount is stopped. This releases unnecessary power limits after the peculiar resistance increase has been alleviated. This makes it possible to restore the battery's power limit value to its original value as quickly as possible while maintaining the battery life as predicted, and restores the performance of the battery 101 to the state it was in before the peculiar increase in resistance occurred.

[0109] The above-described embodiment provides a first battery control device (200) that includes a calculation unit (deterioration calculation unit 232) that calculates the degree of deterioration of a battery, a prediction unit (deterioration prediction unit 502) that predicts the degree of deterioration of the battery, and a control unit (battery pack control management unit 230) that limits charging and discharging of the battery based on a comparison between the change over time of the degree of deterioration of the battery (amount of change over time, rate, degree, etc.) obtained by the calculation of the calculation unit and the change over time of the degree of deterioration of the battery obtained by the prediction of the prediction unit.

[0110] According to the first battery control device, by detecting and preventing specific increases in battery resistance early, it is possible to suppress unexpected abnormal increases in resistance due to continuous operation of the battery under high load or other reasons, while ensuring stable output of the load, and to realize battery control that allows the battery to be used effectively until its expected lifespan.

[0111] The above-described embodiment discloses a second battery control device in which, in the first battery control device, the control unit (battery pack control management unit 230) is provided with a determination unit (resistance increase determination unit 503) that determines the deterioration state of the battery based on the result of the comparison, and a limiting unit (limit value correction unit 504) that limits the charging and discharging of the battery based on the determined deterioration state of the battery.

[0112] The above-described embodiment discloses a third battery control device characterized in that, in the second battery control device, the calculation unit calculates the degree of deterioration of the battery based on battery detection data, the prediction unit predicts the degree of deterioration of the battery based on a battery deterioration prediction model, and the determination unit calculates the difference between the time change in the degree of deterioration calculated by the calculation unit and the time change in the degree of deterioration predicted by the prediction unit, and determines the state of deterioration of the battery based on the calculated difference.

[0113] The deterioration prediction model is a model of the gradual deterioration progression of the battery until the required life span of the battery is reached, based on the normal usage pattern of the battery.

[0114] The above-described embodiment discloses a fifth battery control device, characterized in that, in the third battery control device, the determination unit compares the difference with a threshold value and determines the state of deterioration of the battery if the difference is outside the threshold value, and the restriction unit restricts the charging and discharging of the battery based on the determined state of deterioration of the battery, and continues the restricted charging and discharging of the battery until the difference falls within the threshold value.

[0115] The above-described embodiment discloses a sixth battery control device, which is characterized in that in the third battery control device, the control unit (resistance increase threshold calculation unit 507) calculates the threshold based on an error when calculating the degree of deterioration of the battery and an error when predicting the degree of deterioration of the battery.

[0116] The above-described embodiment discloses a seventh battery control device, which is characterized in that in the fifth battery control device, the limiting unit is provided with a correction unit (limit value correction unit 504) that corrects the limit value for limiting charging and discharging of the battery, and when the determination unit determines that the difference exceeds the threshold value, the correction unit corrects the limit value to decrease it.

[0117] The above-described embodiment discloses an eighth battery control device, which is characterized in that in the sixth battery control device, the correction unit defines the difference between the CCV and OCV of the battery as ΔV and corrects the limit value so that ΔV is within a threshold value.

[0118] The above-described embodiment discloses a ninth battery control device, which is the seventh battery control device, wherein the correction unit corrects the limit value so that charging and discharging of the battery is gradually restricted.

[0119] The above-described embodiment discloses a battery control method in which a processor controls the operation of a battery, in which the processor calculates the degree of deterioration of the battery, predicts the degree of deterioration of the battery, and limits charging and discharging of the battery based on a comparison between the time change in the degree of deterioration of the battery obtained by the calculation and the time change in the degree of deterioration of the battery obtained by the prediction.

[0120] The above-described embodiment discloses a vehicle control device (400) connected to a power conversion unit (320) connected to a motor (330) of a vehicle drive device (300), and a battery control device (200), which controls the power supplied from the battery to the power conversion unit based on a limit value that limits the charging and discharging of the battery.

[0121] The present invention is not limited to the configurations described in the embodiments, and can be appropriately configured based on the content described in the claims. The above-described embodiments are examples for implementing the present invention. When implementing the present invention, only a part of the configurations of the embodiments may be implemented.

[0122] When implementing the present invention, configurations not described in the embodiments may be added to the embodiments. When implementing the present invention, some configurations of the embodiments may be replaced with configurations not described in the embodiments. The "section" in "**** section" disclosed in the embodiments may be replaced with the terms module, means, unit, circuit, or part. "d**** / dt" disclosed in the embodiments may be replaced with "Δ****" representing the amount of change.

[0123] Furthermore, the modules, means, and units may be configured by combining electronic circuits. By using such a configuration, a battery system can be realized that quickly detects the occurrence of an unusual increase in resistance that is different from a normal increase in resistance, and reduces the load on the battery depending on the result of the detection, thereby suppressing the increase in resistance.

[0124] 100: assembled battery, 101: battery, 200: battery control device, 210: battery management unit, 211: battery control unit, 220: detection unit, 221: current detection unit, 222: voltage detection unit, 223: temperature detection unit, 230: assembled battery control management unit, 231: SOC calculation unit, 232: deterioration calculation unit, 233: power limit calculation unit, 234: voltage equalization calculation unit, 235: diagnosis unit, 240: assembled battery storage unit, 300 : Vehicle drive device, 310: Relay, 320: Power conversion unit, 330: Motor, 340: Engine, 400: Vehicle control device, 410: Vehicle control management unit, 420: Vehicle memory unit, 501: Limit value calculation unit, 502: Deterioration prediction unit, 503: Resistance increase determination unit, 504: Limit value correction unit, 505: Prediction calculation error information output unit, 506: Detection calculation error information output unit, 507: Resistance increase threshold calculation unit

Claims

1. A battery control device comprising: a calculation unit that calculates the degree of deterioration of a battery; a prediction unit that predicts the degree of deterioration of the battery; and a control unit that limits charging and discharging of the battery based on a comparison between the change over time in the degree of deterioration of the battery obtained by the calculation of the calculation unit and the change over time in the degree of deterioration of the battery obtained by the prediction of the prediction unit.

2. The battery control device according to claim 1, wherein the control unit comprises: a determination unit that determines the deterioration state of the battery based on the result of the comparison; and a limiting unit that limits charging and discharging of the battery based on the determined deterioration state of the battery.

3. A battery control device as described in claim 2, wherein the calculation unit calculates the degree of deterioration of the battery based on detection data of the battery, the prediction unit predicts the degree of deterioration of the battery based on a deterioration prediction model of the battery, and the determination unit calculates the difference between the time change in the degree of deterioration calculated by the calculation unit and the time change in the degree of deterioration predicted by the prediction unit, and determines the state of deterioration of the battery based on the calculated difference.

4. The battery control device according to claim 3, wherein the deterioration prediction model is a model of the gradual deterioration progression of the battery until the required life span of the battery is reached, based on the normal usage pattern of the battery.

5. A battery control device as described in claim 3, wherein the determination unit compares the difference with a threshold value and determines the state of deterioration of the battery if the difference is outside the threshold value, and the restriction unit restricts charging and discharging of the battery based on the determined state of deterioration of the battery, and continues the restricted charging and discharging of the battery until the difference falls within the threshold value.

6. The battery control device according to claim 5, wherein the control unit calculates the threshold value based on an error when calculating the deterioration level of the battery and an error when predicting the deterioration level of the battery.

7. A battery control device as described in claim 5, wherein the limiting unit includes a correcting unit that corrects a limit value for limiting charging and discharging of the battery, and when the determining unit determines that the difference exceeds the threshold value, the correcting unit corrects the limit value by decreasing it.

8. The battery control device according to claim 7, wherein the correction unit defines a difference between the CCV and OCV of the battery as ΔV and corrects the limit value so that ΔV is within a threshold value.

9. The battery control device according to claim 7, wherein the correction unit corrects the limit value so that charging and discharging of the battery is gradually restricted.

10. A battery control method in which a processor controls the operation of a battery, the processor calculating the degree of deterioration of the battery, predicting the degree of deterioration of the battery, and limiting the charging and discharging of the battery based on a comparison between the time change in the degree of deterioration of the battery obtained by calculation and the time change in the degree of deterioration of the battery obtained by prediction.

11. A vehicle control device connected to a power conversion unit connected to a motor of a vehicle drive device and the battery control device described in claim 1, which controls the power supplied from the battery to the power conversion unit based on a limit value that limits the charging and discharging of the battery.

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