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

Abstract

A battery control device (200) is provided with: a deterioration calculation unit (232) that calculates the degree of deterioration of a battery (101); a deterioration prediction unit (502) that predicts the degree of deterioration 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 the change over time in the degree of deterioration of the battery calculated by the calculation unit and the change over time in the degree of deterioration of the battery predicted by the prediction unit.

Description

Technical Field

[0001] This invention relates to a battery control device, a battery control method, and a vehicle control device. Background Technology

[0002] To prevent global warming, it is necessary to reduce carbon dioxide emissions. Therefore, for example, cars that previously relied solely on gasoline engines are gradually being replaced by hybrid vehicles that combine gasoline engines and electric motors, and electric vehicles that use only electric motors. To prevent a decline in vehicle performance due to this replacement, the large secondary batteries that power hybrid and electric vehicles require high power and large capacity. To achieve high power and large capacity, the battery modules that make up these large secondary batteries are composed of multiple secondary battery cells (batteries) connected in series and parallel. These batteries typically use secondary batteries such as lithium-ion batteries.

[0003] It is known that if secondary batteries such as lithium-ion batteries are used continuously with high current, their internal resistance will rise abnormally, accelerating degradation. After the resistance increase is detected, quickly stopping the power supply will cause this abnormal resistance increase to gradually decrease, recovering within a few days. However, if the resistance increase is detected late and a high load is continuously applied to the secondary battery, it will accelerate and solidify the degradation. Even if the battery is stopped for a long time, temporarily reducing the resistance, the resistance will rise sharply again upon re-energizing.

[0004] A control method for a secondary battery aimed at suppressing such an increase in internal resistance is proposed (e.g., Patent Document 1). The method in Patent Document 1 involves setting thresholds for the charging and discharging current of the rechargeable battery corresponding to multiple periods, thereby limiting the charging and discharging current of the rechargeable battery so that the sum of the currents or the sum of the squares of the currents within each period is below the corresponding threshold.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2011-79447 Summary of the Invention The problem the invention aims to solve In the method of Patent Document 1, the current limit is lowered after a resistance increase due to continuous high load, thus promoting the degradation of the secondary battery. Even after stopping the power supply to the load, the resistance value may not recover to the value before the specific increase. Moreover, if the resistance value returns to the limit value after a certain degree of recovery and the current increases, as mentioned above, the resistance may rise sharply in a short period of time and exceed the threshold again. If this state occurs, the limit is frequently applied, ultimately leading to greater battery degradation. Therefore, in order to effectively use the battery until its expected lifespan, a performance margin in this situation needs to be taken into account.

[0006] From a performance optimization perspective, a smaller margin is better. To minimize this margin, it is necessary to prevent the aforementioned phenomena from occurring. In previous methods, these phenomena arose because it was difficult to detect and prevent early on the specific increase in battery resistance caused by continuous high-load operation. Therefore, to minimize the margin and effectively utilize the battery until its expected lifespan, it is necessary to detect and prevent early on the specific increase in battery resistance caused by continuous high-load operation.

[0007] The purpose of this invention is to provide a battery control device, a battery control method, and a vehicle control device that can suppress unexpected abnormal increases in resistance caused by continuous operation of the battery under high load or other reasons, and ensure stable load output, and can effectively use the battery until its expected lifespan.

[0008] Means used to solve problems To achieve the aforementioned objective, the present invention provides a battery control device comprising: a calculation unit for calculating the degree of battery degradation; a prediction unit for predicting the degree of battery degradation; a determination unit for determining the state of the battery based on a comparison between the calculated change in the degree of battery degradation over time and the predicted change in the degree of battery degradation over time; and a limiting unit for limiting the 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 according to the aforementioned technical solution.

[0009] Invention Effects According to the present invention, it is possible to suppress unexpected and unusual increases in resistance values ​​and ensure stable output of the load, and to effectively utilize the battery until its expected lifespan. Attached Figure Description

[0010] Figure 1 This is a block diagram illustrating a portion of the configuration of a vehicle having an embodiment of the battery control device of the present invention.

[0011] Figure 2 This is a block diagram showing the structure of the battery pack control management unit of the battery control device according to an embodiment.

[0012] Figure 3 This is a block diagram showing the structure of the power limiting calculation unit according to an embodiment.

[0013] Figure 3A This is the error table for the model's predicted values, SOHRest.

[0014] Figure 3B This is a graph showing the error of the model's predicted value, SOHRest.

[0015] Figure 4AThis is the error table for the measured value SOHRcalc.

[0016] Figure 4B This is a graph showing the error of the measured value SOHRcalc.

[0017] Figure 5 This is a graph showing the relationship between the number of cycles and SOHR of a secondary battery.

[0018] Figure 6A It is a graph showing the current value of the battery.

[0019] Figure 6B This is a graph showing the changes in the model prediction value SOHRest and the detected value SOHRcalc of the battery.

[0020] Figure 6C This is a graph showing the variation of the battery's detected value SOHRcalc and the model predicted value SOHRest per unit time.

[0021] Figure 7A It is a graph showing the changes in the battery's OCV and CCV over time.

[0022] Figure 7B This is a graph showing the time-dependent variation of the difference between OCV and CCV.

[0023] Figure 8A This is a graph showing the relationship between the unit time variation of the detected value SOHRcalc and the unit time variation of the model predicted value SOHRest in the battery control method. This relationship reflects the increase in the battery's resistance value.

[0024] Figure 8B This is a graph showing the relationship between the detected value SOHRcalc and the model predicted value SOHRest.

[0025] Figure 8C This is a graph showing the timing of SOHR calculations.

[0026] Figure 9A The graph shows the change in current over time as detected by the current sensing unit, which is related to the recovery of the battery's resistance value.

[0027] Figure 9B This is a graph showing the change of the measured value SOHRcalc over time.

[0028] Figure 10 This is a graph illustrating the time-dependent change of the difference (dSOHRcalc / dt - dSOHRest / dt) in the second example of the determination method related to the increase in the battery's resistance value.

[0029] Figure 11 This is an example of a flowchart of the control method performed by the battery control device.

[0030] Figure 12A This is a graph showing the time-varying changes of the detected value SOHRcalc and the model predicted value SOHRest to illustrate the effectiveness of the battery control method of the battery control device.

[0031] Figure 12B It is a graph showing the change of power limit values ​​over time.

[0032] Figure 12C It is a graph showing the time-dependent variation of difference 1 (dSOHRcalc / dt-dSOHRest / dt). Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the description, to clearly define the dimensions of voltage V, current I, power W, resistance R, temperature T, and time t, symbols corresponding to the dimensions will be added even if not shown in the figures. Alternatively, if a specific value is required, a subscript will be added to the symbol for the dimension. 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 can be listed. Furthermore, units for each dimension are generally omitted throughout the text and all accompanying drawings.

[0034] (Structure of vehicle 1) Figure 1 This is a block diagram showing a partial configuration of a vehicle 1 having an embodiment of the battery control device of the present invention. The vehicle 1 includes a battery pack 100 that supplies power to the vehicle 1, a battery control device 200 that controls the operation of the battery pack 100, such as charging and / or discharging, 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.

[0035] Vehicle 1 is configured as a hybrid electric vehicle (HEV), an electric vehicle (EV), or a plug-in hybrid electric vehicle (PHEV).

[0036] (Structure of vehicle drive unit 300) The vehicle drive unit 300 drives the vehicle 1. The vehicle drive unit 300 includes a relay 310 that energizes or cuts off power, a power conversion unit 320 that converts and transforms power between DC and AC, a motor 330 that serves as the power source for the vehicle 1, and an engine 340 that serves as the power source for the vehicle 1.

[0037] Relay 310 is electrically connected between battery pack 100 and power conversion unit 320. Thus, power is supplied or disconnected between battery pack 100 and motor 330 via power conversion unit 320. Alternatively, in this embodiment, relay 310 can be mounted on vehicle drive unit 300 or battery control unit 200. By mounting it on battery control unit 200, battery pack 100 and battery control unit 200 can be installed in vehicle 1, or, when removed, the output voltage from battery pack 100 can be cut off via relay 310. This prevents accidents such as electric shock and short circuits.

[0038] 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 the AC-DC conversion and voltage transformation required for power transmission between the battery pack 100 and the motor 330.

[0039] Motor 330 serves as either a motor for vehicle operation or power generation, and together with engine 340, it forms the power source for vehicle 1. When the vehicle is in motion, the vehicle operation motor uses electricity from battery pack 100 to rotate the tires of vehicle 1. Conversely, when generating electricity, the power generation motor charges battery pack 100 using regenerative energy generated during deceleration. For cost and space saving, the vehicle operation motor and the power generation motor can be integrated. Alternatively, for optimal performance, they can be installed separately.

[0040] The engine 340 and the motor 330 together serve as the power source for the vehicle 1. The power from the engine 340 causes the tires of the vehicle 1 to rotate or the motor 330 to rotate.

[0041] Based on the above structure, when vehicle 1 is traveling via motor 330, or when vehicle 1 is traveling via engine 340 and suddenly accelerates, the power released by battery pack 100 is converted into alternating current and transformerized by power conversion unit 320 and supplied to motor 330. This reduces engine fuel consumption and improves fuel economy. Furthermore, when vehicle 1 decelerates, motor 330 is operated as a regenerative brake to recover kinetic energy as electricity. This electricity is converted into direct current and transformerized by power conversion unit 320 and used to charge battery 101, thus preparing for the next discharge caused by driving or acceleration.

[0042] (Structure of vehicle control device 400) The vehicle control unit 400 controls the battery control unit 200 and the vehicle drive unit 300, and controls the overall operation of the vehicle 1. The vehicle control unit 400 includes a vehicle control management unit 410 that controls the battery control unit 200 and the vehicle drive unit 300, and a vehicle storage unit 420 that stores information about the vehicle 1.

[0043] The vehicle control management unit 410 controls the relay 310, power conversion unit 320, motor 330, and engine 340, etc. The vehicle control management unit 410 controls a wide variety of things; as an example, it allocates and determines the driving force of the motor 330 and engine 340 based on prescribed information. This prescribed information includes information input from the battery 101 from the battery control device 200, information input from the power conversion unit 320, information input from the motor 330, and information input from the engine 340, etc. The information about the battery 101 includes, for example, its state of charge (SOC).

[0044] The vehicle control management unit 410, by referring to information such as power limit values ​​and SOC from the battery pack control management unit 230, formulates energy management strategies related to the distribution of driving force between the engine 340 and the motor 330, and the charging and discharging of the battery pack 100. Based on these calculations, it outputs control commands to the power conversion unit 320 to control the load or the amount of electricity generated. Through these calculations, the vehicle control management unit 410 can prevent energy losses associated with the acceleration and deceleration of the vehicle, such as energy waste caused by insufficient SOC leading to engine starting or by excessive SOC leading to regenerative failure, thereby improving fuel economy and reducing carbon dioxide emissions.

[0045] The vehicle storage unit 420 stores information related to the vehicle 1. The stored information is data used by the vehicle control unit 400 for control. This information includes data related to the distribution of driving force between the motor 330 and the engine 340, etc.

[0046] (Structure of battery pack 100) The battery pack 100 supplies power to the motor 330 via a relay 310 and a power conversion unit 320. The vehicle 1 is equipped with one or more battery packs 100. The multiple battery packs 100 are electrically connected in series. Each battery pack 100 includes one or more batteries 101. The multiple batteries 101 are electrically connected in series. The batteries 101 are lithium-ion rechargeable batteries. The batteries 101 can also be nickel-metal hydride batteries, lead-acid batteries, all-solid-state batteries, etc.

[0047] (Structure 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 for managing the state of the batteries 101, etc., a detection unit 220 for detecting the state of the batteries 101, etc., a battery pack storage unit 240 for storing information of the batteries 101, etc., and a battery pack control management unit 230 for controlling and managing the battery pack 100.

[0048] The battery control device 200 is configured as a battery management system (BMS). For example, multiple functional blocks (such as the battery pack control management unit 230) of the battery control device 200 can be implemented by executing programs stored in memory using a microcomputer, controller, processor, etc., installed on an integrated circuit board. Alternatively, the functional blocks can also be implemented by dedicated hardware.

[0049] The battery control device 200 appropriately calculates the SOC of the battery 101 and the limit values ​​for charging and discharging, i.e., the power limit values. If the resistance value of the battery 101 rises unusually, the power limit value is further appropriately limited. If the resistance value of the battery 101 recovers, the power limit value is relaxed. An unusual rise in the resistance value of the battery 101 refers to a situation where, as in the case of continuous use under high load, the resistance value of the battery 101 temporarily rises, and then recovers after a prolonged period of inactivity of several days.

[0050] The battery control unit 200 outputs the calculated power limit value to the vehicle control unit 400. Based on this information, the vehicle control unit 400 controls the input and output of the motor 330, thereby achieving safe charging and discharging of the battery pack 100 and preventing the resistance value of the battery 101 from rising abnormally.

[0051] (Battery Management Department 210) The battery management unit 210 manages the state of the battery 101, etc. The battery management unit 210 includes one or more battery control units 211. Each battery control unit 211 corresponds to one or more battery packs 100. Each battery control unit 211 performs state control such as measuring and balancing the voltage of the batteries 101 included in the corresponding battery pack 100.

[0052] (Testing Department 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.

[0053] The current detection unit 221 detects the current value of each battery 101 and the current value of multiple batteries 101 connected in series or the like. When the batteries 101 are connected in series, the current value of one current detection unit 221 for each series connection can be used as the current value of each battery 101. The current detection unit 221 includes a current sensor and wires. The current sensor is electrically connected to a structural member of the battery pack 100 in a manner capable of detecting the current flowing through the battery 101. The structural member of the battery pack 100 is, for example, a busbar. The current detection unit 221 outputs the detected current value to the battery pack control and management unit 230. Thus, the battery pack control and management unit 230 can calculate the SOC and degradation state of the batteries 101, power limit values, and detect overcurrent.

[0054] The voltage detection unit 222 detects the voltage values ​​of multiple battery packs 100 connected in series or similar manner. The voltage detection unit 222 includes a voltage sensor and wiring. The voltage sensor is electrically connected to a structural member such as a busbar in a manner capable of detecting the voltage of one or more battery packs 100 connected in series. The voltage detection unit 222 outputs the detected voltage value to the battery pack control and management unit 230. As a result, the battery pack control and management unit 230 can perform calculations such as battery pack 100 protection and State of Charge (SOC).

[0055] The temperature detection unit 223 detects the temperature of the battery 101 and the ambient temperature of the battery pack 100. The temperature detection unit 223 includes a temperature sensor and wiring. The temperature sensor is installed on both the battery 101 and the battery pack 100. The temperature detection unit 223 outputs the detected temperature to the battery pack control and management unit 230. As a result, the battery pack control and management unit 230 can calculate the highest temperature, average temperature, lowest temperature of the battery 101, and detect excessive temperature rises. Furthermore, by correcting the battery characteristics used in calculating SOC (State of Charge) and other parameters based on temperature, the accuracy of SOC calculations can be improved.

[0056] The detection unit 220 is not limited to the structure described above. The detection unit 220 may also be a communication detection unit that detects the communication status of the battery management unit 210. In such a structure, if a communication error occurs in the battery management unit 210, the communication detection unit notifies the battery pack control management unit 230 of the communication failure of the battery management unit 210. Part or all of the detection unit 220 may also be constituted by the battery control unit 211 of the battery management unit 210.

[0057] Alternatively, the current detection unit 221, voltage detection unit 222, and temperature detection unit 223 can be configured to diagnose the battery 101 and battery pack 100, and output the results and detection values ​​to the battery pack control management unit 230 and the vehicle control management unit 410. With this structure, even in the event of a malfunction in the battery pack control management unit 230, the measured values ​​and diagnostic results can still be output to the vehicle control management unit 410. The detection unit 220 of the battery control device 200 can also be located within the battery pack 100.

[0058] (Battery Pack Control and Management Department 230) use Figure 2 The battery pack control and management unit 230 is described below. Based on information input from the detection unit 220 and the battery management unit 210, as well as current limit values ​​pre-stored in the battery pack storage unit 240 and the battery characteristics of the batteries 101, the battery pack control and management unit 230 performs calculations for appropriately controlling the charging and discharging of the battery pack 100 and for diagnostic and protection operations. Calculations for appropriate control include, for example, calculations of the state of charge (SOC) of the batteries 101, calculations of the state of health (SOHR) based on resistance, and calculations of the limit values ​​for the charging and discharging power of each battery 101. Additionally, calculations for diagnostic and protection operations include, for example, calculations for voltage equalization control of each battery 101, overcharge diagnosis, over-discharge diagnosis, and health diagnosis of the detection unit 220. To implement these calculations, the battery pack control and management unit 230 includes a SOC calculation unit 231, a resistance calculation unit 232, a power limit calculation unit 233, a voltage equalization calculation unit 234, and a diagnostic unit 235. Furthermore, based on the measured values ​​and characteristics of the battery pack 100 and battery 101 obtained from the detection unit 220, battery pack storage unit 240, and battery control unit 211, these calculation results and instructions based on the calculation results are output to the battery management unit 210, battery control unit 211, and vehicle control management unit 410.

[0059] The SOHR calculated by the degradation calculation unit 232 is based on any one of the data input from the detection unit 220 and the battery management unit 210, as well as the battery characteristics of the battery pre-stored in the battery pack storage unit 240, and is calculated as the ratio of the current resistance value to the initial resistance value. Since the current flowing through the battery 101 is inversely proportional to the resistance value, this ratio is suitable as an indicator of the battery's degradation state.

[0060] The power limit value calculated by the power limit calculation unit 233 is 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, and input from the battery pack storage unit 240, etc., and is calculated as the upper limit of the power value that enables each battery 101 and the battery pack 100 to be properly charged and discharged. Conditions for the power value that enables proper charging and discharging include, for example, not exceeding the upper limit current value specified for each component, not exceeding the upper and lower limit voltages of the battery 101 due to charging and discharging, the temperature of the battery 101 and the component not exceeding the upper limit value, the SOC being within the specified range, ensuring the lifespan of the battery 101, and the battery 101 quickly dropping to 0 if an abnormality is detected. The calculated power limit value is output to the vehicle control management unit 410 for charging and discharging control and energy management, etc.

[0061] In this way, by adopting a hierarchical structure that aggregates the data of multiple batteries 101 in the battery management unit 210 and further aggregates it in the battery pack control management unit 230, it is possible to shorten the signal lines required for aggregation and simplify the structure, ensuring flexibility in the number of batteries 101, and enabling the realization of a large secondary battery composed of multiple batteries.

[0062] (Battery pack storage section 240) The battery pack storage unit 240 stores the history, status, statistics, and characteristics of the battery 101. The history includes, for example, the current value, voltage value, and temperature of the battery 101. The status includes, for example, the SOC, current value, voltage value, internal resistance value, and temperature of the battery 101. Statistical values ​​include, for example, the cumulative current value, average value, and the number of times abnormal values ​​were detected. Characteristics include, for example, the internal resistance characteristics, full charge capacity, polarization resistance characteristics, degradation characteristics, individual differences, and an SOC table. The SOC table records the correspondence between SOC and OCV. In this embodiment, the battery pack storage unit 240 and the battery pack control and management unit 230 are separately installed, or they can be located inside the battery management unit 210 or the battery pack control and management unit 230. Alternatively, the history and statistical values ​​can be stored in the vehicle control management unit 410 or the vehicle storage unit 420 located outside the battery control device 200.

[0063] (Power Limitation Calculation Unit 233) Figure 3 The structure of the power limiting calculation unit 233 is shown. The power limiting calculation unit 233 includes a limit value calculation unit 501, a degradation prediction unit 502, a resistance rise determination unit 503, and a limit value correction unit 504. In addition, it may also include a prediction calculation error information output unit 505, a detection calculation error information output unit 506, and a resistance rise threshold calculation unit 507.

[0064] (Limit value calculation unit 501) The limit value calculation unit 501 calculates the upper limit of the power value that allows each battery 101 and the battery pack 100 to 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, and input from the battery pack storage unit 240, etc., and outputs it as a limit value. Conditions for the power value that allows safe charging and discharging include, for example, not exceeding the upper limit current value specified for each component, not exceeding the upper and lower limit voltages of the battery 101 due to charging and discharging, the temperature of the battery 101 and the component not exceeding the upper limit value, the SOC being within a specified range, and rapidly decreasing to 0 if an abnormality is detected in the battery 101. The characteristics of the limit value can vary depending on the purpose of each limit value. Therefore, multiple limit values ​​can be output as needed. Furthermore, charging and discharging can have different limit values.

[0065] (Deterioration Prediction Department 502) The degradation prediction unit 502 predicts the degradation state of battery 101 based on a degradation model of battery 101. The degradation model of battery 101 simulates the degradation of battery 101 based on data such as operating current, voltage range, temperature, power supply frequency, and power consumption. The degradation model may be, for example, a mathematical model (a multivariate degradation prediction formula, etc.) and a table related to degradation conditions.

[0066] The degradation model is based on data from battery 101 obtained weekly or monthly, and estimates the degradation changes up to the required lifespan of the battery applicable to the vehicle. This degradation model assumes that a sharp increase in the resistance of battery 101 will not occur. That is, the degradation model models the relatively slow degradation process of battery 101.

[0067] The degradation prediction unit 502 transforms the information of the battery 101 into predetermined degradation prediction parameters, namely internal degradation parameters. Based on these parameters and the degradation model, the degradation prediction unit 502 calculates a predicted value of the degradation degree of the battery 101. The degradation prediction unit 502 outputs the model prediction value SOHRest as a predicted value of the degradation state of the battery 101. Since the model prediction value SOHRest is calculated based on the degradation model, its change is relatively slow, similar to changes in the degradation model.

[0068] (Calculation of internal degradation parameters) The degradation prediction unit 502 selects data within a predetermined range from the data of the battery 101 stored in the battery pack storage unit 240. Based on the selected data, the degradation prediction unit 502 calculates the capacity of the battery 101 and the internal degradation parameters corresponding to the degradation state of the internal resistance, which are parameters already described.

[0069] Based on the voltage of the battery 101 included in the selected data, the degradation prediction unit 502 calculates, for multiple usage times, 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.

[0070] Based on the charge / discharge end voltage curve, the OCV curve, and the current of the secondary battery represented by selected data, the degradation prediction unit 502 calculates a resistance curve representing the relationship between the SOC and internal resistance of the battery 101 for multiple usage times.

[0071] The degradation prediction unit 502 calculates the internal degradation parameters of battery 101 based on the charge / discharge end voltage curve, OCV curve, and resistance curve. These internal degradation parameters 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 degradation model can also be configured as a model reflecting the degradation state of battery 101, based on the physical properties of the positive and negative electrodes of battery 101.

[0072] (Deterioration model) The degradation model calculates the changes in the utilization rate and resistivity degradation rate of the active materials in the positive and negative electrodes of battery 101 based on conditions such as current, voltage, temperature, and charge ratio, as well as calculated internal degradation parameters. Then, based on these parameters, the SOHR of battery 101 is predicted along a time series. The degradation prediction unit 502 can calculate the predicted value of battery 101 degradation while making the degradation model reflect the state of battery 101 with relatively high accuracy.

[0073] The degradation model can be configured to extract the usage conditions of battery 101 based on calculated values ​​and detected values ​​of battery 101. These calculated values ​​are based on information related to the degradation state of the positive electrode, negative electrode, and other structural components of battery 101. This degradation model can predict the capacity degradation and resistance changes of battery 101 based on its usage conditions. By using various information in this way, the prediction accuracy of SOHR based on the degradation model is improved, and the accuracy of the specific rise in detected resistance values ​​is enhanced, thereby enabling the battery life to approach its expected lifespan. As a result, battery performance can be maintained, and energy loss in the vehicle can be reduced.

[0074] (Resistance rise determination unit 503) The resistance rise determination unit 503 differentiates the model prediction value SOHRest output from the degradation prediction unit 502 and the degradation calculation value SOHRcalc output from the degradation calculation unit 232, and calculates the change per unit time, namely dSOHRest / dt and dSOHRcalc / dt. dSOHRcalc / dt corresponds to the degradation rate (change over time) of the battery 101. On the other hand, dSOHRest / dt corresponds to the degradation rate of the battery 101 without a specific resistance rise.

[0075] In the event of an unusual increase in resistance, the measured value dSOHRcalc / dt is greater than the model-predicted value dSOHRest / dt. The resistance increase determination unit 503 calculates the difference 1 (dSOHRcalc / dt - dSOHRest / dt) between dSOHRcalc / dt and dSOHRest / dt, and determines whether an unusual increase in resistance has occurred in the battery 101 by comparing it to a threshold A. That is, if the difference 1 (dSOHRcalc / dt - dSOHRest / dt) deviates from the threshold A, which is within the allowable range, the resistance increase determination unit 503 can determine that this is the moment when an unusual increase in resistance begins in the battery 101.

[0076] The threshold A is determined by taking into account the calculation error of the battery pack control management unit 230, the estimation range of the degradation model, and other sensor errors. By setting the threshold A in this way, the battery pack control management unit 230 can suppress load output instability and suppress the rise of the specific resistance of the battery 101.

[0077] (Limit value correction section 504) The limit value correction unit 504 corrects the limit value of the charging and discharging power of the battery 101 based on the determination result of the resistance rise determination unit 503. When the resistance rise determination unit 503 determines that the resistance of the battery 101 has risen in a specific way, the limit value correction unit 504 corrects the limit value in the direction of reducing the charging and discharging power of the battery 101.

[0078] The limit correction unit 504 outputs the corrected limit value to the vehicle control management unit 410. Based on the corrected limit value, the vehicle control management unit 410 controls the load (power conversion unit 320) to limit the charging and discharging power of the battery 101.

[0079] In this way, when the measured value of the resistance rise rate and the model prediction value deviate from the threshold A, the limit value correction unit 504 determines that an abnormal resistance rise has occurred and reduces the power limit value. As a result, the power flowing through the load (= the power flowing through the battery 101) is reduced, and the abnormal resistance rise of the battery 101 can be suppressed in the early stage.

[0080] (Prediction calculation error information output unit 505) The prediction calculation error information output unit 505 outputs the error included in the calculation result of the model prediction value SOHRest, i.e., SOHRest_error, based on current, voltage, and temperature. When outputting the error, the prediction calculation error information output unit 505 refers to... Figure 3A as well as Figure 3B The error information shown. Figure 3A This is a table of prediction calculation error information for battery 101 under low load, including SOHRest error information for each cumulative capacity under multiple battery conditions. Figure 3B To convert this table into a graph.

[0081] Figure 3A as well as Figure 3B The error information of the degradation prediction model is shown for the region of low load of battery 101, that is, the region where the resistance of battery 101 does not increase specifically. Figure 3A as well as Figure 3B The error information shown is characterized by the change in the error of the model prediction value SOHRest as the cumulative usage of battery 101 increases. This change in the error of the model prediction value SOHRest is also related to conditions such as the operating range (ΔSOC), current value, and temperature of battery 101. Therefore, even in a degradation model where the error of the degradation estimate changes due to the increase in the cumulative usage of battery 101, i.e., the increase in degradation of battery 101, it is possible to estimate the possible errors contained in the model's output.

[0082] (Detection and calculation error information output unit 506) The error detection output unit 506, based on temperature and SOC, outputs the error that may be contained in the detection value SOHRcalc output by the degradation calculation unit 232, i.e., SOHRcalc_error. This error may include, for example, algorithm errors, detection errors of current, voltage, and temperature, and / or transformation errors. When outputting the error, the error detection output unit 506 refers to... Figure 4A as well as Figure 4B The error information shown. Figure 4A This table contains the detection error information for battery 101 under low load, including the detection error information for each SOC at multiple battery temperatures. Figure 4B This is a graph to convert the table into a curve. In cases where the error of SOHRcalc depends on factors such as current and voltage, it can also be... Figure 4A The table includes multi-dimensional tables with dimensions such as current and voltage values.

[0083] The calculation error of the detected value SOHRcalc increases or decreases depending on the SOHR's ​​SOC dependence and the temperature dependence of various sensors. In this structure, because SOC and temperature are used as inputs to the error information table, even for a detected value SOHRcalc with the aforementioned characteristics, the possible error contained in the detected value can be estimated.

[0084] (Resistance rise threshold calculation unit 507) One method of the resistance rise threshold calculation unit 507 is to output a large threshold A to the resistance rise determination unit 503 when the error is large, and a small threshold A to the resistance rise determination unit 503 when the error is small, based on the model prediction error SOHRest_error and the detection error SOHRcalc_error. With this structure, a threshold A corresponding to the error between the detection value SOHRcalc and the model prediction value SOHRest can be output, enabling more accurate determination of the occurrence of a specific resistance rise.

[0085] In other modes of the resistance rise threshold calculation unit 507, the threshold A calculated using equation (1) based on the detected SOHR is output to the resistance rise determination unit 503.

[0086] A∝SOHR(t,T,I)(1) SOHR increases based on factors such as accumulated current capacity. Furthermore, its main causes are largely related to prediction and detection errors, making it a viable alternative for calculating these errors. By using SOHR to calculate the threshold A, the required tables and memory, as well as the computation time, can be reduced.

[0087] (Function of battery control device 200) Next, the function of the battery control device 200 will be explained.

[0088] (The increase in the resistance of battery 101) Explain how the resistance value of battery 101 increases. Figure 5 It is a graph that shows the unique increase in resistance caused by continuous use of secondary batteries such as lithium-ion batteries under high load. Figure 5 This shows the extent to which the resistance rises relative to the number of cycles when a lithium-ion battery is cycled under high load conditions. SOHR, which indicates the percentage increase in resistance relative to the initial state, is used as an indicator to determine a specific resistance increase.

[0089] like Figure 5As described, when the indicator rises at point (a), and power is stopped for an extended period, although the SOHR decreases (b), if a high-load charge-discharge cycle resumes, the resistance (SOHR) rises again, accelerating battery degradation. If the indicator rise is detected late and the battery is used continuously at a high load, battery degradation cannot be reversed. Even if the battery is stopped, if a high-load cycle is resumed, the resistance rises rapidly, accelerating cumulative battery degradation (c). To avoid this situation, the battery control device 200 reduces the load using power limit values, etc.

[0090] (Determination of a specific increase in resistance) Reference Figure 6A , Figure 6B , Figure 6C This is the first example of a method for determining a specific increase in resistance in battery 101. Figure 6A It is a graph showing the current value of a certain battery 101 among a plurality of batteries 101. Figure 6B This is a graph showing the time-varying values ​​of the model prediction value SOHRest and the detection value SOHRcalc for battery 101. Figure 6C This is a graph showing the changes in the time-dependent rate of change of the model predicted value SOHRest (dSOHRest / dt) and the time-dependent rate of change of the detected value SOHRcalc (dSOHRcalc / dt), as well as their respective differences, i.e., difference 1 (dSOHRcalc / dt - dSOHRest / dt). However, the time-dependent rate of change of SOHRcalc and difference 1 are essentially the same value, and therefore overlap. Figure 6A , Figure 6B as well as Figure 6C Each graph's horizontal axis represents a time axis of the same scale. Subsequently, the horizontal axes of multiple related graphs also represent time axes of the same scale.

[0091] The current value of battery 101 is the current value when multiple batteries 101 are connected in series. The current value of battery 101 varies over time. In the following description, the direction of charging battery 101 will be set to positive.

[0092] exist Figure 6B In the figure, the detected value SOHRcalc increases due to the specific increase in the resistance value of battery 101. On the other hand, since the degree of degradation within the degradation model does not change much during the short period of power supply of battery 101 (approximately several hours), the model predicted value SOHRest is plotted as a roughly flat line.

[0093] exist Figure 6BIn this process, by comparing the detected value SOHRcalc with the model predicted value SOHRest, the degree of degradation of battery 101 can be roughly determined. However, even by directly comparing the detected value SOHRcalc with the model predicted value SOHRest, it is not easy to determine whether the resistance value of battery 101 is experiencing a unique increase due to continuous use under high load. Therefore, the resistance increase determination unit 503 is based on... Figure 6C The method shown determines whether the resistance value of battery 101 is rising unusually.

[0094] Figure 6C The rate of change per unit time for the detected value SOHRcalc and the model predicted value SOHRest of battery 101 is shown. 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 performing a time derivative on the detected value SOHRcalc.

[0095] The degradation prediction unit 502 calculates the rate of change of the model predicted value SOHRest. The model predicted value SOHRest is differentiated over time, and the rate of change of SOHRest is calculated as dSOHRest / dt. If dSOHRest / dt deviates significantly from dSOHRcalc / dt, the resistance rise determination unit 503 determines that a specific increase in resistance has occurred (high load resistance rise determination). That is, as... Figure 6C As shown, when the time derivative difference, i.e., difference 1 (dSOHRcalc / dt-dSOHRest / dt), is positive and the value exceeds the threshold A, the resistance rise determination unit 503 determines that the battery 101 has experienced a unique rise in resistance.

[0096] The limit value correction unit 504 accepts this determination and, in order to suppress the increase in the resistance of the battery 101, updates or changes the limit value by reducing the charging and discharging power of the battery 101. The limit value correction unit 504 can change the limit value gradually instead of making it drop all at once. By making the change in the limit value slow, it is possible to prevent the control of load or power generation from becoming unstable, thereby improving the ride comfort of the vehicle.

[0097] To avoid misjudging high load resistance rise, the resistance rise threshold calculation unit 507 considers the allowable error range, calculation errors in degradation calculations, calculation errors in model prediction calculations, the estimation range of the degradation model, sensor errors, etc., to determine the threshold A. The resistance rise threshold calculation unit 507 preferably sets the threshold A within a range that will not excessively switch between determining a resistance as high load and not determining it as high load resistance. Multiple thresholds A can be set according to conditions and power limits. As a first example, the threshold A is set relatively large.

[0098] If the resistance rise determination unit 503 determines that the difference 1 exceeds the threshold A, the limit value correction unit 504 corrects the limit value of the charging and discharging power of the battery 101 in a manner that applies a relatively strict power limit to the battery 101. As a result, the current limit of the battery 101 is achieved based on the characteristics of the resistance value of the battery 101.

[0099] As a second example of threshold A, threshold A is set to be relatively small. In this second example, if the resistance rise determination unit 503 determines that the difference 1 exceeds threshold A, the limit value correction unit 504 corrects the limit value by applying a relatively slower power limit to the battery 101 than in the first example.

[0100] As a third example of threshold A, threshold A is varied according to the degree of degradation of battery 101. This third example is useful when the rate of increase of the resistance value of battery 101 is affected by SOHR. As shown in equation (1), threshold A can be determined, for example, as a function of SOHR with respect to time, temperature, and current.

[0101] In this way, by setting a threshold, battery control can be performed in a manner that can suppress the load output from becoming unstable and suppress the rise in resistance of battery 101.

[0102] (Revision of the limit value) like Figure 7A as well as Figure 7B As shown, the limit value correction unit 504 can, for example, correct the current or power limit value of the battery 101 based on the ΔV limit method. The ΔV limit method is a method of setting the limit value in such a way that ΔV is within a predetermined threshold Vth. ΔV is the difference between OCV (Open Circuit Voltage) and CCV (Closed Circuit Voltage). OCV is the voltage of the battery 101 when no load is applied. That is, OCV is the voltage (open circuit voltage) when no current flows from the battery 101 into the electrical device.

[0103] CCV is the actual inter-terminal voltage of battery 101. If battery 101 is left unattended for an extended period without current flowing through it, CCV will be the same as OCV. On the other hand, if current flows through battery 101, the CCV changes due to the voltage generated by the internal resistance of battery 101 and the polarization voltage generated by the current, becoming inconsistent with OCV. If battery 101 is charged, CCV increases; if battery 101 is discharged, CCV decreases.

[0104] As described above, the change in CCV increases with increasing resistance, and therefore, ΔV also increases with increasing resistance. Thus, in cases of a significant increase in resistance, ΔV tends to become exceptionally large. By limiting charge and discharge to a value below a predetermined ΔV, even when such a large ΔV occurs, a strict power limit value is set, the load decreases, and the battery recovers. In this embodiment, when the resistance increase determination unit 503 determines that there is a significant increase in resistance, the limit value correction unit 504 reduces the value of the threshold Vth. Therefore, by reducing the limit value early, the limit value correction unit 504 eliminates the significant increase in resistance in the initial stage, preventing rapid battery degradation.

[0105] (Control method of battery 101) Reference Figures 8A to 8C This describes a method for controlling the battery 101, performed by the battery control device 200, in response to an increase in the resistance value of the battery 101. The degradation calculation unit 232 calculates the degradation operation based on a predetermined time point, for example, when conditions suitable for degradation calculation are met, for any switching current. Figure 8C The calculated detection value is SOHRcalc. An example of such an event is when the energized current changes dramatically instantaneously. At this time, such as... Figure 8B As shown, the detected value SOHRcalc varies in stages depending on the timing. By performing calculations at moments when the energized current changes dramatically, the accuracy of the calculations is improved. Alternatively, the calculations can be performed at equal and regular times. This improves the real-time performance of the detected value SOHRcalc.

[0106] like Figure 8A As shown, the resistance rise determination unit 503 calculates dSOHRcalc / dt and dSOHRest / dt according to the time series. As mentioned above, the degradation model that forms the basis for calculating the model prediction value SOHRest is a model that models the degradation progression under conditions where a sharp increase in resistance does not occur; therefore, the model prediction value SOHRest changes slowly. In contrast, the detected value SOHRcalc changes significantly at each calculation time as the battery is charged and discharged.

[0107] exist Figure 8AIn (c), the sudden increase in dSOHRcalc / dt is due to the previously sustained high load; as a result, the specific increase in resistance causes a rapid increase in the detected value SOHRcalc. On the other hand, in Figure 8A In (d), the reason why dSOHRcalc / dt suddenly drops is that, previously, during the period of stopping or suppressing the power supply to the battery, as a result, the battery recovers from the state of specifically rising resistance value, and the detected value SOHRcalc suddenly drops.

[0108] (Recovery of the increased resistance value of battery 101) Reference Figure 9A as well as Figure 9B Compare the detection value SOHRcalc ( Figure 9B ) and the change in current of battery 101 ( Figure 9A This explains the recovery of battery 101 from a resistance increase, as performed by battery control device 200. If resistance increase determination unit 503 determines that battery 101 has experienced an unusual resistance increase, limit value correction unit 504 corrects the limit value to eliminate the unusual resistance increase. As a result, there is a charging / discharging pause period between the two charging / discharging periods.

[0109] Therefore, even if the detected value SOHRcalc increases significantly during high-load operation of the battery control device 200, it can quickly return to its previous value (e). Moreover, in the early stage when the detected value SOHRcalc begins to increase, by stopping the charging and discharging of the battery pack control management unit 230 to prevent irreversible degradation, the detected value SOHRcalc becomes approximately the same as the value before the peculiar increase in resistance (f).

[0110] (Second example of a determination method related to the increase in the resistance value of battery 101) Reference Figure 10 This describes a second example of a determination method performed by the battery control device 200 related to a specific increase in the resistance of the battery 101. If the already described limiting process ( Figure 9A Then the rate of change of SOHRcalc, dSOHRcalc / dt, drops sharply ( Figure 10 (600). This situation can be used to assist in determining the rise in resistance under high load.

[0111] When the difference 1 (dSOHRcalc / dt - dSOHRest / dt) exceeds the threshold A and reaches... Figure 10 , XIn the case of a region where resistance rise is not specified, the resistance rise determination unit 503 determines that a specific resistance rise has begun (700). On the other hand, if the charging and discharging power of the battery 101 is limited, and the battery recovers from the specific resistance rise, then in its initial stage, the differential 1 quickly moves from region X (threshold A) to region Y (600). As a result, the resistance rise determination unit 503 can reconfirm that the battery is in a specific resistance rise state. That is, the battery pack control management unit 230 can realize auxiliary determination of high load resistance rise determination.

[0112] Furthermore, this auxiliary determination can also be used to determine whether the specific resistance rise has been eliminated. That is, once this auxiliary determination is established, if the differential 1 returns to the allowable error range (700), the battery pack control management unit 230 can determine that the battery has recovered from the specific resistance rise. Thus, the battery pack control management unit 230 can determine whether the power limit value can be raised to the value before the high load resistance rise determination. Alternatively, this determination can also be made when the differential 1 returns to 0 or higher but less than a predetermined threshold. Such determination conditions make the determination that the battery has recovered more reliable.

[0113] (Flowchart of the control method executed by the battery control device 200) A microcomputer's processor executes a program stored in memory repeatedly at predetermined intervals. Figure 11 The flowchart shown. Using Figure 1 , Figure 2 , Figure 3 The flowchart is an illustration.

[0114] In step S11, the detection unit 220 detects the current value, voltage value, and temperature of the battery 101, and proceeds to steps S12 and S15. In step S12, the degradation prediction unit 502 converts the detected values ​​of voltage V, current I, and temperature T of the battery 101 into parameters for the degradation model, and proceeds to step S13.

[0115] In step S13, the degradation prediction unit 502 inputs the parameters transformed in step S12 into the degradation model and proceeds to step S14. In step S14, the degradation prediction unit 502 calculates the model prediction value SOHRest based on the degradation model in step S13 and proceeds to step S16. In step S15, the degradation calculation unit 232 calculates the detection value SOHRcalc and proceeds to step S16.

[0116] In step S16, the resistance rise determination unit 503 differentiates the detected value SOHRcalc to calculate dSOHRcalc / dt. Alternatively, the resistance rise determination unit 503 differentiates the model predicted value SOHRest to calculate dSOHRest / dt. Then, the resistance rise determination unit 503 proceeds to step S17.

[0117] In step S17, the resistance rise determination unit 503 compares the difference 1 (dSOHRcalc / dt - dSOHRest / dt) with the threshold A. If the difference 1 is greater than the threshold A (step S17: Yes), the resistance rise determination unit 503 determines that the battery 101 has experienced a specific resistance rise, and the resistance rise determination unit 503 proceeds to step S18.

[0118] On the other hand, in step S17, if the difference 1 is the same as the threshold A (no) or the difference is below the threshold A (no), the resistance rise determination unit 503 determines that the battery 101 has not experienced a specific resistance rise, and the resistance rise determination unit 503 proceeds to step S21.

[0119] In step S18, the limit correction unit 504 corrects downward the correction amount used for changing the limit value of the current or power of the battery 101, and proceeds to step S19. By reducing this correction amount, the load can be reduced, and the peculiar increase in resistance value can be suppressed.

[0120] In step S19, the resistance rise determination unit 503 compares difference 1 with threshold A. Furthermore, the resistance rise determination unit 503 compares difference 2 (detected value SOCRcalc - model predicted value SOCRest) with threshold B. If difference 1 is smaller than threshold A and difference 2 is greater than or equal to 0 and less than threshold B (step S19: Yes), the resistance rise determination unit 503 determines that the specific resistance rise of battery 101 has been eliminated through step S18, and the resistance rise determination unit 503 proceeds to step S20.

[0121] On the other hand, in step S19, if difference 1 is above threshold A, or difference 2 is less than 0 or above threshold B, it is determined that the specific resistance rise of battery 101 has not been eliminated, and the process proceeds to step S21 while still limiting the current or power of battery 101. That is, the resistance rise determination unit 503 and the limit value correction unit 504 continue to limit the battery 101 after the limitation (step S18) until the battery recovers from the specific resistance rise state and approaches the original value, i.e., the model prediction value SOHRest.

[0122] In step S20, the limit value correction unit 504 corrects the amount upward (in a easing direction) and proceeds to step S21. By correcting the amount upward, when recovering from the state of abnormally high resistance, the current value and voltage value of the battery 101 are close to their normal values.

[0123] In step S21, based on the correction amount, a restriction is implemented to reduce the current and power. This restriction includes not only direct restrictions on the current and power, but also effective current restrictions and ΔV restrictions. At this time, the current and power resulting from the restriction will not exceed the restriction value output from the restriction value calculation unit 501. Furthermore, they will also not be less than 0.

[0124] Through this process, the battery pack control and management unit 230 can efficiently drive the load by suppressing battery degradation and shortening the output suppression period, resulting in efficient energy utilization.

[0125] (Effect of the battery 101 control method performed by the battery control device 200) Reference Figures 12A to 12C The diagram illustrates the effectiveness of the control method for battery 101 implemented by battery control device 200. In this figure, the model predicted value SOHRest(n) is a curve that gradually increases due to prolonged use of battery 101. For the battery to be used until its expected lifespan, it is important that the detected value SOHRcalc(m,o) does not deviate significantly from the model predicted value SOHRest(n), i.e., the difference between the two does not exceed the threshold B.

[0126] In this embodiment, if the resistance rise determination unit 503 determines that the difference 1 (dSOHRcalc / dt - dSOHRest / dt) exceeds the threshold A (g), the limit value correction unit 504 synchronously or without delay corrects the power limit value in a decreasing direction (h). This reduces the load on the battery 101, thereby specifically mitigating the resistance rise and decreasing the difference 1. The reduction continues to increase until the difference 1 falls below the threshold A. This creates a low-load state necessary to mitigate the specific resistance rise.

[0127] If the differential 1 is below threshold A, the correction amount of the power limit value is maintained until SOHRcalc becomes below threshold B. This mitigates the specific increase in resistance, resulting in a state where the resistance value decreases.

[0128] If SOHRcalc is below threshold B, the correction amount for the power limit value is reduced, mitigating the power limit. Then, the reduction of the correction amount stops at the point when the correction amount becomes 0. This removes the unwanted power limit after the specific resistance rise has been mitigated. Thus, the battery life is maintained as predicted, and the battery's power limit value returns to its original value as quickly as possible, restoring the performance of battery 101 to the state before the specific resistance rise occurred.

[0129] The described embodiment provides a first battery control device (200) comprising: an arithmetic unit (deterioration arithmetic unit 232) for calculating the degree of battery deterioration; a prediction unit (deterioration prediction unit 502) for predicting the degree of battery deterioration; and a control unit (battery pack control management unit 230) for limiting the charging and discharging of the battery based on a comparison between the time-dependent change (time-dependent change amount, time-dependent change rate, or time-dependent change degree, etc.) of the degree of battery deterioration obtained by the arithmetic unit and the time-dependent change of the degree of battery deterioration predicted by the prediction unit.

[0130] According to the first battery control device, the following battery control can be achieved: by detecting and preventing the unusual rise in battery resistance in the early stage, it is possible to suppress the unexpected abnormal rise in resistance caused by continuous operation of the battery under high load or other reasons, and ensure the stable output of the load, and to effectively utilize the battery until its expected lifespan.

[0131] In the already described embodiments, a second battery control device is disclosed in the first battery control device. The control unit (battery pack control management unit 230) includes: a determination unit (resistance rise determination unit 503) that determines the battery degradation state based on the comparison result; and a limiting unit (limit value correction unit 504) that limits the charging and discharging of the battery based on the determined battery degradation state.

[0132] In the already described embodiments, a third battery control device is disclosed, characterized in that, in the second battery control device, a calculation unit calculates the degree of battery degradation based on battery detection data, a prediction unit predicts the degree of battery degradation based on a battery degradation prediction model, a determination unit calculates the difference between the time-dependent change in the degree of degradation calculated by the calculation unit and the time-dependent change in the degree of degradation predicted by the prediction unit, and determines the battery degradation state based on the calculated difference.

[0133] The degradation prediction model is a model that models the degradation progression from the battery's normal usage to its required lifespan.

[0134] In the already described embodiments, a fifth battery control device is disclosed, characterized in that, in the third battery control device, the determination unit compares the difference with a threshold, determines the degradation state of the battery if the difference is outside the threshold, and the limiting unit limits the charging and discharging of the battery based on the determined degradation state of the battery, so that the limited charging and discharging of the battery continues until the difference becomes within the threshold.

[0135] In the already described embodiments, a sixth battery control device is disclosed, characterized in that, in the third battery control device, the control unit (resistance rise threshold calculation unit 507) calculates the threshold based on the error when calculating the degree of degradation of the battery and the error when predicting the degree of degradation of the battery.

[0136] In the already described embodiments, a seventh battery control device is disclosed, characterized in that, in the fifth battery control device, the limiting unit has a correction unit (limiting value correction unit 504) that corrects the limiting value for limiting the charging and discharging of the battery, and if the determination unit determines that the difference exceeds the threshold, the correction unit corrects the limit value by reducing it.

[0137] In the already described embodiments, an eighth battery control device is disclosed, characterized in that, in the sixth battery control device, the correction unit sets the difference between the battery's CCV and OCV as ΔV, and corrects the limit value in such a way that ΔV becomes within a threshold value.

[0138] In the already described embodiments, a ninth battery control device is disclosed, characterized in that, in the seventh battery control device, the correction unit corrects the limit value in a manner in which the charging and discharging of the battery is gradually restricted.

[0139] In the described embodiments, a battery control method is disclosed, which is a battery control method in which a processor controls the operation of a battery. The processor calculates the degree of battery degradation, predicts the degree of battery degradation, and limits the charging and discharging of the battery based on the obtained change in the degree of battery degradation over time and the comparison between the predicted change in the degree of battery degradation over time.

[0140] Furthermore, in the already described embodiments, a vehicle control device (400) is disclosed, which is connected to a power conversion unit 320 and a battery control device (200). The power conversion unit 320 is connected to a motor 330 of a vehicle drive unit 300. The vehicle control device (400) controls the power supplied from the battery to the power conversion unit based on a limit value that restricts the charging and discharging of the battery.

[0141] This invention is not limited to the configuration described in the embodiments, and can be appropriately configured based on the content described in the claims. The above embodiments are examples for implementing this invention. In implementing this invention, only a portion of the configuration of the embodiments may be implemented.

[0142] In implementing this invention, configurations not described in the embodiments may be added and implemented. In implementing this invention, a portion of the configuration of the embodiments may be replaced with configurations not described in the embodiments. The term "part" in "**** part" disclosed in the embodiments may also be replaced with terms such as module, device, unit, circuit, or part. The term "d**** / dt" disclosed in the embodiments may also be replaced with "Δ****" indicating a change.

[0143] Alternatively, modules, devices, and units can be configured as combined electronic circuits. With such a configuration, a battery system can be implemented that detects early on a specific increase in resistance that differs from a normal increase, and based on this detection, reduces the battery load, thereby suppressing the resistance increase.

[0144] Explanation of reference numerals in the attached figures 100: Battery pack, 101: Battery, 200: Battery control unit, 210: Battery management department, 211: Battery control department, 220: Detection department, 221: Current detection department, 222: Voltage detection department, 223: Temperature detection department, 230: Battery pack control and management department, 231: SOC calculation department, 232: Degradation calculation department, 233: Power limiting calculation department, 234: Voltage equalization calculation department, 235: Diagnostics department, 240: Battery pack storage department, 30 0: Vehicle drive unit; 310: Relay; 320: Power conversion unit; 330: Motor; 340: Engine; 400: Vehicle control unit; 410: Vehicle control management unit; 420: Vehicle storage unit; 501: Limit value calculation unit; 502: Deterioration prediction unit; 503: Resistance rise determination unit; 504: Limit value correction unit; 505: Prediction calculation error information output unit; 506: Detection calculation error information output unit; 507: Resistance rise threshold calculation unit.

Claims

1. A battery control device, wherein, have: The degree of degradation of the computing unit and its battery; The prediction unit predicts the degree of degradation of the battery; and The control unit limits the charging and discharging of the battery based on a comparison between the change in battery degradation over time obtained by the calculation unit and the change in battery degradation over time obtained by the prediction unit.

2. The battery control device according to claim 1, wherein, The control unit has: The determination unit determines the degradation state of the battery based on the comparison results. as well as The limiting unit restricts the charging and discharging of the battery based on the determined deterioration state of the battery.

3. The battery control device according to claim 2, wherein, The computing unit calculates the degree of battery degradation based on the battery's detection data. The prediction unit predicts the degree of battery degradation based on the battery degradation prediction model. The determination unit calculates the difference between the time-dependent change in degradation calculated by the calculation unit and the time-dependent change in degradation predicted by the prediction unit, and determines the degradation state of the battery based on the calculated difference.

4. The battery control device according to claim 3, wherein, The degradation prediction model is a model based on the degradation progression of the battery under normal usage conditions, gradually increasing to the battery's required lifespan.

5. The battery control device according to claim 3, wherein, The determination unit compares the difference with a threshold, and if the difference is outside the threshold, determines the degradation state of the battery. The limiting unit restricts the charging and discharging of the battery based on the determined deterioration state of the battery, so that the restricted charging and discharging of the battery continues until the difference becomes within the threshold.

6. The battery control device according to claim 5, wherein, The control unit calculates the threshold based on the error in calculating the degree of battery degradation and the error in predicting the degree of battery degradation.

7. The battery control device according to claim 5, wherein, The limiting part includes a correction part that corrects the limiting values ​​used to limit the charging and discharging of the battery. If the determination unit determines that the difference exceeds the threshold, the correction unit corrects the difference by reducing the limit value.

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

9. The battery control device according to claim 7, wherein, The correction unit corrects the limit value by gradually restricting the charging and discharging of the battery.

10. A battery control method, which is a battery control method in which a processor controls the operation of a battery, wherein, The processor calculates the degree of battery degradation. The processor predicts the degree of battery degradation. The charging and discharging of the battery is limited by comparing the time-dependent change in the battery's degradation obtained through calculation with the time-dependent change in the battery's degradation obtained through prediction.

11. A vehicle control device, connected to a power conversion unit and the battery control device of claim 1, wherein the power conversion unit is connected to a motor of a vehicle drive unit, wherein... The power supplied from the battery to the power conversion unit is controlled based on the limit values ​​that restrict the charging and discharging of the battery.

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