Battery control device and battery control method

Abstract

As shown in FIG. 2, a battery pack control management unit 230 of a battery control device 200 of a battery 101 implements a life model 2302 that finds deterioration over time of a life prediction parameter of the battery and predicts SOHQ of the battery on the basis of the deterioration over time, a determination unit 2306 that determines the SOHQ of the battery in order to converge the predicted life of the battery to a required life, and a setting unit 2308 that sets the predicted life of the battery to a required life. And a setting unit 2308 that determines whether or not it is necessary to change the performance suppression of the battery, determines an adjustment parameter for the performance suppression of the battery on the basis of the determination result of the determination unit, and sets a suppression level on the basis of the difference between the predicted value of SOHQ and the target value thereof.

Description

Battery control device and battery control method Technical Field

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

[0002] The use of battery control devices with multiple secondary batteries, such as energy storage devices for mobile vehicles like hybrid vehicles and electric vehicles, energy storage devices for system interconnection stabilization that are interconnected with the power system to stabilize the power system, and emergency energy storage devices, is expanding.

[0003] Since a required lifespan is specified for batteries suitable for battery control devices, for example, a battery management device is provided that, by updating charge and discharge limits based on the deviation between the target lifespan value and the predicted lifespan value and the battery usage conditions, can effectively utilize battery performance while ensuring battery lifespan (Patent Document 1).

[0004] Prior art literature, patent literature, patent literature 1: Japanese Patent Application Publication No. 2016-163532 Summary of the Invention The problem this invention aims to solve is that the degree of battery degradation easily varies depending on the battery's usage conditions. Therefore, the following issues exist: the battery's lifespan may fall short of the required lifespan, or conversely, the battery's lifespan may easily exceed the required lifespan. Therefore, the object of this invention is to provide a battery control device and a battery control method that can bring the battery's lifespan closer to the required lifespan based on the battery's operating state, thereby maintaining battery performance before the battery reaches the required lifespan.

[0005] To achieve the aforementioned objective, the present invention provides a battery control device for controlling the charging and discharging of a battery. The device comprises: a battery life model that outputs a dynamic pattern of predicted battery life parameters; a determination unit that determines whether to adjust the battery's operating conditions in order to ensure that the predicted battery life based on the dynamic pattern meets the battery's required lifespan; a setting unit that, based on the determination unit's decision, determines adjustment parameters for adjusting the battery's operating conditions; and a power calculation unit that, based on the control parameters, calculates the battery's allowable power. The setting unit sets a control method for the adjustment parameters based on a comparison between the predicted value and the target value of the lifespan prediction parameters based on the dynamic pattern at the required lifespan time point.

[0006] Furthermore, the second invention is a battery control method in which a processor controls the charging and discharging of the battery. The processor outputs a dynamic pattern of the battery's life prediction parameters based on the battery's life model. By continuously correcting the rate of change of the dynamic pattern according to the battery's operating state, the operating conditions of the battery are adjusted so that the predicted value of the life prediction parameter of the dynamic pattern at the battery's required lifespan converges to the target value of the life prediction parameter.

[0007] The invention provides that, according to the present invention, the battery life can be brought to converge to the required life based on the battery's operating state, thereby maintaining battery performance before the battery reaches the required life. Attached Figure Description

[0008] Figure 1 is a block diagram illustrating the structure of an embodiment of the battery control device of the present invention.

[0009] Figure 2 is a functional block diagram of the battery pack control management unit of the battery control device according to the embodiment.

[0010] Figure 3 is a graph illustrating the operation of the pattern correction section.

[0011] Figure 4 is a graph illustrating the operation of the decision-making unit.

[0012] Figure 5 is a schematic diagram showing the conversion of the usable SOC operating range into a capacity that reflects the degradation rate of SOHQ.

[0013] Figure 6 is a graph showing the rate of change ΔQ of the parameter used in variable control.

[0014] Figure 7 is a graph showing an example of the simulation results of SOHQ when parameter suppression changes are applied under the condition that ΔSOC becomes the lifetime limit.

[0015] Figure 8 is a graph showing an example of the simulation results of SOHQ when the parameter suppression change is applied under the conditions of the current value that becomes the lifespan non-compliance and ΔSOC. Detailed Implementation

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG1 shows a structural block diagram of a motor drive system 1 having an embodiment of the battery control device of the present invention. The motor drive system 1 includes a battery pack 100 that supplies power to a motor 330, a battery control device 200 that controls the charging and discharging of the battery pack 100, a drive device 300 that drives the motor 330 as a load, and a host control device 400 that controls the battery control device 200 and the drive device 300. The motor drive system 1 is suitable for motor-driven vehicles such as hybrid vehicles, electric vehicles, and plug-in hybrid vehicles.

[0017] (Structure of drive unit 300) The drive unit 300 includes a relay 310 for switching power on or off, a power conversion unit 320 for converting and transforming power between DC and AC, and a motor 330 for use as a power source.

[0018] Relay 310 is electrically connected between battery pack 100 and power conversion unit 320. Thus, power is switched on or off between battery pack 100 and motor 330 via power conversion unit 320. Relay 310 is mounted on load drive device 300, but it can also be mounted on battery control device 200. By being mounted on battery control device 200, when battery pack 100 and battery control device 200 are mounted on or removed from motor drive system 1, the output voltage from battery pack 100 can be cut off via relay 310. This prevents accidents such as electric shock and short circuits.

[0019] 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 transfer between the battery pack 100 and the motor 330.

[0020] Motor 330 is used to drive loads such as vehicles or to generate electricity. When driving a load, the motor uses power from the battery pack 100 to rotate the drive unit of the load. On the other hand, when generating electricity, the motor used for power generation charges the battery pack 100 using regenerative energy during deceleration. To reduce costs and save space, the motor used for driving and the motor used for power generation can be integrated. Alternatively, they can be installed separately for performance optimization.

[0021] By adopting the above structure, the power released from the battery pack 100 is converted into AC and then transformerized by the power conversion unit 320 and supplied to the motor 330. In addition, by operating the motor 330 as a regenerative brake, kinetic energy is recovered as electricity, and the battery 101 is charged while the electricity is converted into DC and transformerized by the power conversion unit 320.

[0022] (Structure of the host control device 400) The host control device 400 controls the battery control device 200 and the drive device 300, and also controls the overall operation of the motor drive system 1. The host control device 400 includes a control management unit 410 for controlling the battery control device 200 and the drive device 300, and a storage unit 420.

[0023] The control management unit 410 controls the relay 310, the power conversion unit 320, the motor 330, etc. The control content of the control management unit 410 involves many aspects, but mainly focuses on the control of the motor 330 based on prescribed information. This prescribed information refers to information input from the battery 101 via the battery control device 200, information input from the power conversion unit 320, and information input from the motor 330. For example, the information for the battery 101 is the state of charge (SOC).

[0024] The control management unit 410, by referring to battery operation control information such as allowable current, allowable power, and SOC from the battery pack control management unit 230 (described later), formulates an energy management plan related to the drive of the motor 330 and the charging and discharging of the battery pack 100, and outputs control commands calculated based on this plan to the power conversion unit 320 to control the amount of electricity generated. The storage unit 420 stores information related to the motor drive system 1. The stored information is data used by the upper control device 400.

[0025] (Structure of Battery Pack 100) Battery pack 100 supplies power to motor 330 via relay 310 and power conversion unit 320. One or more battery packs 100 are provided for battery control device 200. Multiple battery packs 100 are electrically connected in series. Battery pack 100 includes one or more batteries 101 (single cells). Multiple batteries 101 are electrically connected in series. Preferably, battery 101 is a lithium-ion secondary battery. Battery 101 can also be a nickel-metal hydride battery, lead-acid battery, all-solid-state battery, etc.

[0026] (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 about the batteries 101, etc., and a battery pack control management unit 230 for controlling and managing the battery pack 100. The battery control device 200 is composed of an integrated circuit board (battery control board) on which these battery pack control management units 230, etc., are installed.

[0027] The battery control device 200 is configured as a battery management system (BMS). Multiple functional blocks (such as the battery pack control management unit 230) of the battery control device 200 are implemented by executing programs stored in memory using a microcomputer, controller, processor, etc., mounted on an integrated circuit board. Alternatively, these functional blocks can be implemented using dedicated hardware. The battery pack control management unit 230 appropriately calculates the state of charge (SOC), allowable charge / discharge current, and allowable charge / discharge power of the battery 101. The battery pack control management unit 230 outputs the allowable values ​​calculated in the above manner to the upper-level control device 400. Based on this information, the upper-level control device 400 controls the input and output of the motor 330, thereby achieving safe charging and discharging of the battery pack 100.

[0028] (Battery Management Unit 210) The battery management unit 210 manages the state of batteries 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. 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, the signal lines required for aggregation can be shortened and the structure simplified, ensuring flexibility relative to the number of batteries 101, and enabling the realization of large secondary batteries composed of multiple batteries.

[0029] (Detection Unit 220) The detection unit 220 detects the current, voltage, temperature, and other states 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. 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 provided for each series connection can be used as the current value of each battery 101.

[0030] The current detection unit 221 includes a current sensor and wires. The current sensor is electrically connected to a structural component of the battery pack 100 in a manner that allows it to detect the current flowing through the battery 101. The structural component 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 perform calculations on the battery 101's SOC, degradation state, power limit value, and detect overcurrent, etc.

[0031] The voltage detection unit 222 detects the voltage values ​​of multiple battery packs 100 connected in series or the like. The voltage detection unit 222 includes a voltage sensor and wiring. The voltage sensor is electrically connected to a structural component such as a busbar so as to detect the voltage of one or more battery packs 100 connected in series. The voltage detection unit 222 outputs the detected voltage values ​​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 SOC (State of Charge) settings.

[0032] 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 for battery characteristics used in SOC calculations based on temperature, the accuracy of SOC calculations can be improved.

[0033] The detection unit 220 is not limited to the structure described above. The detection unit 220 may also be a communication detection unit that includes detecting 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.

[0034] 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 control management unit 410. With this structure, even if the battery pack control management unit 230 malfunctions, the measured values ​​and diagnostic results can still be output to the control management unit 410. The detection unit 220 of the battery control device 200 can also be provided in the battery pack 100.

[0035] (Battery Pack Storage Unit 240) The battery pack storage unit 240 stores the history, status, statistics, characteristics, etc. 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 (Open Circuit Voltage). In this embodiment, the battery pack storage unit 240 and the battery pack control and management unit 230 are separate units, but it is also possible to have the battery pack storage unit 240 located inside the battery management unit 210 or inside the battery pack control and management unit 230. Alternatively, the history and statistical values ​​can be stored in the control management unit 410 or storage unit 420 located outside the battery control device 200.

[0036] (Battery Pack Control Management Unit 230) The battery pack control management unit 230 performs calculations to appropriately control the charging and discharging of the battery pack 100 based on information input from the detection unit 220 and the battery management unit 210, as well as allowable values ​​pre-stored in the battery pack storage unit 240 and the battery characteristics of the battery 101. As an example of the battery pack control management unit 230 appropriately controlling the charging and discharging of the battery 101, sometimes the battery performance is maximized in a way that the lifespan of the battery 101 is below the required lifespan but does not exceed the limit.

[0037] The required lifespan of a battery refers to the period during which the battery maintains its expected performance and continues to operate under specific uses and operating conditions. "Non-compliant" means the battery fails to meet the set required lifespan under specific uses and operating conditions. "Exceeding the required lifespan" means the battery's lifespan is extended beyond the required lifespan. In the case of non-compliant, the battery continuously deteriorates; in the case of exceeding the required lifespan, the battery's performance cannot be fully utilized. Therefore, it is preferable to use the battery in a way that ensures its lifespan meets the required lifespan, as this approach balances preventing battery degradation with efficient battery utilization. However, since battery lifespan varies significantly depending on usage conditions, achieving a balance between these two aspects is not easy.

[0038] Therefore, during battery operation, the battery pack control and management unit 230 adjusts the battery's operating conditions to bring the predicted lifespan of battery 101 closer to the required lifespan. Bringing the predicted lifespan of battery 101 closer to or substantially consistent with the required lifespan means that when the battery reaches its required lifespan, the value of the battery's lifespan prediction parameter is within, for example, ±10% of the target value. These processes will be described below as battery lifespan optimization processes. The battery pack control and management unit 230 can target one or more batteries 101 belonging to the battery pack 100 as objects of battery lifespan optimization processes.

[0039] To optimize battery life, the battery pack control and management unit 230 has, for example, the structure shown in the functional block diagram of FIG2. The battery control and management unit 230 includes a work history calculation unit 2300, a lifespan prediction unit 2302, a pattern correction unit 2304, a determination unit 2306, a working state determination unit 2310, an adjustment setting unit 2308, and a power allowance calculation unit 2312. The battery pack control and management unit 230 outputs the calculation results and instructions based on those results to the battery management unit 210, the battery control unit 211, or the control management unit 410. The battery pack control and management unit 230 is implemented by an integrated circuit board. The processor of the integrated circuit board implements the functional blocks shown in FIG2 by executing programs recorded in memory. The term "unit" in "work history calculation unit 2300," etc., can be replaced as appropriate with device, unit, function, component module, or circuit, etc.

[0040] (Work History Calculation Unit 2300) Based on inputs of battery operating information such as SOC, temperature data detected by temperature detection unit 223, current value detected by current detection unit 220, and voltage value detected by voltage detection unit 221, the work history calculation unit 2300 calculates the working history of each battery and determines its characteristic quantities. Characteristic quantities may include, for example, one or more of the following: average temperature, center SOC, representative current value, operating range of SOC (ΔSOC), and closed-circuit to open-circuit time ratio (Duty) of battery 101. The work history calculation unit 2300 outputs this characteristic quantity to the life prediction unit 2302.

[0041] (Lifetime Prediction Unit 2302) The lifetime prediction unit 2302 has a lifetime model for the battery 101. The lifetime model is a method for predicting battery degradation and evaluating lifespan based on usage conditions, and consists of a mathematical model and tables (databases). For example, a degradation estimation model can be used as a lifetime model. The degradation estimation model monitors the progress of battery degradation in real time and predicts the remaining lifespan of the battery. A degradation table is typically used in the degradation estimation model.

[0042] The degradation table is a dataset that correlates battery operating data (temperature, voltage, current, etc.) with battery degradation indicators (capacity retention, internal resistance, etc.). The degradation table is stored in the battery pack storage unit 240. The output of the degradation prediction model is a predicted value of SOH (State of Health), expressed as SOHQ (State of Health Based on Capacity) or SOHR (State of Health Based on Resistance). These SOH values ​​are indicators of the battery's degradation state and can be considered as parameters used for battery life prediction.

[0043] The degradation prediction model outputs predicted curves of SOHQ and SOHR over time, i.e., a dynamic pattern (life prediction pattern) for predicting battery life. This allows visualization of the battery's remaining life and degradation progress based on the passage of time and usage conditions. SOHQ represents how much the battery capacity has deteriorated relative to its initial capacity, and SOHR represents how much the battery's internal resistance has increased relative to its initial state.

[0044] Furthermore, in the degradation prediction model, prediction curves for related degradation parameters are created to obtain prediction curves for SOHQ and SOHR. This allows for a quantitative understanding of how battery usage conditions affect degradation and prediction of future degradation. The lifespan model calculates the changes in degradation parameters by referring to the characteristic quantities output from the work history calculation unit 2300 and a pre-stored degradation table. Degradation parameters include, for example, the utilization rate of the positive and negative electrodes constituting battery 101 in a single cell, the capacity of the low-potential side of the negative electrode that becomes unusable due to degradation (negative electrode capacity deviation), the rate of increase in resistance of the positive and negative electrodes, or the DC resistance value of the battery.

[0045] Negative electrode utilization rate and negative electrode capacity deviation are considered because, in lithium-ion batteries, the capacity reduction caused by negative electrode capacity deviation is significant, as battery capacity is generated at the discharge end of the negative electrode. The lifetime model plots prediction curves (degradation patterns) based on time series plots of various degradation parameters, and plots prediction curves (lifetime prediction patterns) for capacity retention rate (SOHQ) or rate of increase in resistance (SOHR), which serve as lifetime prediction parameters for the battery. In addition to SOHQ or SOHR, lifetime prediction parameters can also be selected from the degradation parameters described above.

[0046] (Pattern Correction Unit 2304) The pattern correction unit 2304 corrects the lifespan prediction pattern based on the battery's usage performance. The battery's usage performance refers to the value of the lifespan prediction parameter directly detected from the battery 101. The pattern correction unit 2304 calculates the correction parameter and corrects the lifespan prediction pattern based on the correction parameter. The pattern correction unit 2304 determines the correction parameter and corrects the lifespan prediction pattern by multiplying the prediction curve of the lifespan prediction pattern by the correction parameter.

[0047] The pattern correction unit 2304 compares the life prediction pattern with the actual values ​​of the life prediction parameters directly detected from the battery at each correction time, and determines the correction parameters for correcting the life prediction pattern based on the comparison results. At each correction time, the pattern correction unit 2304 continuously applies the correction parameters to the life prediction pattern to correct it. The pattern correction unit 2304 uses the ratio of the time change rate of the actual value of the life prediction parameter to the time change rate of the life prediction pattern as the correction parameter and updates and records it to the battery pack storage unit 240.

[0048] Next, the correction of the lifespan prediction pattern will be explained in detail. Figure 3 is a graph showing the accelerated battery degradation and decreased SOHQ (SOHQ pattern) as time progresses from the start of battery use. In the figure, a on the horizontal axis represents the start time of battery use, d represents the time point at which the required lifespan is achieved, b represents the first correction opportunity, and c represents the second correction opportunity. There can also be more correction opportunities.

[0049] 3000 represents the first SOHQ pattern constructed by the life prediction unit 2302 at the start of battery use. 3002 represents the second SOHQ pattern obtained by correcting the rate of change of SOHQ pattern 3000 at the first correction time. 3004 represents the third SOHQ pattern obtained by correcting the rate of change of SOHQ pattern 3002 at the second correction time.

[0050] ΔQsim_1 is the difference between the first SOHQ pattern at the first correction time point and the battery usage start time point a. ΔQmes_1 is the difference between the measured SOHQ value at the first correction time point b and the battery usage start time point. The measured SOHQ value is the SOHQ value directly detected from the battery. ΔQsim_2 is the difference between the second SOHQ pattern at the second correction time point c and the battery usage start time point a. ΔQmes_2 is the difference between the measured SOHQ value at the second correction time point c and the battery usage start time point.

[0051] The pattern correction unit 2304 calculates [(ΔQmes_1) / (ΔQsim_1)] and uses it as the correction parameter for the first correction timing b. By correcting the rate of change (k) of the first SOHQ pattern 3000 to "k×[(ΔQmes_1) / (ΔQsim_1)] (=k1)", a second SOHQ pattern 3002 is constructed. Further, the pattern correction unit 2304 calculates [(ΔQmes_2-ΔQmes_1) / (ΔQsim_2-ΔQsim_1)] and uses it as the correction parameter for the second correction timing c. By correcting the rate of change (k1) of the third SOHQ pattern 3004 to "k1×[(ΔQmes_2-ΔQmes_1) / (ΔQsim_2-ΔQsim_1)] (=k2)", a third SOHQ pattern 3004 is constructed. From the moment the battery is put into use, as it passes through a→b→c, the SOHQ pattern changes in the order of pattern 3000, pattern 3002, and pattern 3004. Even if the number of correction opportunities increases to 3, 4, etc., it is still handled in the same way.

[0052] The pattern correction unit 2304 corrects the lifespan prediction pattern before the battery reaches its required lifespan in order to optimize the predicted lifespan pattern based on the battery's actual usage performance. By correcting the predicted lifespan pattern based on the battery's actual usage performance, the predicted lifespan pattern can be matched to the actual usage conditions of the battery. If the pattern correction unit 2304 calculates correction parameters, it updates and stores them in the corresponding area of ​​the battery pack storage unit 240. The pattern correction unit 2304 reads the correction parameters and applies them to the lifespan prediction parameters. If the correction of the SOHQ pattern is completed, the pattern correction unit 2304 outputs it to the determination unit 2306.

[0053] (Judgment Unit 2306) To meet the required battery lifespan, the operating conditions of the battery are adjusted to control battery degradation. Adjustment of operating conditions refers to changes (enhancing or relaxing) or even removing restrictions or inhibitions on operating conditions. Relaxing the restrictions on battery operating conditions improves the battery's charge and discharge performance, but shortens its lifespan. Conversely, strengthening the restrictions on operating conditions has the opposite effect.

[0054] Therefore, in order to control battery usage so that the predicted battery life converges to the required life, the determination unit 2306 determines whether the battery's operating conditions need to be adjusted based on the revised life prediction pattern (Fig. 3). The determination unit 2306 compares the target value of SOHQ set as the required battery life with the predicted value of SOHQ at the time when the battery reaches the required life, and uses adjustment parameters, which are indicators for adjusting the battery's operating conditions, to determine whether adjustment is needed.

[0055] Adjustment parameters include, for example, the allowable charging and discharging current (first adjustment parameter) and the operating range of SOC (ΔSOC) (first adjustment parameter). The smaller the allowable current and the smaller the ΔSOC, the greater the limitation level of the battery's operation. The determination unit 2306 performs a determination at at least one of multiple correction times in the life prediction pattern. When the battery's predicted life meets the required life, the determination unit 2306 determines to maintain the current limitation level. When the battery's predicted life exceeds the required life (over-limit), the determination unit 2306 determines to relax the limitations, i.e., increase the allowable current and / or increase ΔSOC. When the battery's predicted life is shorter than the required life (under-limit), the determination unit 2306 determines to strengthen the limitations, i.e., decrease the allowable current and / or decrease ΔSOC. The control of the adjustment parameters is quantified by a control method such as the ratio of parameter values ​​before and after adjustment (adjustment rate).

[0056] When multiple adjustment parameters exist, the determination unit 2306 selects at least one adjustment parameter. Regarding the selection of adjustment parameters, the determination unit 2306 can set priorities for each of the multiple adjustment parameters. Multiple adjustment parameters can be selected all at once, or they can be selected sequentially. When multiple adjustment parameters are selected sequentially, priorities can also be set according to the selection order. For example, when suppressing battery degradation, the determination unit 2306 first determines to reduce the allowable current; then, if battery degradation worsens, it determines to further reduce ΔSOC. On the other hand, when battery degradation is small and actually improves battery performance, the determination unit 2306 determines to remove or relax the allowable current restriction, that is, to increase the allowable current.

[0057] Based on Figure 4, the operation of the determination unit 2306 will be explained in detail. Figure 4 depicts the trajectories of four SOHQ patterns (S1-S4) with different rates of change. The tilt of the SOHQ pattern varies depending on the magnitude of the predicted SOHQ value at the required lifespan point. The magnitude of the predicted SOHQ value is determined by the balance between battery degradation and the promotion of battery reaction.

[0058] In Figure 4, L1 represents the target value of SOHQ at the required lifespan point. M1 is the threshold used by the battery pack control management unit 230 to remove the allowable current restriction. When the predicted value of SOHQ at the required lifespan point is greater than L1 and the difference between the two is greater than or equal to M1, the determination unit 2306 determines to remove the allowable current restriction.

[0059] M2 is a threshold used to limit ΔSOC based on limiting the allowable current. When the predicted value of SOHQ at the required lifetime point is less than L1 and the difference between the two is greater than or equal to M2, the decision unit 2306 determines to limit ΔSOC. Although a decision margin can be set to limit the allowable current, the relationship (L1-M2) < (L1-(decision margin)) is strictly maintained.

[0060] When the SOHQ pattern reaches the correction endpoint (4000), the determination unit 2306 performs a determination for battery suppression based on the predicted value of SOHQ at the required lifespan. As the SOHQ pattern progresses along the change process of S1, since the predicted value P1 of SOHQ at the required battery lifespan becomes P1>L1+M1, the determination unit 2306 decides to relax the limit on the allowable current and writes the limit relaxation flag to the battery pack storage unit 240.

[0061] When the SOHQ pattern of the battery changes along the process of S2, since the predicted value P2 of SOHQ becomes L1+M1>P2>L1, the determination unit 2306 determines the limit of the allowable current, that is, determines the allowable current and writes the limit maintenance flag into the battery pack storage unit 240.

[0062] When the SOHQ pattern of the battery changes along the process of S3, since the predicted value P3 of SOHQ becomes L1>P3>L1-M2, the determination unit 2306 determines to strengthen the limit of the allowable current value of the battery charging and discharging, that is, determines to reduce the allowable current and writes the allowable current limit strengthening flag into the battery suppression regulation storage area of ​​the battery pack storage unit 240.

[0063] When the battery's SOHQ pattern changes along the process of S4, since the predicted value P4 of SOHQ becomes P4≤L1-M2, the determination unit 2306 also writes the ΔSOC enhancement flag into the battery suppression regulation storage area of ​​the battery pack storage unit 240, in addition to allowing the current limit enhancement flag. The determination unit 2306 notifies the adjustment setting unit 2308 of the determination result. If the adjustment setting unit 2308 receives the notification, it refers to the flag information of the battery pack storage unit 240. The adjustment setting unit 2308 also receives the determination result of the operating state of the adjustment parameters from the operating state determination unit 2310. The determination result of the operating state includes flags related to the operating state of the adjustment parameters.

[0064] (Operating Status Determination Unit 2310) If the operating status determination unit 2310 receives a notification (S1) from the pattern correction unit 2304 that the SOHQ pattern has been corrected, the operating status of the SOC operating range (ΔSOC) and the operating status of the allowable charging and discharging current, which are the adjustment parameters, for the target battery as the life optimization treatment.

[0065] As shown in Figure 5, in determining the operating state of ΔSOC, the operating state determination unit 2310 converts the initial capacity 500 of ΔSOC into a capacity 502 that reflects the battery's degradation rate (×SOHQ). First, the operating state determination unit 2310 calculates the upper and lower limits of the battery's usable capacity based on the battery's rated capacity, upper and lower limits of SOC, and predicted SOHQ value (504).

[0066] Next, the operating status determination unit 2310 refers to the initial SOC capacity 502 and the SOC operating history of the battery pack storage unit 240 to calculate the maximum and minimum values ​​of the capacity corresponding to the SOC. The operating status determination unit 2310 compares the battery's usable capacity with the capacity corresponding to the SOC to determine whether the acceptable SOC capacity is appropriate. When "the maximum value of the operating SOC capacity > the upper limit of the usable capacity," the operating status determination unit 2310 outputs a determination flag indicating upper limit departure. When "the maximum value of the operating SOC capacity ≤ the upper limit of the usable capacity," the operating status determination unit 2310 outputs a determination flag indicating upper limit acceptance. When "the lower limit of the usable capacity > the minimum value of the operating SOC capacity," the operating status determination unit 2310 outputs a determination flag indicating lower limit departure. When "the lower limit of the usable capacity ≤ the minimum value of the operating SOC capacity," the operating status determination unit 2310 outputs a determination flag indicating lower limit acceptance.

[0067] The operating status determination unit 2310 compares the input charging current and output discharging current of the battery whose lifespan optimization is desired with the maximum current value to determine the operating status of each charging and discharging current. The operating status determination unit 2310 determines the maximum allowable value of each charging and discharging current based on the current detection value, the battery temperature detection value, and the information management table.

[0068] The operating status determination unit 2310 determines the operating status of each charging and discharging current by comparing the charging and discharging current values ​​with their respective allowable values. When the charging current value is greater than the allowable charging value, the operating status determination unit 2310 outputs a determination flag indicating the disconnection of the charging current. When the charging current value is less than or equal to the allowable charging value, the operating status determination unit 2310 outputs a determination flag indicating the acceptance of the charging current. When the discharging current value is greater than the allowable discharging value, the operating status determination unit 2310 outputs a determination flag indicating the disconnection of the discharging current. When the discharging current value is less than or equal to the allowable discharging value, the operating status determination unit 2310 outputs a determination flag indicating the acceptance of the discharging current.

[0069] (Adjustment Setting Unit 2308) The operating status determination unit 2310 records the multiple flags as described above into the battery pack storage unit 240 and notifies the adjustment setting unit 2308 of the determination result. The adjustment setting unit 2308 checks the flags notified by the operating status determination unit 2310, reduces the allowable current value and / or ΔSOC of the adjustment parameters that are set as disengagement flags, and outputs a command to the allowable power calculation unit 2312 so that it calculates that the battery can meet the allowable power required for the required lifespan.

[0070] Furthermore, when the flag output by the determination unit 2306 indicates either restriction release or restriction enhancement, the adjustment setting unit 2308 increases the allowable current and / or expands ΔSOC in the former case, and outputs a command to the power calculation unit 2312 in the latter case to reduce the allowable current value, or reduce both the allowable current value and ΔSOC. The level (degree) of the increase or decrease in the suppression rate, the rate of change, etc., of the adjustment parameters, i.e., the control method, is set based on, for example, the difference between the predicted SOHQ value and the target SOHQ value under the required battery life.

[0071] The operation of the adjustment setting unit 2308 will be explained based on Figure 6. ΔQ is the absolute value of the difference between the target value Qt of SOHQ under the required lifespan 604 and the predicted value 602 when the required lifespan is achieved based on the SOHQ pattern 600. When the flag from the determination unit 2306 is a restriction relaxation flag, the adjustment setting unit 2308 multiplies the allowable charge and discharge current and / or ΔSOC, which are adjustment parameters, by (1+ΔQ / Qt), thereby relaxing the restriction level (degree) of the adjustment parameters and thus relaxing the charge and discharge suppression of the battery.

[0072] On the other hand, when the flag from the determination unit 2306 is a limit enhancement flag, the adjustment setting unit 2308 multiplies the allowable charging and discharging current and / or ΔSOC, which are adjustment parameters, by (1-ΔQ / Qt) to enhance the limit level of the adjustment parameters, thereby increasing the charging and discharging limit of the battery.

[0073] The adjustment setting unit 2308 sends the calculation results of the allowable current and ΔSOC to the allowable power calculation unit 2312. The allowable power calculation unit 2312 calculates the allowable power to meet the aforementioned parameter conditions. Based on the calculation results, the battery pack control management unit 230 controls the charging and discharging of the battery. (1+ΔQ / Qt) and (1-ΔQ / Qt) are examples of control methods for the adjustment parameters. As long as ΔQ can be used to compare the magnitude, quality, order, and level of the adjustment parameters, its expression form is not limited to percentage-based expression, ratio-based expression, function expression, weighted expression, etc.

[0074] The target value Qt for SOHQ can be the required SOHQ value itself, set according to the required lifespan. However, it is preferable to obtain the target value by adding a margin to the allowable value when comparing the required value with the expected value. This is to prevent the required lifespan from being unmet due to the influence of SOHQ prediction errors when the target SOHQ is equal to the required lifespan SOHQ. Alternatively, ΔQ (difference) can be set not as the numerical difference between the target value Qt and the predicted value of SOHQ, but as a value obtained through a specified function.

[0075] The following describes an embodiment of the present invention. Figure 7 shows simulation results of the SOHQ pattern when a 7.8Ah battery, under conditions where the ΔSOC exceeds the lifespan limit, was modified with parameter suppression changes. The target lifespan was set to achieve an SOHQ of 70% after 3650 days. The initial ΔSOC was 10.0%, and without suppression changes, the SOHQ after 3650 days was 92.0%. On the other hand, with suppression changes performed every six months, the final ΔSOC increased to 49.5%, and the SOHQ after 3650 days was 79.5%. This result demonstrates a measure to de-suppress ΔSOC while meeting the required lifespan, even when the lifespan limit is exceeded.

[0076] Figure 8 shows the simulation results of SOHQ (State of Health) for a 7.8 Ah battery under conditions of substandard current and ΔSOC, with parameter suppression modifications applied. The target life was set at 70% SOHQ after 3650 days. The initial current was 75.0 A, and the initial ΔSOC was 60.0%. Without suppression modifications, the SOHQ after 3650 days was 48.1%. On the other hand, with 11 suppression modifications performed every 10 days, the final current decreased to 28.2 A, the ΔSOC decreased to 38.4%, and the SOHQ after 3650 days reached 70.0%. This result demonstrates that measures were implemented to strengthen the suppression of allowable current and ΔSOC to meet the required lifespan under substandard conditions.

[0077] The power calculation unit 2312 outputs the calculation result of the allowable power to the upper control device 400 based on the input from the adjustment setting unit 2308. At this time, the adjustment parameters of the battery 101 can also be changed by increasing or decreasing the SOHR value according to the input from the adjustment setting unit 2308.

[0078] According to the embodiments described above, the first disclosure relates to a battery control device 200 that controls the charging and discharging of a battery 101. The device is characterized by comprising: a battery life model (life prediction unit) 2302 that outputs a dynamic pattern of battery life prediction parameters; a determination unit 2306 that determines whether battery operating conditions need to be adjusted in order to make the predicted battery life based on the dynamic pattern meet the battery's required lifespan; an adjustment setting unit 2308 that, based on the determination of the determination unit, determines adjustment parameters (allowable current, ΔSOC) for adjusting the battery's operating conditions; and a power calculation unit 2312 that calculates the battery's allowable power based on control parameters; and a setting unit that sets a control method for the adjustment parameters based on a comparison between the predicted value and the target value of the life prediction parameters based on the dynamic pattern at the required lifespan point. According to the first disclosure, a battery control device can be provided that can converge the battery lifespan to the required lifespan based on the battery's operating state, thereby maintaining battery performance until the battery reaches the required lifespan.

[0079] Furthermore, the second disclosure is characterized by, based on the first disclosure, also including a pattern correction unit 2304, which corrects the dynamic pattern according to the battery's operating performance. According to the second disclosure, the lifespan prediction pattern can be optimized based on the battery's operating state.

[0080] Furthermore, the third disclosure is characterized in that, based on the first or second disclosure, the pattern correction unit corrects the dynamic pattern at multiple points before the battery reaches its required lifespan. According to the third disclosure, the lifespan prediction pattern can be further optimized.

[0081] Furthermore, the fourth disclosure is characterized in that, based on any one of the first to third disclosures, the pattern correction unit uses the battery's actual operating performance as a measured value of the life prediction parameter, compares the measured value with the predicted value of the life prediction parameter based on the dynamic pattern, and corrects the dynamic pattern based on the comparison result.

[0082] Furthermore, the fifth disclosure is characterized in that, based on any one of the first to fourth disclosures, the determination unit compares the predicted value of the lifespan prediction parameter with its target value, and based on the comparison result, determines whether to strengthen the limitations of the battery's operating conditions, relax the limitations of the battery's operating conditions, or maintain the limitations of the battery's operating conditions. According to the fifth disclosure, it is possible to control the charging and discharging operation of the battery so that the capacity retention rate reaches the target value when the battery reaches the required lifespan.

[0083] Furthermore, the sixth disclosure is characterized in that, based on any one of the first to fifth disclosures, when the determination unit determines that the restrictions on the battery's operating conditions should be relaxed, the setting unit relaxes the restrictions on the control parameters based on the difference between the predicted value of the life prediction parameter and its target value. With this configuration, the charging and discharging of the battery can be controlled to achieve the required lifespan, without the battery lifespan falling short of or exceeding the required lifespan.

[0084] Furthermore, the seventh disclosure is characterized in that, based on any one of the first to sixth disclosures, when the determination unit determines that the battery's operating conditions are limited, the setting unit reduces the allowable current based on the difference between the predicted value of the life prediction parameter and its target value, and then further reduces the SOC operating range. With this configuration, the charging and discharging of the battery can be controlled to achieve the required lifespan, without the battery lifespan falling short of or exceeding the required lifespan.

[0085] Furthermore, the eighth disclosure relates to a battery control method, wherein a processor controls the charging and discharging of the battery. The method is characterized in that the processor outputs a dynamic pattern of predicted battery life parameters based on a battery life model. By continuously correcting the rate of change of the dynamic pattern according to the battery's operating state, the operating conditions of the battery are adjusted so that the predicted value of the predicted life parameters at the battery's required lifespan converges to the target value of the predicted life parameters. Thus, a battery control method is provided that can converge the battery's lifespan to the required lifespan based on the battery's operating state, thereby maintaining battery performance before the battery reaches its required lifespan.

[0086] 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-described embodiments are examples for implementing this invention. When implementing this invention, only a portion of the configuration of the embodiments may be implemented. When implementing this invention, configurations not described in the embodiments may also be added to the embodiments and implemented. When implementing this invention, a portion of the configuration of the embodiments may be replaced with a configuration not described in the embodiments. Modules, devices, and units may also be configured by combining electronic circuits.

[0087] Explanation of reference numerals in the attached drawings: 101: Battery; 200: Battery control device; 230: Battery pack control and management unit; 2300: Operating history calculation unit; 2302: Lifespan prediction unit; 2304: Pattern correction unit; 2306: Judgment unit; 2308: Adjustment and setting unit; 2310: Operating status judgment unit; 2312: Allowable power calculation unit.

Claims

1. A battery control device for controlling the charging and discharging of a battery, wherein, The device includes: a battery life model that outputs a dynamic pattern of predicted battery life parameters; a determination unit that determines whether the battery's operating conditions need to be adjusted in order to make the predicted battery life based on the dynamic pattern meet the battery's required life; a setting unit that determines adjustment parameters for adjusting the battery's operating conditions based on the determination unit's determination; and a power calculation unit that calculates the battery's allowable power based on the adjustment parameters. The setting unit sets a control method for the adjustment parameters based on a comparison between the predicted value and the target value of the predicted life parameters based on the dynamic pattern at the required lifespan time point.

2. The battery control device according to claim 1, wherein, It has a pattern correction unit that corrects the dynamic pattern based on the battery's operating performance.

3. The battery control device according to claim 2, wherein, The pattern correction unit corrects the dynamic pattern at multiple points before the battery reaches the required lifespan.

4. The battery control device according to claim 2, wherein, The pattern correction unit uses the battery's actual operating performance as the measured value of the life prediction parameter, compares the measured value with the predicted value of the life prediction parameter based on the dynamic pattern, and corrects the dynamic pattern based on the comparison result.

5. The battery control device according to claim 1, wherein, The determination unit compares the predicted value of the life prediction parameter with its target value, and based on the comparison result, determines whether to strengthen the restrictions on the battery's operating conditions, relax the restrictions on the battery's operating conditions, or maintain the restrictions on the battery's operating conditions.

6. The battery control device according to claim 1, wherein, The adjustment parameters are the operating range of the SOC and / or the allowable charging and discharging current.

7. The battery control device according to claim 1, wherein, The lifetime prediction parameters are SOHQ and / or SOHR.

8. The battery control device according to claim 5, wherein, When the determination unit determines that the operating conditions of the battery should be relaxed, the setting unit relaxes the restrictions on the control parameters based on the difference between the predicted value of the life prediction parameter according to the dynamic pattern and its target value.

9. The battery control device according to claim 6, wherein, When the determination unit determines that the operating conditions of the battery are restricted, the setting unit reduces the allowable current based on the difference between the predicted value and the target value of the life prediction parameter, and then reduces the operating range of the SOC.

10. A method for controlling a battery, wherein a processor controls the charging and discharging of the battery, wherein, The processor outputs a dynamic pattern of the battery's lifespan prediction parameters based on the battery's lifespan model. By continuously correcting the rate of change of the dynamic pattern according to the battery's operating state, the processor adjusts the battery's operating conditions so that the predicted value of the lifespan prediction parameters based on the dynamic pattern at the time point of the battery's required lifespan converges to the target value of the lifespan prediction parameters.

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