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 realizes: a service life model 2302 for deriving temporal deterioration of a service life prediction parameter that pertains to the battery and predicting the SOHQ of the battery on the basis of the temporal deterioration; an assessment unit 2306 for assessing whether it is necessary to change performance suppression of the battery so that the predicted service life of the battery falls within a required service life; and a setting unit 2308 for determining an adjustment parameter for the performance suppression of the battery on the basis of an assessment result from the assessment unit. The setting unit 2308 sets a suppression level on the basis of the difference between a predicted value of the SOHQ and a target value therefor.

Description

Battery control device and battery control method

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

[0002] The use of battery control devices equipped with a large number of secondary batteries is becoming increasingly widespread, such as power storage devices for mobile vehicles such as hybrid vehicles and electric vehicles, grid-connected stabilization power storage devices that are connected to power grids to stabilize the power grid, and emergency power storage devices.

[0003] Since the required life span of the batteries used in the battery control device is set, a battery management device is provided that can effectively utilize the battery performance while guaranteeing the battery life span by updating the charge / discharge limit value based on, for example, the deviation between the target life span value and the predicted life span value and the battery usage conditions (Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2016-163532

[0005] Since the degree of battery deterioration is likely to change depending on the battery usage conditions, there is a problem that the battery life may actually fall short of or exceed the required life. Therefore, an object of the present invention is to provide a battery control device and a battery control method that can converge the battery life to the required life depending on the operating state of the battery, thereby maintaining battery performance until the battery reaches the required life.

[0006] In order to achieve the above object, the present invention provides a battery control device that controls the charging and discharging of a battery, and includes: a life model of the battery that outputs a dynamic pattern of life prediction parameters of the battery; a judgment unit that judges whether or not adjustment of the operating conditions of the battery is necessary to make the predicted life of the battery based on the dynamic pattern match the required life of the battery; a setting unit that determines adjustment parameters for adjusting the operating conditions of the battery based on the judgment of the judgment unit; and a power calculation unit that calculates the allowable power of the battery based on the control parameters, and the setting unit sets a control mode for the adjustment parameters based on the result of comparing the predicted value of the life prediction parameter based on the dynamic pattern at the time of the required life with a target value.

[0007] Furthermore, a second invention is a battery control method in which a processor controls the charging and discharging of a battery, wherein the processor outputs a dynamic pattern of a life prediction parameter of the battery based on a life model of the battery, and continuously corrects the rate of change of the dynamic pattern according to the operating state of the battery, thereby adjusting the operating conditions of the battery so that the predicted value of the life prediction parameter of the dynamic pattern at the time of the battery's required life converges to a target value of the life prediction parameter.

[0008] According to the present invention, the battery life is converged to the required life in accordance with the operating state of the battery, and battery performance can be maintained until the battery reaches the required life.

[0009] 1 is a block diagram showing the configuration of an embodiment of a battery control device according to the present invention; FIG. 2 is a functional block diagram of an assembled battery control management unit of the battery control device of the embodiment; FIG. 3 is a graph for explaining the operation of a pattern correction unit; FIG. 4 is a graph for explaining the operation of a determination unit; FIG. 5 is a conceptual diagram showing conversion of a usable SOC operating range into a capacity reflecting the deterioration rate of SOHQ; FIG. 6 is a graph showing a parameter change rate ΔQ used for variable control; FIG. 7 is a graph showing an example of a simulation result of SOHQ when a parameter suppression change is applied under a condition of ΔSOC that results in overshooting of the lifespan; and FIG. 8 is a graph showing an example of a simulation result of SOHQ when a parameter suppression change is applied under a condition of a current value and ΔSOC that results in undershooting of the lifespan.

[0010] Embodiments of the present invention will now be described with reference to the drawings. Fig. 1 shows a block diagram of a motor drive system 1 equipped with an embodiment of a battery control device according to 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 battery operation such as 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 applicable to vehicles that are driven by a motor, such as hybrid vehicles, electric vehicles, and plug-in hybrid vehicles.

[0011] (Configuration of Drive Device 300) The drive device 300 includes a relay 310 that supplies or cuts off power, a power conversion unit 320 that transforms power while converting it between direct current and alternating current, and a motor 330 used as a power source.

[0012] The relay 310 is electrically connected between the battery pack 100 and the power conversion unit 320. This allows power to be passed or cut off between the battery pack 100 and the motor 330 via the power conversion unit 320. The relay 310 is incorporated into the load drive device 300, but it may also be incorporated into the battery control device 200. By incorporating the relay 310 into the battery control device 200, it becomes possible to cut the output voltage from the battery pack 100 by the relay 310 when the battery pack 100 and the battery control device 200 are assembled into or removed from the motor drive system 1. This makes it possible to prevent accidents such as electric shock or short circuit.

[0013] The power conversion unit 320 is electrically connected between the relay 310 and the motor 330. The power conversion unit 320 includes an inverter circuit and a converter circuit, thereby realizing AC / DC conversion and voltage transformation required for power exchange between the battery pack 100 and the motor 330.

[0014] The motor 330 is a motor for driving a load such as a vehicle or for generating electricity. When driving a load, the motor rotates the drive unit of the load using power from the battery pack 100. On the other hand, when generating electricity, the generator motor charges the battery pack 100 using regenerative energy generated during deceleration. The drive motor and generator motor may be integrated to reduce costs and space, or may be provided separately to optimize performance.

[0015] With the above configuration, the power discharged from the battery pack 100 is converted into AC by the power conversion unit 320, transformed, and supplied to the motor 330. In addition, kinetic energy is recovered as electric power by operating the motor 330 as a regenerative brake, and this electric power is converted into DC by the power conversion unit 320, transformed, and charged to the battery 101.

[0016] (Configuration of host control device 400) The host control device 400 controls the operation of the entire motor drive system 1 while controlling the battery control device 200 and the drive device 300. The host control device 400 includes a control management unit 410 that controls the battery control device 200 and the drive device 300, and a storage unit 420.

[0017] 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 is wide-ranging, but it mainly controls the motor 330 based on predetermined information. Here, the predetermined information is information about the battery 101 input from the battery control device 200, information input from the power conversion unit 320, information input from the motor 330, etc. The information about the battery 101 is, for example, the charging rate (SOC: State Of Charge).

[0018] The control management unit 410 formulates an energy management plan for driving the motor 330 and charging and discharging the battery pack 100 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), and outputs control commands calculated based on this to the power conversion unit 320 to control the amount of power generation. The memory unit 420 stores information related to the motor drive system 1. The stored information is data used by the upper control device 400.

[0019] (Configuration of battery pack 100) The battery pack 100 supplies power to the motor 330 via a relay 310 and a power conversion unit 320. One or more battery packs 100 are provided in the battery control device 200. The multiple battery packs 100 are electrically connected in series with each other. The battery pack 100 includes one or more batteries 101 (unit batteries). The multiple batteries 101 are electrically connected in series with each other. A lithium ion secondary battery is preferably used as the battery 101. The battery 101 may also be a nickel-metal hydride battery, a lead battery, an all-solid-state battery, or the like.

[0020] (Configuration of battery control device 200) The battery control device 200 controls the batteries 101 and the like of the battery pack 100. The battery control device 200 includes a battery management unit 210 that manages the states of the batteries 101 and the like, a detection unit 220 that detects the states of the batteries 101 and the like, a battery pack storage unit 240 that stores information about the batteries 101 and the like, and a battery pack control management unit 230 that controls and manages the battery pack 100. The battery control device 200 is configured by an integrated circuit board (battery control board) on which each unit, including the battery pack control management unit 230, is mounted.

[0021] The battery control device 200 is configured as a Battery Management System (BMS). Multiple functional blocks of the battery control device 200 (such as the assembled battery control management unit 230) are realized by a microcomputer, controller, processor, etc. implemented on an integrated circuit board executing programs stored in memory. Note that the functional blocks may also be realized by dedicated hardware. The assembled battery control management unit 230 appropriately calculates the SOC, allowable charge / discharge current, and allowable charge / discharge power of the battery 101. The assembled battery control management unit 230 outputs the calculated allowable values ​​to the upper control device 400. The upper control device 400 controls the input / output of the motor 330 based on this information, thereby achieving safe charging and discharging of the assembled battery 100.

[0022] (Battery management unit 210) The battery management unit 210 manages the states of the batteries 101, etc. The battery management unit 210 includes one or more battery control units 211. One battery control unit 211 corresponds to one or more assembled batteries 100. Each battery control unit 211 performs state control such as measuring the voltage and balancing of the batteries 101 included in the corresponding assembled battery 100. In this way, by adopting a hierarchical structure in which data from multiple batteries 101 is aggregated in the battery management unit 210 and then aggregated in the assembled battery control management unit 230, it is possible to shorten the signal lines required for aggregation, simplify the structure, and ensure flexibility in the number of batteries 101, thereby realizing a large secondary battery consisting of a large number of batteries.

[0023] (Detection unit 220) The detection unit 220 detects the current, voltage, temperature, and other conditions of the batteries 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, etc. When the batteries 101 are connected in series, the current value of one current detection unit 221 provided for each battery 101 may be used as the current value of each battery 101.

[0024] The current detection unit 221 includes a current sensor and an electric wire. The current sensor is electrically connected to a component of the battery pack 100 so as to detect the current flowing through the battery 101. The component of the battery pack 100 is, for example, a bus bar. The current detection unit 221 outputs the detected current value to the battery pack control management unit 230. This enables the battery pack control management unit 230 to calculate the SOC, deterioration state, power limit value, etc. of the battery 101, and to detect overcurrent, etc.

[0025] The voltage detection unit 222 detects the voltage value of multiple battery packs 100 connected in series or the like. The voltage detection unit 222 includes a voltage sensor and an electric wire. The voltage sensor is electrically connected to a component such as a bus bar so as to be able to detect the voltage of one or multiple battery packs 100 connected in series. The voltage detection unit 222 outputs the detected voltage value to the battery pack control management unit 230. This enables the battery pack control management unit 230 to protect the battery pack 100 and calculate the SOC, etc.

[0026] The temperature detection unit 223 detects the temperature of the battery 101, the ambient temperature of the battery pack 100, etc. The temperature detection unit 223 includes a temperature sensor and an electric wire. The temperature sensor is attached to the battery 101 and the battery pack 100. The temperature detection unit 223 outputs the detected temperature to the battery pack control management unit 230. This enables the battery pack control management unit 230 to calculate the maximum temperature, average temperature, and minimum temperature of the battery 101 and detect excessive temperature rise, etc. Furthermore, by correcting the battery characteristics used in the calculation of the SOC, etc. based on the temperature, the calculation accuracy of the SOC, etc. can be improved.

[0027] The detection unit 220 is not limited to the above configuration. The detection unit 220 may be configured to include a communication detection unit that detects the communication state of the battery management unit 210. In such a configuration, when a communication error occurs in the battery management unit 210, the communication detection unit notifies the assembled battery control management unit 230 of the communication failure of the battery management unit 210. A part or all of the detection unit 220 may be configured by the battery control unit 211 of the battery management unit 210.

[0028] Alternatively, the current detection unit 221, voltage detection unit 222, and temperature detection unit 223 may be configured to diagnose the battery 101 and the battery pack 100, and output the results and detected values ​​to the battery pack control management unit 230 and the control management unit 410. With this configuration, even if the battery pack control management unit 230 fails, it is possible to output the measured values ​​and diagnostic results to the control management unit 410. The detection unit 220 of the battery control device 200 may be provided in the battery pack 100.

[0029] (Battery Pack Storage Unit 240) The battery pack storage unit 240 stores the history, state, statistics, characteristics, etc. of the battery 101. The history is, for example, the history of the current value, voltage value, temperature, etc. of the battery 101. The state is, for example, the SOC, current value, voltage value, internal resistance value, and temperature of the battery 101. The statistics are, for example, the integrated value or average value of the current, and the number of times an abnormal value has been detected. The characteristics are, for example, the internal resistance characteristic, full charge capacity, polarization resistance characteristic, degradation characteristic, individual difference, and SOC table of the battery 101. The SOC table records the correspondence between the SOC and the OCV. In this embodiment, the battery pack storage unit 240 is provided separately from the battery pack control management unit 230. However, it may be configured to be provided inside the battery management unit 210 or inside the battery pack control management unit 230. The history, statistics, etc. may also be stored in the control management unit 410 or the memory unit 420, which are external to the battery control device 200.

[0030] (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 tolerances and battery characteristics of the battery 101 pre-stored in the battery pack storage unit 240. One example of the battery pack control management unit 230 appropriately controlling the charging and discharging of the battery 101 is to maximize battery performance by preventing the battery 101 from falling short of or exceeding its required lifespan.

[0031] The required life of a battery is the period during which the battery can continue to operate while maintaining the expected performance in a specific application or usage environment. Underachievement refers to a state in which the battery is unable to meet the set required life period in a specific application or usage environment. Overachievement refers to a state in which the battery life extends beyond the required life. Underachievement indicates that the battery is deteriorating, while overachievement indicates that the battery performance is not being fully utilized. Therefore, it is preferable to use a battery so that its electrical life matches the required life, as this allows for both preventing battery degradation and making effective use of the battery. However, achieving both is not easy, as battery life varies greatly depending on the conditions under which the battery is used.

[0032] Therefore, the battery pack control management unit 230 adjusts the operating conditions of the battery 101 while the battery is in operation so that the predicted life of the battery 101 converges to the required life. Converging the predicted life of the battery 101 to the required life or nearly matching the required life means that when the battery reaches the required life, the value of the battery life prediction parameter is within ±10%, for example, of the target value. Hereinafter, this will be described as battery life optimization processing. The battery pack control management unit 230 can target one or more specified batteries 101 belonging to the battery pack 100 for battery life optimization processing.

[0033] The assembled battery control management unit 230 has, for example, the configuration shown in the functional block diagram of FIG. 2 for the battery life optimization process. The battery control management unit 230 includes an operation history calculation unit 2300, a life prediction unit 2302, a pattern correction unit 2304, a determination unit 2306, an operation state determination unit 2310, an adjustment setting unit 2308, and an allowable power calculation unit 2312. The assembled battery control management unit 230 outputs calculation results and commands based on the calculation results to the battery management unit 210, the battery control unit 211, and the control management unit 410. The assembled battery control management unit 230 is implemented by an integrated circuit board. A processor on the integrated circuit board implements the functional blocks shown in FIG. 2 by executing a program recorded in memory. The term "unit" in the operation history calculation unit 2300 and the like may be appropriately replaced with "means," "unit," "function," "element module," "circuit," or the like.

[0034] (Operation history calculation unit 2300) The operation history calculation unit 2300 calculates the operation history of each battery based on input battery operation information such as SOC, temperature data detected by the temperature detection unit 223, current values ​​detected by the current detection unit 220, and voltage values ​​detected by the voltage detection unit 221, and determines its feature quantities. The feature quantities are, for example, one or more of the average temperature, median SOC, representative current value, SOC operation range (ΔSOC), time ratio (duty) between closed circuit and open circuit of the battery 101, etc. The operation history calculation unit 2300 outputs these feature quantities to the life prediction unit 2302.

[0035] (Lifespan prediction unit 2302) The lifespan prediction unit 2302 has a lifespan model of the battery 101. The lifespan model is a method for predicting battery degradation and evaluating the lifespan based on usage conditions, and is composed of a mathematical model and a table (database). An example of a lifespan model is a deterioration estimation model. The deterioration estimation model monitors the progress of battery degradation in real time and predicts the remaining lifespan of the battery. In the deterioration estimation model, it is common to use a deterioration table.

[0036] The degradation table is a data set that associates battery operation 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 estimation model is a predicted value of SOH (State of Health), which is 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 degradation state and can be considered as a type of parameter for predicting battery life.

[0037] The degradation estimation model outputs time-dependent predicted curves of SOHQ and SOHR, i.e., dynamic patterns (lifetime prediction patterns) for predicting battery life. This makes it possible to visualize the remaining life and progression of battery degradation over time and under usage conditions. SOHQ indicates how much the battery capacity has deteriorated from its initial capacity, and SOHR indicates how much the battery's internal resistance has increased from its initial state.

[0038] In addition, the degradation estimation model creates prediction curves for related degradation parameters to obtain prediction curves for SOHQ and SOHR. This allows for a quantitative understanding of how battery usage conditions affect degradation and predicts future degradation. The life model calculates the amount of change in the degradation parameters by referring to the feature values ​​output from the operation history calculation unit 2300 and a pre-stored degradation table. The degradation parameters include, for example, the utilization rate of the positive and negative electrodes constituting the battery 101, the capacity on the low-potential side of the negative electrode that has become unusable due to degradation (negative electrode capacity deviation), the resistance increase rate between the positive and negative electrodes, or the DC resistance value of the battery.

[0039] The negative electrode utilization rate and negative electrode capacity deviation are the targets because the rate of capacity decrease due to negative electrode capacity deviation is large in lithium-ion batteries, and battery capacity is generated by the discharge end of the negative electrode. The life model draws a prediction curve (deterioration pattern) from a time series plot of each deterioration parameter to draw a prediction curve (life prediction pattern) of the capacity retention rate (SOHQ) or the resistance rise rate (SOHR), which are battery life prediction parameters. The life prediction parameter may be SOHQ or SOHR, or may be selected from the deterioration parameters already described.

[0040] (Pattern correction unit 2304) The pattern correction unit 2304 corrects the life prediction pattern based on the battery usage history. The battery usage history is the value of the life prediction parameter detected directly from the battery 101. The pattern correction unit 2304 calculates the correction parameter and corrects the life prediction pattern based on the correction parameter. The pattern correction unit 2304 determines the correction parameter and corrects the life prediction pattern by multiplying it by the prediction curve of the life prediction pattern.

[0041] The pattern correction unit 2304 compares the life prediction pattern with actual values ​​of life prediction parameters detected directly from the battery at each correction timing, and determines correction parameters for correcting the life prediction pattern based on the comparison results. The pattern correction unit 2304 continuously applies the correction parameters to the life prediction pattern at each correction timing to correct it. The pattern correction unit 2304 determines the ratio of the time rate of change of the actual values ​​of the life prediction parameters to the time rate of change of the life prediction pattern as the correction parameter, and updates and records this in the assembled battery storage unit 240.

[0042] Next, the correction of the lifespan prediction pattern will be specifically described. Fig. 3 is a graph showing the state (SOHQ pattern) in which battery deterioration progresses with the passage of time from the start of battery use and the SOHQ decreases. In the figure, a on the horizontal axis indicates the start of battery use, d indicates the end of the required lifespan, b indicates the first correction timing, and c indicates the second correction timing. More correction timings may also be used.

[0043] Reference numeral 3000 denotes a first SOHQ pattern created by the life prediction unit 2302 at the start of battery use. Reference numeral 3002 denotes a second SOHQ pattern obtained by correcting the rate of change of the SOHQ pattern 3000 at the first correction timing. Reference numeral 3004 denotes a third SOHQ pattern obtained by correcting the rate of change of the SOHQ pattern 3002 at the second correction timing.

[0044] ΔQsim_1 is the difference between the first SOHQ pattern at the first correction timing and the time a when battery use started. ΔQmes_1 is the difference between the actual SOHQ measurement value at the first correction timing b and the time when battery use started. The actual SOHQ measurement value is the SOHQ value detected directly from the battery. ΔQsim_2 is the difference between the second SOHQ pattern at the second correction timing c and the time a when battery use started. ΔQmes_2 is the difference between the actual SOHQ measurement value at the second correction timing c and the time when battery use started.

[0045] The pattern correction unit 2304 calculates [(ΔQmes_1) / (ΔQsim_1)] as a correction parameter at the first correction timing b, and corrects the rate of change (k) of the first SOHQ pattern 3000 to "k*[(ΔQmes_1) / (ΔQsim_1)] (=k1)" to create a second SOHQ pattern 3002. Furthermore, the pattern correction unit 2304 calculates [(ΔQmes_2-ΔQmes_1) / (ΔQsim_2-ΔQsim_1)] as a correction parameter at the second correction timing c, and corrects the rate of change (k1) of the third SOHQ pattern 3004 to "k1*[(ΔQmes_2-ΔQmes_1) / (ΔQsim_2-ΔQsim_1)] (=k2)" to create a third SOHQ pattern 3004. As the battery starts to be used and progresses from a to b to c, the SOHQ pattern changes in the order of pattern 3000, pattern 3002, and pattern 3004. The same applies when the correction timing is increased to 3, 4, and so on.

[0046] The reason why the pattern correction unit 2304 corrects the life prediction pattern until the battery reaches the required life is to optimize the battery's predicted life pattern in accordance with the battery's usage history. By correcting the battery's predicted life pattern in accordance with the battery's credit history, the battery's life prediction pattern can be matched to the actual battery usage. After calculating the correction parameters, the pattern correction unit 2304 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 life prediction parameters. After correcting the SOHQ pattern, the pattern correction unit 2304 outputs them to the determination unit 2306.

[0047] (Determination unit 2306) In order to satisfy the required battery life, the operating conditions of the battery are adjusted to control battery degradation. Adjusting the operating conditions means changing (increasing or relaxing) or releasing the restrictions on the operating conditions. Relaxing the restrictions on the battery operating conditions improves the battery's charge / discharge performance but shortens the battery life. Conversely, strengthening the restrictions on the operating conditions has the opposite effect.

[0048] Therefore, in order to control battery usage so that the predicted battery life converges to the required battery life, the determination unit 2306 determines whether or not the battery operating conditions need to be adjusted based on the corrected life prediction pattern (FIG. 3). The determination unit 2306 compares the target SOHQ value set as the required battery life with the predicted SOHQ value at the time the battery reaches the required battery life, and determines whether or not adjustment is needed using adjustment parameters that serve as indicators for adjusting the battery operating conditions.

[0049] The adjustment parameters include, for example, the allowable current for charging and discharging (first adjustment parameter) and the operating range of the SOC (ΔSOC) (first adjustment parameter). The smaller the allowable current and the smaller the ΔSOC, the greater the restriction level on battery operation. The determination unit 2306 performs the determination at at least one of the multiple correction timings of the life prediction pattern. If the predicted battery life matches the required life, the determination unit 2306 determines to maintain the current restriction level. If the predicted battery life exceeds the required life (overachievement), the determination unit 2306 determines to relax the restriction by increasing the allowable current and / or increasing ΔSOC. If the predicted battery life is shorter than the required life (underachievement), the determination unit 2306 determines to strengthen the restriction by decreasing the allowable current and / or decreasing ΔSOC. Control of the adjustment parameters is quantified by a control aspect, such as the ratio (adjustment rate) of the parameter values ​​before and after adjustment.

[0050] When there are multiple adjustment parameters, the determination unit 2306 selects at least one adjustment parameter. When selecting an adjustment parameter, the determination unit 2306 may assign a priority to each of the multiple adjustment parameters. Multiple adjustment parameters may be selected at once or sequentially. When multiple adjustment parameters are selected sequentially, a priority may be assigned based on the order of selection. For example, when suppressing battery degradation, the determination unit 2306 first determines to reduce the allowable current, and then, if the battery degradation is severe, determines to also reduce the ΔSOC. On the other hand, when the battery degradation is small and battery performance is to be improved, the determination unit 2306 determines to release or relax the limit on the allowable current, i.e., to increase the allowable current.

[0051] The operation of the determination unit 2306 will be described in detail with reference to Fig. 4. Fig. 4 shows the trajectories of four SOHQ patterns (S1-S4), each with a different rate of change. The slope of the SOHQ pattern changes depending on the magnitude of the predicted SOHQ value at the end of the required life. The magnitude of the predicted SOHQ value is determined by the balance between battery degradation and the promotion of the battery reaction.

[0052] 4, L1 indicates the target value of SOHQ at the end of the required life. M1 is a threshold value for the battery pack control management unit 230 to release the limit on the allowable current. If the predicted value of SOHQ at the end of the required life is greater than L1 and the difference between them is equal to or greater than M1, the determination unit 2306 determines whether to release the limit on the allowable current.

[0053] M2 is a threshold value for limiting ΔSOC in addition to limiting the allowable current. The determination unit 2306 determines to limit ΔSOC when the predicted value of SOHQ at the time of the required life is smaller than L1 and the difference between them is M2 or more. A determination margin may be set to limit the allowable current, but the relationship (L1 - M2) < (L1 - (determination margin)) is strictly maintained.

[0054] When the SOHQ pattern reaches the final correction point (4000), the determination unit 2306 determines whether to conserve battery power based on the predicted value of SOHQ at the required life. When the SOHQ pattern progresses along the history of S1, the predicted value P1 of SOHQ at the required battery life satisfies the relationship P1 > L1 + M1. Therefore, the determination unit 2306 determines to relax the allowable current limit and writes a limit relaxation flag to the battery pack storage unit 240.

[0055] When the SOHQ pattern of the battery fluctuates along the course of S2, the predicted SOHQ value P2 has the relationship L1+M1>P2>L1, so the judgment unit 2306 judges that the limit on the allowable current should be maintained, i.e., that the allowable current should be maintained, and writes a limit maintenance flag to the battery pack memory unit 240.

[0056] When the battery's SOHQ pattern fluctuates along the course of S3, the predicted SOHQ value P3 has the relationship L1 > P3 > L1-M2, so the judgment unit 2306 determines that the limit on the allowable current value for charging and discharging the battery should be strengthened, i.e., the allowable current should be reduced, and writes an allowable current limit strengthening flag to the battery restriction adjustment memory area of ​​the battery pack memory unit 240.

[0057] When the SOHQ pattern of the battery fluctuates along the history of S4, the predicted SOHQ value P4 satisfies the relationship P4≦L1−M2, and therefore the determination unit 2306 adds the allowable current limit enhancement flag to the ΔSOC enhancement flag and writes it into the battery restriction adjustment storage area of ​​the assembled battery storage unit 240. The determination unit 2306 notifies the adjustment setting unit 2308 of the determination result. Upon receiving this notification, the adjustment setting unit 2308 refers to the flag information in the assembled battery storage unit 240. The adjustment setting unit 2308 further receives a 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 a flag related to the operating state of the adjustment parameters.

[0058] (Operating state determination unit 2310) When the operating state determination unit 2310 receives notification (S1) from the pattern correction unit 2304 that the SOHQ pattern has been corrected, it determines the state of the SOC operating range (ΔSOC), which is an adjustment parameter, and the operating state of the allowable charge / discharge current for the battery that is the target of the life optimization process.

[0059] 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 deterioration rate (×SOHQ), as shown in Fig. 5. First, the operating state determination unit 2310 determines the upper and lower limits of the battery's usable capacity from the battery's rated capacity, the SOC upper and lower limits, and the SOHQ predicted value (504).

[0060] Next, the operating state determination unit 2310 references the initial SOC capacity 502 and the SOC operating history in the battery pack storage unit 240 to determine the maximum and minimum values ​​of the capacity corresponding to the SOC. The operating state determination unit 2310 compares the battery's usable capacity with the capacity corresponding to the SOC to determine whether the SOC capacity is appropriate. The operating state determination unit 2310 outputs an upper limit deviation determination flag when the "maximum value of the operating SOC capacity > the upper limit of the usable capacity". The operating state determination unit 2310 outputs an upper limit affirmative determination flag when the "maximum value of the operating SOC capacity ≦ the upper limit of the usable capacity". The operating state determination unit 2310 outputs a lower limit deviation determination flag when the "lower limit of the usable capacity > the minimum value of the operating SOC capacity". The operating state determination unit 2310 outputs a lower limit affirmative determination flag when the "lower limit of the usable capacity ≦ the minimum value of the operating SOC capacity".

[0061] The operational status determination unit 2310 compares the input charge current and output discharge current of the battery to the maximum current value to determine the operational status of each charge and discharge current. The operational status determination unit 2310 references the current detection values ​​and determines the maximum allowable values ​​for each charge and discharge current based on the detected battery temperature and the information management table.

[0062] The operating state determination unit 2310 compares each charge / discharge current value with its allowable value to determine the operating state of each charge / discharge current. When the "charge current value > the allowable value for charging", the operating state determination unit 2310 outputs a determination flag indicating a deviation of the charge current. When the "charge current value ≦ the allowable value for charging", the operating state determination unit 2310 outputs a positive determination flag for the charge current. When the "discharge current value > the allowable value for discharging", the operating state determination unit 2310 outputs a determination flag indicating a deviation of the discharge current. When the "discharge current value ≦ the allowable value for discharging", the operating state determination unit 2310 outputs a positive determination flag for the discharge current.

[0063] (Adjustment setting unit 2308) The operating state determination unit 2310 records the above-described multiple flags in the battery pack storage unit 240, and notifies the determination result to the adjustment setting unit 2308. The adjustment setting unit 2308 checks the flags notified by the operating state determination unit 2310, and outputs a command to the allowable power calculation unit 2312 to reduce the allowable current value and / or ΔSOC, which are adjustment parameters for which a deviation flag is set, and calculate an allowable power that enables the battery to satisfy the required lifespan.

[0064] Furthermore, when the flag output from the determination unit 2306 indicates restriction release or restriction strengthening, the adjustment setting unit 2308 outputs a command to the power calculation unit 2312 to increase the allowable current and / or expand ΔSOC in the former case, and to reduce the allowable current value or the allowable current value and ΔSOC in the latter case. The level (degree) of the range or rate of change of the suppression rate of the adjustment parameter, i.e., the control mode, is set based on, for example, the difference as a result of comparison between the predicted value of SOHQ and the target value of SOHQ for the required battery life.

[0065] The operation of the adjustment setting unit 2308 will be described with reference to Fig. 6. ΔQ is the absolute value of the difference between the SOHQ target value Qt for the required life 604 and the predicted value 602 at the required life according to 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 / discharge current and / or ΔSOC, which are adjustment parameters, by (1 + ΔQ / Qt) to relax the restriction level (degree) of the adjustment parameters and thereby relax the suppression of battery charge / discharge.

[0066] On the other hand, if the flag from the judgment unit 2306 is a restriction strengthening flag, the adjustment setting unit 2308 multiplies the adjustment parameters, the allowable current and / or ΔSOC, by (1-ΔQ / Qt) to strengthen the restriction level of the adjustment parameters and increase the battery charging / discharging restriction.

[0067] The adjustment setting unit 2308 transmits 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 so as to satisfy this. The battery pack control management unit 230 controls the charging and discharging of the battery based on the calculation results. (1+ΔQ / Qt) and (1-ΔQ / Qt) are each examples of control modes of the adjustment parameters. As long as the magnitude, superiority, order, high and low, etc. of the adjustment parameters can be compared using ΔQ, any notation based on a percentage, a ratio, a function, a weight, or the like is acceptable.

[0068] The SOHQ target value Qt may be the SOHQ required value itself set in accordance with the required lifespan, but it is preferable that it be a target value obtained by adding a margin to the allowable value when comparing the required value with the predicted value. This is to prevent the required lifespan from being not met due to the influence of SOHQ prediction errors if the target SOHQ is equal to the SOHQ of the required lifespan. Note that ΔQ (difference) may be a value obtained by a predetermined function rather than the actual numerical difference between the SOHQ target value Qt and the SOHQ predicted value.

[0069] An example of the present invention is described below. FIG. 7 shows the simulation results of the SOHQ pattern when a parameter suppression change is applied to a 7.8 Ah battery under the condition of an ΔSOC that results in overlife. The target value of the life was set to an SOHQ of 70% after 3,650 days. The initial ΔSOC was 10.0%, and without the suppression change, the SOHQ after 3,650 days was 92.0%. On the other hand, when the suppression change was performed every six months, the final ΔSOC was expanded to 49.5%, and the SOHQ after 3,650 days was 79.5%. This result shows that when the life is overlife, the ΔSOC is suppressed and released while satisfying the required life.

[0070] Figure 8 shows the simulation results of SOHQ when parameter suppression changes are applied to a 7.8 Ah battery under the conditions of current value and ΔSOC that result in lifespan not being reached. The target lifespan was set to 70% SOHQ after 3,650 days. The initial current value was 75.0 A and ΔSOC was 60.0%. Without suppression changes, the SOHQ after 3,650 days was 48.1%. On the other hand, when suppression changes were performed 11 times every 10 days, the final current value was 28.2 A, ΔSOC was reduced to 38.4%, and the SOHQ after 3,650 days was 70.0%. This result shows the behavior of strengthened suppression of allowable current and ΔSOC to meet the required lifespan when lifespan is not reached.

[0071] The allowable 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 may be changed by increasing or decreasing the value of the SOHR according to the input from the adjustment setting unit 2308.

[0072] According to the above-described embodiment, the first disclosure provides a battery control device 200 for controlling charging and discharging of a battery 101, the battery control device 200 including: a battery life model (life prediction unit) 2302 that outputs a dynamic pattern of a battery life prediction parameter; a determination unit 2306 that determines whether or not adjustment of the battery operating conditions is necessary to make the predicted battery life based on the dynamic pattern match the battery's required life; an adjustment setting unit 2308 that determines adjustment parameters (allowable current, ΔSOC) for adjusting the battery operating conditions based on the determination by the determination unit; and a power calculation unit 2312 that calculates the battery's allowable power based on the control parameters, wherein the setting unit sets a control mode for the adjustment parameters based on a comparison result between a predicted value of the life prediction parameter based on the dynamic pattern at the time of the required life and a target value. According to the first disclosure, it is possible to provide a battery control device that can maintain battery performance until the battery reaches the required life by converging the battery life to the required life in accordance with the operating state of the battery.

[0073] Furthermore, the second disclosure is characterized in that, in the first disclosure, it further includes a pattern correction unit 2304 that corrects the dynamic pattern in accordance with the operating history of the battery. According to the second disclosure, it is possible to optimize the life prediction pattern in accordance with the operating state of the battery.

[0074] Furthermore, a third disclosure is characterized in that, in the first or second disclosure, the pattern correction unit corrects the dynamic pattern at multiple times until the battery reaches the required life. According to the third disclosure, it is possible to further optimize the life prediction pattern.

[0075] Furthermore, a fourth disclosure is characterized in that, in any of the first to third disclosures, the pattern correction unit uses the battery's operating history as a measurement value of a life prediction parameter, compares the measurement value with a predicted value of the life prediction parameter based on the dynamic pattern, and corrects the dynamic pattern based on the comparison result.

[0076] Furthermore, a fifth disclosure is characterized in that, in any of the first to fourth disclosures, the determination unit compares a predicted value of a life prediction parameter with a target value thereof, and determines, based on the comparison result, to tighten restrictions on the operating conditions of the battery, relax restrictions on the operating conditions of the battery, or maintain the restrictions on the operating conditions of the battery. According to the fifth disclosure, when the battery reaches the required life, it is possible to control the charge and discharge operation of the battery so that the capacity retention rate becomes a target value.

[0077] Furthermore, a sixth disclosure is characterized in that, in any one of the first to fifth disclosures, when the determination unit determines to relax the restrictions on the battery operating conditions, 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. By configuring in this way, it is possible to control the charging and discharging of the battery so that the battery life is the required life, without falling short of or exceeding the required life.

[0078] Furthermore, a seventh disclosure is characterized in that, in any one of the first to sixth disclosures, when the determination unit determines to strengthen the restrictions on the battery operating conditions, 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 operating range of the SOC. By configuring in this way, it is possible to control charging and discharging of the battery so that the battery life is the required life without falling short of or exceeding the required life.

[0079] Furthermore, an eighth disclosure is a battery control method in which a processor controls charging and discharging of a battery, the processor outputting a dynamic pattern of a battery life prediction parameter based on the battery life model, and continuously correcting a rate of change of the dynamic pattern in accordance with the operating state of the battery, thereby adjusting the operating conditions of the battery so that a predicted value of the life prediction parameter at the time of the required battery life of the dynamic pattern converges to a target value of the life prediction parameter. This makes it possible to provide a battery control method that can maintain battery performance until the battery reaches the required life by converging the battery life to the required life in accordance with the operating state of the battery.

[0080] The present invention is not limited to the configurations described in the embodiments, and can be configured appropriately based on the contents described in the claims. The above-described embodiments are examples for implementing the present invention. When implementing the present invention, only part of the configuration of the embodiments may be implemented. When implementing the present invention, configurations not described in the embodiments may be added to the embodiments. When implementing the present invention, part of the configuration of the embodiments may be replaced with configurations not described in the embodiments. Modules, means, and units may be configured by combining electronic circuits.

[0081] 101: Battery, 200: Battery control device, 230: Assembled battery control management unit, 2300: Operation history calculation unit, 2302: Life expectancy prediction unit, 2304: Pattern correction unit, 2306: Determination unit, 2308: Adjustment setting unit, 2310: Operation state determination unit, 2312: Allowable power calculation unit

Claims

1. A battery control device that controls the charging and discharging of a battery, comprising: a life model of the battery that outputs a dynamic pattern of a life prediction parameter of the battery; a judgment unit that judges whether or not adjustment of the operating conditions of the battery is necessary to make the predicted life of the battery based on the dynamic pattern match the required life of the battery; a setting unit that determines adjustment parameters for adjusting the operating conditions of the battery based on the judgment of the judgment unit; and a power calculation unit that calculates the allowable power of the battery based on the adjustment parameters, wherein the setting unit sets a control mode for the adjustment parameters based on a comparison result between a predicted value of the life prediction parameter based on the dynamic pattern at the time of the required life and a target value.

2. The battery control device according to claim 1, further comprising a pattern correction unit that corrects the dynamic pattern in accordance with the operational performance of the battery.

3. The battery control device according to claim 2, wherein the pattern correction unit corrects the dynamic pattern at multiple times until the battery reaches the required life.

4. A battery control device as described in claim 2, wherein the pattern correction unit uses the operating history of the battery as a measured value of the life prediction parameter, compares the measured value with a predicted value of the life prediction parameter based on the dynamic pattern, and corrects the dynamic pattern based on the comparison result.

5. A battery control device as described in claim 1, wherein the judgment unit compares the predicted value of the life prediction parameter with its target value, and based on the comparison result, judges whether to tighten the restrictions on the operating conditions of the battery, relax the restrictions on the operating conditions of the battery, or maintain the restrictions on the operating conditions of the battery.

6. The battery control device according to claim 1, wherein the adjustment parameter is an operating range of SOC and / or an allowable charge / discharge current.

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

8. A battery control device as described in claim 5, wherein, when the determination unit determines that the restrictions on 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 based on the dynamic pattern and its target value.

9. A battery control device as described in claim 6, wherein, when the determination unit determines that the restrictions on the operating conditions of the battery should be strengthened, 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 reduces the operating range of the SOC.

10. A battery control method in which a processor controls the charging and discharging of a battery, wherein the processor outputs a dynamic pattern of a life prediction parameter of the battery based on a life model of the battery, and continuously corrects the rate of change of the dynamic pattern according to the operating state of the battery, thereby adjusting the operating conditions of the battery so that the predicted value of the life prediction parameter based on the dynamic pattern at the time of the required life of the battery converges to a target value of the life prediction parameter.

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