Battery storage system and method for controlling battery storage system

Abstract

The storage battery system (100) according to the present disclosure comprises: a plurality of storage battery modules (201) each having a BMU (202) and one or more temperature sensors (105); a control device (104) that controls the plurality of storage battery modules (201) via the BMUs (202); and an air conditioner (101) that controls one or more of the blowout air volume, air direction, and blowout temperature for each of the storage battery modules (201) on the basis of a target temperature set for each of the storage battery modules (201). The control device (104) is equipped with: a lifetime prediction unit (301) that predicts the lifetime using the capacity and measured temperature of each of the storage battery modules (201); and a temperature control unit (302) that calculates a target temperature for each of the storage battery modules (201) and transmits the target temperature to the air conditioner (101) so that the lifetime of each of the storage battery modules (201) predicted at the control start point is a lifetime averaged from the control start point onwards.

Description

[Technical field]

[0001] The present disclosure relates to a storage battery system and a control method for a storage battery system. [Background technology]

[0002] Due to the increasing demand for renewable energy, the spread of solar power generation, wind power generation, etc. is expected. Since the power generated by renewable energy fluctuates depending on the weather, etc., it is often installed in conjunction with a large storage battery system to stabilize the power grid. In addition, the recent increase in the size of renewable energy facilities requires large-capacity storage battery systems, and storage battery systems designed for long-term operation are becoming more widespread. Such large-capacity storage battery systems are expected to operate for 10 to 20 years, so highly efficient and long-term stable operation technology is required.

[0003] However, as the size of a storage battery system increases, there is a risk that the temperature will vary depending on the location of each storage battery module that constitutes the storage battery system, and the lifespan of the storage battery modules will vary. A storage battery module that has reached the end of its life during use must be replaced, or the entire storage battery system must be replaced if it is determined that the lifespan of the entire storage battery system has reached the end, even if there are healthy storage battery modules. Therefore, it is important to have a technology that extends the lifespan of the entire storage battery system by controlling the temperature within the storage battery system and controlling the lifespan of each storage battery module in the storage battery system to match each other.

[0004] As a technology for extending the life of a battery storage system, for example, the power storage system and temperature control method for the power storage system described in Patent Document 1 divides the inside of the power storage system into areas and determines whether to start or stop the fan for each area based on the temperature difference between the average temperatures of the areas, thereby maintaining a uniform temperature inside the power storage system. [Prior art documents] [Patent documents]

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2014-203536 Summary of the Invention Problems to be Solved by the Invention

[0006] In the temperature control method of the large-capacity power storage system disclosed in Patent Document 1, since the control of the fan is carried out based on the temperature difference of the average temperature of each area, a temperature distribution is generated due to the threshold value of the temperature difference, and it is difficult to match the lifetimes of the battery modules installed in each area due to the difference in the degree of deterioration between the battery modules caused by the generated temperature distribution.

[0007] In addition, in the air conditioner inside the power storage system, when the average temperature of each area is low (for example, a temperature of about 15°C), the battery modules in the area operating at normal temperature (for example, a temperature of 25°C) with less deterioration are cooled, which promotes deterioration and leads to a reduction in life. Furthermore, considering that the deterioration during operation at normal temperature is small as a characteristic of the battery, there is a problem that the battery modules in areas where cooling is not necessary, such as areas at normal temperature, are cooled, resulting in a decrease in the efficiency of the air conditioner.

[0008] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power storage system and a control method for a power storage system that enable highly efficient and long-term stable operation in a large-capacity power storage system. Means for Solving the Problems

[0009] The power storage system according to the present disclosure is a plurality of battery cells, a battery management unit that controls the plurality of battery cells, and a plurality of battery modules each having at least one or more temperature sensors, A control device that controls the plurality of storage battery modules via the battery management unit; an air conditioner that controls at least one of an air volume, an air direction, and an outlet temperature of air for each of the plurality of storage battery modules based on a target temperature set for each of the storage battery modules; The control device includes: a lifetime prediction unit that predicts a lifetime for each of the plurality of storage battery modules using a capacity of each of the plurality of storage battery modules and a temperature measured by the temperature sensor for each of the plurality of storage battery modules; a temperature control unit that calculates the target temperature for each of the plurality of storage battery modules so that a life span predicted by the life span prediction unit at a control start point for each of the plurality of storage battery modules becomes an average life span after the control start point, and transmits the target temperature to the air conditioner. 、 The temperature control unit has a control temperature determination unit, The control temperature determination unit calculates the target temperature for each of the storage battery modules, for a storage battery module having a lifespan shorter than the average value among the lifespans predicted for each of the storage battery modules at the control start point, such that the lifespan of the storage battery module having a lifespan shorter than the average value after the control start point matches the average value of the lifespan; or calculates the target temperature for each of the storage battery modules, for a storage battery module having a lifespan longer than the average value among the lifespans predicted for each of the storage battery modules at the control start point, such that the lifespan of the storage battery module having a lifespan longer than the average value after the control start point matches the average value of the lifespan. .

[0010] The control method for a storage battery system according to the present disclosure includes: A control method for a storage battery system including a plurality of storage battery cells, a battery management unit that controls the plurality of storage battery cells, and a plurality of storage battery modules each having at least one temperature sensor, comprising: acquiring a capacity of each of the plurality of storage battery modules via the battery management unit; measuring temperatures of the storage battery modules by at least one temperature sensor installed in each of the storage battery modules; predicting a lifetime of each of the plurality of storage battery modules using a capacity and a temperature of each of the plurality of storage battery modules; calculating a target temperature for each of the plurality of storage battery modules such that the lifetimes predicted for each of the plurality of storage battery modules are an average lifetime; and controlling at least one of an air volume, an air direction, and an outlet temperature of air blown by an air conditioner to each of the storage battery modules based on the target temperature; The target temperature is calculated for each of the plurality of storage battery modules, for a storage battery module having a lifespan shorter than the average value among the lifespans predicted for each of the plurality of storage battery modules at a control start point, such that the lifespan of the storage battery module having a lifespan shorter than the average value after the control start point matches the average value of the lifespan; or the target temperature is calculated for each of the plurality of storage battery modules, for a storage battery module having a lifespan longer than the average value among the lifespans predicted for each of the plurality of storage battery modules at a control start point, such that the lifespan of the storage battery module having a lifespan longer than the average value after the control start point matches the average value of the lifespan. . Effect of the Invention

[0011] According to the storage battery system and the control method for the storage battery system of the present disclosure, the lifespans of multiple storage battery modules installed in the storage battery system can be equalized, thereby making it possible to use the entire storage battery system until its original target lifespan. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic view of a storage battery system according to a first embodiment. [Diagram 2] 1 is a diagram illustrating a configuration of a storage battery system according to a first embodiment. [Diagram 3] 1 is a block diagram illustrating a configuration of a storage battery system according to a first embodiment. [Figure 4] 4 is a schematic diagram showing the amount of deterioration of storage deterioration and storage deterioration + cycle deterioration of a storage battery module in the storage battery system according to the first embodiment. FIG. [Diagram 5] 4 is a diagram showing changes in capacity of each storage battery module in the storage battery system according to the first embodiment. FIG. [Figure 6] 4 is a diagram illustrating correlation data between deterioration coefficients and temperatures of the storage battery modules in the storage battery system according to the first embodiment. FIG. [Figure 7] 6 is a diagram showing changes in capacity of each storage battery module when temperature distribution occurs in the storage battery system according to the first embodiment. FIG. [Figure 8] 1 is a diagram showing the relationship between the temperature distribution from the start of use time to the control start point and the deterioration amount of the storage battery module in the storage battery system according to embodiment 1. FIG. [Figure 9]4 is a diagram showing the relationship between the temperature distribution between control start points and the deterioration amount of the storage battery module in the storage battery system according to the first embodiment. FIG. [Figure 10] 4 is a diagram showing the relationship between the temperature distribution between control start points and the deterioration amount of the storage battery module in the storage battery system according to the first embodiment. FIG. [Figure 11] 4 is a diagram showing the relationship between the temperature distribution between control start points and the deterioration amount of the storage battery module in the storage battery system according to the first embodiment. FIG. [Figure 12] 10 is a diagram illustrating an example of a method for controlling the temperature of a storage battery module using the capacity of each storage battery module at a control start point in the storage battery system and the control method for the storage battery system according to the first embodiment. FIG. [Figure 13] 11 is a diagram showing changes in the capacity of a storage battery system and a storage battery module when a control method for a storage battery system according to a comparative example is applied. FIG. [Figure 14] 11 is a diagram showing changes in the capacity of a storage battery system and a storage battery module when a control method for a storage battery system according to a comparative example is applied. FIG. [Figure 15] 4 is a flowchart illustrating a control method for the storage battery system according to the first embodiment. [Figure 16] FIG. 13 is a diagram showing a temperature transition when control is applied and a comparative example. [Figure 17] 4 is a diagram showing control of the battery storage system according to embodiment 1 and transition of capacity when the control is applied. FIG. [Figure 18] 11A and 11B are diagrams illustrating a control according to a comparative example and a transition of capacity when the control is applied. [Figure 19] 4 is a diagram showing control of the battery storage system according to embodiment 1 and transition of capacity when the control is applied. FIG. [Figure 20] 11A and 11B are diagrams illustrating a control according to a comparative example and a transition of capacity when the control is applied. [Figure 21] 4 is a diagram showing control of the battery storage system according to embodiment 1 and transition of temperature when the control is applied. FIG. [Figure 22] 4 is a diagram showing the transition of power consumption of an air conditioner before and after application of the control method for the storage battery system according to the first embodiment. FIG. [Figure 23] It is a diagram showing an example of the hardware of the battery system according to Embodiment 1.

Embodiments for Carrying Out the Invention

[0013] Embodiment 1. <Configuration of the battery system according to Embodiment 1> FIG. 1 is an overview diagram of a battery system 100 according to Embodiment 1. The battery system 100 includes an air conditioner 101, a battery rack 102, a converter 103, a control device 104, a temperature sensor 105, and a signal line 106. The battery system 100 is housed, for example, in a housing 150.

[0014] The battery rack 102 stores a plurality of battery modules 201 inside. At least one of the plurality of battery modules 201 stored in the battery rack 102 is provided with a temperature sensor 105. Temperature sensors 105 may be provided for all of the battery modules 201 stored in the battery rack 102.

[0015] The temperature sensor 105 may be provided for each of the plurality of battery cells 203 that make up the battery module 201. In this case, the average value of the temperatures of the plurality of battery cells 203 measured for each battery cell 203 may be used as the temperature of the battery module 201. Also, one temperature sensor 105 may be provided inside the battery module 201, and the temperature measured by this temperature sensor 105 may be used as the temperature of the battery module 201.

[0016] The air conditioner 101 is an air conditioner capable of controlling the wind direction, air volume, and blowing temperature, and is controlled by the control device 104 via the signal line 106. That is, the wind direction, air volume, blowing temperature, etc. of the air blown from the air conditioner 101 are controlled according to the command of the control device 104.

[0017] The converter 103 may be an AC / DC converter that converts direct current into alternating current, or a DC / DC converter that converts the voltage of the battery rack into an arbitrary voltage.

[0018] 2 is a diagram illustrating a portion of the configuration of the storage battery system 100 according to the first embodiment. The storage battery rack 102 is configured so that a plurality of storage battery modules 201 are connected in series-parallel. Each of the plurality of storage battery modules 201 housed in the storage battery rack 102 is configured so that one battery management unit (BMU) 202 and a plurality of storage battery cells 203 are connected in series-parallel.

[0019] The storage battery cells 203 in the storage battery module 201 are, for example, chargeable and dischargeable secondary batteries. The storage battery cells 203 are composed of lithium ion batteries, nickel metal hydride batteries, lead storage batteries, or the like.

[0020] The BMU 202 has upper and lower voltage limits, maximum charge / discharge current, maximum cell temperature, etc. set for the purpose of preventing overcharging, over-discharging, overvoltage, overcurrent, temperature abnormalities, etc. of the storage battery cells 203, and has a function of protecting the storage battery cells 203, as well as a function of monitoring the status of the storage battery cells 203 and the storage battery module 201, such as measuring the voltage, current, and power of the storage battery cells 203, measuring the temperature of the storage battery module 201, managing full charge, and managing remaining capacity.

[0021] A battery rack 102 in which a plurality of battery modules 201 are installed is connected to a converter 103. Furthermore, the plurality of battery racks 102 are each connected to a load or a grid 500 via the converter 103.

[0022] 3 is a block diagram showing the configuration of the storage battery system 100 according to the first embodiment. The control device 104 includes a life prediction unit 301 and a temperature control unit 302. The life prediction unit 301 includes a capacity acquisition unit 303 that acquires the capacity of the storage battery module 201, and a life calculation unit 304 that estimates the life of the storage battery module 201 based on a change in the capacity over time.

[0023] The temperature control unit 302, which constitutes part of the control device 104, is composed of a target life determination unit 305 that determines a target life of the storage battery module 201, a data storage unit 306 that stores correlation data between the deterioration coefficient and temperature, and a control temperature determination unit 307 that determines a target temperature (also called a control temperature) based on the target life and the correlation between the deterioration coefficient and temperature.

[0024] The capacity acquisition unit 303 constituting a part of the life prediction unit 301 will be described below. The BMU 202 has a function of performing full charge management and remaining capacity management of the storage battery module 201, and therefore it is possible for the BMU 202 to acquire the capacity of the storage battery module 201. The BMU 202 can also calculate the capacity of the storage battery module 201, for example, by integrating a current value. The BMU 202 can calculate the capacity Q by applying the following formula (1) to integrate a current value I during charging from SOC 0% to SOC 100%.

[0025]

number

[0026] In formula (1), SOC (State Of Charge) is a parameter that indicates the state of charge of the storage battery, with SOC 0% indicating a discharged state and SOC 100% indicating a charged state.

[0027] In addition to calculating the capacity Q using the above formula (1), the BMU202 can also calculate the capacity Q at SOC100% based on the integrated value of the current value I when the SOC changes from SOCa% to SOCb% within a certain section by applying the following formula (2).

[0028]

number

[0029] The capacity acquisition unit 303 receives data on the capacity of each storage battery module 201 output from the BMU 202 provided in each storage battery module 201 , calculates the capacity of all storage battery modules 201 , and outputs it to the life calculation unit 304 .

[0030] The life calculation unit 304 will be described below. Various methods have been proposed for predicting the life of a storage battery module based on the capacity at the time of prediction. A general life prediction method will be described below. The capacity Q of a storage battery module is expressed as the time of use t w The prediction based on the root law is used and is expressed by the following equation (3).

[0031]

number

[0032] In equation (3), Q is the current capacity of the battery module, Q r is the rated capacity (initial capacity) of the battery module, k w is the degradation coefficient, t w indicates the usage time of the battery storage system.

[0033] The capacity of the storage battery system 100 at the end of its life is Q L , the life time is t we If we assume that the life time is t we is expressed by the following formula (4). L For example, if the lifespan is set to 60% deterioration of the initial capacity Qr, then Q L =0.6×Q r It becomes.

[0034]

number

[0035] Degradation coefficient k in equation (4) wis determined by the current applied to the storage battery module 201, the SOC range (settings of the charging voltage and discharging voltage), the temperature during use, etc. w A method to obtain the deterioration coefficient k in advance or during operation w There is a method to obtain the value and predict the life span.

[0036] Fig. 4 is a schematic diagram showing the amount of deterioration due to storage deterioration and storage deterioration + cycle deterioration in the storage battery module 201. Fig. 4 particularly shows the characteristics of the temperature and deterioration amount of the lithium ion battery. In the case of storage deterioration alone, as shown by the dotted line 401, the generation of by-products due to the decomposition reaction of the electrolyte inside the storage battery becomes smaller at lower temperatures and becomes larger at higher temperatures, which is characterized in that the amount of deterioration of the storage battery module 201 increases with increasing temperature.

[0037] On the other hand, when the charge / discharge cycle shown by the dotted line 402 is performed, deterioration occurs due to lithium metal precipitation, which is different from the generation of by-products due to the decomposition reaction of the electrolyte, and when the charge / discharge cycle is taken into consideration, the deterioration of the storage battery module 201 progresses even in a low temperature region. In order to reduce the deterioration of the storage battery module 201, it is desirable to use the storage battery module 201 by controlling its temperature within a temperature range in which the decomposition reaction of the electrolyte does not progress and a temperature range in which the deterioration is small and lithium metal precipitation does not occur, for example, within a range from temperature Tn to temperature Tn+1 in FIG. 4.

[0038] Fig. 5 is a diagram showing the transition of the capacity of each of the storage battery modules 201a, 201b, and 201c in the storage battery module 201 in the storage battery system 100 according to the first embodiment, when the horizontal axis represents the √ of the usage time of the storage battery module 201. In Fig. 5, a capacity transition line 501 represents the storage battery module 201a, a capacity transition line 502 represents the storage battery module 201b, and a capacity transition line 503 represents the storage battery module 201c. When the transition of the capacity is plotted against the √ of the usage time of the storage battery module 201, as shown in the above-mentioned formula (3), the storage battery module 201 has a deterioration coefficient k wThe degradation occurs linearly with a slope of . In the following description, the square root of time may be referred to as time for convenience.

[0039] Degradation factor K in Fig. 5 w1 represents the gradient of the capacity transition of the storage battery module 201a, and the deterioration coefficient K w2 represents the gradient of the capacity transition of the storage battery module 201b, and the deterioration coefficient K w3 represents the gradient of the capacity transition of the storage battery module 201c. That is, the gradient differs between the multiple storage battery modules 201 depending on the temperature and conditions of use.

[0040] The storage battery module 201a is used under the condition of temperature T1, and the deterioration coefficient K w1 The degradation progresses with a slope of Q r decreases over time. When the usage time of the storage battery module 201a becomes x, the capacity Q L It is predicted that the life of the storage battery module 201a defined by

[0041] The storage battery module 201b is used under the condition of temperature T2, and the deterioration coefficient K w2 The degradation progresses with a slope of Q r decreases over time. When the usage time of the storage battery module 201b becomes y, the capacity Q L It is predicted that the life of the storage battery module 201b defined by is reached.

[0042] The storage battery module 201c is used under the condition of temperature T3, and the deterioration coefficient K w3 The degradation progresses with a slope of Q r decreases over time. When the usage time of the storage battery module 201c becomes z, the capacity Q L It is predicted that the life of the storage battery module 201c defined by is reached.

[0043] The temperatures T1, T2, and T3 have the relationship of T1 < T3 < T2, and it can be seen from FIG. 5 that the use of the battery module 201c at the temperature T3 in the intermediate region has the tendency of the least deterioration.

[0044] The target life determination unit 305 will be described with reference to FIG. 5. Regarding the target life, among the battery modules 201a, 201b, and 201c installed in the battery system 100, for example, the most average life (hereinafter referred to as the average life L ave ), the life prediction result (indicated by the time x in FIG. 5) of the battery module 201a is set as the target life L. The average life L ave may coincide with the target life L of the battery system 100 itself, but it is desirable that it is equal to or greater than the target life L of the battery system 100 itself. When setting the average life L ave as the target life L, it is desirable to control the deterioration coefficient so that the target life L can be achieved by temperature control based on the predicted lives, i.e., the times x, y, and z, of the respective battery modules 201a, 201b, and 201c.

[0045] FIG. 6 is a diagram showing the correlation data between the deterioration coefficient k wn of the battery module 201 in the battery system 100 according to Embodiment 1 and the temperature. The deterioration coefficient k wn is determined by the current applied to the battery module 201, the range of SOC, that is, the setting of the charging voltage and the discharging voltage, and the temperature during the use of the battery module 201. Regarding the deterioration coefficient k wn , there are methods of obtaining it in advance, or methods of estimating it based on data such as the capacity and temperature obtained during operation. Furthermore, there are also methods of conducting life tests at each temperature in advance to obtain the deterioration coefficient k wn , and methods of predicting in each temperature range by the Arrhenius equation. In the battery system 100 according to Embodiment 1, any of the above methods may be used to obtain the deterioration coefficient k wn .

[0046] As a method of obtaining the deterioration coefficient k w , as shown in FIG. 6, the deterioration coefficient k for each temperaturew , and set the target temperature of the storage battery module 201 to obtain the deterioration coefficient k wn In the Arrhenius method, when there are three or more points of temperature measurement data, the deterioration coefficient k wn This leads to improved accuracy. wn The Arrhenius equation required to calculate is shown in the following equation (5).

[0047]

number

[0048] In equation (5), A is a constant, Ea is the activation energy, R is the gas constant, and Tn is the absolute temperature. The degradation coefficient k measured under a certain temperature condition wn Based on the measurement data, the degradation factor k of other temperatures wn In the following explanation, it is possible to predict the degradation coefficient k wn and temperature correlation data are used.

[0049] Next, a description will be given of the control temperature determination unit 307 which constitutes a part of the temperature control unit 302. The control temperature determination unit 307 determines the deterioration coefficient k wn Based on the correlation data between the temperature of the storage battery module 201 and the temperature of the storage battery module 201, a deterioration coefficient k wn In order to control the temperature of each storage battery module 201 so as to satisfy the above condition, the target temperature of each storage battery module 201 is determined individually.

[0050] The longest life span (hereinafter, the longest life span L max ) and the battery module 201c with the shortest life (hereinafter, the shortest life L min The temperature of each of the storage battery modules 201a, 201b, and 201c is controlled by the air conditioner 101, including the storage battery module 201b having a battery module 201a having a battery module 201b having a battery module 201c ...c having a battery module 201 aveIf the order of the lifespans of the storage battery modules 201a, 201b, and 201c in the storage battery system 100 is changed as a result of such temperature control, the storage battery module to be controlled is changed accordingly.

[0051] In addition, when the number of storage battery modules 201 is more than three, the control temperature determination unit 307 determines the average life L ave For a battery module with a lifespan longer than ave The life of a storage battery module that has a lifespan longer than the average lifespan L ave The target temperature for each of the battery modules can be calculated so that it matches the target lifespan such as the average lifespan L ave For a battery module with a lifespan shorter than ave The life of a storage battery module having a life shorter than the average life L ave A target temperature may be calculated for each of the multiple battery modules so as to match the target life span.

[0052] <Control method of storage battery system according to embodiment 1> A method for controlling the battery system according to the first embodiment, that is, a method for determining a control temperature and a method for matching the lives of the battery modules, will be described below. Fig. 7 is a diagram showing changes in capacity versus usage time in each of the storage battery modules 201a, 201b, and 201c when temperature distribution occurs in the storage battery system 100 according to embodiment 1. Fig. 7 shows changes in capacity versus usage time √ of each of the storage battery modules 201a, 201b, and 201c when the storage battery module 201a is operated at temperature T1, the storage battery module 201b at temperature T2, and the storage battery module 201c at temperature T3 from zero usage time to a control start point t1.

[0053] Between the zero usage time and the control start point t1 in FIG. 7, the capacity transition line 701 represents the battery module 201a, the capacity transition line 702 represents the battery module 201b, and the capacity transition line 703 represents the battery module 201c, respectively.

[0054] From the zero usage time to the control start point t1, since it is operating without temperature control, a temperature distribution occurs within the battery system 100. Assume the temperatures during operation of each battery module 201a, 201b, 201c are T1(201a), T2(201b), and T3(201c), respectively. Due to the influence of the temperature distribution, the degradation coefficients of each battery module 201a, 201b, 201c are respectively K w1 、K w2 、K w3 and are different from each other. That is, it represents a situation where the degradation rates are different among the battery modules 201a, 201b, 201c. Assume the magnitude relationship of the temperatures is T1 < T3 < T2.

[0055] From the control start point t1, the control method of the battery system according to Embodiment 1 is implemented. The battery module 201b has a high usage temperature of T2 and thus a high degradation rate as shown by the capacity transition line 702 from the zero usage time to the control start point t1, that is, the degradation coefficient K w2 is large. Therefore, after the control start point t1, in order to suppress the degradation of the battery module 201b, that is, to reduce the degradation coefficient, the temperature of the battery module 201b is decreased by temperature control with the air conditioner 101.

[0056] As a result of the temperature control for the battery module 201b, the degradation rate becomes slower from the capacity transition line 702 to the capacity transition line 704 between the control start point t1 and the control start point t2. With further temperature control for the battery module 201b, the degradation rate becomes even slower to the capacity transition line 706 between the control start point t2 and the control start point t3, and to the capacity transition line 708 after the control start point t3, and the battery module 201b reaches the time x when it reaches the capacity Q L that defines its lifespan.

[0057] As a result of the temperature control of the storage battery module 201c, the deterioration rate increases from the capacity change line 703 to the capacity change line 705 between the control start point t1 and the control start point t2. Further temperature control of the storage battery module 201c further increases the deterioration rate to the capacity change line 707 between the control start point t2 and the control start point t3, and to the capacity change line 709 after the control start point t3. As a result, the capacity Q L Then, time x is reached where

[0058] In the storage battery module 201a, the operating temperature is T1 from zero usage time to the control start point t1, and the deterioration coefficient K w1 The degradation factor K w1 When the life of the storage battery module 201a is predicted based on L Since the time x at which the temperature T1 is reached is reached, no particular temperature control is performed on the storage battery module 201a, or temperature control is performed using the air conditioner 101 to maintain the operating temperature at T1.

[0059] At any control point such as the control start points t1, t2, and t3 shown in FIG. 7, the lifespan of each storage battery module is predicted, and the direction of temperature control for each storage battery module, whether to increase or decrease the temperature of the storage battery module, is determined, thereby making it possible to reduce the difference in lifespan between each storage battery module.

[0060] 8 to 11 are diagrams showing the relationship between the temperature distribution up to each control start point t1, t2, and t3 in the storage battery system 100 according to the first embodiment and the deterioration amount of each storage battery module.

[0061] FIG. 8 is a diagram showing the relationship between the temperature distribution from the start of the usage time of each battery module 201a, 201b, 201c to the control start point t1 and the amount of deterioration of each battery module. From the deterioration curves shown in FIG. 8, between the start of the usage time and the control start point t1, the temperature T2 of the battery module 201b is the highest, and the temperature T3 of the battery module 201c is expected to be in the middle temperature range, for example, within the range of 20 to 30°C. Also, the temperature T1 of the battery module 201a is expected to be the lowest. That is, the relationship of each temperature is T1 < T3 < T2.

[0062] From FIG. 8, the magnitude relationship of the amount of deterioration among the battery modules 201a, 201b, 201c up to the control start point t1 is battery module 201b > battery module 201a > battery module 201c. In order to match the lifetimes among the battery modules, temperature control is performed to increase or decrease the temperature of the battery module 201c and to decrease the temperature of the battery module 201b.

[0063] FIG. 9 is a diagram showing the relationship between the temperature distribution from the control start point t1 to the control start point t2 in the battery system 100 according to Embodiment 1 and the amount of deterioration of each battery module. From the deterioration curves shown in FIG. 9, between the control start point t1 and the control start point t2, the temperature T2' of the battery module 201b is the highest, the temperature T3' of the battery module 201c is slightly higher than the middle temperature range, and the temperature T1 of the battery module 201a is expected to be the lowest. However, the temperature difference between the temperature T2' and the temperature T3' is smaller than the temperature difference between the temperature T1 and the temperature T3'.

[0064] The reason why the temperature of the battery module 201b decreased from the temperature T2 from the start of the usage time to the control start point t1 to the temperature T2' after the control start point t1 is that at the control start point t1, based on the command from the temperature control unit 302, the air conditioner 101 controls the wind direction, air volume, blowing temperature, etc. of the wind blowing to the battery module 201b, so that the battery module 201b is cooled and the temperature decreased from the temperature T2 before the control start to the temperature T2' after the control start.

[0065] The temperature of the storage battery module 201c rises from temperature T3 from the start of usage time to control start point t1 to temperature T3' after control start point t1 because, at control start point t1, the temperature of the storage battery module 201c rises as a result of the air conditioner 101 controlling the wind direction, air volume, blowing temperature, etc. of the air blown to the storage battery module 201c based on instructions from the temperature control unit 302.

[0066] Fig. 10 is a diagram showing the relationship between the temperature distribution between control start point t2 and control start point t3 and the deterioration amount of the storage battery modules in the storage battery system 100 according to the first embodiment. From the deterioration curves shown in Fig. 10, it is expected that the temperature T2'' of the storage battery module 201b is the highest between control start point t2 and control start point t3, and the temperature T3'' of the storage battery module 201c is in the intermediate temperature range or slightly higher. Also, the temperature T1 of the storage battery module 201a is expected to be the lowest.

[0067] The temperature of the storage battery module 201b further drops from temperature T2' from control start point t1 to control start point t2 to temperature T2'' after control start point t2 because, at control start point t2, the air conditioner 101 adjusts the direction, volume, and outlet temperature of the air blown to the storage battery module 201b based on instructions from the temperature control unit 302, thereby further cooling the storage battery module 201b.

[0068] The temperature of the storage battery module 201c further changed from temperature T3' from control start point t1 to control start point t2 to temperature T3'' after control start point t2 because, at control start point t2, the temperature of the storage battery module 201c further increased as a result of the air conditioner 101 adjusting the wind direction, air volume, and blowing temperature of the air blown to the storage battery module 201c based on instructions from the temperature control unit 302.

[0069] Fig. 11 is a diagram showing the relationship between the temperature distribution and the deterioration amount of the storage battery modules from the control start point t3 to the time x which is the life end time in the storage battery system 100 according to embodiment 1. From the deterioration curves shown in Fig. 11, it is expected that from the control start point t3 to the time x which is the life end time, the temperature T2''' of the storage battery module 201b is the highest, and the temperature T3''' of the storage battery module 201c is in the intermediate temperature range or slightly higher.

[0070] The reason why the temperature of the storage battery module 201b further drops from temperature T2'' from control start point t2 to control start point t3 to temperature T2''' after control start point t3 is because at control start point t3, the air conditioner 101 adjusts the direction, volume, and outlet temperature of the air blown to the storage battery module 201b based on a command from temperature control unit 302, thereby further cooling the storage battery module 201b. As a result of the temperature control of the storage battery module 201b, the temperature difference between temperature T2''' of storage battery module 201b and temperature T3''' of storage battery module 201c becomes even smaller.

[0071] The temperature of the storage battery module 201c changed from temperature T3'' from control start point t2 to control start point t3 to temperature T3''' after control start point t3 because, at control start point t3, the air conditioner 101 adjusts the wind direction, air volume, and blowing temperature of the air blown to the storage battery module 201c based on instructions from the temperature control unit 302, thereby further reducing the temperature difference between temperature T3'''' of the storage battery module 201c and temperature T2'''' of the storage battery module 201b.

[0072] As described above, in the control method for the storage battery system of embodiment 1, the lifetime of each storage battery module 201a, 201b, and 201c is predicted at each control start point t1, t2, and t3, and the target temperature of each storage battery module 201a, 201b, and 201c is determined individually.

[0073] In the above description, as a control method of the battery system according to Embodiment 1, the temperatures of both the battery modules 201b and 201c are controlled. However, since the temperature of the battery module 201c can be controlled in both the rising and falling directions, while controlling the temperature of the battery module 201b, the temperature of the battery module 201c may not be controlled, and it may be temperature control accompanying the control of the battery module 201b. If only the temperature of the battery module 201b is controlled, the load on the air conditioner 101 will be reduced, and thus a further improvement in the efficiency of the air conditioner 101 can be expected.

[0074] FIG. 12 is a diagram showing an example of a method of individually controlling the temperature of each battery module using the capacity of each battery module at the control start point in the battery system 100 and the control method of the battery system according to Embodiment 1.

[0075] At the control start point t, when the capacities of the battery modules 201a, 201b, and 201c are determined to be the capacities Q La , Q Lb , Q Lc , respectively, the degradation coefficient k wm is calculated by the following formula (6).

[0076]

Equation

[0077] In formula (6), the degradation coefficient k wm is the degradation coefficient of the battery module to be calculated, Q Ln is the capacity at the control start point of the battery module to be controlled, Q Lb is the capacity at the control start point of the battery module serving as the reference for the degradation coefficient k w1 , Q e is the capacity at the end of life, and the degradation coefficient k w1 is the degradation coefficient of the reference battery module. That is, the control temperature determination unit 307 uses formula (6) to calculate the capacity Q Ln at the control start point of the battery module to be controlled and the capacity Q e of the target lifeThe difference value and the degradation coefficient k w1 The capacity Q of the battery module that serves as the reference for the control start point Lb and the target life capacity Q Ln The deterioration coefficient k of the storage battery module to be controlled is calculated based on the ratio of the difference between the wm The target temperature is determined by calculating

[0078] The deterioration coefficient k stored in the data storage unit 306 of the temperature control unit 302 shown in FIG. wn Based on the correlation data between the temperature of the storage battery module 201 and the temperature of the storage battery module 201, the target life determination unit 305 of the temperature control unit 302 determines the deterioration coefficient k w1 , k w2 , k w3 The target life is determined by referring to the above.

[0079] Control temperature determination unit 307 of temperature control unit 302 sets a target temperature for each storage battery module to be controlled. Control temperature determination unit 307 outputs the set target temperature to air conditioner 101, and air conditioner 101 adopts the target temperature as a control target value.

[0080] 13 and 14 are diagrams illustrating temperature control of the storage battery modules 201a, 201b, and 201c. Before the start of control by the control method for the storage battery system according to the first embodiment, it is assumed that the storage battery modules 201a, 201b, and 201c are operating at temperatures T1, T2, and T3, respectively. The control device 104 of the storage battery system 100 predicts deterioration of each of the storage battery modules 201a, 201b, and 201c, and determines a target temperature for each storage battery module.

[0081] 13, since the temperatures before the start of control have a relationship of T2>T3>T1, the control device 104 determines that it is necessary to perform temperature control of the storage battery module 201b and the storage battery module 201c. Based on the results of the prediction of the lifetimes of the storage battery modules 201a, 201b, and 201c by the lifetime calculation unit 304, the control device 104 determines that it is necessary to control the temperature of the storage battery module 201b to a temperature T2' that is lower than the temperature T2 before the control start point t, as shown in FIG.

[0082] On the other hand, the control device 104 determines that the temperature of the storage battery module 201c needs to be controlled to a temperature higher or lower than the temperature T3 before the control start point. In the example shown in Fig. 14, the control device 104 determines that the temperature of the storage battery module 201c needs to be controlled to a temperature higher than the temperature T3.

[0083] To summarize the above, at control start point t, the temperature of storage battery module 201b is controlled to the lower temperature side and the temperature of storage battery module 201c is controlled to the higher temperature side by controlling the air direction, air volume, and blowing temperature of air conditioner 101 based on a command from temperature control unit 302. As a result of the temperature control, the temperature difference between temperature T1 of storage battery module 201a and temperature T2' of storage battery module 201b after control starts is controlled to decrease, while the temperature difference between temperature T1 of storage battery module 201a and temperature T3' of storage battery module 201c after control starts is controlled to increase.

[0084] In the above description, an example has been given in which the air conditioner 101 controls the temperature of each storage battery module 201 individually, but temperature control may also be performed separately for each storage battery area. When controlling the temperature for each storage battery area, a method of controlling the temperature may be used in which the average temperature, which is the average value of the temperatures of the storage battery modules installed in the storage battery area, or the temperature of the storage battery module that represents the storage battery area is used as the standard.

[0085] As shown in FIG. 12, before the control start point t, the storage battery module 201a has a deterioration coefficient k w1The storage battery module 201b has a deterioration coefficient k along a capacity transition line 901 having a slope of w2 The deterioration coefficient k w3 However, after the control start point t, as a result of the above-mentioned temperature control being performed, the capacity of the storage battery module 201a decreased with a deterioration coefficient k w1 While maintaining the above, the deterioration coefficient k' of the storage battery module 201b continues to change along the capacity transition line 901. w2 The deterioration coefficient k' of the storage battery module 201c is along a capacity transition line 904 having a slope of w3 12 , control start point capacity 906 represents the capacity of storage battery module 201a at control start point t, control start point capacity 907 represents the capacity of storage battery module 201b at control start point t, and control start point capacity 908 represents the capacity of storage battery module 201c at control start point t.

[0086] After the control start point t, the deterioration rates of the storage battery modules 201b and 201c are adjusted by temperature control, and as a result, all of the storage battery modules 201a, 201b, and 201c reach the capacity Q L In other words, the lifespan of each of the storage battery modules 201a, 201b, and 201c coincides with the time x.

[0087] In the above description, the temperature of the storage battery module 201c is controlled to increase. The temperature control value (target temperature) may be set to a lower temperature to accelerate deterioration.

[0088] In the above description, an example has been shown in which both the temperature T2 of the storage battery module 201b and the temperature T3 of the storage battery module 201c are controlled. However, since the temperature T3 of the storage battery module 201c can be controlled in both directions, that is, to increase or decrease, it is also possible to control only the temperature of the storage battery module 201b and not the temperature of the storage battery module 201c, and to perform temperature control in conjunction with the control of the storage battery module 201b. This is because, if only the temperature T2 of the storage battery module 201b is controlled, the load on the air conditioner 101 is reduced, and further improvement in the efficiency of the air conditioner can be expected.

[0089] When the target temperature for each storage battery module 201 has been determined, the control device 104 sends a command to the air conditioner 101 to control the airflow direction, airflow volume, and outlet temperature of the air for each storage battery module 201. When the air conditioner 101 is operated such that the airflow direction before control is θ0, the airflow volume is W0, and the outlet temperature is T0, and when the airflow direction after control is controlled to θ0+Δθ, the airflow volume is W0+ΔW, and the outlet temperature is T0+ΔT, it is sufficient if the target temperatures of the storage battery modules 201 each shift toward the individually set control target values.

[0090] In the above description, temperature control by the air conditioner 101 is performed by changing all of the parameters of the airflow direction, airflow volume, and outlet temperature. However, as long as the target temperature of the storage battery module 201 shifts to the individually set control target side, at least one or more parameters of the airflow direction, airflow volume, and outlet temperature may be changed. For example, the temperature of each storage battery module 201 may be controlled only by the airflow volume of the air conditioner 101.

[0091] <Control method of storage battery system according to embodiment 1> A control flow in the control method for the storage battery system according to the first embodiment will be described with reference to the flowchart shown in FIG.

[0092] In step S101, control is started using the control method for the storage battery system according to embodiment 1. The capacity acquisition unit 303 in the control device 104 acquires the capacity of each storage battery module 201 output from the BMU 202 provided for each storage battery module 201 in the storage battery system 100.

[0093] In step S102, the life calculation unit 304 in the control device 104 analyzes the acquired capacity of each storage battery module 201 in time series, and calculates the life of each storage battery module 201.

[0094] In step S103, the target lifespan determination unit 305 in the control device 104 calculates an average lifespan L ave A target life span is determined for matching the life span of another storage battery module 201 with the storage battery module having the life span closest to that of the other storage battery module 201.

[0095] In step S104, the deterioration coefficient k stored in the data storage unit 306 in the control device 104 is w Refer to the correlation data for temperature.

[0096] In step S105, the control temperature determination unit 307 in the control device 104 determines a target temperature for each storage battery module 201.

[0097] In step S106, the control temperature determination unit 307 in the control device 104 transmits an air conditioner control command based on the target temperature to the air conditioner 101 via the signal line 106. Note that the air conditioner control command may be transmitted by wireless communication instead of via the signal line 106.

[0098] In step S107, the control device 104 determines whether the temperature of each storage battery module 201 has transitioned to the target temperature for each storage battery module 201 individually. If the transition to the target temperature has been completed in each storage battery module 201, that is, if the answer is YES in step S107, the control ends. On the other hand, if the transition to the target temperature has not been completed, that is, if the answer is NO in step S107, the process returns to step S106 and the air conditioner control continues. The above are the operations of the storage battery system control method according to the first embodiment.

[0099] 16 and 17 are diagrams respectively showing the capacity transitions of a storage battery system and each storage battery module of a comparative example and the capacity transitions of a storage battery system and each storage battery module when the control method for the storage battery system according to embodiment 1 is applied. Note that, as a comparative example, the capacity transitions are shown when the control method for the storage battery system according to embodiment 1 is not applied.

[0100] Fig. 16 is a diagram showing the transition of the capacity of each storage battery module in a comparative example. When the control method of the storage battery system according to the first embodiment is not applied, the deterioration rate differs between the storage battery modules due to the influence of the temperature distribution in the storage battery system, and as a result, the life of the entire storage battery system is limited to the storage battery module with the shortest life, resulting in a shortened life of the entire storage battery system. A specific description will be given below with reference to Fig. 16.

[0101] The changes in capacity over time of the storage battery modules 201a, 201b, and 201c are indicated by capacity change lines 1401, 1402, and 1403, respectively, in Fig. 16. The storage battery module 201a deteriorates over time along the capacity change line 1401 and reaches the end of its life at time z. The storage battery module 201b deteriorates over time along the capacity change line 1402 and reaches the end of its life at time x. The storage battery module 201c deteriorates over time along the capacity change line 1403 and reaches the end of its life at time y.

[0102] In other words, the deterioration coefficient kw is the largest, and the deterioration coefficient k w is the smallest. Therefore, the magnitude relationship between times x, y, and z at which each storage battery module reaches its life is z>x>y. That is, the storage battery module 201c reaches its life the fastest. The life of the entire storage battery system formed of multiple storage battery modules 201 is determined by the storage battery module that reaches its life the fastest. That is, in the above example, the time y of the storage battery module 201c is the life of the entire storage battery system according to the comparative example.

[0103] Fig. 17 is a diagram showing changes in capacity of each storage battery module 201 in the storage battery system 100 according to the first embodiment. When the control method for the storage battery system according to the first embodiment is applied, the deterioration rates differ among the storage battery modules 201 due to the influence of the temperature distribution in the storage battery system before the control start point, but after the control start point, the lifespan of each of the storage battery modules 201a, 201b, and 201c matches the time x, and therefore the lifespan of the entire storage battery system 100 increases. This will be specifically described below with reference to Fig. 17.

[0104] The changes in capacity over time of the storage battery modules 201a, 201b, and 201c are shown by capacity change lines 1407, 1406, and 1405 in Fig. 17, respectively. The storage battery module 201a deteriorates over time along the capacity change line 1407 before the control start point, but the degree of deterioration is relatively small. The storage battery module 201b deteriorates over time along the capacity change line 1406 after the control start point, with a constant deterioration coefficient k w The battery module 201c deteriorates with time along the capacity transition line 1405 before the control start point, but the degree of deterioration is large.

[0105] In other words, before the control start point, the deterioration coefficient k w is the largest, and the deterioration coefficient k wTherefore, it is predicted that the storage battery module 201c will reach the end of its life the fastest. After the control start point, the controller 104 controls the temperature of the air conditioner 101 to reduce the deterioration coefficient k w In addition, the deterioration coefficient k of the storage battery module 201c is increased. w As a result, the lifespan of each of the storage battery modules 201a, 201b, and 201c coincides with the time x.

[0106] In other words, by applying the control method for the storage battery system according to the first embodiment, it is possible to equalize the deterioration rate of each storage battery module, and as a result, it is possible to equalize the life span of each storage battery module. Equalizing the life span of each storage battery module leads to a longer life span of the storage battery system itself. Note that "equalizing the life span" in the control method for the storage battery system according to the first embodiment means, for example, shortening the average life span L of the storage battery modules 201 constituting the storage battery system 100. ave The lifespan of each battery module is the average lifespan L ave This means that the temperature is controlled within a range of ±5%.

[0107] 18 and 19 are diagrams respectively showing the transition of capacity of the entire battery system of the comparative example and the transition of capacity of the entire battery system when the control method for the battery system according to embodiment 1 is applied. Note that, as the comparative example, the transition of capacity is shown when the control method for the battery system according to embodiment 1 is not applied.

[0108] As shown in Fig. 18, the lifetime of the entire storage battery system of the comparative example is determined by time y, which is the lifetime of storage battery module 201c constituting the storage battery system shown in Fig. 16. In other words, the lifetime of the entire storage battery system of the comparative example is determined by time y, which is the lifetime of storage battery module 201c, which has the shortest lifetime in the storage battery system according to the comparative example.

[0109] On the other hand, the life of the storage battery system 100 according to the first embodiment, indicated by the capacity transition line 1408 in Fig. 19, is determined by the time x which is the life of all the storage battery modules 201 determined after the start of control. That is, it is possible to reach a life of time x which is longer than the time y which is the life of the entire storage battery system of the comparative example, indicated by the capacity transition line 1404 in Fig. 19.

[0110] 20 and 21 are diagrams respectively showing temperature transitions due to temperature control in a comparative example and temperature transitions due to temperature control when applying the control method for the storage battery system according to embodiment 1. In the control of the storage battery system in the comparative example shown in Fig. 20, in order to make the temperature in the storage battery system uniform, the storage battery module with a higher temperature is cooled by setting a target temperature (the temperature of the storage battery module on the lower temperature side in Fig. 20) as a control target.

[0111] On the other hand, in the control method for the storage battery system according to the first embodiment, as shown in Fig. 21, since the control goal is to match the life spans of the storage battery modules 201, there is no need to equalize the temperatures of the storage battery modules 201. Therefore, in cooling the storage battery modules 201, it is possible to set a higher temperature as a local target temperature than in the control according to the comparative example.

[0112] In addition, in the control method for the storage battery system according to the first embodiment, while some storage battery modules 201 are heated depending on the results of life prediction, other storage battery modules 201 are automatically heated depending on the control of the airflow direction, air volume, and outlet temperature of the air conditioner 101, and therefore it is not necessary to implement temperature control for such storage battery modules 201. As a result, as shown in Fig. 22, the power consumption of the air conditioner 101 can be suppressed, which has the effect of contributing to high efficiency of the entire storage battery system 100.

[0113] <Advantages of the First Embodiment> According to the storage battery system and the control method for the storage battery system of the first embodiment, the lives of the multiple storage battery modules installed in the storage battery system can be equalized, so that the entire storage battery system can be used until its original target lifespan. In addition, since it is not necessary to uniformly control the temperature of each storage battery module to an average temperature, it is possible to prevent each storage battery module from being excessively cooled, and as a result, the efficiency of the air conditioner is improved.

[0114] In the configuration of the storage battery system 100 according to the above-mentioned first embodiment, the storage battery system 100 has been described as functional blocks, but an example of a configuration as hardware that stores the storage battery system 100 is shown in Fig. 23. The hardware 800 includes a processor 801 and a storage device 802. Although not shown, the storage device 802 includes a volatile storage device such as a random access memory, and a non-volatile auxiliary storage device such as a flash memory.

[0115] Also, a hard disk auxiliary storage device may be provided instead of a flash memory. The processor 801 executes a program input from the storage device 802. In this case, the program is input from the auxiliary storage device to the processor 801 via a volatile storage device. The processor 801 may output data such as a calculation result to a volatile storage device of the storage device 802, or may store the data in the auxiliary storage device via the volatile storage device.

[0116] Although the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.

[0117] Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed in the present specification. For example, when modifying, adding, or omitting at least one component, or even when extracting at least one component and combining it with components of other embodiments shall be included.

Explanation of Reference Numerals

[0118] 100 Battery system, 101 Air conditioner, 102 Battery rack, 103 Converter, 104 Control device, 105 Temperature sensor, 106 Signal line, 150 Housing, 201, 201a, 201b, 201c Battery module, 202 BMU, 203 Battery cell, 301 Life prediction unit, 302 Temperature control unit, 303 Capacity acquisition unit, 304 Life calculation unit, 305 Target life determination unit, 306 Data storage unit, 307 Control temperature determination unit, 401, 402 Dashed lines, 501, 502, 503, 701, 702, 703, 704, 705, 706, 707, 708, 709, 901, 902, 903, 904, 905, 1401, 1402, 1403, 1404, 1405, 1406, 1407, 1408 Capacity transition lines, 800 Hardware, 801 Processor, 802 Storage device, 906, 907, 908 Control start point capacity

Claims

1. a plurality of storage battery modules each including a plurality of storage battery cells, a battery management unit that controls the plurality of storage battery cells, and at least one temperature sensor; A control device that controls the plurality of storage battery modules via the battery management unit; an air conditioner that controls at least one of an air volume, an air direction, and an outlet temperature of air for each of the plurality of storage battery modules based on a target temperature set for each of the storage battery modules; The control device includes: a lifetime prediction unit that predicts a lifetime for each of the plurality of storage battery modules using a capacity of each of the plurality of storage battery modules and a temperature measured by the temperature sensor for each of the plurality of storage battery modules; a temperature control unit that calculates the target temperature for each of the plurality of storage battery modules so that a life span predicted by the life span prediction unit at a control start point for each of the plurality of storage battery modules becomes an average life span after the control start point, and transmits the target temperature to the air conditioner; The temperature control unit has a control temperature determination unit, the control temperature determination unit calculates the target temperature for each of the plurality of storage battery modules, for a storage battery module having a lifespan shorter than the average value among the lifespans predicted for each of the plurality of storage battery modules at the control start point, so that the lifespan of the storage battery module having a lifespan shorter than the average value after the control start point matches the average value of the lifespan; or calculates the target temperature for each of the plurality of storage battery modules, for a storage battery module having a lifespan longer than the average value among the lifespans predicted for each of the plurality of storage battery modules at the control start point, so that the lifespan of the storage battery module having a lifespan longer than the average value after the control start point matches the average value of the lifespan.

2. The battery management unit measures the capacity of the storage battery module, The storage battery system according to claim 1, characterized in that the life prediction unit predicts the life for each of the plurality of storage battery modules based on a deterioration coefficient expressed by a slope of the change in capacity versus the square root of usage time, using data on change in capacity of the storage battery module.

3. The storage battery system according to claim 2, characterized in that the control temperature determination unit calculates the deterioration rate of the storage battery module to be controlled based on a ratio between a difference value between a capacity at a control start point and a target life of the storage battery module to be controlled, and a difference value between a capacity at a control start point and a target life of the storage battery module that is a reference for the deterioration coefficient, and determines the target temperature.

4. The storage battery system according to any one of claims 1 to 3, characterized in that the temperature sensor is provided for each of a plurality of storage battery cells that constitute the storage battery module, and the average value of the temperatures of the plurality of storage battery cells measured for each storage battery cell is set as the temperature of the storage battery module.

5. The storage battery system according to any one of claims 1 to 3, characterized in that one temperature sensor is provided within the storage battery module, and the temperature measured by the temperature sensor is regarded as the temperature of the storage battery module.

6. The storage battery system according to claim 1 , further comprising a converter connected to the battery management unit.

7. 4. The storage battery system according to claim 1, wherein the battery management unit measures a current value of the storage battery cell.

8. A control method for a storage battery system including a plurality of storage battery cells, a battery management unit that controls the plurality of storage battery cells, and a plurality of storage battery modules each having at least one temperature sensor, comprising: acquiring a capacity of each of the plurality of storage battery modules via the battery management unit; measuring temperatures of the storage battery modules by at least one temperature sensor installed in each of the storage battery modules; predicting a lifetime of each of the plurality of storage battery modules using a capacity and a temperature of each of the plurality of storage battery modules; calculating a target temperature for each of the plurality of storage battery modules such that the lifetimes predicted for each of the plurality of storage battery modules are an average lifetime; and controlling at least one of an air volume, an air direction, and an outlet temperature of air blown by an air conditioner to each of the storage battery modules based on the target temperature; a control method for a battery system, characterized in that the target temperature is calculated for each of the plurality of storage battery modules, for a storage battery module having a lifespan shorter than the average value among the lifespans predicted for each of the plurality of storage battery modules at the control start point, such that the lifespan of the storage battery module having a lifespan shorter than the average value after the control start point matches the average value of the lifespan; or the target temperature is calculated for each of the plurality of storage battery modules, for a storage battery module having a lifespan longer than the average value among the lifespans predicted for each of the plurality of storage battery modules at the control start point, such that the lifespan of the storage battery module having a lifespan longer than the average value after the control start point matches the average value of the lifespan.

9. A control method for a storage battery system including a plurality of storage battery cells, a battery management unit that controls the plurality of storage battery cells, and a plurality of storage battery modules each having at least one temperature sensor, comprising: acquiring a capacity of each of the plurality of storage battery modules via the battery management unit; measuring temperatures of the storage battery modules by at least one temperature sensor installed in each of the storage battery modules; predicting a lifetime of each of the plurality of storage battery modules using a capacity and a temperature of each of the plurality of storage battery modules; a step of calculating a deterioration rate of the storage battery module to be controlled and determining a target temperature for each of the plurality of storage battery modules based on a ratio between a difference value between a capacity at a control start point and a target life of the storage battery module to be controlled and a difference value between a capacity at a control start point and a target life of the storage battery module serving as a reference for the deterioration coefficient, using data on the change in capacity of the storage battery module measured by the battery management unit, so that the life predicted for each of the plurality of storage battery modules becomes an average life based on a deterioration coefficient expressed by a slope of the change in capacity with respect to a square root of usage time; controlling at least one of an air volume, an air direction, and an outlet temperature of air blown by an air conditioner to each of the storage battery modules based on the target temperature; A control method for a storage battery system comprising:

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