Battery Management System

Abstract

To provide a battery management system in which variations in input / output characteristics among batteries of different types can be suppressed.SOLUTION: A battery management system 1 includes a plurality of battery units 100 that are connected in parallel with one another, and a control device 200 that executes temperature adjustment control on each of the battery units 100. The plurality of battery units 100 include a first battery unit 100A having an LFP battery 120A, and a second battery unit 100B having a ternary battery 120B. In a case where the temperature of the battery management system 1 is equal to or lower than a reference temperature, the control device 200 executes first temperature adjustment control to set the temperature of the LFP battery 120A to be higher than the temperature of the ternary battery 120B.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a battery management system. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2014-103804 (Patent Document 1) discloses a battery system in which a plurality of assembled batteries are connected in parallel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-103804 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a system such as that disclosed in Patent Document 1, the types of the multiple assembled batteries may differ from one another. Here, the internal resistances of the different types of assembled batteries may differ from one another. In this case, the input / output characteristics vary from one assembled battery to another, particularly in the low temperature range. Therefore, it is desirable to suppress the variation in the input / output characteristics between assembled batteries of different types.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to suppress variations in input / output characteristics between different types of batteries. [Means for solving the problem]

[0006] A battery management system according to a first aspect of the present disclosure is a battery management system that manages batteries, and includes a plurality of battery units each including a battery and connected in parallel with each other, and a control device that executes temperature adjustment control on each battery of the plurality of battery units. The plurality of battery units include a first battery unit having an LFP battery and a second battery unit having a ternary battery. When the temperature of the battery management system is equal to or lower than a reference temperature, the control device executes a first temperature adjustment control so that the temperature of the LFP battery is higher than the temperature of the ternary battery.

[0007] In the battery management system according to the first aspect of the present disclosure, as described above, when the temperature of the battery management system is equal to or lower than the reference temperature, the first temperature adjustment control is executed so that the temperature of the LFP battery is higher than the temperature of the ternary battery. Here, the internal resistance of the LFP battery is higher than the internal resistance of the ternary battery. Therefore, in the low temperature range, the input / output characteristics of the LFP battery are lower than the input / output characteristics of the ternary battery. Thus, the first temperature adjustment control can improve the input / output characteristics of the LFP battery. As a result, even if the input / output characteristics of the LFP battery are lower than the input / output characteristics of the ternary battery due to the low temperature of the battery management system, it is possible to suppress the input / output characteristics of the LFP battery from deviating from the input / output characteristics of the ternary battery. As a result, it is possible to suppress the input / output characteristics of the LFP battery and the ternary battery from varying from each other.

[0008] In the battery management system according to the first aspect, the first temperature adjustment control preferably includes control for making the charge / discharge power of the LFP battery higher than the charge / discharge power of the ternary battery. With this configuration, the amount of temperature rise of the LFP battery due to the charge / discharge power can be made higher than the amount of temperature rise of the ternary battery due to the charge / discharge power.

[0009] In the battery management system according to the first aspect, the first temperature adjustment control preferably includes control for making the warming ripple current for the LFP battery larger than the warming ripple current for the ternary battery. With this configuration, the amount of temperature rise of the LFP battery due to the warming ripple current can be made larger than the amount of temperature rise of the ternary battery due to the warming ripple current.

[0010] In the battery management system according to the first aspect described above, the first battery unit preferably further has a heater for heating the LFP battery. The first temperature adjustment control includes control for heating the LFP battery by the heater. With this configuration, the temperature of the LFP battery can be easily increased by the heater.

[0011] In the battery management system according to the first aspect, preferably, when the temperature of the battery management system is within a predetermined temperature range higher than a reference temperature, the control device executes a second temperature control for making the charge / discharge power of the ternary battery larger than the charge / discharge power of the LFP battery, and when the temperature of the battery management system is higher than the reference temperature and lower than the lower limit of the predetermined temperature range, the control device executes a third temperature control for making the charge / discharge power of the LFP battery and the charge / discharge power of the ternary battery equal to each other. Here, when the temperature of the battery management system is relatively high, the effect of the amount of heat generated by the battery on the deterioration level of the battery becomes large. Also, a battery with a relatively high internal resistance is likely to generate a large amount of heat. Therefore, as described above, when the temperature of the battery management system is relatively high within the above-mentioned predetermined temperature range, the charge / discharge power of the ternary battery is made larger than the charge / discharge power of the LFP battery, thereby making it possible to suppress the deviation between the amount of heat generated by the ternary battery and the amount of heat generated by the LFP battery. As a result, it is possible to suppress the deviation between the deterioration level of the ternary battery and the deterioration level of the LFP battery. Furthermore, in the intermediate temperature range between the reference temperature and the predetermined temperature range, it is possible to prevent a difference from occurring between the charge / discharge power of an LFP battery and the charge / discharge power of a ternary battery. Effect of the Invention

[0012] According to the present disclosure, it is possible to suppress variations in input / output characteristics between different types of batteries. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a configuration of a battery management system according to a first embodiment. [Diagram 2] FIG. 4 is a diagram showing the relationship between temperature and charge / discharge power of a battery according to the first embodiment. [Diagram 3] FIG. 2 is a flow chart showing a control flow of the control device according to the first embodiment. [Figure 4] FIG. 11 is a diagram showing a configuration of a battery management system according to a second embodiment. [Diagram 5] FIG. 11 is a flow chart showing a control flow of a control device according to a second embodiment. [Figure 6] FIG. 13 is a diagram showing a configuration of a battery management system according to a third embodiment. [Figure 7] FIG. 11 is a flow chart showing a control flow of a control device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0015] [First embodiment] 1 is a diagram showing the configuration of a battery management system 1 according to a first embodiment. The battery management system 1 includes a plurality of battery units 100, a control device 200, and a temperature sensor 300.

[0016] The multiple battery units 100 are connected in parallel to a PCS (Power Conditioning System) 10. The PCS 10 is a power conversion device capable of both AC / DC conversion and DC / AC conversion. The PCS 10 receives DC power from, for example, a solar power generation device 20. The PCS 10 also supplies AC power to a load 30. The load 30 includes electrical appliances used at home (for example, air conditioners and lighting fixtures). The PCS 10 also exchanges AC power with a power system PG.

[0017] The multiple battery units 100 include a first battery unit 100A and a second battery unit 100B. Although only one each of the first battery unit 100A and the second battery unit 100B is illustrated in Fig. 1, multiple each of the first battery unit 100A and the second battery unit 100B may be provided.

[0018] The first cell unit 100A includes a converter 111 and a plurality of iron phosphate lithium ion batteries (hereinafter referred to as "LFP batteries") 120A. The converter 111 is provided in a PCU (Power Control Unit) 110. The converter 111 performs voltage conversion of DC power between the PCS 10 and the batteries 120A. More specifically, the converter 111 boosts the DC power from the PCS 10. As a result, the plurality of LFP batteries 120A are charged by the DC power from the PCS 10. The converter 111 also reduces the DC power from the plurality of LFP batteries 120A. As a result, the power of the plurality of LFP batteries 120A is discharged to the PCS 10. The converter 111 may also boost / step down the DC power so that charging / discharging is performed between the first cell unit 100A and the second cell unit 100B.

[0019] The second cell unit 100B includes a converter 111 and a plurality of ternary lithium ion batteries (hereinafter referred to as "ternary batteries") 120B. The operation of the converter 111 in the second cell unit 100B is similar to that of the converter 111 in the first cell unit 100A.

[0020] The internal resistance of LFP battery 120A is higher than the internal resistance of ternary battery 120B. Each of LFP battery 120A and ternary battery 120B is an example of the "battery" of the present disclosure.

[0021] The temperature sensor 300 measures the temperature of the battery management system 1. The temperature of the battery management system 1 may be the temperature of the LFP battery 120A or the temperature of the ternary battery 120B. The control device 200 acquires information on the temperature measured by the temperature sensor 300.

[0022] The control device 200 includes a processor and a memory (neither shown), and controls each of the multiple battery units 100. For example, the control device 200 executes temperature regulation control of each of the batteries (120A, 120B) of the multiple battery units 100.

[0023] In a conventional system including different types of assembled batteries, the input / output characteristics (typically the upper limit of the power / current that can be charged / discharged) vary from one assembled battery to another due to differences in internal resistance between the assembled batteries, particularly in the low temperature range. It is desirable to suppress the variation in the input / output characteristics between assembled batteries of different types.

[0024] Therefore, in the first embodiment, when the temperature of the battery management system 1 is equal to or lower than a reference temperature (for example, in a low temperature range of 10° C. or lower), the control device 200 executes a first temperature adjustment control so that the temperature of the LFP battery 120A is higher than the temperature of the ternary battery 120B. For ease of understanding, an example will be described below in which the first temperature control is executed when the LFP battery 120A and the ternary battery 120B are being charged. However, the first temperature control (and the second temperature adjustment control and third temperature adjustment control described below) may also be executed when each battery is being discharged.

[0025] 2, the first temperature adjustment control includes control to make the charging power of LFP battery 120A greater than the charging power of ternary battery 120B. In particular, control device 200 increases the charging power of LFP battery 120A based on the fact that the temperature measured by temperature sensor 300 has dropped to 10° C. or below. On the other hand, control device 200 does not change the charging power of ternary battery 120B even when the temperature measured by temperature sensor 300 has dropped to 10° C. or below.

[0026] 2, when the temperature of the battery management system 1 is equal to or lower than the reference temperature, the control device 200 fixes the charging power of the LFP battery 120A to P1. Also, when the temperature of the battery management system 1 is equal to or lower than the reference temperature, the control device 200 fixes the charging power of the ternary battery 120B to P2, which is smaller than P1.

[0027] In addition, when the temperature of the battery management system 1 is within a predetermined temperature range higher than the above-mentioned reference temperature (10°C) (for example, within a high temperature range of 25°C to 40°C), the control device 200 executes a second temperature adjustment control to make the charging power in the ternary battery 120B greater than the charging power in the LFP battery 120A.

[0028] Specifically, control device 200 increases the charging power in ternary battery 120B when the temperature measured by temperature sensor 300 increases to 25° C. (the lower limit of the above-mentioned predetermined range) or higher. On the other hand, control device 200 does not change the charging power in LFP battery 120A even when the temperature measured by temperature sensor 300 increases to 25° C. or higher.

[0029] In the example shown in Fig. 2, when the temperature of the battery management system 1 is within the above-mentioned predetermined temperature range, the control device 200 fixes the charging power of the LFP battery 120A to P2. Furthermore, when the temperature of the battery management system 1 is within the above-mentioned predetermined temperature range, the control device 200 fixes the charging power of the ternary battery 120B to P3, which is greater than P2. Note that, although Fig. 2 shows an example in which P1 is greater than P3, P3 may be greater than or equal to P1.

[0030] In addition, when the temperature of the battery management system 1 is higher than the above-mentioned reference temperature and lower than the lower limit of the specified temperature range (i.e., in the medium temperature range higher than 10°C and lower than 25°C), the control device 200 executes a third temperature adjustment control that makes the charging power in the LFP battery 120A and the charging power in the ternary battery 120B equal to each other.

[0031] Specifically, in the above-mentioned intermediate temperature range, control device 200 fixes the charge / discharge power of each of LFP battery 120A and ternary battery 120B to P2. Note that, for ease of understanding, in Fig. 2, the charge / discharge power of LFP battery 120A and the charge power of ternary battery 120B in the above-mentioned intermediate temperature range are shown slightly offset from each other.

[0032] 2 shows an example in which the charging power is fixed to a predetermined value in each temperature range, but the present disclosure is not limited to this. In each temperature range, the charging and discharging power may change according to the temperature change of the battery management system 1.

[0033] (Control flow of the control device) Next, a control flow of the control device 200 will be described with reference to Fig. 3. The process flow shown in Fig. 3 may be repeatedly executed at predetermined time intervals (for example, every hour). In step S1, the control device 200 acquires information on the temperature measured by the temperature sensor 300 (the temperature of the battery management system 1).

[0034] In step S2, the control device 200 determines whether the temperature of the battery management system 1 is 10° C. or less (within the low temperature range) based on the temperature information acquired in step S1. If the temperature is 10° C. or less (Yes in S2), the process proceeds to step S3. If the temperature is higher than 10° C. (No in S2), the process proceeds to step S4.

[0035] In step S3, controller 200 executes the first temperature adjustment control to make the charge / discharge power of LFP battery 120A greater than the charge / discharge power of ternary battery 120B.

[0036] In step S4, the control device 200 determines whether the temperature of the battery management system 1 is within the range of 25°C to 40°C (within the high temperature range) based on the temperature information acquired in step S1. If the temperature is within the range (Yes in S4), the process proceeds to step S5. If the temperature is outside the range and within the range of 10°C to 25°C (No in S4), the process proceeds to step S6.

[0037] In step S5, controller 200 executes the second temperature adjustment control to make the charge / discharge power of ternary battery 120B greater than the charge / discharge power of LFP battery 120A.

[0038] In step S6, control device 200 executes the third temperature adjustment control for making the charge / discharge power of LFP battery 120A and the charge / discharge power of ternary battery 120B equal to each other.

[0039] As described above, in the first embodiment, when the temperature of the battery management system 1 is equal to or lower than the reference temperature, the control device 200 executes the first temperature adjustment control so that the temperature of the LFP battery 120A is higher than the temperature of the ternary battery 120B. This makes it possible to prevent the input / output characteristics of the LFP battery 120A from decreasing due to a decrease in the temperature of the battery management system 1. As a result, the input / output characteristics of the LFP battery 120A and the input / output characteristics of the ternary battery 120B can be easily made uniform.

[0040] [Second embodiment] Next, a second embodiment of the present disclosure will be described with reference to Fig. 4 and Fig. 5. In the second embodiment, unlike the first embodiment that controls the charge and discharge power of the battery, the temperature rise ripple current is controlled. The same components as those in the first embodiment are denoted by the same reference numerals and will not be described repeatedly.

[0041] As shown in FIG. 4, the battery management system 2 includes a plurality of battery units 101, a control device 210, and a temperature sensor 300.

[0042] The multiple battery units 101 include a first battery unit 101A and a second battery unit 101B. The first battery unit 101A further includes a ripple generating unit 130A in addition to the configuration of the first battery unit 100A (see FIG. 1) of the first embodiment. The second battery unit 101B further includes a ripple generating unit 130B in addition to the configuration of the second battery unit 100B (see FIG. 1) of the first embodiment.

[0043] The ripple generating unit 130A is connected to the LFP battery 120A. The ripple generating unit 130A generates a warming ripple current of a predetermined frequency, a predetermined duty, and a predetermined amplitude in the LFP battery 120A. The ripple generating unit 130B is connected to the ternary battery 120B. The ripple generating unit 130B generates a warming ripple current of a predetermined frequency, a predetermined duty, and a predetermined amplitude in the ternary battery 120B. The frequency and amplitude of the warming ripple current are each controlled by the control device 200.

[0044] In the second embodiment, when the temperature of the battery management system 2 is equal to or lower than a reference temperature, the control device 210 makes the temperature-raising ripple current for the LFP battery 120A larger than the temperature-raising ripple current for the ternary battery 120B. This executes a first temperature adjustment control that makes the temperature of the LFP battery 120A higher than the temperature of the ternary battery 120B.

[0045] (Control flow of the control device) Next, the control flow of the control device 210 will be described with reference to Fig. 5. The process flow shown in Fig. 5 may be repeatedly executed at predetermined time intervals (for example, every hour). The same processes as those in the first embodiment are denoted by the same reference numerals and will not be described repeatedly.

[0046] If the answer is Yes in step S2, the process of step S13 is performed. In step S13, control device 210 executes the first temperature adjustment control so that the heating ripple current of LFP battery 120A is larger than the heating ripple current of ternary battery 120B. Specifically, control device 210 controls ripple generating section 130A and ripple generating section 130B to control the heating ripple current of LFP battery 120A and the heating ripple current of ternary battery 120B. For example, control device 210 makes the amplitude of the heating ripple current of LFP battery 120A larger than the amplitude of the heating ripple current of ternary battery 120B. Control device 210 may make the duty of the heating ripple current of LFP battery 120A larger than the duty of the heating ripple current of ternary battery 120B. The frequency of the warming ripple current of each of LFP battery 120A and ternary battery 120B may be controlled. At this time, it is not necessary to generate a warming ripple current of ternary battery 120B.

[0047] If the answer is Yes in step S4, the process of step S15 is performed. In step S15, control device 210 executes the second temperature adjustment control so that the warming ripple current of ternary battery 120B is larger than the warming ripple current of LFP battery 120A. For example, control device 210 controls ripple generating section 130A and ripple generating section 130B to make the amplitude and / or duty of the warming ripple current of ternary battery 120B larger than the amplitude and / or duty of the warming ripple current of LFP battery 120A. At this time, it is not necessary to generate a warming ripple current for LFP battery 120A.

[0048] If the answer is No in step S4, the process of step S16 is performed. In step S16, control device 210 executes third temperature adjustment control so that the heating ripple current of LFP battery 120A and the heating ripple current of ternary battery 120B are equal to each other. For example, control device 210 controls ripple generating section 130A and ripple generating section 130B to make the amplitude and duty of the heating ripple current of LFP battery 120A and the amplitude and duty of the heating ripple current of ternary battery 120B equal to each other. Note that at this time, it is not necessary to generate the heating ripple current of LFP battery 120A and the heating ripple current of ternary battery 120B.

[0049] [Third embodiment] Next, a third embodiment of the present disclosure will be described with reference to Fig. 6 and Fig. 7. In the third embodiment, unlike the first embodiment in which the temperature of the battery is controlled by controlling the charge and discharge power of the battery, the temperature of the battery is controlled by controlling a heater. The same components as those in the first embodiment are denoted by the same reference numerals and will not be described repeatedly.

[0050] As shown in FIG. 6, the battery management system 3 includes a plurality of battery units 102, a control device 220, and a temperature sensor 300.

[0051] The multiple battery units 102 include a first battery unit 102A and a second battery unit 102B. The first battery unit 102A further includes a heater 140A in addition to the configuration of the first battery unit 100A (see FIG. 1) of the first embodiment. The second battery unit 102B further includes a heater 140B in addition to the configuration of the second battery unit 100B (see FIG. 1) of the first embodiment.

[0052] The heater 140A heats the LFP battery 120A. The heater 140B heats the ternary battery 120B.

[0053] In the third embodiment, when the temperature of the battery management system 3 is equal to or lower than a reference temperature, the control device 220 controls the heater 140A to heat the LFP battery 120A. This executes a first temperature adjustment control that makes the temperature of the LFP battery 120A higher than the temperature of the ternary battery 120B.

[0054] (Control flow of the control device) Next, the control flow of the control device 220 will be described with reference to Fig. 7. The process flow shown in Fig. 7 may be repeatedly executed at predetermined time intervals (for example, every hour). The same processes as those in the first embodiment are denoted by the same reference numerals and will not be described repeatedly.

[0055] If the answer is Yes in step S2, the process of step S23 is performed. In step S23, the control device 220 executes the first temperature adjustment control described above, in which the heater 140A of the first battery unit 102A heats the LFP battery 120A. At this time, the heater 140B of the second battery unit 102B may or may not be operated with low power. This causes the temperature of the LFP battery 120A to become higher than the temperature of the ternary battery 120B.

[0056] If the answer is Yes in step S4, the process of step S25 is performed. In step S25, the control device 220 executes a second temperature adjustment control to heat the ternary battery 120B by the heater 140B of the second battery unit 102B. At this time, the heater 140A of the first battery unit 102A may or may not be operated with low power. This causes the temperature of the ternary battery 120B to be higher than the temperature of the LFP battery 120A.

[0057] If the result of step S4 is No, the process proceeds to step S26. In step S26, the controller 220 executes a third temperature adjustment control for putting each of the heaters 140A and 140B into a non-operating state.

[0058] In the above second embodiment, the first cell unit 101A and the second cell unit 101B are provided with the ripple generating units (130A, 130B), respectively, but the present disclosure is not limited to this. For example, the second cell unit 101B does not have to be provided with the ripple generating unit 130B.

[0059] In the above third embodiment, the heaters (140A, 140B) are provided in the first battery unit 102A and the second battery unit 102B, respectively, but the present disclosure is not limited to this. For example, the heater 140B does not have to be provided in the second battery unit 102B.

[0060] Also, in each of the first battery unit 102A and the second battery unit 102B, a cooling device may be provided instead of a heater. For example, in the case of a low temperature range, the ternary battery 120B may be cooled by a cooling device. In the case of a high temperature range, the LFP battery 120A may be cooled by a cooling device.

[0061] The controls of the first to third embodiments may be combined with each other. For example, the first temperature adjustment control may include control of charge / discharge power, and the second temperature adjustment control may include control of temperature rise ripple current.

[0062] In the above first to third embodiments, an example was shown in which the battery management system (1, 2, 3) was provided with the temperature sensor 300, but the present disclosure is not limited to this. For example, the control device may acquire a temperature measured by a temperature sensor (air temperature sensor) outside the battery management system as the temperature of the battery management system through communication or the like.

[0063] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 1, 2, 3: battery management system, 100, 101, 102: battery unit, 100A, 101A, 102A: first battery unit, 100B, 101B, 102B: second battery unit, 120A: LFP battery (battery), 120B: ternary battery (battery), 140A: heater, 200, 210, 220: control device.

Claims

1. A battery management system for managing batteries, a plurality of battery units each including the battery and connected in parallel with each other; a control device that executes temperature regulation control for the batteries of each of the plurality of battery units; the plurality of battery units includes a first battery unit having an LFP battery and a second battery unit having a ternary battery; The control device, when a temperature of the battery management system is equal to or lower than a reference temperature, makes a charging / discharging power of the LFP battery greater than a charging / discharging power of the ternary battery.

2. A battery management system for managing batteries, comprising: a plurality of battery units each including the battery and connected in parallel with each other; a control device that executes temperature regulation control for the batteries of each of the plurality of battery units; the plurality of battery units includes a first battery unit having an LFP battery and a second battery unit having a ternary battery; The control device, when a temperature of the battery management system is equal to or lower than a reference temperature, makes a warm-up ripple current for the LFP battery larger than a warm-up ripple current for the ternary battery.

3. A battery management system for managing batteries, comprising: a plurality of battery units each including the battery and connected in parallel with each other; a control device that executes temperature regulation control for the batteries of each of the plurality of battery units; the plurality of battery units includes a first battery unit having an LFP battery and a second battery unit having a ternary battery; the first battery unit further includes a heater for heating the LFP battery; The control device heats the LFP battery using the heater when the temperature of the battery management system is equal to or lower than a reference temperature.

4. The control device includes: When the temperature of the battery management system is within a predetermined temperature range higher than the reference temperature, charging and discharging power of the ternary battery is made larger than charging and discharging power of the LFP battery; 2. The battery management system according to claim 1, wherein when the temperature of the battery management system is higher than the reference temperature and lower than a lower limit value of the predetermined temperature range, the charging and discharging power of the LFP battery and the charging and discharging power of the ternary battery are made equal to each other.

Images