Power System

Abstract

To provide a power supply system that can use battery performance of a battery pack further efficiently while maintaining the temperature of the battery pack at a temperature lower than an upper limit temperature for use.SOLUTION: A power supply system 10 includes a battery pack 20 having a solid battery cell 21 and a cushioning member 22 that restrains the solid battery cell 21 and a battery ECU 30. When the battery pack 20 is charged, the surface pressure applied to the solid battery cell 21 increases due to the compression of the cushioning member 22 by the expansion of the solid battery cell 21. When the battery pack 20 is discharged, the cushioning member 22 is restored by the contraction of the solid battery cell 21, and the surface pressure applied to the solid battery cell 21 is reduced. The battery ECU 30 is capable of performing temperature rise suppression output restriction control. In the temperature rise suppression output restriction control, the battery ECU 30 sets a control start temperature Ts on the basis of a usage state of the battery pack 20 and a battery state of the battery pack 20.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a power supply system including a battery pack and a battery control device. [Background technology]

[0002] In recent years, research and development on secondary batteries that contribute to energy efficiency has been conducted to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. In the field of secondary batteries, research on solid-state batteries, in which solid materials are used for at least a part of the electrolyte, has been particularly active in recent years.

[0003] In a power supply system including a battery pack and a battery control device, the temperature of the battery pack needs to be kept lower than the upper limit temperature for use in order to ensure safety. For example, Patent Document 1 describes a solid-state battery system that cools the solid-state battery when the temperature of the solid-state battery reaches or exceeds a predetermined temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-100622 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a power supply system including a battery pack and a battery control device, it is necessary to maintain the temperature of the battery pack below the upper limit temperature for use, while at the same time it is required to utilize the battery performance of the battery pack more efficiently.

[0006] The present invention provides a power supply system that can more efficiently utilize the battery performance of a battery pack while maintaining the temperature of the battery pack lower than the upper limit temperature for use, thereby contributing to improved energy efficiency. [Means for solving the problem]

[0007] The present invention 、 electric Ike Have a A battery pack for a battery control device for controlling charging and discharging power of the battery pack; A power supply system comprising: 、 before The battery control device includes: When the temperature of the battery pack becomes equal to or higher than a control start temperature, a temperature rise suppression output limiting control is executed to limit an output release rate of the battery pack, In the temperature rise suppression output limiting control, the control start temperature is set based on a usage state of the battery pack and a battery state of the battery pack. death , the usage state of the battery pack includes a charge / discharge state of the battery pack, The battery status of the battery pack includes a remaining charge of the battery pack. , The battery control device includes: classifying the usage state of the battery pack into a discharging state and a charging state based on a charging / discharging state of the battery pack; classifying the battery state of the battery pack into a high remaining charge state and a low remaining charge state based on the remaining charge of the battery pack; whether the usage state of the battery pack is the discharging state or the charging state; whether the battery state of the battery pack is the high remaining charge state or the low remaining charge state; Based on the above, the control start temperature in the temperature rise suppression output limiting control is set, In the temperature rise suppression output limiting control, setting the control start temperature when the usage state of the battery pack is the charging state higher than the control start temperature when the usage state of the battery pack is the discharging state; When the usage state of the battery pack is the discharged state, The control start temperature when the battery state of the battery pack is the high remaining charge state is set higher than the control start temperature when the battery state of the battery pack is the low remaining charge state. The present invention also provides a method for producing a semiconductor device comprising the steps of: a battery pack having battery cells; a battery control device for controlling charging and discharging power of the battery pack; A power supply system comprising: The battery control device includes: When the temperature of the battery pack becomes equal to or higher than a control start temperature, a temperature rise suppression output limiting control is executed to limit an output release rate of the battery pack, In the temperature rise suppression output limiting control, the control start temperature is set based on a usage state of the battery pack and a battery state of the battery pack; the usage state of the battery pack includes a charge / discharge state of the battery pack, the battery status of the battery pack includes a remaining charge of the battery pack; The battery control device includes: classifying the usage state of the battery pack into a discharging state and a charging state based on a charging / discharging state of the battery pack; classifying the battery state of the battery pack into a high remaining charge state and a low remaining charge state based on the remaining charge of the battery pack; whether the usage state of the battery pack is the discharging state or the charging state, whether the battery state of the battery pack is the high remaining charge state or the low remaining charge state, based on this, set the control start temperature in the temperature rise suppression output limit control, in the temperature rise suppression output limit control, when the usage state of the battery pack is the discharging state and the battery state of the battery pack is the high remaining charge state, the control start temperature is T1, when the usage state of the battery pack is the discharging state and the battery state of the battery pack is the low remaining charge state, the control start temperature is T2, when the usage state of the battery pack is the charging state and the battery state of the battery pack is the low remaining charge state, the control start temperature is T3, when the usage state of the battery pack is the charging state and the battery state of the battery pack is the high remaining charge state, the control start temperature is T4, set the control start temperature so that T2 < T1 < T4 < T3. Effect of the Invention

[0008] According to the present invention, the battery performance of the battery pack can be utilized more efficiently while maintaining the temperature of the battery pack lower than the upper limit temperature for use. [Brief description of the drawings]

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0010] Hereinafter, an embodiment of a power supply system of the present invention will be described with reference to the accompanying drawings. Note that the drawings are to be viewed in the direction indicated by the reference symbols.

[0011] <Power supply system> The power supply system 10 of this embodiment is mounted on a vehicle.

[0012] As shown in FIG. 1, the power supply system 10 includes a battery pack 20 and a battery ECU 30.

[0013] In this embodiment, the power supply system 10 includes two battery packs 20, which are connected in series.

[0014] The battery pack 20 is connected to a power distribution unit 91. The power distribution unit 91 is connected to a drive device 92, a charger 93, auxiliary devices 94, and the like mounted on the vehicle. The drive device 92 has, for example, a vehicle drive motor that drives the vehicle. The vehicle can run by the power of this motor. The charger 93 has a power conversion device that receives AC power from a power supply device outside the vehicle and converts it into DC power of a predetermined voltage. The battery pack 20 can be charged with the power from the power supply device outside the vehicle that has been converted by the charger 93. The auxiliary devices 94 include a vehicle air conditioning device and the like. The power of the battery pack 20 can be supplied to the auxiliary devices 94, and the auxiliary devices 94 can operate with the power supplied from the battery pack 20.

[0015] The battery pack 20 is equipped with a battery voltage sensor 41 that detects the input / output voltage of the battery pack 20 and a battery temperature sensor 42 that detects the temperature of the battery pack 20.

[0016] The battery ECU 30 is connected to the battery pack 20. The battery ECU 30 controls the charging and discharging power of the battery pack 20.

[0017] The battery voltage sensor 41 and the battery temperature sensor 42 are connected to the battery ECU 30. The battery voltage sensor 41 and the battery temperature sensor 42 output detection signals to the battery ECU 30.

[0018] As shown in FIG. 2, the battery pack 20 includes a plurality of solid-state battery cells 21, a cushion member 22 that restrains the plurality of solid-state battery cells 21, and an end plate .

[0019] The solid-state battery cell 21 is a secondary battery in which a solid material is used for at least a part of the electrolyte. The solid-state battery cell 21 is not limited to an all-solid-state battery in which only a solid electrolyte is used as the electrolyte, and may be a semi-solid battery. The solid-state battery cell 21 may be, for example, a gel polymer type semi-solid battery in which an electrolyte solution is contained in a polymer gel, a clay type semi-solid battery in which a clay-like material is used in which an electrolyte solution is kneaded into the electrode materials of the positive and negative electrodes, or a liquid-added type semi-solid battery in which a small amount of a fluid liquid material or a flexible gel polymer is added to a solid electrolyte.

[0020] The solid-state battery cell 21 is of a rectangular or laminated type. The battery pack 20 has a plurality of solid-state battery cells 21 stacked in a first direction. The solid-state battery cell 21 has a predetermined thickness in the first direction, and a surface perpendicular to the first direction is substantially flat.

[0021] The cushion member 22 is a restraining member that restrains the multiple solid-state battery cells 21. The cushion member 22 fills the gap between the solid-state battery cells 21 adjacent to each other in the first direction.

[0022] A pair of end plates 23 are provided on one side and the other side in the first direction of the assembly of the stacked solid-state battery cells 21. Therefore, the assembly of the stacked solid-state battery cells 21 is disposed between the pair of end plates 23 in the first direction. The space between the solid-state battery cell 21 disposed on the furthest side in the first direction and the end plate 23, and the space between the solid-state battery cell 21 disposed on the furthest other side in the first direction and the end plate 23 are both filled with the cushion member 22.

[0023] As shown in (a) of Fig. 2, each solid-state battery cell 21 contracts when the battery pack 20 is discharged, whereas as shown in (b) of Fig. 2, each solid-state battery cell 21 expands when the battery pack 20 is charged. Therefore, when the battery pack 20 is charged, the cushion member 22 is compressed due to the expansion of the solid-state battery cells 21, and the surface pressure applied to the solid-state battery cells 21 increases. On the other hand, when the battery pack 20 is discharged, the cushion member 22 is restored due to the contraction of the solid-state battery cells 21, and the surface pressure applied to the solid-state battery cells 21 decreases.

[0024] At this time, when the horizontal axis represents the remaining charge of the solid-state battery cell 21 and the vertical axis represents the surface pressure applied to the solid-state battery cell 21, the relationship between the remaining charge of the solid-state battery cell 21 and the surface pressure applied to the solid-state battery cell 21 is as shown in FIG.

[0025] 3, when the remaining charge (SOC) of the battery pack 20 is 0%, the surface pressure applied to the solid battery cell 21 is equal to or greater than the battery performance guarantee lower limit. If the surface pressure applied to the solid battery cell 21 is equal to or less than a predetermined value, the contact resistance between the solid electrolyte interface and the electrode active material increases, and the required battery performance cannot be ensured. For this reason, the battery performance guarantee lower limit is set as the lower limit voltage at which the battery performance can be ensured. On the other hand, when the remaining charge of the battery pack 20 is 100%, the surface pressure applied to the solid battery cell 21 is equal to or less than the strength upper limit of the end plate 23.

[0026] When the battery pack 20 is being charged, the surface pressure applied to the solid-state battery cell 21 increases in an upwardly convex curve as the remaining charge of the solid-state battery cell 21 increases. In contrast, when the battery pack 20 is being discharged, the surface pressure applied to the solid-state battery cell 21 decreases in a downwardly convex curve as the remaining charge of the solid-state battery cell 21 decreases.

[0027] In this way, the relationship between the remaining charge of the solid-state battery cell 21 and the surface pressure applied to the solid-state battery cell 21 exhibits hysteresis characteristics during charging and discharging.

[0028] Furthermore, since the surface pressure applied to the solid-state battery cell 21 according to the remaining charge of the solid-state battery cell 21 exhibits hysteresis characteristics during charging and discharging, the direct current internal resistance (hereinafter also referred to as DCIR: Direct Current Internal Resistance) of the solid-state battery cell 21 also exhibits hysteresis characteristics.

[0029] 4 is a diagram showing the relationship between the remaining charge of the solid-state battery cell 21 and the discharge DCIR or charge DCIR of the solid-state battery cell 21, with the horizontal axis representing the remaining charge of the solid-state battery cell 21 and the vertical axis representing the discharge DCIR or charge DCIR of the solid-state battery cell 21. Note that (a) and (b) of FIG. 4 are diagrams in which the remaining charge of the solid-state battery cell 21 and the reference current value are adjusted so that the heat generation amount is the same, taking into consideration that the discharge DCIR and the charge DCIR are different.

[0030] 4(a), as the remaining charge of the solid-state battery cell 21 decreases due to discharging, the discharge DCIR rises in an upward convex curve as shown by the thick line. For reference, when the remaining charge of the solid-state battery cell 21 increases due to charging, the discharge DCIR falls in a downward convex curve as shown by the dotted line. Note that the thin line shows the discharge DCIR when it is assumed that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic, and although the details depend on the battery configuration, it generally shows a negative correlation with the remaining charge.

[0031] 4(b), as the remaining charge of the solid-state battery cell 21 increases due to charging, the discharge DCIR rises in a downward convex curve as shown by the thick line. For reference, when the remaining charge of the solid-state battery cell 21 decreases due to discharging, the charge DCIR falls in an upward convex curve as shown by the dotted line. Note that the thin line shows the charge DCIR when it is assumed that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic, and although the details depend on the battery configuration, it generally shows a positive correlation with the remaining charge.

[0032] As shown in FIG. 5, the usage state of the battery pack 20 is classified into a discharge state and a charge state, and the battery state of the battery pack 20 is classified into a high charge remaining state (high SOC state) and a low charge remaining state (low SOC state). A state where the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the high SOC state is defined as state 1, a state where the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the low SOC state is defined as state 2, a state where the usage state of the battery pack 20 is the charge state and the battery state of the battery pack 20 is the low SOC state is defined as state 3, and a state where the usage state of the battery pack 20 is the charge state and the battery state of the battery pack 20 is the high SOC state is defined as state 4.

[0033] And, the heat generation amount of the solid-state battery cell 21 in state 1 is W1, the heat generation amount of the solid-state battery cell 21 in state 2 is W2, the heat generation amount of the solid-state battery cell 21 in state 3 is W3, and the heat generation amount of the solid-state battery cell 21 in state 4 is W4. Assuming that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic, when the heat generation amount of the solid-state battery cell 21 is WA, since the heat generation amount of the solid-state battery cell 21 is approximately proportional to the internal resistance value of the solid-state battery cell 21, as shown in FIG. 4(a), WA < W1 < W2, and as shown in FIG. 4(b), W3 < W4 < WA. Therefore, the relationship between the heat generation amounts W1 to W4 of the solid-state battery cell 21 from state 1 to state 4 and the heat generation amount WA of the solid-state battery cell 21 when it is assumed that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic is W3 < W4 < WA < W1 < W2.

[0034] Therefore, for the cases from state 1 to state 4, the battery pack 20 is more likely to heat up in the order of (state 2) > (state 1) > (when it is assumed that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic) > (state 4) > (state 3).

[0035] Returning to FIG. 1, the battery ECU 30 is connected to the battery pack 20. The battery ECU 30 controls the charge and discharge power of the battery pack 20.

[0036] When the temperature of the battery pack 20 becomes equal to or higher than a control start temperature Ts, the battery ECU 30 can execute temperature rise suppression output limiting control that limits the output release rate of the battery pack 20. Fig. 6 shows an example of the temperature rise suppression output limiting control.

[0037] The battery ECU 30 includes a battery temperature acquisition unit 31, a battery voltage acquisition unit 32, a battery remaining charge calculation unit 33, a target input / output power setting unit , an output release rate setting unit 35, and an output limit control start temperature setting unit .

[0038] In this embodiment, the battery ECU 30 is connected to a vehicle control device 90 mounted on the vehicle. The vehicle control device 90 includes a number of ECUs (Electronic Control Units) and performs driving control of the vehicle and integrated control of auxiliary devices. The vehicle control device 90 outputs a signal related to the control of the battery pack 20 to the battery ECU 30.

[0039] The battery ECU 30 sets a target input / output power of the battery pack 20 in a target input / output power setting unit 34 based on a signal related to control of the battery pack 20 output from the vehicle control device 90. Then, the battery ECU 30 outputs a signal indicating the target input / output power set in the target input / output power setting unit 34 to the battery pack 20, and controls the input / output power of the battery pack 20 to become the target input / output power set in the target input / output power setting unit 34.

[0040] The battery temperature acquisition unit 31 acquires the temperature of the battery pack 20 based on a detection signal output from the battery voltage sensor 41 .

[0041] The battery voltage acquisition unit 32 acquires the input / output voltage of the battery pack 20 based on the detection signal output from the battery temperature sensor 42 .

[0042] The battery remaining charge calculation unit 33 calculates the remaining charge of the battery pack 20 based on the temperature of the battery pack 20 acquired by the battery temperature acquisition unit 31 and the input / output voltage of the battery pack 20 acquired by the battery voltage acquisition unit 32 .

[0043] The output release rate setting unit 35 sets the output release rate of the battery pack 20 based on the temperature of the battery pack 20 acquired by the battery temperature acquisition unit 31. In this embodiment, the battery ECU 30 pre-stores a table showing the output release rate corresponding to the temperature of the battery pack 20 as shown in FIG.

[0044] When the temperature of the battery pack 20 acquired by the battery temperature acquisition unit 31 becomes equal to or higher than the control start temperature Ts, the output release rate setting unit 35 limits the output release rate of the battery pack 20 according to a table showing the output release rate corresponding to the temperature of the battery pack 20 shown in Fig. 6. In this manner, the battery ECU 30 can execute temperature rise suppression output limiting control that limits the output release rate of the battery pack 20 when the temperature of the battery pack 20 acquired by the battery temperature acquisition unit 31 becomes equal to or higher than the control start temperature Ts.

[0045] When the temperature rise suppression output limiting control is executed and the temperature of the battery pack 20 becomes equal to or higher than the control start temperature Ts, the output release rate of the battery pack 20 is limited, thereby preventing the battery pack 20 from reaching the upper limit temperature Tmax. This allows the temperature of the battery pack 20 to be maintained at a temperature lower than the upper limit temperature Tmax.

[0046] The output limit control start temperature setting unit 36 ​​sets a control start temperature Ts in the temperature rise suppression output limit control. The output limit control start temperature setting unit 36 ​​sets the control start temperature Ts based on the usage state of the battery pack 20 and the battery state of the battery pack 20.

[0047] Therefore, based on the usage state of the battery pack 20 and the battery state of the battery pack 20, the output limiting control start temperature setting unit 36 ​​is able to set the control start temperature Ts to a high temperature when the surface pressure on the battery pack 20 is large and the amount of heat generated by the battery pack 20 is small, and to set the control start temperature Ts to a low temperature when the surface pressure on the battery pack 20 is small and the amount of heat generated by the battery pack 20 is large.

[0048] This makes it possible to set an optimal control start temperature Ts based on the usage state of the battery pack 20 and the battery state of the battery pack 20, thereby making it possible to more efficiently utilize the battery performance of the battery pack 20 while maintaining the temperature of the battery pack 20 lower than the upper usage temperature Tmax.

[0049] In the output limit control start temperature setting unit 36, the usage state of the battery pack 20 used when setting the control start temperature Ts includes the charge / discharge state of the battery pack 20, and the battery state of the battery pack 20 includes the remaining charge of the battery pack 20.

[0050] This allows the control start temperature Ts to be set according to the amount of heat generated by the battery pack 20, which changes depending on the surface pressure applied to the battery pack 20, based on the charge / discharge state of the battery pack 20 and the remaining charge of the battery pack 20, so that a more optimal control start temperature Ts can be set according to the amount of heat generated by the battery pack 20.

[0051] When setting the control start temperature Ts, the output limit control start temperature setting unit 36 ​​classifies the usage state of the battery pack 20 into a discharging state and a charging state based on the charging / discharging state of the battery pack 20, and classifies the battery state of the battery pack 20 into a high SOC state and a low SOC state based on the remaining charge of the battery pack 20. Then, the control start temperature Ts is set based on whether the usage state of the battery pack 20 is a discharging state or a charging state and whether the battery state of the battery pack 20 is a high SOC state or a low SOC state.

[0052] This makes it possible to set an optimal control start temperature Ts according to the amount of heat generated by the battery pack 20, which varies depending on the surface pressure applied to the battery pack 20, through simple control.

[0053] Then, the output limit control start temperature setting unit 36 ​​sets the control start temperature Ts when the usage state of the battery pack 20 is in a charging state, in the temperature rise suppression output limit control, to be higher than the control start temperature Ts when the usage state of the battery pack 20 is in a discharging state.

[0054] As described above, when the battery pack 20 is charged, the surface pressure applied to the solid-state battery cell 21 increases in an upwardly convex curve as the remaining charge of the solid-state battery cell 21 increases. In contrast, when the battery pack 20 is discharged, the surface pressure applied to the solid-state battery cell 21 decreases in a downwardly convex curve as the remaining charge of the solid-state battery cell 21 decreases (see FIG. 3). Therefore, when the remaining charge of the solid-state battery cell 21 is the same, the surface pressure applied to the battery pack 20 is higher when the battery pack 20 is charged than when the battery pack 20 is discharged, so that the internal resistance value of the battery pack 20 is lower when the battery pack 20 is charged than when the battery pack 20 is discharged, and the amount of heat generated is smaller. Therefore, when the battery pack 20 is in a charging state, even if the temperature is set higher than the control start temperature Ts when the battery pack 20 is in a discharging state, the temperature of the battery pack 20 can be maintained lower than the upper usage limit temperature Tmax.

[0055] As a result, in the temperature rise suppression output limiting control, the control start temperature Ts when the usage state of the battery pack 20 is in a charging state is set higher than the control start temperature Ts when the usage state of the battery pack 20 is in a discharging state, thereby making it possible to more efficiently utilize the battery performance of the battery pack 20 while maintaining the temperature of the battery pack 20 lower than the upper usage temperature Tmax.

[0056] More specifically, as described above with reference to FIG. 5, the usage state of the battery pack 20 is classified into a discharge state and a charge state, and the battery state of the battery pack 20 is classified into a high charge remaining state (high SOC state) and a low charge remaining state (low SOC state). A state in which the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the high SOC state is defined as state 1, a state in which the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the low SOC state is defined as state 2, a state in which the usage state of the battery pack 20 is the charge state and the battery state of the battery pack 20 is the low SOC state is defined as state 3, and a state in which the usage state of the battery pack 20 is the charge state and the battery state of the battery pack 20 is the high SOC state is defined as state 4.

[0057] Then, based on the charge / discharge state of the battery pack 20 and the remaining charge of the battery pack 20, the output limit control start temperature setting unit 36 determines which of states 1 to 4 the state of the battery pack 20 belongs to. When it is state 1, the control start temperature Ts is set (updated) to T1. When it is state 2, the control start temperature Ts is set to T2. When it is state 3, the control start temperature Ts is set to T3. When it is state 4, the control start temperature Ts is set to T4.

[0058] As described above, when assuming that the heat generation amounts W1 to W4 of the solid-state battery cells 21 in states 1 to 4 and the heat generation amount WA of the solid-state battery cells 21 when the surface pressure applied to the solid-state battery cells 21 does not have a hysteresis characteristic, the relationship is W3 < W4 < WA < W1 < W2. Therefore, for the cases of states 1 to 4, the battery pack 20 is more likely to increase in temperature in the order of (state 2) > (state 1) > (when assuming that the surface pressure applied to the solid-state battery cells 21 does not have a hysteresis characteristic) > (state 4) > (state 3).

[0059] Then, as shown in FIG. 6, when the control start temperature Ts when assuming that the surface pressure applied to the solid-state battery cells 21 does not have a hysteresis characteristic is defined as the reference control start temperature TA, the output limit control start temperature setting unit 36 sets the control start temperature Ts so that T2 < T1 < TA < T4 < T3.

[0060] Therefore, when the usage state of the battery pack 20 is a discharging state, the output limit control start temperature setting unit 36 ​​sets the control start temperature Ts when the battery state of the battery pack 20 is a high SOC state, i.e., T1, to be higher than the control start temperature Ts when the battery state of the battery pack 20 is a low SOC state, i.e., T2.

[0061] In this way, when the usage state of the battery pack 20 is a discharged state, in a high SOC state in which the amount of heat generated by the battery pack 20 is small, the control start temperature Ts is set to a higher temperature than when the battery pack 20 is in a low SOC state in which the amount of heat generated by the battery pack 20 is large, thereby making it possible to utilize the battery performance of the battery pack 20 while maintaining the temperature of the battery pack 20 at a temperature lower than the upper usage temperature Tmax.

[0062] In addition, when the usage state of the battery pack 20 is in a charging state, the output limit control start temperature setting unit 36 ​​sets the control start temperature Ts when the battery state of the battery pack 20 is in a low SOC state, i.e., T3, to be higher than the control start temperature Ts when the battery state of the battery pack 20 is in a high SOC state, i.e., T4.

[0063] In this way, when the usage state of the battery pack 20 is in a charging state, and the amount of heat generated by the battery pack 20 is small, i.e., in a low SOC state, the control start temperature Ts is set to a higher temperature than when the amount of heat generated by the battery pack 20 is large, in a high SOC state. This makes it possible to more efficiently utilize the battery performance of the battery pack 20 while maintaining the temperature of the battery pack 20 lower than the upper usage temperature Tmax.

[0064] Then, in the output control start temperature setting unit 36, the usage state and battery state of the battery pack 20 are classified into states 1 to 4, and the control start temperature Ts is set so that T2 < T1 < TA < T4 < T3 according to states 1 to 4. By doing so, considering the change in the heat generation amount of the battery pack 20 accompanying the change in the surface pressure applied to the battery pack 20 according to the usage state and battery state of the battery pack 20, while maintaining the temperature of the battery pack 20 at a temperature lower than the usage upper limit temperature Tmax, the battery performance of the battery pack 20 can be utilized more efficiently.

[0065] Specifically, for example, as shown in FIG. 7(a), when the usage state of the battery pack 20 is a discharge state and the battery state of the battery pack 20 is a low SOC state (state 2 described above), since the heat generation amount W2 is larger than the heat generation amount WA of the solid battery cell 21 when it is assumed that the surface pressure applied to the solid battery cell 21 does not have a hysteresis characteristic, if the control start temperature Ts is set to the reference control start temperature TA, as shown by the broken line in FIG. 7(a), the usage upper limit temperature Tmax will be reached earlier than expected. Therefore, by setting the control start temperature Ts to T2, which is a temperature lower than the reference control start temperature TA, as shown by the solid line in FIG. 7(a), the battery pack 20 can be continuously used without reaching the usage upper limit temperature Tmax.

[0066] Also, for example, as shown in (b) of Fig. 7, when the usage state of the battery pack 20 is a charging state and the battery state of the battery pack 20 is a low SOC state (state 3 described above), the heat generation amount W3 is smaller than the heat generation amount WA of the solid-state battery cell 21 when it is assumed that the surface pressure applied to the solid-state battery cell 21 does not have a hysteresis characteristic. Therefore, if the control start temperature Ts is set to the reference control start temperature TA, the temperature rises only to a lower temperature than expected as shown by the dashed line in (b) of Fig. 7, and an excessive output limit is applied with respect to the upper limit temperature Tmax of use, which may result in an insufficient amount of charge of the battery pack 20. Therefore, by setting the control start temperature Ts to T3, which is a temperature higher than the reference control start temperature TA, the battery pack 20 can be utilized until it reaches a temperature closer to the upper limit temperature Tmax of use, as shown by the solid line in (b) of Fig. 7, and a sufficient amount of charge of the battery pack 20 can be secured.

[0067] <Setting flow of control start temperature used for temperature rise suppression output limit control> Next, a setting flow of the control start temperature Ts used in the temperature rise suppression output limiting control will be described with reference to FIG.

[0068] First, the battery ECU 30 acquires the remaining charge SOC [%] of the battery pack 20 by calculation in the battery remaining charge calculator 33 (step S101).

[0069] Next, the process proceeds to step S102, where the battery ECU 30 receives a vehicle state signal from the vehicle control device 90. The vehicle state signal includes information such as whether the vehicle is running on electric power or charging by regeneration or the like. If the vehicle is a hybrid vehicle, the vehicle state signal may further include information as to whether the vehicle is running on electric assist.

[0070] Next, the process proceeds to step S103, where the battery ECU 30 determines whether the battery pack 20 continues to be in a discharging state for a predetermined time t1 or more. If the battery pack 20 continues to be in a discharging state for the predetermined time t1 or more (step S103: YES), the battery ECU 30 proceeds to step S104, and if the battery pack 20 does not continue to be in a discharging state for the predetermined time t1 or more (step S103: NO), the battery ECU 30 proceeds to step S107. If the battery pack 20 continues to be in a discharging state for the predetermined time t1 or more (step S103: YES), the battery pack 20 is determined to be in a discharging state. On the other hand, if the battery pack 20 does not continue to be in a discharging state for the predetermined time t1 or more (step S103: NO), the vehicle is, for example, in a state of regenerative charging or short-time electric assist running.

[0071] In step S104, it is determined whether the remaining charge SOC [%] of the battery pack 20 acquired in step S101 is smaller than a predetermined SOC1 [%]. SOC1 is an arbitrary value that is preset according to the battery characteristics of the battery pack 20.

[0072] In step S104, if the remaining charge SOC [%] of the battery pack 20 acquired in step S101 is smaller than a predetermined SOC1 [%] (step S104: YES), the process proceeds to step S105, where the control start temperature Ts is updated to T2, and the series of setting flows ends. T2 is the control start temperature Ts that is set in the above-mentioned state 2, that is, when the usage state of the battery pack 20 is a discharge state and the battery state of the battery pack 20 is a low SOC state.

[0073] In step S104, if the remaining charge SOC [%] of the battery pack 20 acquired in step S101 is equal to or greater than a predetermined SOC1 [%] (step S104: NO), the process proceeds to step S106, where the control start temperature Ts is updated to T1, and the series of setting flows ends. T1 is the control start temperature Ts that is set in the above-mentioned state 1, that is, when the usage state of the battery pack 20 is a discharge state and the battery state of the battery pack 20 is a high SOC state.

[0074] On the other hand, in step S107, the battery ECU 30 judges whether the battery pack 20 continues to be in a charging state for a predetermined time t2 or more. If the battery pack 20 continues to be in a charging state for the predetermined time t2 or more (step S107: YES), the battery ECU 30 proceeds to step S108, and if the battery pack 20 does not continue to be in a charging state for the predetermined time t2 or more (step S107: NO), the battery ECU 30 ends a series of setting flows without changing or updating the control start temperature Ts. If the battery pack 20 continues to be in a charging state for the predetermined time t2 or more (step S107: YES), the battery pack 20 is judged to be in a charging state. On the other hand, if the battery pack 20 does not continue to be in a charging state for the predetermined time t2 or more (step S107: NO), the vehicle is, for example, in a short-time regenerative charging state.

[0075] In step S108, it is determined whether the remaining charge SOC [%] of the battery pack 20 acquired in step S101 is smaller than a predetermined SOC2 [%]. SOC2 is an arbitrary value that is preset according to the battery characteristics of the battery pack 20. Note that SOC2 may be the same value as SOC1 described above, or may be a value different from SOC1.

[0076] In step S108, when the remaining charge SOC [%] of the battery pack 20 obtained in step S101 is less than a predetermined SOC2 [%] (step S108: YES), the process proceeds to step S109, where the control start temperature Ts is updated to T3, and a series of setting flows ends. T3 is the control start temperature Ts set when in the aforementioned state 3, that is, when the usage state of the battery pack 20 is the charging state and the battery state of the battery pack 20 is the low SOC state.

[0077] In step S108, when the remaining charge SOC [%] of the battery pack 20 obtained in step S101 is equal to or greater than the predetermined SOC2 [%] (step S108: NO), the process proceeds to step S110, where the control start temperature Ts is updated to T4, and a series of setting flows ends. T4 is the control start temperature Ts set when in the aforementioned state 4, that is, when the usage state of the battery pack 20 is the charging state and the battery state of the battery pack 20 is the high SOC state.

[0078] In this way, by executing the setting flow of the control start temperature, based on the charge and discharge state of the battery pack 20, the usage state of the battery pack 20 is classified into the discharge state and the charging state, and based on the remaining charge of the battery pack 20, the battery state of the battery pack 20 is classified into the high SOC state and the low SOC state. Then, when the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the high SOC state, the control start temperature Ts is T1; when the usage state of the battery pack 20 is the discharge state and the battery state of the battery pack 20 is the low SOC state, the control start temperature Ts is T2; when the usage state of the battery pack 20 is the charging state and the battery state of the battery pack 20 is the low SOC state, the control start temperature Ts is T3; when the usage state of the battery pack 20 is the charging state and the battery state of the battery pack 20 is the high SOC state, the control start temperature Ts is T4. The control start temperature Ts is set such that T2 < T1 < T4 < T3.

[0079] This makes it possible to set the control start temperature Ts with simple control, taking into account the change in the amount of heat generated by the battery pack 20 due to changes in the surface pressure on the battery pack 20 depending on the usage state of the battery pack 20 and the battery state, while maintaining the temperature of the battery pack 20 at a temperature lower than the upper usage limit temperature Tmax, so as to more efficiently utilize the battery performance of the battery pack 20.

[0080] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiment may be arbitrarily combined within the scope of the invention.

[0081] For example, the vehicle in which the power supply system 10 is installed may be a battery-electric vehicle or a hybrid vehicle.

[0082] Furthermore, for example, the restraining member that restrains the solid-state battery cell 21 is not limited to the cushion member 22, and may be any member that, when the battery pack 20 is charged, the restraining member is compressed due to the expansion of the solid-state battery cell 21, increasing the surface pressure applied to the solid-state battery cell 21, and when the battery pack 20 is discharged, the restraining member is restored due to the contraction of the solid-state battery cell 21, decreasing the surface pressure applied to the solid-state battery cell 21.

[0083] Also, for example, in the present embodiment, the battery ECU 30 receives a vehicle state signal from the vehicle control device 90 in step S102, and determines in step S103 whether the vehicle continues the electric running state for a predetermined time t1 or more. However, a current sensor connected to the battery ECU 30 may be attached to the battery pack 20, and step S102 may be omitted, and in step S103, it may be determined whether the output current value I of the battery pack 20 is I>0 for a predetermined time t1 or more. If the output current value I of the battery pack 20 is I>0 for a predetermined time t1 or more, the battery pack 20 is in a discharging state. In this case, in step S107, it may be determined whether the output current value I of the battery pack 20 is I<0 for a predetermined time t2 or more. If the output current value I of the battery pack 20 is I<0 for a predetermined time t2 or more, the battery pack 20 is in a charging state.

[0084] This specification describes at least the following items. In parentheses, components corresponding to the above-described embodiment are shown as examples, but the present invention is not limited to these.

[0085] (1) a battery pack (battery pack 20) ​​having a solid-state battery cell (solid-state battery cell 21) and a restraining member (cushion member 22) that restrains the solid-state battery cell; a battery control device (battery ECU 30) for controlling charging and discharging power of the battery pack; A power supply system (power supply system 10) comprising: When the battery pack is charged, the restraining member is compressed due to the expansion of the solid-state battery cell, and a surface pressure applied to the solid-state battery cell increases, When the battery pack is discharged, the restraining member is restored due to contraction of the solid-state battery cell, and the surface pressure applied to the solid-state battery cell is reduced, The battery control device includes: When the temperature of the battery pack becomes equal to or higher than a control start temperature (control start temperature Ts), a temperature rise suppression output limiting control is executed to limit an output release rate of the battery pack, In the temperature rise suppression output limiting control, the control start temperature is set based on a usage state of the battery pack and a battery state of the battery pack. Power supply system.

[0086] According to (1), the optimal control start temperature can be set based on the usage state of the battery pack and the battery state of the battery pack, so that the battery performance of the battery pack can be utilized more efficiently while maintaining the temperature of the battery pack lower than the upper limit usage temperature.

[0087] (2) The power supply system according to (1), the usage state of the battery pack includes a charge / discharge state of the battery pack, the battery status of the battery pack includes a remaining charge of the battery pack; Power supply system.

[0088] According to (2), the control start temperature can be set according to the amount of heat generated by the battery pack, which changes depending on the surface pressure applied to the battery pack, based on the charge / discharge state of the battery pack and the remaining charge of the battery pack, so that a more optimal control start temperature can be set according to the amount of heat generated by the battery pack.

[0089] (3) The power supply system according to (2), The battery control device includes: classifying the usage state of the battery pack into a discharging state and a charging state based on a charging / discharging state of the battery pack; classifying the battery state of the battery pack into a high remaining charge state and a low remaining charge state based on the remaining charge of the battery pack; whether the usage state of the battery pack is the discharging state or the charging state; whether the battery state of the battery pack is the high remaining charge state or the low remaining charge state; and setting the control start temperature in the temperature rise suppression output limiting control based on the above. Power supply system.

[0090] According to (3), an optimal control start temperature can be set through simple control in accordance with the amount of heat generated by the battery pack, which changes depending on the surface pressure applied to the battery pack.

[0091] (4) The power supply system according to (3), The battery control device, in the temperature rise suppression output limiting control, setting the control start temperature when the usage state of the battery pack is the charging state higher than the control start temperature when the usage state of the battery pack is the discharging state; Power supply system.

[0092] According to (4), in the temperature rise suppression output limiting control, by setting the control start temperature when the battery pack is in a charging state higher than the control start temperature when the battery pack is in a discharging state, the temperature of the battery pack can be maintained lower than the upper limit usage temperature while more efficiently utilizing the battery performance of the battery pack.

[0093] (5) The power supply system according to (4), The battery control device, in the temperature rise suppression output limiting control, When the usage state of the battery pack is the discharged state, setting the control start temperature when the battery state of the battery pack is the high remaining charge state higher than the control start temperature when the battery state of the battery pack is the low remaining charge state; Power supply system.

[0094] According to (5), when the battery pack is in a discharging state and the amount of heat generated by the battery pack is small (high charge remaining capacity), the control start temperature is set to a higher temperature than when the battery pack is in a low charge remaining capacity and the amount of heat generated by the battery pack is large. This makes it possible to utilize the battery performance of the battery pack while maintaining the temperature of the battery pack lower than the upper limit operating temperature.

[0095] (6) The power supply system according to (4) or (5), The battery control device, in the temperature rise suppression output limiting control, When the usage state of the battery pack is the charging state, setting the control start temperature when the battery state of the battery pack is the low remaining charge state higher than the control start temperature that is set when the battery state of the battery pack is the high remaining charge state; Power supply system.

[0096] According to (6), when the battery pack is in a charging state and the amount of heat generated by the battery pack is small (i.e., a low remaining charge state), the control start temperature is set to a higher temperature than when the amount of heat generated by the battery pack is large (i.e., a high remaining charge state), thereby making it possible to more efficiently utilize the battery performance of the battery pack while maintaining the temperature of the battery pack lower than the upper limit operating temperature.

[0097] (7) The power supply system according to (3), In the temperature rise suppression output limiting control, The control start temperature when the usage state of the battery pack is the discharge state and the battery state of the battery pack is the high remaining charge state is T1, The control start temperature when the usage state of the battery pack is the discharge state and the battery state of the battery pack is the low remaining charge state is T2, Let the control start temperature when the usage state of the battery pack is the charging state and the battery state of the battery pack is the low remaining charge state be T3. When the control start temperature when the usage state of the battery pack is the charging state and the battery state of the battery pack is the high remaining charge state is T4, Set the control start temperature so that T2 < T1 < T4 < T3. Power supply system.

[0098] According to (7), considering the change in the heat generation amount of the battery pack accompanying the change in the surface pressure applied to the battery pack according to the usage state and battery state of the battery pack, while maintaining the temperature of the battery pack at a temperature lower than the upper limit temperature of use, the battery performance of the battery pack can be utilized more efficiently.

Explanation of symbols

[0099] 10 Power supply system 20 Battery pack 21 Solid battery cell 22 Cushion member (constraint member) 30 Battery ECU (battery control device) Ts Control start temperature

Claims

1. A battery pack having battery cells; a battery control device for controlling charging and discharging power of the battery pack; A power supply system comprising: The battery control device includes: When the temperature of the battery pack becomes equal to or higher than a control start temperature, a temperature rise suppression output limiting control is executed to limit an output release rate of the battery pack, In the temperature rise suppression output limiting control, the control start temperature is set based on a usage state of the battery pack and a battery state of the battery pack; the usage state of the battery pack includes a charge / discharge state of the battery pack, the battery status of the battery pack includes a remaining charge of the battery pack; The battery control device includes: classifying the usage state of the battery pack into a discharging state and a charging state based on a charging / discharging state of the battery pack; classifying the battery state of the battery pack into a high remaining charge state and a low remaining charge state based on the remaining charge of the battery pack; whether the usage state of the battery pack is the discharging state or the charging state; whether the battery state of the battery pack is the high remaining charge state or the low remaining charge state; Based on the above, the control start temperature in the temperature rise suppression output limiting control is set, In the temperature rise suppression output limiting control, setting the control start temperature when the usage state of the battery pack is the charging state higher than the control start temperature when the usage state of the battery pack is the discharging state; When the usage state of the battery pack is the discharged state, setting the control start temperature when the battery state of the battery pack is the high remaining charge state higher than the control start temperature when the battery state of the battery pack is the low remaining charge state; Power supply system.

2. 2. The power supply system of claim 1, The battery control device, in the temperature rise suppression output limiting control, When the usage state of the battery pack is the charging state, setting the control start temperature when the battery state of the battery pack is the low remaining charge state higher than the control start temperature that is set when the battery state of the battery pack is the high remaining charge state; Power supply system.

3. A battery pack having battery cells; a battery control device for controlling charging and discharging power of the battery pack; A power supply system comprising: The battery control device includes: When the temperature of the battery pack becomes equal to or higher than a control start temperature, a temperature rise suppression output limiting control is executed to limit an output release rate of the battery pack, In the temperature rise suppression output limiting control, the control start temperature is set based on a usage state of the battery pack and a battery state of the battery pack; the usage state of the battery pack includes a charge / discharge state of the battery pack, the battery status of the battery pack includes a remaining charge of the battery pack; The battery control device includes: classifying the usage state of the battery pack into a discharging state and a charging state based on a charging / discharging state of the battery pack; classifying the battery state of the battery pack into a high remaining charge state and a low remaining charge state based on the remaining charge of the battery pack; whether the usage state of the battery pack is the discharging state or the charging state; whether the battery state of the battery pack is the high remaining charge state or the low remaining charge state; Based on the above, the control start temperature in the temperature rise suppression output limiting control is set, In the temperature rise suppression output limiting control, The control start temperature when the usage state of the battery pack is the discharged state and the battery state of the battery pack is the high remaining charge state is T1, The control start temperature when the usage state of the battery pack is the discharged state and the battery state of the battery pack is the low remaining charge state is T2, The control start temperature when the usage state of the battery pack is the charging state and the battery state of the battery pack is the low remaining charge state is T3, When the usage state of the battery pack is the charging state and the battery state of the battery pack is the high remaining charge state, the control start temperature is T4, The control start temperature is set so as to satisfy T2<T1<T4<T3. Power supply system.

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