Battery temperature control device and control program
Patent Information
- Application Number
- JP2023126610
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-08-02
- Publication Date
- 2025-02-14
Smart Images
Figure 2025022220000001_ABST
Abstract
Description
[Technical field]
[0001] The disclosure described in this specification relates to a battery temperature regulator and a control program. [Background technology]
[0002] The battery pack includes a current generator electrically connected to the battery pack having a plurality of battery cells electrically connected to each other, and generates a ripple current, and a temperature difference reduction unit that reduces the temperature difference between battery cells among the plurality of battery cells that are to be heated by the ripple current. This makes it possible to generate a ripple current in the battery cells while reducing the temperature difference between the battery cells, thereby making it possible to increase the current that can be passed through the battery cells, and therefore to heat up the battery cells more quickly. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2020-98681 A Summary of the Invention [Problem to be solved by the invention]
[0004] Patent Document 1 aims to reduce the temperature difference between the center and ends or due to layout when energy is applied to a battery cell by a ripple current, but its capabilities are insufficient for technology that reduces the difference in temperature rise capacity of several dozen times due to differences in voltage between assembled batteries.
[0005] An object of the present disclosure is to provide a battery temperature regulator and a control program that can appropriately cool a plurality of assembled batteries having different voltages in a temperature-raising mode. [Means for solving the problem]
[0006] A battery temperature regulating device according to one aspect of the present disclosure includes: A battery temperature regulating device (100) is applied to a power conversion system (1) in which a first assembled battery (21) and a second assembled battery (22), each including at least one battery cell (23), are electrically connected to a motor (3) and an inverter (6), the first assembled battery and the second assembled battery have different voltages, and charging and discharging are performed between the first assembled battery and the second assembled battery to provide a temperature rise mode for raising the temperatures of the first assembled battery and the second assembled battery, a cooling circuit (110) having a plurality of flow paths (111, 112, 113, 114) through which a refrigerant flows to cool the first assembled battery and the second assembled battery; A switching valve (130, 140, 150, 210, 310, 410) that is provided in the cooling circuit and is capable of switching which of a plurality of flow paths a refrigerant flows through; A switching device (160) that controls the opening and closing of the switching valve, The amount of heat generated during heating mode differs between the first and second assembled batteries. The switching device controls the opening and closing of the switching valve so as to suppress the temperature difference between the first assembled battery and the second assembled battery that occurs in the temperature rise mode.
[0007] According to this battery temperature adjustment device, in the temperature increase mode, it is possible to appropriately cool the first assembled battery (21) and the second assembled battery (22) which have different voltages.
[0008] A control program according to an embodiment of the present disclosure includes: In a power conversion system (1), a first assembled battery (21) and a second assembled battery (22), each including at least one battery cell (23), are electrically connected to a motor (3) and an inverter (6), the first assembled battery and the second assembled battery have different voltages, and charging and discharging are performed between the first assembled battery and the second assembled battery to provide a temperature rise mode for raising the temperatures of the first assembled battery and the second assembled battery, The heat generation amount of the first and second assembled batteries during the heating mode differs. the power conversion system is provided with a cooling circuit (110) including a plurality of flow paths (111, 112, 113, 114) through which a refrigerant for cooling a first assembled battery and a second assembled battery flows, and a switching valve (130, 140, 150, 210, 310, 410) capable of switching which of the plurality of flow paths the refrigerant flows through; A control program for a switching device (160) that controls opening and closing of a switching valve, comprising: The switching valve is controlled to open and close so as to suppress the temperature difference between the first assembled battery and the second assembled battery that occurs in the temperature rise mode.
[0009] According to this control program, in the temperature increasing mode, it is possible to appropriately cool the first assembled battery (21) and the second assembled battery (22) which have different voltages.
[0010] It should be noted that the reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments described below, and do not in any way limit the technical scope. [Brief description of the drawings]
[0011] [Figure 1] 1 is a configuration diagram of a power conversion system according to a first embodiment. [Diagram 2] FIG. 2 is a configuration diagram showing a cooling system in a normal mode and a charging mode. [Diagram 3] FIG. 4 is a diagram showing the flow of refrigerant in a normal mode and a charging mode. [Figure 4] FIG. 2 is a configuration diagram showing the cooling system in a temperature increasing mode. [Diagram 5] FIG. 4 is a diagram showing the flow of the refrigerant in a temperature increasing mode. [Figure 6] 1 is a table showing the on / off states of the relay for each mode. [Figure 7] 4 is a table showing the open / closed state of a solenoid valve for each mode. [Figure 8] FIG. 2 is a schematic diagram illustrating a control device according to the first embodiment. [Figure 9] 4 is a flowchart showing the control in the first to fourth embodiments. [Figure 10] FIG. 11 is a configuration diagram showing the flow of refrigerant in a normal mode and a charging mode in the second embodiment. [Figure 11] FIG. 11 is a configuration diagram showing a flow of a refrigerant in a temperature increasing mode in the second embodiment. [Figure 12]FIG. 11 is a configuration diagram showing the flow of refrigerant in a normal mode and a charging mode in a third embodiment. [Figure 13] FIG. 11 is a configuration diagram showing a flow of a refrigerant in a temperature increasing mode in the third embodiment. [Figure 14] FIG. 13 is a configuration diagram showing the flow of refrigerant in a normal mode and a charging mode in a fourth embodiment. [Figure 15] FIG. 13 is a configuration diagram showing a flow of a refrigerant in a temperature increasing mode in the fourth embodiment. [Figure 16] FIG. 13 is a schematic diagram illustrating a control device according to a fifth embodiment. [Figure 17] 13 is a flowchart showing a control according to a fifth embodiment. [Figure 18] FIG. 13 is a schematic diagram illustrating a control device according to a sixth embodiment. [Figure 19] 13 is a flowchart showing a control according to a sixth embodiment. [Figure 20] 13 is a flowchart showing a control according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.
[0013] In addition to combinations of parts that are explicitly stated as possible in each embodiment, it is also possible to partially combine embodiments, embodiments and variations, and variations even if not explicitly stated, provided that there are no particular problems with the combination.
[0014] (First embodiment) FIG. 1 is a configuration diagram of a power conversion system 1 of the first embodiment. FIG. 2 and FIG. 4 are configuration diagrams showing a cooling system. The battery temperature regulator 100 of this embodiment is applied to, for example, a power conversion system 1 of a mobile body using a rotating electric machine as a drive source. The mobile body is, for example, an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an aircraft such as an electric vertical take-off and landing aircraft or a drone, a ship, a construction machine, or an agricultural machine. An example of application to a vehicle will be described below.
[0015] First, there will be described a schematic configuration of a vehicle power conversion system 1. As shown in FIG.
[0016] The battery 2 is a DC voltage source composed of a chargeable and dischargeable secondary battery. The secondary battery is, for example, a lithium-ion battery or a nickel-metal hydride battery. The motor generator 3 is a three-phase AC rotating electric machine. The motor generator 3 functions as a drive source for the vehicle, i.e., an electric motor. The motor generator 3 functions as a generator during regeneration. The power conversion device 4 performs power conversion between the battery 2 and the motor generator 3.
[0017] <Power conversion device> Next, a description will be given of the circuit configuration of the power conversion device 4. The power conversion device 4 includes a power conversion circuit. As shown in FIG 1, the power conversion device 4 includes a smoothing capacitor 5, an inverter 6 which is a power conversion circuit, and a control device 7.
[0018] The smoothing capacitor 5 mainly smoothes the DC voltage supplied from the battery 2. The smoothing capacitor 5 is connected to a P line 8, which is a power line on the high potential side, and an N line 9, which is a power line on the low potential side. The P line 8 is connected to the positive electrode of the battery 2, and the N line 9 is connected to the negative electrode of the battery 2. The positive electrode of the smoothing capacitor 5 is connected to the P line 8 between the battery 2 and the inverter 6. Similarly, the negative electrode of the smoothing capacitor 5 is connected to the N line 9 between the battery 2 and the inverter 6. The smoothing capacitor 5 is connected in parallel to the battery 2.
[0019] The inverter 6 is a DC-AC conversion circuit. The inverter 6 converts a DC voltage into a three-phase AC voltage in accordance with switching control by a control circuit 7B described below, and outputs the voltage to the motor generator 3. This drives the motor generator 3 to generate a predetermined torque. During regenerative braking of the vehicle, the inverter 6 converts the three-phase AC voltage generated by the motor generator 3 upon receiving rotational force from the wheels into a DC voltage, and outputs the DC voltage to the P line 8. In this way, the inverter 6 performs bidirectional power conversion between the battery 2 and the motor generator 3.
[0020] The inverter 6 is configured with upper and lower arm circuits 10H, 10L for three phases. The upper and lower arm circuits 10H, 10L are sometimes referred to as legs. The upper and lower arm circuits 10H, 10L have an upper arm 10H and a lower arm 10L. The upper arm 10H and the lower arm 10L are connected in series between the P line 8 and the N line 9, with the upper arm 10H on the P line 8 side. A connection point between the upper arm 10H and the lower arm 10L is connected to a corresponding winding 3a of the motor generator 3 via an output line 13. The inverter 6 has six arms. At least a portion of each of the P line 8, the N line 9, and the output line 13 is formed of a conductive member such as a bus bar.
[0021] The elements constituting each arm include an IGBT 11 which is a switching element, and a freewheeling diode 12. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. In this embodiment, an n-channel IGBT 11 is adopted. The diode 12 is connected inversely parallel to the corresponding IGBT 11. In the upper arm 10H, the collector of the IGBT 11 is connected to a P line 8. In the lower arm 10L, the emitter of the IGBT 11 is connected to an N line 9. The emitter of the IGBT 11 in the upper arm 10H and the collector of the IGBT 11 in the lower arm 10L are connected to each other. The anode of the diode 12 is connected to the emitter of the corresponding IGBT 11, and the cathode is connected to the collector.
[0022] FIG. 8 is a schematic diagram illustrating the control device 7. The control device 7 includes a drive circuit 7A for the switching elements that constitute the inverter 6 and the like. The drive circuit 7A supplies a drive voltage to the gate of the IGBT 11 of the corresponding arm based on a drive command from a control circuit 7B. The drive circuit 7A drives the corresponding IGBT 11, i.e., turns it on and off, by applying the drive voltage. The drive circuit 7A is sometimes referred to as a driver.
[0023] The control device 7 may further include a control circuit 7B for the switching element. The control circuit 7B generates a drive command for operating the IGBT 11 and outputs it to the drive circuit 7A. The control circuit 7B generates the drive command based on a torque request input from a higher-level ECU 1A (not shown) and signals detected by various sensors. The various sensors include, for example, a current sensor, a rotation angle sensor, and a voltage sensor. The current sensor detects the phase current flowing through the winding 3a of each phase. The rotation angle sensor detects the rotation angle of the rotor of the motor generator 3. The voltage sensor detects the voltage across the smoothing capacitor 5. The control circuit 7B outputs, for example, a PWM signal as the drive command.
[0024] The battery 2 is an electricity storage device in which two assembled batteries 21, 22 are connected in series. The assembled batteries 21, 22 are provided with a plurality of battery cells 23. The cell voltages of the battery cells 23 provided in the assembled batteries 21, 22 are set to the same voltage. Of the two assembled batteries 21, 22, one connected to the P line 8 may be referred to as the first assembled battery 21. Of the two assembled batteries 21, 22, one connected to the N line 9 may be referred to as the second assembled battery 22. The first assembled battery 21 is provided with a plurality of battery cells 23. The second assembled battery 22 is provided with a plurality of battery cells 23. The number of battery cells 23 included in the first assembled battery 21 is different from the number of battery cells 23 included in the second assembled battery 22. The number of battery cells 23 included in the second assembled battery 22 is greater than the number of battery cells 23 included in the first assembled battery 21.
[0025] It should be noted that the first assembled battery 21 needs to have at least one battery cell 23. The second assembled battery 22 needs to have at least one battery cell 23. In the first assembled battery 21, the voltages of the multiple battery cells 23 may be the same or different. In the second assembled battery 22, the voltages of the multiple battery cells 23 may be the same or different. Furthermore, as long as the voltages of the first assembled battery 21 and the second assembled battery 22 are different, the number of battery cells 23 included in the first assembled battery 21 and the second assembled battery 22 may be the same.
[0026] The voltage of the first assembled battery 21 and the voltage of the second assembled battery 22 are different. As an example, the voltage of the first assembled battery 21 is 100 V. The voltage of the second assembled battery 22 is 400 V. As an example, the number of battery cells 23 included in the second assembled battery 22 is four times the number of battery cells 23 included in the first assembled battery 21.
[0027] An intermediate point P1 between the first assembled battery 21 and the second assembled battery 22 and the N line 9 are electrically connected via a first connection line 31. An intermediate point P2 between the first assembled battery 21 and the second assembled battery 22 and a neutral point P0 of the motor generator 3 are electrically connected via a second connection line 32. Relays 41, 42 are used as connection switches in the connection lines 31, 32. The intermediate point P1 is provided closer to the first assembled battery 21 than the intermediate point P2.
[0028] When the relay 41 provided in the connection line 31 is turned on, the first assembled battery 21 and the inverter 6 are electrically connected. When the relay 41 is turned off, the first assembled battery 21 and the inverter 6 are electrically disconnected. When the relay 42 provided in the connection line 32 is turned on, the second assembled battery 22 and the motor generator 3 are electrically connected. When the relay 42 is turned off, the second assembled battery 22 and the motor generator 3 are electrically disconnected. The relay 41 may be referred to as a first relay. The relay 42 may be referred to as a second relay.
[0029] Furthermore, a relay 43 is provided between the first assembled battery 21 and the second assembled battery 22. When the relay 43 is turned on, the first assembled battery 21 and the second assembled battery 22 are electrically connected. When the relay 43 is turned off, the first assembled battery 21 and the second assembled battery 22 are electrically disconnected. An on / off control unit 7C that controls the on / off of the relays 41, 42, 43 is provided in the control device 7. The on / off control unit 7C generates a signal that turns on and off the relays 41, 42, 43 based on information such as the vehicle state input from the higher-level ECU 1A. The relays 41, 42, 43 perform on / off operations based on the on / off signal. The relay 43 is sometimes referred to as a third relay.
[0030] The battery 2 can be charged by a charging device 50. An intermediate point P3 between the first assembled battery 21 and the second assembled battery 22 is electrically connected to the charging device 50 via a first charging line 51. As an example, the intermediate point P3 is provided closer to the second assembled battery 22 than the intermediate point P2. A connection point P4 between the second assembled battery 22 and the N line 9 is electrically connected to the charging device 50 via a second charging line 52. Power is supplied from the charging device 50 to the battery 2 via the first charging line 51 and the second charging line 52.
[0031] In this embodiment, during normal operation, relays 41 and 42 are off and relay 43 is on. Normal operation refers to a state in which the IG switch is on. Normal operation includes operation when the vehicle is running and when the vehicle is stopped. When the vehicle is running and when the vehicle is stopped, electricity is supplied to the battery 2 from the charging device 50, and therefore cooling of the battery 2 is necessary. The vehicle state when the vehicle is running and when the vehicle is stopped may be referred to as normal mode. During normal mode, the first assembled battery 21 and the second assembled battery 22 are connected in series.
[0032] During charging, relays 42 and 43 are on and relay 41 is off. During charging, the battery 2 is connected to the charging device 50. During charging, current is still flowing to the battery 2, so the battery 2 needs to be cooled. The vehicle state during charging is sometimes referred to as the charging mode. During the charging mode, the first assembled battery 21 and the second assembled battery 22 are connected in series.
[0033] The vehicle state includes a temperature rise mode in addition to the normal mode and the charging mode. The vehicle state is determined by the control device 7. A mode determination unit 7D of the control device 7 determines the vehicle mode by receiving information from the upper ECU 1A. The mode determination unit 7D provides the vehicle with one of the normal mode, the charging mode, and the temperature rise mode. In the temperature rise mode, the relays 41 and 42 are on and the relay 43 is off. The temperature rise mode is a mode in which the temperature of the battery packs 21 and 22 is intentionally raised by charging and discharging between the multiple battery packs 21 and 22. In the temperature rise mode, the first battery pack 21 and the second battery pack 22 are connected in parallel. Hereinafter, the first battery pack 21 and the second battery pack 22 may be collectively referred to simply as the battery packs 21 and 22.
[0034] FIG. 2 is a configuration diagram showing the cooling system in normal and charging modes. FIG. 3 is a configuration diagram showing the flow of refrigerant in normal and charging modes. FIG. 4 is a configuration diagram showing the cooling system in temperature increase mode. FIG. 5 is a configuration diagram showing the flow of refrigerant in temperature increase mode. FIG. 6 is a table showing the on / off states of relays 41, 42, 43 for each mode. FIG. 7 is a table showing the open / closed states of solenoid valves 130, 140, 150 for each mode. FIG. 9 is a flowchart showing the control of the first to fourth embodiments.
[0035] When the temperature of the battery 2 becomes low, the internal resistance of the battery 2 increases, and the input / output characteristics of the battery 2 deteriorate. In order to run electric vehicles and hybrid vehicles in an environment with a low outside air temperature, it is necessary to heat up the battery 2. As a technique for heating the battery 2 from within, a technique that utilizes the self-heating of the battery 2 is known. In this technique, for example, a control device 7 or the like generates a ripple current between the smoothing capacitor 5 and the assembled batteries 21, 22. In addition, the control device 7 actively heats up the assembled batteries 21, 22 by repeatedly charging and discharging between the assembled batteries 21, 22.
[0036] In the temperature rise mode, the motor generator 3 and the inverter 6 operate as a boost converter. In this case, the switches 11H, 11L of the upper and lower arm circuits 10H, 10L are alternately turned on. When the upper arm switch 11H is turned on, a current flows from the first assembled battery 21 to the winding 3a. When the upper arm switch 11H is turned off, a current flows through the second assembled battery 22 and the diode 12 of the lower arm switch 11L to the winding 3a.
[0037] On the other hand, when the lower arm switch 11L is turned on, a current flows from the second assembled battery 22 to the winding 3a. When the lower arm switch 11L is turned off, a current flows to the winding 3a through the diode 12 of the upper arm switch 11H and the first assembled battery 21. This causes mutual charging and discharging between the assembled batteries 21, 22, and the temperatures of the assembled batteries 21, 22 rise as a result of this current flow.
[0038] In this embodiment, as an example, the ratio of the voltage of the first assembled battery 21 to the voltage of the second assembled battery 22 is 1:4. In the temperature increase mode, the ratio of the current value flowing through the first assembled battery 21 to the current value flowing through the second assembled battery 22 is 4:1. The heat generation amount of the assembled batteries 21, 22 is the resistance value multiplied by the square of the current value. That is, the ratio of the heat generation amount of the first assembled battery 21 to the heat generation amount of the second assembled battery 22 is 16:1. In this system in which the temperature of the battery 2 is increased by exchanging current between the assembled batteries 21, 22 having different voltages, a difference occurs in the heat generation amount of each assembled battery 21, 22, and therefore a difference occurs in the rate of temperature increase of the assembled batteries 21, 22. A large temperature difference occurs between the first assembled battery 21 and the second assembled battery 22.
[0039] Therefore, in this embodiment, the battery temperature adjustment device 100 suppresses the occurrence of a large temperature difference between the first assembled battery 21 and the second assembled battery 22. The configuration of the battery temperature adjustment device 100 will be described below. The battery temperature adjustment device 100 has a cooling circuit 110, a refrigerant circulation device 120, solenoid valves 130, 140, 150, and a switching device 160. The cooling circuit 110 is connected to an outlet 121 and an inlet 122 of the refrigerant circulation device 120.
[0040] The refrigerant circulation device 120 is a device that cools or regulates the temperature of the assembled batteries 21, 22 by circulating a refrigerant controlled at a constant temperature. The refrigerant circulation device 120 has an outlet 121 through which the refrigerant flows out and an inlet 122 through which the refrigerant flows in. The refrigerant is supplied to the cooling circuit 110 from the outlet 121. The refrigerant cools the multiple battery cells 23 included in the assembled batteries 21, 22. The refrigerant individually cools the battery cells 23 included in the first assembled battery 21 and the battery cells 23 included in the second assembled battery 22.
[0041] The cooling circuit 110 has a first flow path 111, a second flow path 112, a third flow path 113, and a fourth flow path 114. The first flow path 111 is a flow path connected to an outlet 121. The third flow path 113 is a flow path connected to an inlet 122. The first flow path 111 and the third flow path 113 are connected via a second flow path 112. The second flow path 112 is a flow path connected to the first flow path 111 and the third flow path 113.
[0042] The second flow path 112 has a first assembled battery side second flow path 112A for cooling the first assembled battery 21 and a second assembled battery side second flow path 112B for cooling the second assembled battery 22. The first assembled battery side second flow path 112A is connected to the first flow path 111 on the outlet 121 side of the second assembled battery side second flow path 112B. The number of the first assembled battery side second flow paths 112A corresponds to the number of the battery cells 23 included in the first assembled battery 21. The number of the second assembled battery side second flow paths 112B corresponds to the number of the battery cells 23 included in the second assembled battery 22. The ratio of the number of the battery cells 23 included in the first assembled battery 21 to the number of the battery cells 23 included in the second assembled battery 22 is 1:4. The ratio of the number of the first assembled battery side second flow paths 112A to the number of the second assembled battery side second flow paths 112B is 1:4.
[0043] The first assembled battery side second flow path 112A extends along the battery cells 23 included in the first assembled battery 21. In the drawings, the number of the first assembled battery side second flow paths 112A is shown as one for convenience. The second assembled battery side second flow path 112B extends along the battery cells 23 included in the second assembled battery 22. The second assembled battery side second flow path 112B is connected to the first flow path 111 and the third flow path 113. The battery cells 23 included in the first assembled battery 21 are cooled by the refrigerant flowing through the first assembled battery side second flow path 112A.
[0044] In addition, in the drawings, the number of second assembled battery side second flow paths 112B is shown as four for convenience. The second assembled battery side second flow paths 112B extend along the corresponding battery cells 23. The second assembled battery side second flow paths 112B are connected in parallel between the first flow path 111 and the third flow path 113. The battery cells 23 included in the second assembled battery 22 are individually cooled by the refrigerant flowing through the second assembled battery side second flow paths 112B.
[0045] The first assembled battery side second flow path 112A and the second assembled battery side second flow path 112B are connected in parallel between the first flow path 111 and the third flow path 113. The fourth flow path 114 is a flow path that connects the first flow path 111 and the third flow path 113 without the second flow path 112. An end of the fourth flow path 114 is connected to a connection point P9 that is an end of the first flow path 111 on the inlet 122 side. An end of the fourth flow path 114 is connected to a connection point P7 that is an end of the third flow path 113 on the inlet 122 side. The refrigerant flowing through the first flow path 111 can flow through the first assembled battery side second flow path 112A, the second assembled battery side second flow path 112B, and the fourth flow path 114.
[0046] The cooling circuit 110 is also provided with solenoid valves 130, 140, and 150. The solenoid valves 130, 140, and 150 are valves with two-way inlets and outlets for the refrigerant. The solenoid valves 130, 140, and 150 may also be referred to as two-way valves. The solenoid valve 130 is provided in the first flow path 111. Specifically, the solenoid valve 130 is provided between a connection point P5 between the first flow path 111 and the second flow path 112A of the first assembled battery, and a connection point P6 between the first flow path 111 and the second flow path 112B of the second assembled battery that is closest to the outlet 121. The solenoid valve 130 may also be referred to as the first solenoid valve.
[0047] The solenoid valve 140 is provided in the third flow path 113. Specifically, the solenoid valve 140 is provided between a connection point P7 between the fourth flow path 114 and the third flow path 113 and a connection point P8 between the second assembled battery side second flow path 112B closest to the inlet 122 and the third flow path 113. The solenoid valve 140 may be referred to as a second solenoid valve. The solenoid valve 150 is provided in the fourth flow path 114. Specifically, the solenoid valve 150 is provided between a connection point P9 between the fourth flow path 114 and the second assembled battery side second flow path 112B closest to the inlet 122 and the connection point P7. The solenoid valve 150 may be referred to as a third solenoid valve.
[0048] In this embodiment, in the normal mode and the charging mode, the same amount of current flows through the first assembled battery 21 and the second assembled battery 22. Therefore, in the normal mode and the charging mode, there is almost no difference between the amount of heat generated by the first assembled battery 21 and the amount of heat generated by the second assembled battery 22. There is almost no temperature difference between the first assembled battery 21 and the second assembled battery 22. In this case, the battery temperature regulator 100 receives information about the vehicle state from the upper ECU 1A and opens the solenoid valve 130, opens the solenoid valve 140, and closes the solenoid valve 150. In the drawings, a white circle with a cross is shown as the open state. A black circle is shown as the closed state.
[0049] According to this, the refrigerant flows from the first flow path 111 through the first assembled battery side second flow path 112A and the second assembled battery side second flow path 112B to the third flow path 113. The refrigerant that has passed through the first flow path 111 flows almost evenly into the first assembled battery side second flow path 112A and the second assembled battery side second flow path 112B. The refrigerant at almost the same temperature flows into the first assembled battery side second flow path 112A and the second assembled battery side second flow path 112B. Since there is almost no temperature difference between the first assembled battery 21 and the second assembled battery 22, the first assembled battery 21 and the second assembled battery 22 can be cooled almost evenly. Hereinafter, this cooling method may be referred to as even cooling. The temperature difference between the first assembled battery 21 and the second assembled battery 22 can be reduced by the even cooling.
[0050] Furthermore, in the temperature rise mode, a larger current flows through the first assembled battery 21 than through the second assembled battery 22. Therefore, in the temperature rise mode, the amount of heat generated by the first assembled battery 21 is larger than the amount of heat generated by the second assembled battery 22. There is a large temperature difference between the first assembled battery 21 and the second assembled battery 22. In this case, the battery temperature regulator 100 receives information on the vehicle state from the host ECU 1A and closes the solenoid valve 130, closes the solenoid valve 140, and opens the solenoid valve 150.
[0051] According to this, the refrigerant passes from the first flow path 111 to the first assembled battery side second flow path 112A. The refrigerant that passes through the first assembled battery side second flow path 112A passes through a part of the third flow path 113, and then passes through the second assembled battery side second flow path 112B. The refrigerant that passes through the second assembled battery side second flow path 112B flows into the fourth flow path 114. The refrigerant that passes through the fourth flow path 114 flows into the third flow path 113 at the connection point P7.
[0052] As described above, the refrigerant passes through the first assembled battery side second flow path 112A, and then passes through the second assembled battery side second flow path 112B. The temperature of the first assembled battery 21 is higher than the temperature of the second assembled battery 22. A refrigerant that is cold enough to cool the first assembled battery 21 flows out from the refrigerant circulation device 120. The cold refrigerant flowing out from the refrigerant circulation device 120 cools the first assembled battery 21 while passing through the first assembled battery side second flow path 112A.
[0053] The refrigerant that has passed through the first assembled battery side second flow path 112A absorbs heat emitted by the first assembled battery 21. The refrigerant that has absorbed the heat of the first assembled battery 21 cools the second assembled battery 22 while passing through the second assembled battery side second flow path 112B. After cooling the first assembled battery 21, the refrigerant cools the second assembled battery 22. The refrigerant cools the first assembled battery 21 and the second assembled battery 22 in series. Hereinafter, this cooling method may be referred to as series cooling. According to the series cooling, the temperature of the first assembled battery 21 is significantly lowered and the temperature of the second assembled battery 22 is slightly lowered. Accordingly, the temperatures of the first assembled battery 21 and the second assembled battery 22 can be made closer to each other. The temperature difference between the first assembled battery 21 and the second assembled battery 22 can be reduced.
[0054] The refrigerant that has absorbed heat from the first assembled battery 21 may warm the second assembled battery 22 while passing through the second flow path 112B on the second assembled battery side. In this case, the refrigerant lowers the temperature of the first assembled battery 21 and raises the temperature of the second assembled battery 22. This also makes it possible to bring the temperatures of the first assembled battery 21 and the second assembled battery 22 closer to each other. The temperature difference between the first assembled battery 21 and the second assembled battery 22 can be reduced.
[0055] <Switching device> The control unit and the method described herein may be implemented by a special-purpose computer having a processor programmed to execute one or more functions embodied in a computer program. Alternatively, the device and the method described herein may be implemented by a special-purpose hardware logic circuit. Alternatively, the device and the method described herein may be implemented by one or more special-purpose computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by the computer.
[0056] In this embodiment, as an example, the switching device 160 is applied to a microcomputer. As an example, the switching device 160 is mounted on the control device 7 described above. The switching device 160 does not have to be mounted on the control device 7. The switching device 160 includes a calculation unit 175 such as a CPU, a storage unit 176 including a volatile memory such as a RAM and a non-volatile memory such as a ROM, and an input / output interface (not shown). In the switching device 160, the calculation unit 175 executes a program stored in the storage unit 176. The calculation unit 175 executes the program to perform various calculation processes. The calculation unit 175 executes a predetermined mathematical formula when performing various calculation processes. The calculation unit 175 also performs calculation processes using various signals input to the interface.
[0057] The open / closed states of the solenoid valves 130, 140, 150 according to the vehicle state are stored in the memory unit 176. When the vehicle state is the normal mode or the charging mode, the memory unit 176 stores therein that the solenoid valves 130, 140 are opened and the solenoid valve 150 is closed. When the vehicle state is the temperature rise mode, the memory unit 176 stores therein that the solenoid valves 130, 140 are closed and the solenoid valve 150 is opened.
[0058] <Processing operation of switching device> Here, the processing operation of the switching device 160 will be described. The processing operation of the switching device 160 is mainly the processing operation of the calculation unit 175. The calculation unit 175 includes, as functional blocks, a state acquisition unit 171, a state determination unit 172, and an opening / closing control unit 173. The calculation unit 175 may also be referred to as a control unit. The switching device 160 switches the cooling circuit 110 by executing each functional block.
[0059] FIG. 8 is a flowchart explaining a method for switching the cooling circuit 110. In step S10, the state acquisition unit 171 acquires the vehicle state from the host ECU 1A. Then, the state determination unit 172 determines whether the vehicle state is in the charging mode. If the state determination unit 172 determines that the vehicle state is in the charging mode in step S10, the process proceeds to step S20. In step S20, opening and closing control is performed to achieve uniform cooling. In step S20, the opening and closing control unit 173 opens the solenoid valves 130, 140 and closes the solenoid valve 150 based on the information stored in the storage device 80. After the opening and closing control is performed by the opening and closing control unit 173 in step S20, the process proceeds to END.
[0060] If the state determination unit 172 determines in step S10 that the vehicle state is not the charging mode, the process proceeds to step S30. In step S30, the state determination unit 172 determines whether the vehicle state is in the heating mode. If the state determination unit 172 determines in step S30 that the vehicle state is in the heating mode, the process proceeds to step S40. In step S40, opening and closing control is performed to perform series cooling. In step S40, equal cooling is performed to evenly cool the first assembled battery 21 and the second assembled battery 22. In step S40, the opening and closing control unit 173 closes the solenoid valves 130, 140 and opens the solenoid valve 150 based on the information stored in the storage device 80. After the opening and closing control is performed by the opening and closing control unit 173 in step S40, the process proceeds to END.
[0061] If the state determination unit 172 determines in step S30 that the vehicle state is not in the temperature increase mode, the process proceeds to step S50. In step S50, the state determination unit 172 determines whether the vehicle state is in the normal mode. If the state determination unit 172 determines in step S50 that the vehicle state is in the normal mode, the process proceeds to step S60. In step S60, opening and closing control is performed to achieve uniform cooling. In step S60, the opening and closing control unit 173 opens the solenoid valves 130 and 140 and closes the solenoid valve 150 based on the information stored in the memory device 80. After the opening and closing control is performed by the opening and closing control unit 173 in step S60, the process proceeds to END.
[0062] It can be said that the switching device 160 is provided with a control program for controlling the opening and closing of the solenoid valves 130, 140, and 150 as shown in steps S10 to S60. This control program controls the opening and closing of the solenoid valve 130 so as to suppress the temperature difference between the first assembled battery 21 and the second assembled battery 22 that occurs in the temperature rise mode.
[0063] <Action and effect> The battery temperature regulating device 100 of this embodiment is applied to a power conversion system 1 that provides a temperature raising mode for raising the temperatures of the assembled batteries 21 and 22 by charging and discharging between the assembled batteries 21 and 22 having different voltages. The battery temperature regulating device 100 has a cooling circuit 110, solenoid valves 130, 140, and 150, and a switching device 160. The cooling circuit 110 has a plurality of flow paths through which a refrigerant for cooling the assembled batteries 21 and 22 flows. The solenoid valves 130, 140, and 150 are provided in the flow paths. The solenoid valves 130, 140, and 150 are switching valves that can switch which of the flow paths the refrigerant flows through.
[0064] Furthermore, the amount of heat generated by the first assembled battery 21 in the temperature rise mode differs from the amount of heat generated by the second assembled battery 22 in the temperature rise mode. The switching device 160 controls the opening and closing of the solenoid valves 130, 140, 150 so as to suppress the temperature difference between the assembled batteries 21 and 22 that occurs in the temperature rise mode. This allows the first assembled battery 21 and the second assembled battery 22, which have different voltages, to be appropriately cooled in the temperature rise mode. Also, the first assembled battery 21 and the second assembled battery 22 can be quickly made to have equal temperatures.
[0065] The amount of heat generated by the first assembled battery 21 in the temperature rise mode is greater than the amount of heat generated by the second assembled battery 22 in the temperature rise mode. In the temperature rise mode, the switching device 160 switches the solenoid valves 130, 140, 150 so that the second assembled battery 22 is cooled after the first assembled battery 21 is cooled by the refrigerant. This makes it possible to significantly lower the temperature of the first assembled battery 21 and to slightly lower the temperature of the second assembled battery 22. The temperatures of the first assembled battery 21 and the second assembled battery 22 can be made closer to each other. The temperature difference between the first assembled battery 21 and the second assembled battery 22 can be suppressed, and the assembled batteries 21 and 22 can be appropriately cooled.
[0066] In the normal mode, the heat generation amount of the first assembled battery 21 and the heat generation amount of the second assembled battery 22 are almost equal. The cooling circuit 110 forms different circuits in the temperature rise mode and in the normal mode. In the normal mode, the switching device 160 switches the solenoid valves 130, 140, 150 so that the first assembled battery 21 and the second assembled battery 22 are individually cooled by refrigerant at the same temperature. Since there is almost no difference in the heat generation amount of the first assembled battery 21 and the second assembled battery 22, the first assembled battery 21 and the second assembled battery 22 can be cooled almost evenly. This also suppresses the temperature difference between the first assembled battery 21 and the second assembled battery 22, and the assembled batteries 21 and 22 can be appropriately cooled.
[0067] The switching device 160 has a state acquisition unit 171, a state determination unit 172, and an opening / closing control unit 173. The state acquisition unit 171 acquires the current vehicle state of the upper ECU 1A. The state determination unit 172 determines whether the vehicle state acquired by the state acquisition unit 171 is the normal mode or the temperature increase mode. The opening / closing control unit 173 performs opening / closing control of the solenoid valves 130, 140, 150 based on the determination result of the state determination unit 172. This makes it possible to appropriately cool the first assembled battery 21 and the second assembled battery 22 each time according to the current state of the vehicle.
[0068] Second embodiment FIG. 10 is a configuration diagram showing the flow of the refrigerant in the normal and charging modes of the second embodiment. FIG. 11 is a configuration diagram showing the flow of the refrigerant in the heating mode of the second embodiment. In the second embodiment, the battery temperature adjustment device 100 has a cooling circuit 110, a refrigerant circulation device 120, a solenoid valve 130, a switching device 160, and a three-way valve 210. The three-way valve 210 is a switching valve. In the second embodiment, the solenoid valves 140 and 150 are not included. In the second embodiment, the solenoid valves 140 and 150 are not included except for the three-way valve 210, and the second embodiment is the same as the first embodiment. Therefore, the description of the basic structure is omitted. The three-way valve 210 is a valve with three inlets and outlets for the refrigerant. The three-way valve 210 is provided at the connection point P7. The three-way valve 210 has a first inlet / outlet 211 that leads to a portion of the third flow path 113 closer to the outlet 121 than the connection point P7, a second inlet / outlet 212 that leads to a portion of the third flow path 113 closer to the inlet 122 than the connection point P7, and a third inlet / outlet 213 that leads to the fourth flow path 114.
[0069] In the normal mode and the charging mode, the switching device 160 receives information on the vehicle state from the higher-level ECU 1A and opens the first entrance / exit 211, opens the second entrance / exit 212, and closes the third entrance / exit 213. The solenoid valve 130 is controlled to open and close in the same manner as in the first embodiment. This results in a circuit similar to that in the normal mode and the charging mode of the first embodiment. The refrigerant flows almost evenly through the first assembled battery side second flow path 112A and the second assembled battery side second flow path 112B. In the normal mode and the charging mode, the temperature difference between the first assembled battery 21 and the second assembled battery 22 is suppressed, and the assembled batteries 21 and 22 can be appropriately cooled.
[0070] In the temperature rise mode, the switching device 160 receives information on the vehicle state from the higher-level ECU 1A and closes the first inlet / outlet 211, opens the second inlet / outlet 212, and opens the third inlet / outlet 213. The solenoid valve 130 is controlled to open and close in the same manner as in the first embodiment. This results in a circuit similar to that in the temperature rise mode of the first embodiment. The refrigerant flows through the first assembled battery side second flow path 112A and then flows into the second assembled battery side second flow path 112B. The refrigerant cools the first assembled battery 21 and then cools the second assembled battery 22. Even in the temperature rise mode, the temperature difference between the first assembled battery 21 and the second assembled battery 22 is suppressed, and the assembled batteries 21 and 22 can be appropriately cooled.
[0071] Third embodiment FIG. 12 is a configuration diagram showing the flow of refrigerant in normal and charging modes in the third embodiment. FIG. 13 is a configuration diagram showing the flow of refrigerant in the heating mode in the third embodiment. In the third embodiment, the battery temperature regulator 100 has a cooling circuit 110, a refrigerant circulation device 120, a switching device 160, and three-way valves 210 and 310. The three-way valves 210 and 310 are switching valves. The third embodiment is configured to remove the solenoid valve 130 from the second embodiment and further include a three-way valve 310. For this reason, the description of the configuration of the third embodiment other than the three-way valve 310 will be omitted. The three-way valve 310 is a valve with three inlets and outlets for the refrigerant. The three-way valve 310 is provided at the connection point P5.
[0072] The three-way valve 310 has a first port 311, a second port 312, and a third port 313. The first port 311 communicates with a portion of the first flow path 111 that is closer to the outlet 121 side than the connection point P5. The second port 312 communicates with a portion of the first flow path 111 that is closer to the inlet 122 side than the connection point P5. The third port 313 communicates with the first assembled battery side second flow path 112A.
[0073] In the normal mode and the charging mode, the switching device 160 receives information on the vehicle state from the host ECU 1A and opens the first inlet / outlet 311, the second inlet / outlet 312, and the third inlet / outlet 313. The three-way valve 210 is controlled to open and close in the same manner as in the second embodiment. This forms a circuit similar to that in the normal mode and the charging mode of the second embodiment.
[0074] In the temperature rise mode, the switching device 160 receives information on the vehicle state from the host ECU 1A and opens the first inlet / outlet 311, closes the second inlet / outlet 312, and opens the third inlet / outlet 313. The three-way valve 210 is controlled to open and close in the same manner as in the second embodiment. This results in a circuit similar to that in the temperature rise mode of the second embodiment. In the third embodiment as well, the temperature difference between the first assembled battery 21 and the second assembled battery 22 is suppressed, and the assembled batteries 21, 22 can be appropriately cooled.
[0075] (Fourth embodiment) Fig. 14 is a configuration diagram showing the flow of refrigerant in normal and charging modes in the fourth embodiment. Fig. 15 is a configuration diagram showing the flow of refrigerant in the heating mode in the fourth embodiment. In the fourth embodiment, the battery temperature regulator 100 has a cooling circuit 110, a refrigerant circulation device 120, a switching device 160, and a six-way valve 410. The six-way valve 410 is a switching valve. The fourth embodiment is configured to remove the three-way valves 210 and 310 from the third embodiment, and further has a six-way valve 410. Therefore, a description of the configuration of the fourth embodiment other than the six-way valve 410 will be omitted.
[0076] The six-way valve 410 is a valve with six inlets and outlets for the refrigerant. The six-way valve 410 is provided between the connection point P5 and the connection point P7. The six-way valve 410 has a first inlet / outlet 411, a second inlet / outlet 412, a third inlet / outlet 413, a fourth inlet / outlet 414, a fifth inlet / outlet 415, and a sixth inlet / outlet 416.
[0077] The first inlet / outlet 411 communicates with a portion of the first flow path 111 closer to the outlet 121 than the connection point P5. The second inlet / outlet 412 communicates with a portion of the first flow path 111 closer to the inlet 122 than the connection point P5. The third inlet / outlet 413 communicates with the second flow path 112A on the first assembled battery side. The fourth inlet / outlet 414 communicates with the fourth flow path 114. The fifth inlet / outlet 415 communicates with a portion of the third flow path 113 closer to the outlet 121 than the connection point P7. The sixth inlet / outlet 416 communicates with a portion of the third flow path 113 closer to the inlet 122 than the connection point P7.
[0078] In the normal mode and the charging mode, the switching device 160 receives information on the vehicle state from the higher-level ECU 1A and opens the first entrance 411, the second entrance 412, the third entrance 413, the fifth entrance 415, and the sixth entrance 416. It closes the fourth entrance 414. This forms a circuit similar to that in the normal mode and the charging mode of the third embodiment.
[0079] In the temperature rise mode, the switching device 160 receives vehicle state information from the host ECU 1A and opens the first entrance 411, the third entrance 413, the fourth entrance 414, and the sixth entrance 416. The second entrance 412 and the fifth entrance 415 are closed. This results in a circuit similar to that in the temperature rise mode of the third embodiment. In the fourth embodiment as well, the temperature difference between the first assembled battery 21 and the second assembled battery 22 is suppressed, and the assembled batteries 21 and 22 can be appropriately cooled.
[0080] Fifth embodiment FIG. 16 is a schematic diagram for explaining the control device 7 of the fifth embodiment. FIG. 17 is a flowchart showing the control of the fifth embodiment. The calculation unit 175 of the fifth embodiment has a temperature acquisition unit 571, a temperature comparison unit 572, and a temperature difference determination unit 573 in addition to the state acquisition unit 171, the state determination unit 172, and the opening / closing control unit 173. In the fifth embodiment, the temperature difference determination unit 573 determines whether the first temperature of the first assembled battery 21 is higher than the second temperature of the second assembled battery 22 by a predetermined temperature or more in step S30. The predetermined temperature is, for example, 20 degrees. Note that the predetermined temperature is not limited to 20 degrees. If the first temperature is higher than the second temperature by a predetermined temperature or more, the first assembled battery 21 and the second assembled battery 22 cannot be appropriately cooled by uniform cooling. The input / output characteristics of the assembled batteries 21 and 22 deteriorate.
[0081] In step S30, temperature acquisition unit 571 acquires the first temperature and the second temperature. The first temperature and the second temperature are measured, for example, by a temperature sensor (not shown). The acquired first temperature and second temperature are temporarily stored in storage device 80. Temperature comparison unit 572 retrieves the first temperature and the second assembled temperature stored in storage device 80 and compares them. Based on the comparison information obtained by temperature comparison unit 572, temperature difference determination unit 573 determines whether the temperature of first assembled battery 21 is higher than the temperature of second assembled battery 22 by a predetermined temperature or more.
[0082] If it is determined in step S30 that the temperature of the first assembled battery 21 is higher than the temperature of the second assembled battery 22 by a predetermined temperature or more, the process proceeds to step S40. If it is determined in step S30 that the temperature of the first assembled battery 21 is lower than the temperature of the second assembled battery 22 by a predetermined temperature or more, the process proceeds to step S50. This also provides the same effect as the first embodiment. Even when the vehicle state is not in the temperature rise mode, if an extreme temperature difference of 20 degrees or more occurs, the temperature difference between the first assembled battery 21 and the second assembled battery 22 can be suppressed, and the assembled batteries 21, 22 can be appropriately cooled.
[0083] Sixth embodiment Fig. 18 is a schematic diagram for explaining the control device 7 of the sixth embodiment. Fig. 19 is a flowchart showing the control of the sixth embodiment. The calculation unit 175 of the sixth embodiment has a refrigerant temperature acquisition unit 671, a refrigerant temperature comparison unit 672, and a refrigerant temperature difference determination unit 673 in addition to the state acquisition unit 171, the state determination unit 172, and the opening / closing control unit 173. In the sixth embodiment, the refrigerant temperature difference determination unit 673 determines in step S30 whether the first refrigerant temperature at which the first assembled battery 21 is cooled is higher than the second refrigerant temperature at which the second assembled battery 22 is cooled by a predetermined temperature or more. The predetermined temperature is the same as in the fifth embodiment, and therefore will not be described.
[0084] In step S30, refrigerant temperature acquisition unit 671 acquires the first refrigerant temperature and the second refrigerant temperature. The first refrigerant temperature and the second refrigerant temperature are measured, for example, by a refrigerant sensor (not shown). The acquired first refrigerant temperature and second refrigerant temperature are temporarily stored in memory device 80. Refrigerant temperature comparison unit 672 retrieves the first refrigerant temperature and the second refrigerant temperature stored in memory device 80 and compares them. Based on the comparison information obtained by refrigerant temperature comparison unit 672, refrigerant temperature difference determination unit 673 determines whether the first refrigerant temperature is higher than the second refrigerant temperature by a predetermined temperature or more.
[0085] If it is determined in step S30 that the temperature difference is equal to or greater than the predetermined temperature, the process proceeds to step S40. If it is determined in step S30 that the temperature difference is less than the predetermined temperature, the process proceeds to step S50. This also provides the same effects as the fifth embodiment.
[0086] Seventh embodiment FIG. 20 is a flowchart showing the control of the seventh embodiment. The battery temperature regulator 100 is applied to the power conversion system 1 of a vehicle. The calculation unit 175 of the seventh embodiment has an outside air temperature acquisition unit 771, a soak time acquisition unit 772, and an environment determination unit 773 in addition to the state acquisition unit 171, the state determination unit 172, and the opening / closing control unit 173. The soak time is the time from when the engine is stopped to when it is started again. In the seventh embodiment, the environment determination unit 773 determines whether the outside air temperature is equal to or lower than a predetermined temperature and the soak time is equal to or longer than a predetermined time in step S30. The predetermined temperature is, for example, 0 degrees. Note that the predetermined temperature is not limited to 0 degrees. The predetermined temperature is the temperature at which the input / output characteristics of the assembled batteries 21 and 22 start to deteriorate. The predetermined temperature is, for example, 8 hours. Note that the predetermined time is not limited to 8 hours. The predetermined time is the time at which the input / output characteristics of the assembled batteries 21 and 22 start to deteriorate when the vehicle is kept parked at the predetermined temperature.
[0087] In step S30, the outside air temperature acquisition unit 771 acquires the outside air temperature outside the vehicle cabin. The soak time acquisition unit 772 acquires the soak time. The outside air temperature is measured by an outside air temperature sensor (not shown) or the like. The soak time is measured by a clock (not shown) or the like. The acquired outside air temperature and soak time are temporarily stored in the memory device 80. The environment judgment unit 773 retrieves the outside air temperature and soak time stored in the memory device 80, and judges whether the outside air temperature is below a predetermined temperature and the soak time is equal to or longer than a predetermined time.
[0088] If it is determined in step S30 that the outside air temperature is below the predetermined temperature and the soak time is equal to or longer than the predetermined time, the process proceeds to step S40. If it is determined in step S30 that the outside air temperature is not below the predetermined temperature and the soak time is not equal to or longer than the predetermined time, the process proceeds to step S50. This also provides the same effects as the first embodiment.
[0089] Eighth embodiment In the switching device 160 in the first embodiment, after the state determination unit 172 determines in step S30 that the vehicle is in the temperature increase mode, the opening / closing control unit 173 controls the opening / closing of the solenoid valves 130, 140, and 150 so as to achieve serial cooling in step S40. However, the order of the steps is not limited to this. The switching device 160 may have the control device 7 switch the solenoid valves 130, 140, and 150 so as to achieve serial cooling, and then the state determination unit 172 may determine whether the current vehicle mode is the temperature increase mode. [Explanation of symbols]
[0090] 1 Power conversion system, 1A Upper ECU, 100 Battery temperature control device, 110 Cooling circuit, 111, 112, 113, 114 Flow path, 130, 140, 150, 210, 310, 410 Switching valve, 130, 140, 150 Two-way valve, 160 Switching device, 171 Status acquisition unit, 172 Status judgment unit, 173 Opening / closing control unit, 21, 22 Assembled battery, 21 First assembled battery, 210 Three-way valve, 22 Second assembled battery, 23 Battery cell, 3 Motor, 310 Three-way valve, 410 Six-way valve, 571 Temperature acquisition unit, 572 Temperature comparison unit, 573 Temperature difference judgment unit, 6 Inverter, 671 Coolant temperature acquisition unit, 672 Refrigerant temperature comparison unit, 673 refrigerant temperature difference determination unit, 771 outside air temperature acquisition unit, 772 soak time acquisition unit, 773 environment determination unit
Claims
1. A battery temperature regulating device (100) is applied to a power conversion system (1) in which a first assembled battery (21) and a second assembled battery (22) each including at least one battery cell (23) are electrically connected to a motor (3) and an inverter (6), the first assembled battery and the second assembled battery have different voltages, and charging and discharging are performed between the first assembled battery and the second assembled battery to provide a temperature rise mode for raising the temperatures of the first assembled battery and the second assembled battery, a cooling circuit (110) having a plurality of flow paths (111, 112, 113, 114) through which a refrigerant for cooling the first assembled battery and the second assembled battery flows; A switching valve (130, 140, 150, 210, 310, 410) that is provided in the cooling circuit and is capable of switching which of the multiple flow paths to flow the refrigerant through; A switching device (160) that controls opening and closing of the switching valve, the first assembled battery and the second assembled battery have different amounts of heat generated during the temperature rise mode; The battery temperature regulating device, wherein the switching device controls opening and closing of the switching valve so as to suppress a temperature difference between the first assembled battery and the second assembled battery that occurs in the temperature increase mode.
2. the second assembled battery has a higher voltage than the first assembled battery, a heat generation amount of the first assembled battery in the temperature rise mode is greater than a heat generation amount of the second assembled battery in the temperature rise mode, The battery temperature regulating device according to claim 1 , wherein in the temperature increasing mode, the switching device switches the switching valve so that the second assembled battery is cooled after the first assembled battery is cooled by the refrigerant.
3. the power conversion system provides a normal mode in which an equal amount of current flows between the first assembled battery and the second assembled battery; a heat generation amount of the first assembled battery in the normal mode is equal to a heat generation amount of the second assembled battery in the normal mode, The cooling circuit forms different circuits in the temperature increase mode and in the normal mode, The battery temperature regulator according to claim 2 , wherein in the normal mode, the switching device switches the switching valve so that the first assembled battery and the second assembled battery are individually cooled by the refrigerant having the same temperature.
4. The battery temperature regulating device according to claim 3 , wherein the switching valve comprises at least one of a two-way valve (130, 140, 150), a three-way valve (210, 310), and a six-way valve (410).
5. The switching device is A status acquisition unit (171) that acquires a current status from a host ECU (1A); A state determination unit (172) that determines whether the current state is the normal mode or the temperature increase mode; The battery temperature regulating device according to claim 4 , further comprising an opening / closing control unit (173) that controls opening / closing of the switching valve based on a result of the determination by the state determination unit.
6. The switching device is a temperature acquisition unit (571) that acquires a first temperature of the first assembled battery and a second temperature of the second assembled battery separately; a temperature comparison unit (572) for comparing the first temperature with the second temperature; a temperature difference determination unit (573) that determines whether the first temperature is higher than the second temperature by a predetermined temperature or more; 6. The battery temperature control device according to claim 5, wherein when the temperature difference determination unit determines that the first temperature is higher than the second temperature by at least the predetermined temperature, the opening / closing control unit controls the opening and closing of the switching valve so that the second battery is cooled after the first battery pack is cooled by the refrigerant.
7. The switching device is a refrigerant temperature acquisition unit (671) that acquires a first refrigerant temperature of the refrigerant that has cooled the first assembled battery and a second refrigerant temperature of the refrigerant that has cooled the second assembled battery separately; a refrigerant temperature comparison unit (672) that compares the first refrigerant temperature with the second refrigerant temperature; a refrigerant temperature difference determination unit (673) that determines whether the first refrigerant temperature is higher than the second refrigerant temperature by a predetermined temperature or more; 6. The battery temperature control device according to claim 5, wherein when the refrigerant temperature difference determination unit determines that the first refrigerant temperature is higher than the second refrigerant temperature by at least the predetermined temperature, the opening / closing control unit controls the opening and closing of the switching valve so that the second battery is cooled after the first battery pack is cooled by the refrigerant.
8. The power conversion system of a vehicle is applied to the power conversion system, The switching device An outside air temperature acquisition unit (771) that acquires an outside air temperature; A soak time acquisition unit (772) for acquiring a soak time which is a time from when the engine is stopped until when the engine is next started; an environment determination unit (773) that determines whether the outside air temperature is equal to or lower than a predetermined temperature and the soak time is equal to or longer than a predetermined time; 6. The battery temperature control device according to claim 5, wherein when the environmental determination unit determines that the outside air temperature is below the predetermined temperature and the soak time is equal to or longer than the predetermined time, the opening / closing control unit controls the opening / closing of the switching valve so that the second assembled battery is cooled after the first assembled battery is cooled by the refrigerant.
9. A power conversion system (1) in which a first assembled battery (21) and a second assembled battery (22) each including at least one battery cell (23) are electrically connected to a motor (3) and an inverter (6), the first assembled battery and the second assembled battery have different voltages, and a temperature rise mode is provided in which the first assembled battery and the second assembled battery are heated by charging and discharging between the first assembled battery and the second assembled battery, the first assembled battery and the second assembled battery have different heat generation amounts in the temperature rise mode; the power conversion system is provided with a cooling circuit (110) including a plurality of flow paths (111, 112, 113, 114) through which a refrigerant for cooling the first assembled battery and the second assembled battery flows, and a switching valve (130, 140, 150, 210, 310, 410) capable of switching which of the plurality of flow paths the refrigerant flows through; A control program for a switching device (160) that controls opening and closing of the switching valve, a control program for controlling opening and closing of the switching valve so as to suppress a temperature difference between the first assembled battery and the second assembled battery that occurs in the temperature increase mode;
Citation Information
Patent Citations
Battery temperature rising device
JP2020098681A