Cooling system and cooling control method

Abstract

The cooling system aims to suppress a temperature rise of an inverter and enable motor driving as intended by a user. The cooling system is a cooling system for an electric drive device including a motor that drives wheels and an inverter that controls the motor, and includes a refrigerant circulation flow path in which an oil cooler that cools oil supplied to the motor, a radiator that cools the refrigerant, and the inverter that is cooled by the refrigerant are arranged in a refrigerant circulation path, a refrigerant temperature sensor that detects a refrigerant temperature that is the temperature of the refrigerant, a refrigerant cooling unit that cools the refrigerant, and a cooling control unit that controls the cooling capacity of the refrigerant cooling unit, and the cooling control unit predicts an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature sensor and drive information of the inverter, and controls the refrigerant cooling unit to increase the cooling capacity based on the prediction result.

Description

[Technical field]

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

[0002] In recent years, electric vehicles or hybrid vehicles are required to be equipped with a cooling system that cools the motor and inverter (see, for example, Patent Document 1). Such conventional cooling systems calculate the drive output of a refrigerant pump based on the temperature of the motor and the drive output of a refrigerant pump based on the temperature of the inverter, and select the larger drive output to drive the refrigerant pump. In other words, the conventional cooling system controls the cooling of the inverter and the motor in response to temperature changes of the inverter and the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-68637 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional cooling system described above, the motor temperature and inverter temperature are measured at a certain point in time, and the drive output of the refrigerant pump is increased only after a rise in these temperatures is detected, which causes a problem that the temperature rise precedes an increase in cooling capacity. Therefore, in the conventional cooling system, for example, when the control of the motor must be restricted due to a temperature rise in the inverter, etc., there is a possibility that the motor cannot be driven as intended by the user.

[0005] The present disclosure has been made to solve the above problems, and its purpose is to provide a cooling system and a cooling control method that can appropriately suppress temperature rise and drive a motor as intended by the user. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present disclosure is a cooling system for an electric drive device including a motor that drives wheels and an inverter that controls the motor, the system including a refrigerant circulation flow path in which an oil cooler that cools oil supplied to the motor, a radiator that cools the refrigerant, and the inverter that is cooled by the refrigerant are arranged in a refrigerant circulation path, a refrigerant temperature detection unit that detects a refrigerant temperature that is the temperature of the refrigerant, a refrigerant cooling unit that cools the refrigerant, and a cooling control unit that controls the cooling capacity of the refrigerant cooling unit, the cooling control unit predicting an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature detection unit and drive information of the inverter, and controlling the refrigerant cooling unit to increase the cooling capacity based on the prediction result, and a motor temperature detection unit that detects a motor temperature that is the temperature of the motor. an inverter temperature detection unit for detecting an inverter temperature, which is the temperature of the inverter; a refrigerant pump for pumping the refrigerant is disposed in the refrigerant circulation flow path, and the refrigerant pump is disposed at a position where the inverter and the motor are directly thermally affected by the refrigerant; and the cooling control unit is configured to determine whether the predicted temperature rise of the refrigerant is No. 1 When the temperature of the refrigerant is equal to or higher than the threshold value, the drive output of the refrigerant pump is controlled to be increased, and the predicted temperature rise of the refrigerant is No. 1 If it is less than the threshold, moreover, The motor temperature detected by the motor temperature detection unit is equal to or greater than a second threshold value, and the motor temperature is greater than the inverter temperature detected by the inverter temperature detection unit by a specific value or more. The cooling system performs control to increase the cooling capacity of the refrigerant.

[0007] Also, one aspect of the present disclosure is a vehicle control system including a motor that drives wheels, an inverter that controls the motor, a refrigerant circulation flow path in which an oil cooler that cools oil supplied to the motor, a radiator that cools the refrigerant, and the inverter that is cooled by the refrigerant are arranged in a refrigerant circulation path, a refrigerant temperature detection unit that detects a refrigerant temperature that is the temperature of the refrigerant, a refrigerant cooling unit that cools the refrigerant, a cooling control unit that controls the cooling capacity of the refrigerant cooling unit, and a motor temperature detection unit that detects a motor temperature that is the temperature of the motor. an inverter temperature detection unit that detects an inverter temperature, which is the temperature of the inverter; a refrigerant pump for pumping the refrigerant is disposed in the refrigerant circulation flow path, and is disposed at a position where the refrigerant is directly thermally affected by the inverter and the motor; the cooling control unit predicts an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature detection unit and drive information of the inverter, and the predicted temperature increase of the refrigerant is No. 1 When the temperature of the refrigerant is equal to or higher than the threshold value, the drive output of the refrigerant pump is controlled to be increased, and the predicted temperature rise of the refrigerant is No. 1 If it is less than the threshold, moreover, The motor temperature detected by the motor temperature detection unit is equal to or greater than a second threshold value, and the motor temperature is greater than the inverter temperature detected by the inverter temperature detection unit by a specific value or more. The cooling control method performs control to increase the cooling capacity of the refrigerant. Effect of the Invention

[0008] According to the present disclosure, it is possible to appropriately suppress temperature rise and drive the motor as intended by the user. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic block diagram illustrating an example of a cooling system according to a first embodiment. [Diagram 2] 2 is a diagram illustrating an example of a hardware configuration of an inverter control unit, a host ECU, and a cooling control unit illustrated in FIG. 1. [Diagram 3] 4 is a flowchart showing an example of the operation of the cooling system according to the first embodiment. [Figure 4]10 is a flowchart showing an example of the operation of the cooling system according to the second embodiment. [Diagram 5] 10 is a flowchart showing an example of the operation of the cooling system according to the third embodiment. [Figure 6] 10 is a flowchart showing an example of the operation of the cooling system according to the fourth embodiment. [Figure 7] 13 is a flowchart showing an example of the operation of the cooling system according to the fifth embodiment. [Figure 8] FIG. 13 is a schematic block diagram illustrating an example of a cooling system according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a cooling system and a cooling control method according to an embodiment of the present disclosure will be described with reference to the drawings.

[0011] [First embodiment] FIG. 1 is a schematic block diagram showing an example of a cooling system 1 according to the present embodiment.

[0012] The electric drive device 100 is a drive device for an electric vehicle, and includes a cooling system 1, an e-Axle unit 2, drive wheels 3, a drive shaft 4, and a host ECU 60, as shown in FIG.

[0013] The electric vehicle here is a so-called four-wheeled vehicle, and may be a BEV (Battery Electric Vehicle), an HEV (Hybrid Electric Vehicle), a PHEV (Plug in Hybrid Electric Vehicle), or an FCEV (Fuel Cell Electric Vehicle).

[0014] The e-Axle unit 2 includes an inverter 10, a transmission 20, and a motor 30, and has a structure in which the inverter 10, the transmission 20, and the motor 30 are integrated together. In the e-Axle unit 2, the inverter 10 and the motor 30 are disposed in close proximity to each other.

[0015] The inverter 10 generates a drive signal for driving the motor 30 from DC power supplied from a battery (not shown) to control the motor 30. The inverter 10 includes an inverter control unit 11, an inverter circuit unit 12, and an inverter temperature sensor 13.

[0016] The inverter circuit unit 12 generates a drive signal for driving the motor 30 from DC power supplied from a battery (not shown) by switching a switching element (not shown).

[0017] The inverter control unit 11 controls the inverter circuit unit 12 in response to a command value for the motor 30 from the host ECU 60. The inverter control unit 11 controls, for example, switching of a switching element (not shown) of the inverter circuit unit 12 to generate a drive signal for driving the motor 30.

[0018] The inverter temperature sensor 13 detects the inverter temperature, which is the temperature of the inverter 10. The inverter temperature sensor 13 is an example of an inverter temperature detection unit that detects the inverter temperature.

[0019] The motor 30 is a drive unit of the electric drive device 100, and drives (e.g., rotates) drive wheels 3, which are wheels of an electric vehicle, via the transmission 20. The motor 30 has an output shaft (not shown), and converts the rotation of the output shaft via the transmission 20 (described later), and transmits power to the drive wheels 3 via the drive shaft 4.

[0020] The motor 30 also includes a motor temperature sensor 31 . The motor temperature sensor 31 detects the motor temperature, which is the temperature of the motor 30. The motor temperature sensor 31 is an example of a motor temperature detection unit that detects the motor temperature.

[0021] The transmission 20 has a drive gear, a driven gear, a differential gear, etc. (not shown) for converting rotation. Using these gears, the transmission 20 converts the rotation of the output shaft of the motor 30 and transmits the rotation to the drive wheels 3 via the drive shaft 4.

[0022] The drive shaft 4 is disposed between the transmission 20 and the drive wheels 3, and transmits the rotation converted by the transmission 20 to the drive wheels 3. A pair of drive shafts 4 are connected to the transmission 20, and the pair of drive shafts 4 transmit the rotation to the pair of drive wheels 3.

[0023] The drive wheels 3 are, for example, wheels of an electric vehicle, and the drive (rotation) of a motor 30 is transmitted to the drive wheels 3 via a transmission 20 and a drive shaft 4.

[0024] The host ECU (Electronic Control Unit) 60 is a control unit that electronically controls the electric vehicle, and generates, for example, a command value for the motor 30 in response to a user's operation. An example of the hardware configuration of the host ECU 60 will be described later with reference to FIG.

[0025] As shown in FIG. 1, the cooling system 1 includes an inverter temperature sensor 13, a motor temperature sensor 31, an oil cooler 40, an oil pump 41, a radiator 50, a refrigerant pump 51, a refrigerant temperature sensor 52, a blower fan 53, a cooling control unit 70, an oil circulation path OC, and a refrigerant circulation path WC.

[0026] The oil circulation flow path OC is a flow path that circulates oil that cools the motor 30. In the oil circulation flow path OC, an oil cooler 40 and an oil pump 41 are arranged in a circulation path of the refrigerant. The oil circulation flow path OC supplies oil to the motor 30 via the oil cooler 40 and the oil pump 41, and supplies the oil from the motor 30 back to the oil cooler 40, thereby circulating the oil.

[0027] The oil pump 41 is provided in the oil circulation flow path OC and pumps oil. The oil pump 41 is, for example, an electric pump that is driven by electricity. The oil pump 41 supplies the pumped oil to the motor 30 via the oil cooler 40.

[0028] The oil cooler 40 cools the oil passing through the oil circulation passage OC (for example, the oil supplied to the motor 30). A refrigerant circulation passage WC is connected to the oil cooler 40. The oil passing through the inside of the oil cooler 40 is cooled by heat exchange with the refrigerant passing through the refrigerant circulation passage WC. That is, the refrigerant cools the motor 30 via the oil cooler 40 and the oil.

[0029] The refrigerant circulation flow path WC is a flow path that circulates the refrigerant that cools the oil passing through the inverter 10 and the oil circulation flow path OC. An oil cooler 40, a radiator 50, a refrigerant pump 51, and a refrigerant temperature sensor 52 are arranged in the refrigerant circulation flow path WC. The refrigerant circulation flow path WC supplies the refrigerant to the inverter 10 and the oil cooler 40 via the radiator 50 and the refrigerant pump 51, and supplies the refrigerant from the inverter 10 and the oil cooler 40 back to the radiator 50, thereby circulating the refrigerant. The coolant flowing through the coolant circulation flow path WC is, for example, water.

[0030] The radiator 50 cools the refrigerant flowing through the refrigerant circulation channel WC. The radiator 50 can increase the cooling capacity for cooling the refrigerant flowing through the refrigerant circulation channel WC by blowing air from a blower fan 53, which will be described later.

[0031] The refrigerant pump 51 is provided in the refrigerant circulation flow path WC and pumps the refrigerant. The refrigerant pump 51 is, for example, an electric pump driven by electricity. The refrigerant pump 51 supplies the pumped refrigerant to the inverter 10 and cools the inverter 10 with the refrigerant. The refrigerant pump 51 can change its drive output in response to a control signal from a cooling control unit 70, which will be described later.

[0032] The coolant temperature sensor 52 is provided, for example, in the coolant circulation flow path WC and detects the coolant temperature (for example, water temperature). The coolant temperature rises in response to heat generation by the inverter 10 and drops as the coolant is cooled by the radiator 50.

[0033] The blower fan 53 blows outside air, which is a heat medium, toward the radiator 50 to cool the refrigerant. The blower fan 53 is an example of a refrigerant cooling unit that cools the refrigerant. The blower fan 53 is disposed close to the radiator 50 and is configured as an electric fan whose blowing capacity can be adjusted according to the amount of current supplied to the blower fan 53. The amount of current supplied to the blower fan 53 is adjusted according to a control signal from a cooling control unit 70, which will be described later.

[0034] Cooling control unit 70 controls the cooling capacity of blower fan 53. Cooling control unit 70 predicts an increase in refrigerant temperature based on the refrigerant temperature detected by refrigerant temperature sensor 52 and drive information of inverter 10, and controls blower fan 53 to increase its cooling capacity based on the prediction result. For example, when an increase in refrigerant temperature is predicted, cooling control unit 70 controls blower fan 53 to increase its cooling capacity.

[0035] The drive information of the inverter 10 may be, for example, information such as the output power of the inverter 10, the speed pattern and drive torque of the driven motor 30, or an actual measured value or a command value of the load current of the inverter 10. When the drive information of the inverter 10 is a command value, it may be a value transmitted from the host ECU 60 or a value set in a storage unit (not shown) of the inverter control unit 11.

[0036] In addition, this information may be data acquired in real time, or, in the case where a speed pattern is set in advance, such as when driving the motor 30, the preset future speed pattern may be used as the driving information for the inverter 10. Furthermore, the drive information for the inverter 10 may include temperature information for the inverter 10 estimated based on the above information.

[0037] In addition, the cooling control unit 70 may change and control the cooling capacity of the blower fan 53 or the driving output of the refrigerant pump 51 based on the motor temperature detected by the motor temperature sensor 31 and the inverter temperature detected by the inverter temperature sensor 13.

[0038] The refrigerant temperature rise is separated into a refrigerant temperature rise component due to inverter heat generated based on the operation of inverter 10 and a refrigerant temperature rise due to an oil temperature rise caused by motor drive. Here, since the inverter heat generation components based on the operation of inverter 10 can be estimated to some extent, if the refrigerant temperature is known, the refrigerant temperature rise due to the oil temperature rise caused by motor drive can also be estimated. The refrigerant temperature rise due to the oil temperature rise may be a real-time value calculated using (refrigerant temperature - inverter heat generation component).

[0039] Next, with reference to FIG. 2, a hardware configuration of the inverter control unit 11, the host ECU 60, and the cooling control unit 70 shown in FIG. 1 will be described. FIG. 2 is a diagram illustrating an example of a hardware configuration of the inverter control unit, the host ECU, and the cooling control unit illustrated in FIG.

[0040] As shown in FIG. 2, each of the inverter control unit 11, the host ECU 60, and the cooling control unit 70 has a control board PB, and the control board PB includes a communication device H11, a memory H12, and a processor H13.

[0041] The communication device H11 is a CAN (Controller Area Network) communication device, various interface modules, etc., and performs communication with other control units.

[0042] The memory H12 is a storage device such as a RAM, a flash memory, or a HDD, and stores various pieces of information and programs used by the inverter control unit 11, the host ECU 60, and the cooling control unit 70, respectively.

[0043] The processor H13 is a processing circuit including, for example, a CPU (Central Processing Unit). The processor H13 executes various processes of the inverter control unit 11, the upper ECU 60, and the cooling control unit 70 by executing programs stored in the memory H12.

[0044] Each of the above-mentioned inverter control unit 11, the host ECU 60, and the cooling control unit 70 is a functional unit that is realized by causing the processor H13 to execute a program stored in the memory H12.

[0045] Next, the operation of the cooling system 1 according to the present embodiment will be described with reference to the drawings. FIG. 3 is a flowchart showing an example of the operation of the cooling system 1 according to the first embodiment.

[0046] 3, the cooling control unit 70 of the cooling system 1 first acquires the temperature of the refrigerant (step S101). The cooling control unit 70 acquires the refrigerant temperature in the refrigerant circulation flow path WC detected by the refrigerant temperature sensor 52.

[0047] Next, the cooling control unit 70 acquires driving information of the inverter 10 (step S102). The cooling control unit 70 acquires, for example, a command value for the motor 30 (a command value for the inverter 10) from the host ECU 60 as the driving information for the inverter 10.

[0048] Next, the cooling control unit 70 predicts a rise in the temperature of the refrigerant based on the temperature of the refrigerant and the drive information of the inverter 10 (step S103). The cooling control unit 70 predicts a rise in the temperature of the refrigerant due to heat generation by the inverter 10 based on the temperature of the refrigerant and the drive information of the inverter 10.

[0049] Next, the cooling control unit 70 determines whether or not a rise in the temperature of the refrigerant is predicted (step S104). For example, the cooling control unit 70 determines that a rise in the temperature of the refrigerant is predicted when the predicted rise in the temperature of the refrigerant is equal to or greater than a threshold (above a specific threshold). If a rise in the temperature of the refrigerant is predicted (step S104: YES), the cooling control unit 70 advances the process to step S105. If a rise in the temperature of the refrigerant is not predicted (step S104: NO), the cooling control unit 70 returns the process to step S101.

[0050] In step S105, the cooling control unit 70 performs control to increase the air volume of the blower fan 53. For example, the cooling control unit 70 transmits a control signal to the blower fan 53 to increase the amount of electricity supplied to the blower fan 53, thereby increasing the air volume of the blower fan 53. After the process of step S105, the cooling control unit 70 returns the process to step S101.

[0051] As described above, the cooling system 1 according to this embodiment is a cooling system for an electric drive device 100 including a motor 30 that drives wheels and an inverter 10 that controls the motor 30, and includes a refrigerant circulation flow path WC, a refrigerant temperature sensor 52 (refrigerant temperature detection unit), a refrigerant cooling unit (e.g., blower fan 53), and a cooling control unit 70. The refrigerant circulation flow path WC includes an oil cooler 40 that cools oil supplied to the motor 30, a radiator 50 that cools the refrigerant, and an inverter 10 that is cooled by the refrigerant, arranged in a refrigerant circulation path. The refrigerant temperature sensor 52 detects the refrigerant temperature, which is the temperature of the refrigerant. The refrigerant cooling unit (e.g., blower fan 53) cools the refrigerant. The cooling control unit 70, which controls the cooling capacity of the refrigerant cooling unit (e.g., blower fan 53), predicts an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature sensor 52 and drive information of the inverter 10. The cooling control unit 70 controls the refrigerant cooling unit (e.g., the blower fan 53) to increase its cooling capacity based on the prediction result. For example, when an increase in the refrigerant temperature is predicted, the cooling control unit 70 controls the refrigerant cooling unit (e.g., the blower fan 53) to increase its cooling capacity.

[0052] As a result, the cooling system 1 according to this embodiment predicts an increase in the refrigerant temperature and controls to increase the cooling capacity of the refrigerant cooling unit (e.g., the blower fan 53) before the temperature of the inverter 10 increases, thereby making it possible to appropriately and efficiently suppress an increase in the temperature of the inverter 10. Therefore, the cooling system 1 according to this embodiment can drive the motor as intended by the user.

[0053] The refrigerant temperature rise is divided into a refrigerant temperature rise component due to heat generation by inverter 10 based on the operation of inverter 10 and a refrigerant temperature rise due to an oil temperature rise caused by motor drive. Here, the inverter heat generation components based on the operation of inverter 10 can be estimated to some extent from the inverter 10 drive information, so if the refrigerant temperature is known, the refrigerant temperature rise due to the oil temperature rise caused by motor drive can also be estimated. Also, the temperature rise of inverter 10 due to the operation of inverter 10 is relatively rapid (small heat capacity), but the temperature rise of oil cooling motor 30 is relatively gradual in comparison (larger heat capacity than inverter 10), so the refrigerant temperature rise can be easily predicted by controlling based on inverter 10.

[0054] As a result, the cooling system 1 according to this embodiment predicts a future rise in refrigerant temperature based on the operation of the inverter 10 caused by the temperature rise and the refrigerant temperature, and controls the drive output of the blower fan 53 of the radiator 50 (= the cooling capacity of the refrigerant cooling section) to be increased in advance based on the prediction result. As a result, the cooling system 1 according to this embodiment can lower the refrigerant temperature in advance before the refrigerant temperature rises excessively, and can drive the motor as intended by the user without restrictions on motor drive due to heat generation.

[0055] The cooling control method according to the present embodiment is a cooling control method for an electric drive device 100. Here, the electric drive device 100 includes a motor 30 that drives wheels, an inverter 10 that controls the motor 30, a refrigerant circulation flow path WC, a refrigerant temperature sensor 52, a blower fan 53 (refrigerant cooling unit) that cools the refrigerant, and a cooling control unit 70 that controls the cooling capacity of the blower fan 53. The refrigerant circulation flow path WC includes an oil cooler 40 that cools oil supplied to the motor 30, a radiator 50 that cools the refrigerant, and an inverter 10 that is cooled by the refrigerant, arranged in a circulation path of the refrigerant. In the cooling control method according to the present embodiment, the cooling control unit 70 predicts an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature sensor 52 and drive information of the inverter 10, and controls the blower fan 53 to increase its cooling capacity based on the prediction result.

[0056] As a result, the cooling control method according to this embodiment has the same effect as the cooling system 1 described above, and can appropriately and efficiently suppress the temperature rise of the inverter 10, thereby enabling the motor to be driven as intended by the user.

[0057] [Second embodiment] Next, a cooling system 1 according to a second embodiment will be described with reference to the drawings. In this embodiment, as an example of a case where a rise in the refrigerant temperature is predicted, a modified example will be described in which the cooling capacity of the blower fan 53 is increased and the drive output of the refrigerant pump 51 is further increased when the predicted rise in the refrigerant temperature is equal to or greater than a threshold value.

[0058] The configuration of the cooling system 1 according to this embodiment is similar to that of the first embodiment shown in Fig. 1, and therefore a description thereof will be omitted here. In this embodiment, the processing of the cooling control unit 70 is different.

[0059] In the present embodiment, cooling control unit 70 controls so as to increase the driving output of coolant pump 51 as well as the cooling capacity of blower fan 53 when the predicted coolant temperature rise is equal to or greater than a threshold (first threshold or greater). Other processing by the cooling control unit 70 is similar to that in the first embodiment, and therefore a description thereof will be omitted here.

[0060] Next, the operation of the cooling system 1 according to the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing an example of the operation of the cooling system 1 according to the second embodiment.

[0061] In FIG. 4, the processes from step S201 to step S203 are similar to the processes from step S101 to step S103 shown in FIG. 1 described above, and therefore the description thereof will be omitted here.

[0062] In step S204, the cooling control unit 70 determines whether the predicted coolant temperature rise is equal to or greater than a threshold (equal to or greater than a first threshold). If the predicted coolant temperature rise is equal to or greater than a threshold (equal to or greater than a first threshold) (step S204: YES), the cooling control unit 70 advances the process to step S205. If the predicted coolant temperature rise is less than a threshold (less than the first threshold) (step S204: NO), the cooling control unit 70 returns the process to step S201.

[0063] In step S205, the cooling control unit 70 performs control to increase the air volume of the blower fan 53 and the flow rate of the refrigerant pump 51. That is, the cooling control unit 70 performs control to increase the cooling capacity of the blower fan 53 and the drive output of the refrigerant pump 51. After the process of step S205, the cooling control unit 70 returns the process to step S201.

[0064] 4, cooling control unit 70 may increase the air volume of blower fan 53 when a temperature rise of the refrigerant is predicted, and may further control to increase the flow rate of refrigerant pump 51 when the predicted temperature rise of the refrigerant is equal to or greater than a threshold (above a first threshold). That is, cooling control unit 70 may increase the cooling capacity of the refrigerant in two stages by increasing the cooling capacity of blower fan 53 and increasing the drive output of refrigerant pump 51.

[0065] As described above, in the cooling system 1 according to the present embodiment, the coolant pump 51 that pumps the coolant is disposed in the coolant circulation passage WC. The cooling control unit 70 controls the drive output of the coolant pump 51 to increase when the predicted temperature rise of the coolant is equal to or greater than a threshold value (first threshold value or greater).

[0066] As a result, in the cooling system 1 of this embodiment, when, for example, the predicted temperature rise of the refrigerant is high and insufficient cooling capacity is expected by simply increasing the driving output of the blower fan 53 of the radiator 50 (= the cooling capacity of the refrigerant cooling section), the cooling capacity can be strengthened by additionally increasing the driving output of the refrigerant pump 51 (by increasing the flow rate).

[0067] [Third embodiment] Next, a cooling system 1 according to a third embodiment will be described with reference to the drawings. In this embodiment, a modification of the second embodiment described above will be described in which control for increasing the cooling capacity of the refrigerant based on the motor temperature is added.

[0068] The configuration of the cooling system 1 according to this embodiment is similar to that of the first embodiment shown in Fig. 1, and therefore a description thereof will be omitted here. In this embodiment, the processing of the cooling control unit 70 is different.

[0069] In this embodiment, for example, by employing the e-Axle unit 2, the inverter 10 and the motor 30 are disposed in close proximity to each other. The cooling control unit 70 in this embodiment performs control to increase the cooling capacity of the refrigerant based on the motor temperature detected by the motor temperature sensor 31, in addition to the cooling control process according to the second embodiment described above.

[0070] Here, the control to increase the cooling capacity of the refrigerant includes, for example, control to increase the cooling capacity of blower fan 53 and control to increase the drive output of refrigerant pump 51. That is, cooling control unit 70 performs control to increase the cooling capacity of blower fan 53 or the drive output of refrigerant pump 51 as control to increase the cooling capacity of the refrigerant. Other processing by the cooling control unit 70 is similar to that in the second embodiment, and therefore a description thereof will be omitted here.

[0071] Next, the operation of the cooling system 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing an example of the operation of the cooling system 1 according to the third embodiment.

[0072] In FIG. 5, the processes in steps S301 and S302 are similar to the processes in steps S201 and S206 shown in FIG. 4 described above, and therefore the description thereof will be omitted here.

[0073] In step S303, the cooling control unit 70 acquires the motor temperature. The cooling control unit 70 acquires the motor temperature detected by the motor temperature sensor 31, for example.

[0074] Next, the processes from step S304 to step S306 are similar to the processes from step S203 to step S205 shown in FIG. 4 described above, and therefore the description thereof will be omitted here. In step S305, if the predicted temperature rise of the refrigerant is less than the threshold value (less than the first threshold value) (step S305: NO), cooling control unit 70 advances the process to step S307.

[0075] In step S307, the cooling control unit 70 determines whether the motor temperature is equal to or higher than the threshold (equal to or higher than the second threshold). The cooling control unit 70 acquires the motor temperature detected by the motor temperature sensor 31 and determines whether the motor temperature is equal to or higher than the threshold (equal to or higher than the second threshold). If the motor temperature is equal to or higher than the threshold (equal to or higher than the second threshold) (step S307: YES), the cooling control unit 70 advances the process to step S308. If the motor temperature is less than the threshold (less than the second threshold) (step S307: NO), the cooling control unit 70 returns the process to step S301.

[0076] In step S308, the cooling control unit 70 performs control to increase the cooling capacity of the refrigerant. For example, the cooling control unit 70 performs control to increase the cooling capacity of the blower fan 53 or the drive output of the refrigerant pump 51. After the process of step S308, the cooling control unit 70 returns the process to step S301.

[0077] As described above, in the cooling system 1 according to this embodiment, the inverter 10 and the motor 30 are disposed in close proximity to each other. The cooling system 1 further includes a motor temperature sensor 31 (motor temperature detection unit) that detects the motor temperature, which is the temperature of the motor 30. The cooling control unit 70 performs control to increase the cooling capacity of the refrigerant based on the motor temperature detected by the motor temperature sensor 31.

[0078] For example, when the inverter 10 and the motor 30 are arranged close to each other, as in the e-Axle unit 2, there is a concern that the inverter 10 may be directly thermally affected by the motor 30. In the cooling system 1 according to this embodiment, in addition to the cooling control of the second embodiment described above, when the motor temperature becomes equal to or higher than a threshold (above a second threshold), it is determined that the inverter 10 is thermally affected (thermal interference), and the cooling capacity of the refrigerant can be increased in advance in consideration of this. Therefore, the cooling system 1 according to this embodiment can further suppress the temperature rise of the inverter 10, and can drive the motor as intended by the user. That is, the cooling system 1 according to this embodiment can maintain the power performance because the output of the motor 30 is not limited.

[0079] In this embodiment, the cooling control unit 70 performs control to increase the cooling capacity of the blower fan 53 or the drive output of the refrigerant pump 51 as control to increase the cooling capacity of the refrigerant.

[0080] As a result, the cooling system 1 according to the present embodiment can further appropriately suppress the temperature rise of the inverter 10 by controlling the blower fan 53 or the refrigerant pump 51.

[0081] In the example shown in Figure 5 above, an example has been described in which the cooling control unit 70 obtains the motor temperature from the motor temperature sensor 31, but the cooling control unit 70 may also estimate the motor temperature from the operating state of the motor.

[0082] [Fourth embodiment] Next, a cooling system 1 according to a fourth embodiment will be described with reference to the drawings. In this embodiment, a modification of the second embodiment described above will be described in which control for increasing the cooling capacity of the refrigerant based on the motor temperature and the inverter temperature is added.

[0083] The configuration of the cooling system 1 according to this embodiment is similar to that of the first embodiment shown in Fig. 1, and therefore a description thereof will be omitted here. In this embodiment, the processing of the cooling control unit 70 is different.

[0084] In addition to the cooling control process according to the second embodiment described above, the cooling control unit 70 in this embodiment performs control to increase the cooling capacity of the refrigerant when the motor temperature detected by the motor temperature sensor 31 is greater than the inverter temperature detected by the inverter temperature sensor 13 by a specific value or more. The cooling control unit 70 performs control to increase the cooling capacity of the refrigerant when, for example, the value of (motor temperature-inverter temperature) is equal to or greater than a threshold value (equal to or greater than a third threshold value). Other processing by the cooling control unit 70 is similar to that in the second embodiment, and therefore a description thereof will be omitted here.

[0085] Next, the operation of the cooling system 1 according to the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing an example of the operation of the cooling system 1 according to the fourth embodiment.

[0086] In FIG. 6, the processes in steps S401 and S402 are similar to the processes in steps S201 and S206 shown in FIG. 4 described above, and therefore the description thereof will be omitted here.

[0087] In step S403, the cooling control unit 70 acquires the motor temperature and the inverter temperature. The cooling control unit 70 acquires the motor temperature detected by the motor temperature sensor 31 and the inverter temperature detected by the inverter temperature sensor 13, for example.

[0088] Next, the processes from step S404 to step S406 are similar to the processes from step S203 to step S205 shown in FIG. 4 described above, and therefore the description thereof will be omitted here. In step S405, if the predicted temperature rise of the refrigerant is less than the threshold value (less than the first threshold value) (step S405: NO), cooling control unit 70 advances the process to step S407.

[0089] In step S407, the cooling control unit 70 judges whether the value of (motor temperature-inverter temperature) is equal to or greater than the threshold value (equal to or greater than the third threshold value). The cooling control unit 70 acquires the motor temperature detected by the motor temperature sensor 31 and the inverter temperature detected by the inverter temperature sensor 13, and calculates the value of (motor temperature-inverter temperature). If the value of (motor temperature-inverter temperature) is equal to or greater than the threshold value (equal to or greater than the third threshold value) (step S407: YES), the cooling control unit 70 advances the process to step S408. If the value of (motor temperature-inverter temperature) is less than the threshold value (less than the third threshold value) (step S407: NO), the cooling control unit 70 returns the process to step S401.

[0090] In step S408, the cooling control unit 70 performs control to increase the cooling capacity of the refrigerant. For example, the cooling control unit 70 performs control to increase the cooling capacity of the blower fan 53 or the drive output of the refrigerant pump 51. After the process of step S408, the cooling control unit 70 returns the process to step S401.

[0091] As described above, the cooling system 1 according to this embodiment further includes an inverter temperature sensor 13 (inverter temperature detection unit) that detects the inverter temperature, which is the temperature of the inverter 10. When the motor temperature detected by the motor temperature sensor 31 is greater than the inverter temperature detected by the inverter temperature sensor 13 by a specific value or more (for example, when the value of (motor temperature-inverter temperature) is greater than or equal to a threshold End (Third Threshold End )), control is performed to increase the cooling capacity of the refrigerant.

[0092] As a result, in the cooling system 1 according to this embodiment, in addition to the cooling control of the second embodiment described above, when the motor temperature is higher than the inverter temperature by a specific value or more (for example, when the value of (motor temperature-inverter temperature) is equal to or higher than a threshold End (Third Threshold End )), it is simply determined that there is a thermal effect (thermal interference) on the inverter 10, and taking this into consideration, the cooling capacity of the refrigerant can be increased in advance. Therefore, the cooling system 1 according to this embodiment can further suppress the temperature rise of the inverter 10, and can drive the motor as intended by the user. In other words, the cooling system 1 according to this embodiment can maintain the power performance because the output of the motor 30 is not limited.

[0093] [Fifth embodiment] Next, a cooling system 1 according to a fifth embodiment will be described with reference to the drawings. In this embodiment, a modified example in which the above-described third and fourth embodiments are combined will be described.

[0094] The configuration of the cooling system 1 according to this embodiment is similar to that of the first embodiment shown in Fig. 1, and therefore a description thereof will be omitted here. In this embodiment, the processing of the cooling control unit 70 is different.

[0095] In this embodiment, the cooling control unit 70 performs control to increase the cooling capacity of the refrigerant when the motor temperature is above a threshold value (above a second threshold value) and when the motor temperature is higher than the inverter temperature by a specific value (for example, when the value of (motor temperature - inverter temperature) is above a threshold value (above a third threshold value)). Other processing by the cooling control unit 70 is similar to that in the second embodiment, and therefore a description thereof will be omitted here.

[0096] Next, the operation of the cooling system 1 according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing an example of the operation of the cooling system 1 according to the fourth embodiment.

[0097] In FIG. 7, the processes from step S501 to step S506 are similar to the processes from step S401 to step S406 shown in FIG. 6 described above, and therefore the description thereof will be omitted here.

[0098] In step S505, if the predicted temperature rise of the refrigerant is less than the threshold value (less than the first threshold value) (step S505: NO), cooling control unit 70 advances the process to step S507.

[0099] In step S507, the cooling control unit 70 determines whether the motor temperature is equal to or higher than the threshold (equal to or higher than the second threshold). If the motor temperature is equal to or higher than the threshold (equal to or higher than the second threshold) (step S507: YES), the cooling control unit 70 advances the process to step S508. If the motor temperature is lower than the threshold (lower than the second threshold) (step S507: NO), the cooling control unit 70 returns the process to step S501.

[0100] In step S508, the cooling control unit 70 determines whether the value of (motor temperature-inverter temperature) is equal to or greater than the threshold value (equal to or greater than the third threshold value). If the value of (motor temperature-inverter temperature) is equal to or greater than the threshold value (equal to or greater than the third threshold value) (step S508: YES), the cooling control unit 70 advances the process to step S509. If the value of (motor temperature-inverter temperature) is less than the threshold value (less than the third threshold value) (step S508: NO), the cooling control unit 70 returns the process to step S501.

[0101] In step S509, the cooling control unit 70 performs control to increase the cooling capacity of the refrigerant. For example, the cooling control unit 70 performs control to increase the cooling capacity of the blower fan 53 or the drive output of the refrigerant pump 51. After the process of step S509, the cooling control unit 70 returns the process to step S501.

[0102] As described above, in the cooling system 1 according to the present embodiment, when the motor temperature is equal to or higher than the threshold value (equal to or higher than the second threshold value) and the value of (motor temperature-inverter temperature) is equal to or higher than the threshold value, the cooling control unit 70 End (Third Threshold End )), control is performed to increase the cooling capacity of the refrigerant.

[0103] As a result, the cooling system 1 according to this embodiment, like the third and fourth embodiments, can further suppress the temperature rise of the inverter 10, and can drive the motor as intended by the user.

[0104] In this embodiment, when the motor temperature is equal to or higher than the threshold value (equal to or higher than the second threshold value), or when the value of (motor temperature-inverter temperature) is equal to or higher than the threshold value End (Third Threshold End In the case where ) is ...). control may be performed to increase the cooling capacity of the refrigerant.

[0105] [Sixth embodiment] Next, a cooling system 1 according to a sixth embodiment will be described with reference to the drawings. In this embodiment, a modified example in which a cooling control unit 70 is mounted in an inverter 10 and an inverter control unit 11 includes the cooling control unit 70 will be described.

[0106] FIG. 8 is a schematic block diagram showing an example of a cooling system 1 according to the sixth embodiment. As shown in FIG. 8, in the cooling system 1 according to the present embodiment, the inverter control unit 11 includes a cooling control unit . The other configuration is similar to that of the first embodiment shown in FIG. 1 described above, and therefore a description thereof will be omitted here.

[0107] As described above, in the cooling system 1 according to this embodiment, the inverter 10 includes an inverter circuit section 12 that generates a drive signal for the motor 30, and an inverter control section 11 that controls the inverter circuit section 12, and the inverter control section 11 includes a cooling control section 70.

[0108] As a result, the cooling system 1 according to this embodiment does not need to provide a cooling control unit 70 in addition to the part (inverter control unit 11) that operates the inverter, and communication loss can be reduced. Furthermore, the cooling system 1 according to this embodiment can simplify the configuration by sharing the inverter control unit 11 and the cooling control unit 70.

[0109] The present disclosure is not limited to the above-described embodiments, and can be modified without departing from the spirit and scope of the present disclosure. For example, in each of the above embodiments, an example has been described in which the inverter 10, the transmission 20, and the motor 30 are configured as an integrated e-Axle unit 2, but this is not limited to this, and each of the inverter 10, the transmission 20, and the motor 30 may be configured to be arranged separately.

[0110] In addition, in each of the above embodiments, the cooling system 1 has been described as a system used in the electric drive device 100 of an electric vehicle, but the present invention is not limited to this and may be applied to an electric drive device 100 for purposes other than electric vehicles.

[0111] In addition, in the above embodiment, an example was described in which the motor temperature and inverter temperature are obtained from the motor temperature sensor 31 and the inverter temperature sensor 13, but this is not limited to this, and the cooling control unit 70 may estimate and use the motor temperature and inverter temperature.

[0112] In addition, in the above sixth embodiment, an example was described in which the inverter control unit 11 includes the cooling control unit 70, but this is not limited to this, and the upper ECU 60 may be configured to include the cooling control unit 70.

[0113] Each of the components of the cooling system 1 described above has a computer system inside. A program for realizing the function of each of the components of the cooling system 1 described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing in each of the components of the cooling system 1 described above. Here, "reading a program recorded on a recording medium into a computer system and executing it" includes installing the program into a computer system. The "computer system" referred to here includes hardware such as an OS and peripheral devices.

[0114] Furthermore, a "computer system" may include multiple computer devices connected via a network including communication lines such as the Internet, WAN, LAN, and dedicated lines. Furthermore, a "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. In this way, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

[0115] The recording medium also includes a recording medium installed inside or outside and accessible from a distribution server to distribute the program. The program may be divided into a plurality of parts, downloaded at different times, and then combined with each component of the cooling system 1, or each divided program may be distributed by a different distribution server. Furthermore, the "computer-readable recording medium" includes a recording medium that holds a program for a certain period of time, such as a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network. The above program may also be a recording medium for realizing part of the above-mentioned functions. Furthermore, the above-mentioned functions may be realized in combination with a program already recorded in the computer system, that is, a so-called difference file (difference program). [Explanation of symbols]

[0116] 1...cooling system, 2...e-Axle unit, 3...drive wheel, 4...drive shaft, 10...inverter, 11...inverter control unit, 12...inverter circuit unit, 13...inverter temperature sensor, 20...transmission, 30...motor, 31...motor temperature sensor, 40...oil cooler, 41...oil pump, 50...radiator, 51...refrigerant pump, 52...refrigerant temperature sensor, 53...blower fan, 60...host ECU, 70...cooling control unit, 100...electric drive unit, OC...oil circulation path, WC...refrigerant circulation path

Claims

1. A cooling system for an electric drive device including a motor that drives wheels and an inverter that controls the motor, a refrigerant circulation flow path in which an oil cooler for cooling oil supplied to the motor, a radiator for cooling the refrigerant, and the inverter cooled by the refrigerant are disposed in a circulation path of the refrigerant; A refrigerant temperature detection unit that detects a refrigerant temperature, which is the temperature of the refrigerant; A refrigerant cooling unit that cools the refrigerant; a cooling control unit that controls the cooling capacity of the refrigerant cooling unit, the cooling control unit predicting an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature detection unit and drive information of the inverter, and controlling the refrigerant cooling unit to increase the cooling capacity based on the prediction result; a motor temperature detection unit for detecting a motor temperature, which is the temperature of the motor; Equipped with A refrigerant pump that pumps the refrigerant is disposed in the refrigerant circulation passage, The inverter and the motor are disposed in a position where they are directly thermally affected by each other, The cooling control unit controls the drive output of the refrigerant pump to be increased when the predicted temperature rise of the refrigerant is equal to or greater than a threshold value, and controls the drive output of the refrigerant pump to be increased when the predicted temperature rise of the refrigerant is less than the threshold value, based on the motor temperature detected by the motor temperature detection unit. Cooling system.

2. An inverter temperature detection unit that detects an inverter temperature, which is the temperature of the inverter, The cooling control unit performs control to increase the cooling capacity of the refrigerant when the motor temperature detected by the motor temperature detection unit is higher than the inverter temperature detected by the inverter temperature detection unit by a specific value or more. The cooling system of claim 1 .

3. The cooling control unit controls to increase the cooling capacity of the refrigerant by increasing the cooling capacity of the refrigerant cooling unit or the drive output of the refrigerant pump. The cooling system of claim 1 .

4. The inverter includes an inverter circuit unit that generates a drive signal for the motor, and an inverter control unit that controls the inverter circuit unit, The inverter control unit includes the cooling control unit. A cooling system according to any one of claims 1 to 3.

5. A cooling control method for an electric drive device including a motor that drives wheels, an inverter that controls the motor, a refrigerant circulation flow path in which an oil cooler that cools oil supplied to the motor, a radiator that cools the refrigerant, and the inverter that is cooled by the refrigerant are disposed in a refrigerant circulation path, a refrigerant temperature detection unit that detects a refrigerant temperature that is a temperature of the refrigerant, a refrigerant cooling unit that cools the refrigerant, a cooling control unit that controls a cooling capacity of the refrigerant cooling unit, and a motor temperature detection unit that detects a motor temperature that is a temperature of the motor, A refrigerant pump that pumps the refrigerant is disposed in the refrigerant circulation passage, The inverter and the motor are disposed in a position where they are directly thermally affected by each other, The cooling control unit, predicting an increase in the refrigerant temperature based on the refrigerant temperature detected by the refrigerant temperature detection unit and drive information of the inverter; When the predicted temperature rise of the refrigerant is equal to or greater than a threshold value, the drive output of the refrigerant pump is controlled to be increased, and when the predicted temperature rise of the refrigerant is less than the threshold value, the cooling capacity of the refrigerant is controlled to be increased based on the motor temperature detected by the motor temperature detection unit. Cooling control method.

Images