Warm-up control method and warm-up control device

Abstract

The present invention provides a warm-up control method for warming up an on-vehicle device designated to be warmed up by circulating a coolant in a cooling circuit of the vehicle and thus recovering waste heat from an electric motor unit including a motor and an inverter. This warm-up control method comprises: acquiring a motor temperature, an inverter temperature, and a coolant temperature; calculating a motor coolant temperature difference, which is the difference between the motor temperature and the coolant temperature, and an inverter coolant temperature difference, which is the difference between the inverter temperature and the coolant temperature; and referring to the motor coolant temperature difference and the inverter coolant temperature difference, and executing at least one of a current adjustment process for adjusting the current flowing to the electric motor unit and a frequency adjustment process for adjusting the frequency of the inverter.

Description

Warm-up control method and warm-up control device

[0001] The present invention relates to a warm-up control method and a warm-up control device for accelerating the warm-up of an on-board device to be warmed up in an electric vehicle equipped with an electric motor unit including a motor and an inverter.

[0002] JP2008-189249A discloses a cooling system that utilizes heat generated by driving a motor and inverter mounted on an electric vehicle to promote warming up of an on-board device (particularly a battery) that is arranged in a cooling system common to the motor and inverter.

[0003] In low-temperature environments where warm-up is required, the temperature and flow rate of the refrigerant in the cooling system are low, increasing the refrigerant's thermal resistance. This reduces the amount of heat transferred from the motor and inverter (electric motor unit), which are heat sources, to the coolant, increasing thermal stress in the electric motor unit and raising concerns about its impact on strength reliability.

[0004] Therefore, an object of the present invention is to promote the warm-up of a device to be warmed up while ensuring the strength reliability of an electric motor unit.

[0005] According to one aspect of the present invention, there is provided a warm-up control method for warming up an on-board device to be warmed up by circulating a refrigerant in a cooling circuit of a vehicle, thereby recovering waste heat from an electric motor unit including a motor and an inverter.

[0006] In this warm-up control method, the motor temperature, inverter temperature, and refrigerant temperature are acquired, and a motor refrigerant temperature difference, which is the difference between the motor temperature and the refrigerant temperature, and an inverter refrigerant temperature difference, which is the difference between the inverter temperature and the refrigerant temperature, are calculated. Then, at least one of a current adjustment process that adjusts the current flowing to the electric motor unit and a frequency adjustment process that adjusts the frequency of the inverter is executed based on the motor refrigerant temperature difference and the inverter refrigerant temperature difference.

[0007] Fig. 1 is a block diagram showing the configuration of a vehicle system in which a warm-up control method according to one embodiment of the present invention is executed. Fig. 2 is a flowchart illustrating the overall processing in the warm-up control method of this embodiment. Fig. 3 is a flowchart illustrating details of a first current adjustment process. Fig. 4 is a flowchart illustrating details of a second frequency adjustment process. Fig. 5 is a flowchart illustrating details of the first frequency adjustment process. Fig. 6 is a flowchart illustrating details of the second current adjustment process.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0009] FIG. 1 is a block diagram showing the configuration of a vehicle system 10 in which a warm-up control method according to this embodiment is executed.

[0010] In particular, the vehicle system 10 shown in FIG. 1 includes an electric motor unit E, a battery 32, a cooling circuit C (a first cooling circuit C1 and a second cooling circuit C2) for cooling these, and a controller 50 for controlling various devices, all of which are mounted on an electric vehicle (an electric automobile or a hybrid vehicle).

[0011] The electric motor unit E is configured by a case that houses the motor 20 and the inverter 30 together and that is equipped with a cooling supply system (water jacket) for heat exchange between the motor 20 and the inverter 30 and cooling water.

[0012] The motor 20 is an electric motor that functions as a drive source for the electric vehicle, and is particularly configured as a three-phase AC motor. The motor 20 also includes a temperature sensor for detecting the temperature of the windings that configure the motor 20 (hereinafter referred to as the "motor temperature T ｍ A motor temperature sensor 60 is provided to detect the temperature of the motor (hereinafter referred to as "motor temperature sensor 60"). The motor temperature sensor 60 is configured by, for example, a thermistor.

[0013] The inverter 30 controls the power supplied from the battery 32 to the motor 20. In particular, the inverter 30 has a plurality of semiconductor elements (IGBTs, etc.). The semiconductor elements are driven (turned on or off) in response to a switching command signal (duty command signal) generated based on a command from the controller 50. The inverter 30 also includes a temperature sensor for the temperature of the elements in the inverter 30 (hereinafter referred to as "inverter temperature T ｉ An inverter temperature sensor 61 is provided to detect the inverter temperature (hereinafter referred to as "temperature") in the inverter circuit. The inverter temperature sensor 61 is configured by, for example, a thermistor.

[0014] The battery 32 is a DC power supply that functions as a drive power source for the motor 20. For example, the battery 32 is configured as an in-vehicle high-voltage battery (driving battery) such as a lithium-ion secondary battery.

[0015] The cooling circuit C has a first cooling circuit C1 through which the cooling water to be supplied to the electric motor unit E circulates, and a second cooling circuit C2 through which the cooling water to be supplied to the battery 32 circulates.

[0016] In the first cooling circuit C1, the coolant is circulated by driving a coolant pump 41, and the refrigerant (coolant) that is heat exchanged in a radiator 42 is supplied to the electric motor unit E. The output (coolant flow rate) of the coolant pump 41 is adjusted by a controller 50. In particular, the controller 50 adjusts the output of the coolant pump 41 in accordance with the required driving force for the electric vehicle and the warm-up requirement (required heat amount) of the battery 32. In addition, a temperature sensor for the coolant (hereinafter referred to as "coolant temperature T ｗ A coolant temperature sensor 62 is provided to detect the coolant temperature.

[0017] In the second cooling circuit C2, the coolant is circulated by driving the coolant pump 44, and the coolant that flows in from the first cooling circuit C1 via the three-way valve 43 is supplied to the battery 32. The output (coolant flow rate) of the coolant pump 44 and the opening degree of the three-way valve 43 (the amount of coolant that flows into the second cooling circuit C2) are adjusted by the controller 50. In particular, the controller 50 adjusts the output of the coolant pump 44 and the opening degree of the three-way valve 43 in accordance with the warm-up requirement (required heat amount) of the battery 32.

[0018] The controller 50 is an on-board computer that controls each device mounted on the electric vehicle. The controller 50 may be configured by a single piece of hardware, or may be configured by multiple pieces of hardware. Typically, the controller 50 is configured by a vehicle controller that comprehensively controls each part of the electric vehicle, including the cooling water pump 41, the three-way valve 43, and the cooling water pump 44, and a controller that controls the operation of the electric motor unit E (particularly, the current I that flows through the electric motor unit E). Ｅ and a motor controller that controls the frequency f) of the inverter 30, and these are made to execute the various processes described below in a distributed manner.

[0019] The controller 50 operates the electric motor unit E and each cooling actuator (cooling water pump 41, three-way valve 43, and cooling water pump 44) based on the amount of accelerator pedal operation by the occupant or the required driving force in response to commands from the automatic driving controller and inputs from various sensors.

[0020] In particular, in a situation where the battery 32 is charged using an external charging facility in a low-temperature environment, the controller 50 of this embodiment recovers waste heat (particularly heat generated by the motor 20 and the inverter 30) from the electric motor unit E to warm up the battery 32 that is the target of warm-up. More specifically, when the controller 50 detects a warm-up request for the battery 32, it operates each cooling actuator to circulate the cooling water in the cooling circuit C, while controlling the current I to be flowed through the electric motor unit E. Ｅ and adjusts the frequency f of the inverter 30.

[0021] Here, during the warm-up period, the current I flowing through the motor unit E is Ｅ(Current I flowing through the motor 20 ｍ and the current I flowing through the inverter 30 ｉ ) (to the target value set for warm-up), the amount of heat generated by the electric motor unit E is increased, thereby promoting warm-up. ｗ The cooling water flow rate is low, the thermal resistance of the cooling water is large, and the amount of heat transferred from the motor unit E to the cooling water is small. As a result, the inventors have found that the temperature of the motor unit E (motor temperature T ｍ and / or inverter temperature T ｉ ) and cooling water temperature T ｗ This leads to an increase in the thermal stress of the motor 20 and / or the inverter 30.

[0022] In view of the above circumstances, the inventors have determined that when warming up an in-vehicle device such as the battery 32 to be warmed up in a low-temperature environment, the motor temperature T ｍ and cooling water temperature T ｗ (hereinafter referred to as "motor cooling water temperature difference ΔT ｍｗ "), and inverter temperature T ｉ and cooling water temperature T ｗ (hereinafter referred to as "inverter cooling water temperature difference ΔT ｉｗ ") and the current I flowing through the motor unit E Ｅ The present inventors have come up with a technical idea of ​​promoting warm-up while protecting the electric motor unit E (motor 20 and inverter 30) by performing a process of adjusting the current (hereinafter referred to as "current adjustment process" as appropriate) and / or a process of adjusting the frequency f of the inverter 30 (hereinafter referred to as "frequency adjustment process" as appropriate).

[0023] The warm-up control method will be described in detail below.

[0024] 2 is a flowchart illustrating the warm-up control method of this embodiment. It is assumed that the processes in FIG. 2 are executed in a warm-up scenario for the battery 32 when charging is performed using a predetermined external charging facility in a low-temperature environment. In particular, the processes shown in FIG. 2 are initiated by the controller 50 upon detection of a warm-up request.

[0025] In the warm-up control method shown in FIG. 2, in step S100, the controller 50 ｍ Measured value of inverter temperature T ｉ and the cooling water temperature T ｗ Obtain the measurement value.

[0026] More specifically, the controller 50 calculates the moving average value of the detected values ​​of the motor temperature sensor 60 obtained at a plurality of sampling timings as the motor temperature T ｍ The moving average value is calculated by applying a moving average filter to each of the acquired detection values. Similarly, the controller 50 calculates the moving average value of each detection value of the inverter temperature sensor 61 and the moving average value of each detection value of the cooling water temperature sensor 62 as the inverter temperature T ｉ and the cooling water temperature T ｗ The measured value is obtained as:

[0027] In step S110, the controller 50 calculates the motor temperature T obtained in step S100. ｍ , inverter temperature T ｉ , and cooling water temperature T ｗ From the motor cooling water temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗ More specifically, the controller 50 calculates the motor temperature T ｍ to the cooling water temperature T ｗ Subtract the motor coolant temperature difference ΔT ｍｗ The controller 50 also calculates the inverter temperature T ｉ to the cooling water temperature T ｗ Subtract the inverter cooling water temperature difference ΔT ｉｗ Ask for.

[0028] In step S120, the controller 50 calculates the motor coolant temperature difference ΔT ｍｗ The first motor determination value is a value that is allowed from the viewpoint of protecting the motor 20, and is a motor temperature T ｍ and cooling water temperature T ｗThe first motor determination value is determined as the maximum value of the difference between the first motor determination value and the second motor determination value. The first motor determination value is determined in advance to be an appropriate value through experiments or simulations.

[0029] The controller 50 calculates the motor cooling water temperature difference ΔT ｍｗ is equal to or less than the first motor determination value (if step S120 is No), the inverter coolant temperature difference ΔT calculated in step S110 is further ｉｗ The first inverter judgment value is a value that is allowed from the viewpoint of protecting the inverter 30 and is lower than the inverter temperature T ｉ and cooling water temperature T ｗ The first inverter determination value is determined as the maximum value of the difference between the first inverter determination value and the second inverter determination value. The first inverter determination value is determined in advance to be an appropriate value through experiments or simulations.

[0030] The controller 50 then calculates the motor coolant temperature difference ΔT ｍｗ exceeds the first motor determination value (Yes in step S120), the first current adjustment process is executed in step S140.

[0031] 3 is a flowchart illustrating the details of the first current adjustment process. As shown in the figure, in the first current adjustment process, in step S141, the controller 50 adjusts the current I flowing through the motor unit E in accordance with the determination result of step S120. Ｅ More specifically, the controller 50 reduces the motor coolant temperature difference ΔT ｍ exceeds the first motor determination value, the current I flowing through the motor unit E is reduced by, for example, reducing the current supplied from the external charging facility to the motor unit E. Ｅ is set to be smaller than the base warm-up target value.

[0032] As a result, the motor cooling water temperature difference ΔT ｍ The motor cooling water temperature difference ΔT ｍ In such a case (when there is no room for error), the amount of heat generated by the motor 20 can be suppressed to protect the motor 20.

[0033] Then, in step S142, the controller 50 calculates the current I flowing through the motor unit E as described above. Ｅ With the motor temperature T ｍ and the cooling water temperature T ｗ More specifically, the controller 50 obtains the motor temperature T ｍ and the cooling water temperature T ｗ Obtain the measurement value.

[0034] In step S143, the controller 50 calculates the motor temperature T ｍ and cooling water temperature T ｗ Then, by the same calculation as in step S110, the motor coolant temperature difference ΔT ｍｗ is calculated again.

[0035] In step S144, the controller 50 calculates the calculated motor coolant temperature difference ΔT ｍｗ The second motor determination value is determined based on the motor cooling water temperature difference ΔT ｍ The second motor determination value is determined as a value for determining whether a certain margin has been generated in the second motor. The second motor determination value is determined in advance to be an appropriate value through experiments or simulations.

[0036] The controller 50 then calculates the motor coolant temperature difference ΔT ｍｗ is equal to or less than the second motor determination value, the current I Ｅ More specifically, the controller 50 increases the current I flowing through the electric motor unit E by, for example, increasing the current supplied from the external charging facility to the electric motor unit E (step S145). Ｅ is made larger than the value after the decrease in the process of step S141.

[0037] In the first current adjustment process, the current I ＥWhile protecting the motor 20, the cooling water in the cooling circuit C is circulated so that the cooling water receives heat from the electric motor unit E and the cooling water temperature T ｗ Therefore, the flow rate of the cooling water increases, the thermal resistance decreases, and the motor cooling water temperature difference ΔT ｍ The motor cooling water temperature difference ΔT ｍ approaches 0). Then, the motor coolant temperature difference ΔT ｍ has dropped sufficiently (motor cooling water temperature difference ΔT ｍ If it is determined that there is a margin in the current I Ｅ By increasing the value of the heat generated by the motor unit E (amount of recovered heat), the warm-up can be further promoted.

[0038] Then, the controller 50 calculates the current I flowing through the motor unit E. Ｅ After increasing the frequency, the first frequency adjustment process of step S150 is executed.

[0039] 4 is a flowchart illustrating the details of the first frequency adjustment process. As shown in the figure, in the first frequency adjustment process, in step S151, the controller 50 adjusts the inverter temperature T ｉ and the cooling water temperature T ｗ The measurement value is taken again.

[0040] More specifically, the controller 50 calculates the inverter temperature T ｉ and the cooling water temperature T ｗ The measured value is obtained as:

[0041] In step S152, the controller 50 calculates the inverter temperature T ｉ and cooling water temperature T ｗ Then, the inverter cooling water temperature difference ΔT is calculated in the same manner as in step S110. ｉｗ is calculated again.

[0042] In step S153, the controller 50 calculates the inverter cooling water temperature difference ΔT ｉｗThe controller 50 compares the inverter coolant temperature difference ΔT ｉｗ becomes equal to or less than the first inverter determination value (No in step S153), the process of step S154 is executed.

[0043] In step S154, the controller 50 calculates the inverter coolant temperature difference ΔT ｉｗ is equal to or less than a predetermined second inverter determination value. ｉｗ The second inverter judgment value is a feedback control that adjusts the frequency f so that the difference between the inverter cooling water temperature difference ΔT and the second inverter judgment value is within a predetermined value. ｉｗ The second inverter determination value is determined in advance to be an appropriate value through experiments or simulations.

[0044] As described above, the current I Ｅ In the scene where the warm-up is promoted by the above, the inverter cooling water temperature difference ΔT ｉｗ If it is determined that there is a certain margin, the process of step S154 increases the amount of heat generated (recovered heat) from the motor unit E (particularly the inverter 30), thereby further accelerating warm-up.

[0045] Returning to Figure 2, the motor cooling water temperature difference ΔT ｍ is equal to or less than the first motor determination value, and the inverter cooling water temperature difference ΔT ｉｗ exceeds the first inverter determination value (No in step S120 and Yes in step S130), the controller 50 executes the second current adjustment process in step S160 and the second frequency adjustment process in step S170.

[0046] 5 is a flowchart illustrating the details of the second frequency adjustment process. As shown in the figure, in the second frequency adjustment process, in step S161, the controller 50 reduces the frequency f of the inverter 30. More specifically, the controller 50 reduces the frequency f by, for example, lowering the frequency f of the inverter 30 below a predetermined basic value (a specified frequency during warm-up).

[0047] As a result, the motor cooling water temperature difference ΔT ｍ Although there is a margin for error, the inverter cooling water temperature difference ΔT ｉｗ In a situation where there is no margin for error, the amount of heat generated by the inverter 30 can be suppressed to protect the inverter 30.

[0048] In the process of step S161, the frequency f is decreased while the current I flowing through the motor unit E is increased. Ｅ (In particular, the current I ｍ ) is preferably set to a target value set for warm-up or higher. ｍ Even though there is a margin for improvement, it is possible to suppress a decrease in warm-up efficiency due to a reduction in the amount of heat generated by the motor 20.

[0049] Furthermore, when the frequency f of the inverter 30 is reduced, there is a concern that torque control accuracy will be reduced, which may result in unintended torque being generated in the motor 20 and leading to vehicle vibrations. For this reason, it is preferable to tighten the gears in the drive system connected to the motor 20 by, for example, applying a predetermined torque to the motor 20 in advance when the electric vehicle is stopped.

[0050] In step S162, the controller 50 calculates the inverter temperature T ｉ and the cooling water temperature T ｗ The measurement value is taken again.

[0051] In step S163, the controller 50 calculates the inverter temperature T ｉ and cooling water temperature T ｗ Then, by the same calculation as in step S110, the inverter cooling water temperature difference ΔT ｉｗis calculated again.

[0052] In step S164, the controller 50 calculates the inverter coolant temperature difference ΔT ｉｗ The controller 50 compares the inverter coolant temperature difference ΔT ｉｗ becomes equal to or less than the first inverter determination value (No in step S164), the process of step S165 is executed.

[0053] In step S165, the controller 50 calculates the inverter coolant temperature difference ΔT calculated in step S163 in the same manner as in step S154. ｉｗ is equal to or less than the second inverter determination value.

[0054] In the second frequency adjustment process, the inverter 30 is protected by the frequency f reduced through the process of step S161, and the cooling water in the cooling circuit C is circulated so that the cooling water receives heat from the motor unit E and the cooling water temperature T ｗ Therefore, the flow rate of the cooling water increases, the thermal resistance decreases, and the inverter cooling water temperature difference ΔT ｉｗ The inverter cooling water temperature difference ΔT ｉｗ approaches 0). Then, the inverter cooling water temperature difference ΔT ｉｗ has dropped sufficiently (the inverter cooling water temperature difference ΔT ｉｗ If it is determined that there is a margin in the inverter cooling water temperature difference ΔT, the frequency f is increased in step S165. ｉｗ By utilizing this surplus, the amount of heat generated (the amount of heat recovered) by the motor unit E (particularly the inverter 30) can be increased, thereby further accelerating the warm-up.

[0055] Then, the controller 50 executes the second current adjustment process in step S170 in parallel with the feedback control of the frequency f of the inverter 30 in step S165.

[0056] 6 is a flowchart illustrating the details of the second current adjustment process. As shown in the figure, in the second current adjustment process, in step S171, the controller 50 performs the feedback control of the frequency f of the inverter 30, and calculates the motor temperature T ｍ and the cooling water temperature T ｗ The measurement value is taken again.

[0057] In step S172, the controller 50 calculates the motor temperature T ｍ and cooling water temperature T ｗ Then, the motor coolant temperature difference ΔT is calculated in the same manner as in step S110. ｍｗ is calculated again.

[0058] In step S173, the controller 50 calculates the calculated motor coolant temperature difference ΔT ｍｗ and the second motor determination value are compared to determine which is larger.

[0059] And the motor cooling water temperature difference ΔT ｍｗ becomes equal to or less than the second motor determination value (No in step S173), the controller 50 reduces the current I Ｅ is increased (step S174).

[0060] As described above, during the feedback control of the frequency f of the inverter 30, the motor coolant temperature difference ΔT ｍｗ If it is determined that there is a certain margin, the process of step S174 increases the amount of heat generated (the amount of heat recovered) from the electric motor unit E (particularly the motor 20), thereby further accelerating warm-up.

[0061] The configuration of the warm-up control method of the present embodiment described above and the resulting effects will now be described.

[0062] According to this embodiment, a warm-up control method is provided in which waste heat is recovered from an electric motor unit E including a motor 20 and an inverter 30 in a vehicle's cooling circuit C (first cooling circuit C1 and second cooling circuit C2) to warm up an on-board device (battery 32) to be warmed up.

[0063] In this warm-up control method, the motor temperature T ｍ , inverter temperature T ｉ , and refrigerant temperature (cooling water temperature T ｗ ) and the motor temperature T ｍ and cooling water temperature T ｗ The difference between the motor refrigerant temperature difference (motor cooling water temperature difference ΔT ｍｗ ), and inverter temperature T ｉ and cooling water temperature T ｗ The inverter refrigerant temperature difference (inverter cooling water temperature difference ΔT ｉｗ ) is calculated. Then, the motor cooling water temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗ With reference to the current I Ｅ and a frequency adjustment process (first frequency adjustment process and second frequency adjustment process) that adjusts the frequency f of the inverter 30.

[0064] As a result, the motor cooling water temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗ The current I flowing through the motor unit E is determined by referring to the Ｅ (Current I flowing through the motor 20 ｍ and the current I flowing through the inverter 30 ｉ ), and / or the frequency f of the inverter 30, it is possible to adjust the amount of heat generated (amount of recovered heat) by the motor 20 and the inverter 30. Therefore, it is possible to protect the components of the electric motor unit E consisting of the motor 20 and the inverter 30, and to promote the warm-up of the in-vehicle devices.

[0065] In particular, as a result of intensive research, the inventors have found that the limits of component strength of the motor 20 and the inverter 30 are respectively the motor temperature T ｍ and inverter temperature T ｉ Rather than the temperature itself, it is ｗ Therefore, the motor cooling water temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗBy referring to the above, it is possible to appropriately estimate the range in which the motor 20 and the inverter 30 do not reach their strength limits, and to increase the amount of recovered heat as much as possible within that range to improve the warm-up efficiency.

[0066] In particular, the current adjustment process includes a first current adjustment process (step S140), and the motor coolant temperature difference ΔT ｍｗ If the current I exceeds the predetermined first motor determination value, the first current adjustment process is executed (Yes in step S120 and step S141). Ｅ Reduces.

[0067] As a result, the motor cooling water temperature difference ΔT ｍｗ In a situation where there is no margin for error, the amount of heat generated by the motor 20 can be reduced to prioritize protection of the motor 20.

[0068] More specifically, in the first current adjustment process, the current I Ｅ While the cooling water is circulating while decreasing the motor temperature T ｍ and cooling water temperature T ｗ Then, the motor temperature T ｍ and cooling water temperature T ｗ Based on this, the motor coolant temperature difference ΔT ｍｗ (Step S143). ｍｗ When the current I flows through the electric motor unit E, the Ｅ is increased (No in step S144 and step S145).

[0069] This results in a current I Ｅ When the motor coolant temperature difference ΔT ｍｗ It accurately detects situations where there is a margin for current I Ｅ Therefore, the amount of heat generated (amount of recovered heat) can be increased as much as possible within the range where the motor 20 is protected, thereby further improving the warm-up efficiency.

[0070] The frequency adjustment process includes a first frequency adjustment process, and the current I Ｅ When the current I is increased (step S145), the first frequency adjustment process (step S150) is executed. Ｅ With the inverter temperature T ｉ and cooling water temperature T ｗ is acquired again (step S151), and the acquired inverter temperature T ｉ and cooling water temperature T ｗ From the inverter cooling water temperature difference ΔT ｉｗ (Step S152). ｉｗ is equal to or less than a predetermined first inverter judgment value, the inverter cooling water temperature difference ΔT ｉｗ The frequency f of the inverter 30 is increased within a range in which the frequency f is equal to or less than a predetermined second inverter determination value (No in step S153 and step S154).

[0071] As a result, the current I flowing through the motor unit E Ｅ In addition, the inverter cooling water temperature difference ΔT ｉｗ Therefore, the amount of heat generated (amount of recovered heat) can be increased as much as possible within the range where the components of the electric motor unit E can be protected, thereby further improving the warm-up efficiency.

[0072] Furthermore, the frequency adjustment process includes a second frequency adjustment process (step S160), and the motor coolant temperature difference ΔT ｍｗ is equal to or less than a predetermined first motor judgment value and the inverter cooling water temperature difference ΔT ｉｗ exceeds the predetermined first inverter determination value (step S120: No and step S130: Yes), the second frequency adjustment process is executed. Then, in the second frequency adjustment process, the frequency f of the inverter 30 is reduced (step S161).

[0073] As a result, the motor cooling water temperature difference ΔT ｍ Although there is a margin for error, the inverter cooling water temperature difference ΔT ｉｗIn a situation where there is no margin for error (a situation where protection of the inverter 30 is required), the frequency f can be reduced to suppress the amount of heat generated by the inverter 30, and protection of the inverter 30 can be prioritized.

[0074] More specifically, in the second frequency adjustment process, the frequency f of the inverter 30 is reduced while the cooling water is circulating, and the inverter temperature T ｉ and cooling water temperature T ｗ is acquired again (step S162), and the acquired inverter temperature T ｉ and cooling water temperature T ｗ From the inverter cooling water temperature difference ΔT ｉｗ Then, the inverter coolant temperature difference ΔT is calculated again (step S163). ｉｗ becomes equal to or less than the first inverter determination value, the inverter cooling water temperature difference ΔT ｉｗ The frequency f of the inverter 30 is increased within a range in which the frequency f is equal to or less than a predetermined second inverter determination value (No in step S164 and step S165).

[0075] As a result, when the frequency f of the inverter 30 is reduced, the inverter coolant temperature difference ΔT ｉｗ Therefore, the amount of heat generated (amount of recovered heat) can be increased as much as possible within the range that realizes protection of the inverter 30, thereby further improving the warm-up efficiency.

[0076] The current adjustment process also includes a second current adjustment process (step S170), in which the second current adjustment process is executed while adjusting the frequency f of the inverter 30 (steps S165 and S171). ｍ and cooling water temperature T ｗ is acquired again (step S171), and the acquired motor temperature T ｍ and cooling water temperature T ｗ Based on this, the motor coolant temperature difference ΔT ｍｗ Then, the motor coolant temperature difference ΔT is calculated again (step S172). ｍｗbecomes equal to or less than a predetermined motor determination value (second motor determination value) (No in step S173), the current I Ｅ is increased (step S174).

[0077] As a result, when the frequency f of the inverter 30 is increased, the motor coolant temperature difference ΔT ｍｗ The current I that flows to the motor unit E in this situation is accurately detected. Ｅ Therefore, the amount of heat generated (amount of recovered heat) can be increased as much as possible within the range where the motor 20 is protected, thereby further improving the warm-up efficiency.

[0078] In this embodiment, the motor temperature T ｍ , inverter temperature T ｉ , and cooling water temperature T ｗ are obtained as moving average values ​​of the sensor values ​​obtained at predetermined sampling times.

[0079] As a result, the motor cooling water temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗ can be calculated with higher accuracy, and the accuracy of the determination of the need for protection of the motor 20 and / or the inverter 30 based on these can be improved.

[0080] Furthermore, in this embodiment, a controller 50 is provided that functions as a warm-up control device suitable for executing the above-described warm-up control method. In particular, the controller 50 ｍ , inverter temperature T ｉ , and refrigerant temperature (cooling water temperature T ｗ ) and an acquisition unit for acquiring the motor temperature T ｍ and cooling water temperature T ｗ The difference between the motor refrigerant temperature difference (motor cooling water temperature difference ΔT ｍｗ ), and inverter temperature T ｉ and cooling water temperature T ｗ The inverter refrigerant temperature difference (inverter cooling water temperature difference ΔT ｉｗ ) and a motor coolant temperature difference ΔT ｍｗ and inverter cooling water temperature difference ΔT ｉｗWith reference to the current I Ｅ and an adjustment processing unit that executes at least one of a current adjustment process (first current adjustment process and second current adjustment process) that adjusts the frequency f of the inverter 30, and a frequency adjustment process (first frequency adjustment process and second frequency adjustment process) that adjusts the frequency f of the inverter 30.

[0081] The processing procedures shown in each of the above-described embodiments are examples for realizing each embodiment, and the order of some of the processing procedures may be changed within the scope that allows each embodiment to be realized, and some of the processing procedures may be omitted or other processing procedures may be added.

[0082] Furthermore, each process shown in each embodiment is executed based on a program for causing a computer to execute each processing procedure, and therefore each embodiment can also be understood as an embodiment of a program that realizes the function of executing each process, or a recording medium that stores the program.

[0083] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

Claims

1. A warm-up control method for warming up an on-board device to be warmed up by circulating refrigerant in a vehicle's cooling circuit to recover waste heat from an electric motor unit including a motor and an inverter, the warm-up control method comprising: acquiring a motor temperature, an inverter temperature, and a refrigerant temperature; calculating a motor refrigerant temperature difference, which is the difference between the motor temperature and the refrigerant temperature, and an inverter refrigerant temperature difference, which is the difference between the inverter temperature and the refrigerant temperature; and performing at least one of a current adjustment process for adjusting the current flowing to the electric motor unit and a frequency adjustment process for adjusting the frequency of the inverter, by referring to the motor refrigerant temperature difference and the inverter refrigerant temperature difference.

2. A warm-up control method according to claim 1, wherein the current adjustment process includes a first current adjustment process, and when the motor refrigerant temperature difference exceeds a predetermined first motor judgment value, the first current adjustment process is executed, and in the first current adjustment process, the current flowing to the electric motor unit is reduced.

3. A warm-up control method as claimed in claim 2, wherein the first current adjustment process comprises: acquiring the motor temperature and the refrigerant temperature again while the refrigerant is circulating while the current flowing through the electric motor unit is reduced; recalculating the motor refrigerant temperature difference based on the acquired motor temperature and refrigerant temperature; and increasing the current flowing through the electric motor unit when the motor refrigerant temperature difference becomes equal to or less than a predetermined second motor judgment value.

4. A warm-up control method as claimed in claim 3, wherein the frequency adjustment process includes a first frequency adjustment process, and when the current flowing to the electric motor unit is increased, the first frequency adjustment process is executed, and in the first frequency adjustment process, the inverter temperature and the refrigerant temperature are acquired again with the current flowing to the electric motor unit increased, the inverter refrigerant temperature difference is calculated again from the acquired inverter temperature and refrigerant temperature, and when the inverter refrigerant temperature difference is equal to or less than a predetermined first inverter judgment value, the inverter frequency is increased within a range where the inverter refrigerant temperature difference is equal to or less than a predetermined second inverter judgment value.

5. A warm-up control method according to claim 1, wherein the frequency adjustment process includes a second frequency adjustment process, and when the motor refrigerant temperature difference is equal to or less than a predetermined first motor judgment value and the inverter refrigerant temperature difference exceeds a predetermined first inverter judgment value, the second frequency adjustment process is executed, and in the second frequency adjustment process, the frequency of the inverter is reduced.

6. A warm-up control method as claimed in claim 5, wherein in the second frequency adjustment process, the inverter temperature and the refrigerant temperature are acquired again while the refrigerant is circulating while the inverter frequency is reduced, the inverter refrigerant temperature difference is calculated again from the acquired inverter temperature and refrigerant temperature, and when the inverter refrigerant temperature difference becomes equal to or less than the first inverter judgment value, the inverter frequency is increased within a range where the inverter refrigerant temperature difference becomes equal to or less than a predetermined second inverter judgment value.

7. A warm-up control method according to claim 6, wherein the current adjustment process includes a second current adjustment process, and the second current adjustment process is executed while adjusting the frequency of the inverter, and in the second current adjustment process, the motor temperature and the refrigerant temperature are acquired again, the motor refrigerant temperature difference is calculated again based on the acquired motor temperature and refrigerant temperature, and the current flowing to the electric motor unit is increased within a range in which the motor refrigerant temperature difference is equal to or less than a predetermined motor judgment value.

8. A warm-up control method according to any one of claims 1 to 7, wherein the motor temperature, the inverter temperature, and the refrigerant temperature are each obtained as a moving average of each sensor value obtained at a plurality of sampling timings.

9. A warm-up control device that warms up an on-board device to be warmed up by circulating refrigerant in a vehicle's cooling circuit to recover waste heat from an electric motor unit including a motor and an inverter, comprising: an acquisition unit that acquires the motor temperature, the inverter temperature, and the refrigerant temperature; a calculation unit that calculates a motor refrigerant temperature difference, which is the difference between the motor temperature and the refrigerant temperature, and an inverter refrigerant temperature difference, which is the difference between the inverter temperature and the refrigerant temperature; and an adjustment processing unit that performs at least one of a current adjustment process that adjusts the current flowing to the electric motor unit and a frequency adjustment process that adjusts the frequency of the inverter, by referring to the motor refrigerant temperature difference and the inverter refrigerant temperature difference.

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