Motor controller thermal management method, vehicle and storage medium

Abstract

The application provides a motor controller thermal management method, a vehicle and a storage medium, and relates to the technical field of vehicles.The method comprises the following steps: acquiring the temperature of a switch tube corresponding to a motor controller and the temperature of a cooling medium; when at least one of the temperature of the switch tube and the temperature of the cooling medium is greater than a corresponding temperature threshold, the flow of the cooling medium is regulated; if the temperature of the switch tube continues to rise after the regulation, the motor controller is subjected to torque control according to the three-phase current thermal cumulative value of the IGBT.The application can regulate the flow of the cooling medium when at least one of the temperature of the switch tube and the temperature of the cooling medium is greater than a corresponding temperature threshold, and if the temperature of the switch tube continues to rise after the regulation, it indicates that the cooling medium alone cannot avoid the problem of thermal failure, and at this time, torque control is performed on the motor controller according to the three-phase current thermal cumulative value, the torque is subjected to thermal degradation, and the thermal failure of the motor controller is avoided.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a thermal management method for an electric motor controller, a vehicle, and a storage medium. Background Technology

[0002] The electric drive system of an electric vehicle includes components such as a motor and a motor controller. It is mainly responsible for converting electrical energy into mechanical energy to drive the vehicle. The electric drive system is susceptible to failure due to overheating, and the most common component to fail due to overheating is the motor controller.

[0003] If the heat dissipation system is poorly designed or insufficient to effectively cool the motor controller during long-term or high-load operation, thermal failure may occur, leading to a decrease in the performance of the motor controller, damage, or cessation of operation. Summary of the Invention

[0004] The problem solved by this invention is how to avoid thermal failure of the motor controller.

[0005] To address the above problems, the present invention provides a thermal management method for a motor controller, a vehicle, and a storage medium.

[0006] In a first aspect, the present invention provides a thermal management method for a motor controller, comprising:

[0007] Obtain the temperature of the switching transistor and the temperature of the cooling medium corresponding to the motor controller;

[0008] When at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than the corresponding temperature threshold, the flow rate of the cooling medium is regulated.

[0009] If the temperature of the switching transistor continues to rise after adjustment, the motor controller will perform torque control based on the cumulative thermal value of the three-phase current of the IGBT.

[0010] Optionally, regulating the flow rate of the cooling medium when at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than a corresponding temperature threshold includes:

[0011] Determine the temperature of the switching transistor and the magnitude of the first temperature threshold;

[0012] Determine the temperature of the cooling medium and the magnitude of the second temperature threshold;

[0013] If the temperature of the switching transistor is greater than the first temperature threshold, and / or the temperature of the cooling medium is greater than the second temperature threshold, then the flow rate of the cooling medium is regulated.

[0014] Optionally, regulating the flow rate of the cooling medium includes:

[0015] The target flow rate of the cooling medium is determined based on the temperature of the switching transistor and the temperature of the cooling medium.

[0016] The final target flow rate is determined based on the target flow rate and the corresponding cooling medium flow coefficient.

[0017] The flow rate of the cooling medium is regulated according to the final target flow rate.

[0018] Optionally, determining the target flow rate of the cooling medium based on the temperature of the switching transistor and the temperature of the cooling medium includes:

[0019] The target flow rate of the cooling medium is determined based on the temperature of the switching transistor, the temperature of the cooling medium, and a preset relationship, wherein the preset relationship includes the correspondence between the temperature of the switching transistor, the temperature of the cooling medium, and the target flow rate.

[0020] Optionally, regulating the flow rate of the cooling medium further includes:

[0021] The cooling medium flow coefficient is determined based on the vehicle controller's required torque for the electric drive system and the rate of change of required torque.

[0022] Optionally, after regulating the flow rate of the cooling medium, the motor controller thermal management method further includes:

[0023] The temperature of the switching transistor and the third temperature threshold are compared. If the temperature of the switching transistor after adjustment is greater than the third temperature threshold, it is determined that the temperature of the switching transistor will continue to rise, wherein the third temperature threshold is greater than the first temperature threshold.

[0024] Optionally, the torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor includes:

[0025] The heat accumulation difference is determined based on the three-phase current heat accumulation value and the preset heat accumulation upper limit value;

[0026] The degradation coefficient is determined based on the accumulated heat difference and the corresponding difference threshold.

[0027] The control torque is reduced according to the degradation factor.

[0028] Optionally, the torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor further includes:

[0029] The cumulative thermal value of the three-phase current is determined based on the effective value of the three-phase current and the resistance of the motor stator winding.

[0030] In a second aspect, the present invention provides a vehicle including a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the above-mentioned motor controller thermal management method.

[0031] Thirdly, the present invention provides a computer-readable storage medium storing a computer program, which, when read and run by a processor, implements the above-mentioned motor controller thermal management method.

[0032] This invention can regulate the flow rate of the cooling medium when at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than the corresponding temperature threshold. For example, the temperature of the switching transistor can be reduced by increasing the flow rate of the cooling medium. If the temperature of the switching transistor continues to rise after regulation, it indicates that thermal failure cannot be avoided by relying solely on the cooling medium. At this time, torque control is performed by the three-phase current thermal accumulation value. For example, when the three-phase current thermal accumulation value exceeds the threshold, the torque is thermally degraded to avoid thermal failure of the motor controller. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the thermal management method for a motor controller according to an embodiment of the present invention.

[0034] Figure 2 This is an overall block diagram of the motor controller thermal management method according to an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram illustrating the preset relationships in an embodiment of the present invention. Detailed Implementation

[0036] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0037] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0038] like Figure 1 As shown, an embodiment of the present invention provides a thermal management method for a motor controller, comprising:

[0039] The temperature of the switching transistor corresponding to the motor controller and the temperature of the cooling medium used to cool the switching transistor are obtained.

[0040] Specifically, the temperature of the switching transistor (e.g., IGBT) corresponding to the motor controller and the temperature of the cooling medium used to cool the switching transistor are first obtained. For example, a temperature sensor (thermometer, thermistor, thermistor diode, etc.) can be installed on the IGBT module or heat sink, or an infrared thermometer can be used to measure the surface temperature of the IGBT without direct contact. For example, a temperature sensor can be installed to measure the temperature of the cooling medium (e.g., coolant or air blown by a fan).

[0041] Among them, the most important heat source and thermal failure component in the motor controller is the IGBT (Insulated Gate Bipolar Transistor) drive bridge.

[0042] The medium used to cool the IGBT is called the cooling medium, which specifically includes:

[0043] (1) Heat sink: The heat sink is one of the most common cooling media for IGBTs. It is usually an aluminum or copper metal sheet connected to the IGBT. It conducts heat to the surface of the heat sink and then dissipates the heat through air or other cooling media.

[0044] (2) Fan: Fans are usually used in conjunction with heat sinks. By installing fans above or beside the heat sink, the heat dissipation effect is enhanced. Fans can accelerate airflow and improve heat dissipation efficiency.

[0045] (3) Liquid cooling system: The liquid cooling system uses liquid to cool the IGBT. Usually, the coolant is circulated to the vicinity of the IGBT through pipes, absorbs heat, and then flows back to the heat dissipation system or heat sink. This method is very effective for high power density applications.

[0046] (4) Thermal conductive plate: Thermal conductive plate is usually a metal or composite material used to improve the heat conduction efficiency in different parts and ensure uniform heat dissipation of the entire device.

[0047] (5) Heat pipe: A heat pipe is a heat transfer device that uses the principle of liquid phase change to transfer heat from one place to another. Heat pipes can be used to improve the heat transfer efficiency in a system.

[0048] In this embodiment, unless otherwise specified, the cooling medium generally refers to cooling water.

[0049] When at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than the corresponding temperature threshold, the flow rate of the cooling medium is regulated.

[0050] Specifically, when at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than the corresponding temperature threshold, the thermal degradation control strategy of the IGBT is triggered to regulate the flow of the cooling medium, such as increasing the cooling water flow and reducing the temperature of the IGBT.

[0051] If the temperature of the switching transistor continues to rise after adjustment, the motor controller will perform torque control based on the cumulative thermal value of the three-phase current of the IGBT.

[0052] Specifically, if the temperature of the switching transistor continues to rise after increasing the cooling water flow, the motor controller is used for torque control based on the cumulative three-phase current of the IGBT. For example, the degradation coefficient of the target torque is determined based on the cumulative three-phase current, thereby avoiding thermal failure of the IGBT drive bridge.

[0053] The electric drive system of electric vehicles includes:

[0054] (1) Electric motor: The electric motor is a key component of electric vehicles, responsible for converting the DC power provided by the battery into mechanical power to propel the vehicle forward. Electric vehicles typically use AC motors or DC motors, with AC asynchronous motors and permanent magnet synchronous motors being common choices.

[0055] (2) Motor controller: The motor controller is the intelligent control core of the electric drive system of electric vehicles. Its main functions include:

[0056] ① Current control: Controls the motor current and adjusts the motor torque and speed.

[0057] ②Speed ​​control: Controls the motor speed to meet the vehicle's driving requirements.

[0058] ③ Phase sequence control: In AC motors, the phase sequence of the motor is controlled to ensure the correct matching of current and torque.

[0059] ④ Energy feedback: The feedback system obtains information on the status of the motor and vehicle to achieve efficient energy utilization.

[0060] ⑤ Fault detection and protection: Detect system faults and take protective measures to prevent damage to the motor and electrical control system.

[0061] (3) Battery: The battery is the energy source for electric vehicles, and lithium-ion batteries are commonly used. The battery provides DC power, which the motor controller converts into current and voltage suitable for the motor's operation.

[0062] The main causes of thermal failure in motor controllers include:

[0063] (1) Overload operation: Long-term high-load operation will cause the motor and motor controller to generate a lot of heat. If the heat dissipation system is poorly designed or insufficient to effectively cool down, thermal failure is likely to occur.

[0064] (2) Ambient temperature: High temperature environments make the motor controller more prone to overheating. Especially in hot summers or high-temperature areas, special attention needs to be paid to heat dissipation.

[0065] (3) Inadequate heat dissipation system: Motor controllers usually need a heat dissipation system to dissipate the heat generated. If the heat dissipation system is poorly designed or obstructed, it will lead to thermal failure.

[0066] (4) Quality of electronic components: Poor quality or aging of electronic components inside the motor controller, such as transistors and capacitors, may lead to performance degradation or failure at high temperatures.

[0067] Optionally, regulating the flow rate of the cooling medium when at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than a corresponding temperature threshold includes:

[0068] Determine the temperature of the switching transistor and the magnitude of the first temperature threshold.

[0069] Specifically, in combination Figure 2 As shown, in torque control mode, the temperature of the monitoring switch is monitored to see if it is greater than threshold 1 (i.e., the first temperature threshold, for example, 80°C to 90°C).

[0070] Determine the temperature of the cooling medium and the magnitude of the second temperature threshold.

[0071] Specifically, in combination Figure 2 As shown, in torque control mode, the temperature of the cooling water (i.e., the temperature of the cooling medium) is monitored to see if it is greater than a threshold (i.e., a second temperature threshold, such as 50°C to 60°C).

[0072] If the temperature of the switching transistor is greater than the first temperature threshold, and / or the temperature of the cooling medium is greater than the second temperature threshold, then the flow rate of the cooling medium is regulated.

[0073] Specifically, if the temperature of the switching transistor is greater than the first temperature threshold, and / or the temperature of the cooling medium is greater than the second temperature threshold, the thermal degradation control strategy of the IGBT is triggered to regulate the flow rate of the cooling medium.

[0074] Optionally, regulating the flow rate of the cooling medium includes:

[0075] The target flow rate of the cooling medium is determined based on the temperature of the switching transistor and the temperature of the cooling medium.

[0076] Specifically, the target flow rate (demanded cooling water flow rate) of the cooling medium is first determined based on the temperature of the switching tube and the temperature of the cooling medium. At this point, the target flow rate is not the final control target and needs to be multiplied by a coefficient to determine the final target flow rate.

[0077] The final target flow rate is determined based on the target flow rate and the corresponding cooling medium flow rate coefficient.

[0078] Specifically, the final target flow rate is then determined based on the target flow rate and the corresponding cooling medium flow coefficient.

[0079] The flow rate of the cooling medium is regulated according to the final target flow rate.

[0080] Specifically, the final target flow rate (the required cooling water flow rate obtained by multiplying the above required cooling water flow rate by a coefficient) is sent to the vehicle thermal management system to regulate the flow rate of the cooling medium.

[0081] Optionally, determining the target flow rate of the cooling medium based on the temperature of the switching transistor and the temperature of the cooling medium includes:

[0082] The target flow rate of the cooling medium is determined based on the temperature of the switching transistor, the temperature of the cooling medium, and a preset relationship, wherein the preset relationship includes the correspondence between the temperature of the switching transistor, the temperature of the cooling medium, and the target flow rate.

[0083] Specifically, in combination Figure 2 As shown, the target flow rate of the cooling water is determined by looking up a 2D table (i.e., a preset relationship) based on the temperature of the switching transistor and the temperature of the cooling water (i.e., the temperature of the cooling medium). The 2D table contains the correspondence between the temperature of the switching transistor and the temperature of the cooling medium and the target flow rate. For example... Figure 3 As shown, when the temperature of the switching transistor is 130℃ and the cooling water temperature is 20℃, the corresponding cooling water flow rate is 20L / min.

[0084] Optionally, regulating the flow rate of the cooling medium further includes:

[0085] The cooling medium flow coefficient is determined based on the vehicle controller's required torque for the electric drive system and the rate of change of required torque.

[0086] Specifically, in combination Figure 2 As shown, the cooling water flow coefficient (i.e., cooling medium flow coefficient) is determined by looking up a 2D table based on the vehicle controller's required torque and the rate of change of required torque for the electric drive system. The range is [1, N]. For example, when the required torque and the rate of change of required torque are too high, the coefficient obtained by looking up the table is assumed to be 2. Then, the final target flow rate sent to the vehicle thermal management system is twice the target flow rate.

[0087] Optionally, after regulating the flow rate of the cooling medium, the motor controller thermal management method further includes:

[0088] The temperature of the switching transistor and the third temperature threshold are compared. If the temperature of the switching transistor after adjustment is greater than the third temperature threshold, it is determined that the temperature of the switching transistor will continue to rise, wherein the third temperature threshold is greater than the first temperature threshold.

[0089] Specifically, in combination Figure 2 As shown, after adjustment, monitor whether the temperature of the switching transistor is greater than threshold 2 (i.e., the third temperature threshold, for example, 95℃ to 105℃, the third temperature threshold is greater than the first temperature threshold). If the judgment result is "no", it means that the temperature of the IGBT can be controlled to stop rising by increasing the water flow (return to the step of monitoring whether the temperature of the switching transistor is greater than threshold 1); if the judgment result is "yes", it means that the temperature of the IGBT continues to rise.

[0090] Optionally, the torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor includes:

[0091] The heat accumulation difference is determined based on the three-phase current heat accumulation value and the preset heat accumulation upper limit value.

[0092] Specifically, the heat accumulation difference ΔQ = Qmax - Q is determined based on the three-phase current heat accumulation value Q and the preset heat accumulation upper limit value Qmax.

[0093] Combination Figure 2 As shown, the system monitors whether the accumulated heat is greater than a threshold and then triggers "degradation control torque". This threshold is usually less than the preset upper limit value of accumulated heat Qmax. If the accumulated heat value of the three-phase current Q is not greater than this threshold, the system returns to the step of monitoring whether the temperature of the switching transistor is greater than threshold 2.

[0094] The degradation coefficient is determined based on the cumulative thermal difference and the corresponding difference threshold.

[0095] Specifically, if the threshold ΔQmax of the cumulative heat difference ΔQ is set, then the degradation coefficient is (ΔQmax-ΔQ) / ΔQmax, which ranges from [0-1].

[0096] The control torque is reduced according to the degradation factor.

[0097] Specifically, the target torque of the motor controller is reduced according to the aforementioned degradation factor. For example, if the control torque before degradation is A and the degradation factor is 0.5, then the control torque after degradation is 0.5A. Thus, thermal degradation of torque can be achieved, thereby reducing the three-phase current and ultimately reducing the temperature of the IGBT.

[0098] Optionally, the torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor further includes:

[0099] The cumulative three-phase current heat value is determined based on the effective value of the three-phase current and the resistance of the motor stator winding. Specifically, the cumulative three-phase current heat value Q satisfies:

[0100] Q = I 2 Rt;

[0101] Where I represents the effective value of the three-phase current, R represents the resistance of the motor stator winding, and t represents time.

[0102] Another embodiment of the present invention provides a vehicle including a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the above-described motor controller thermal management method.

[0103] Another embodiment of the present invention provides a computer-readable storage medium storing a computer program, which, when read and run by a processor, implements the above-mentioned motor controller thermal management method.

[0104] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A thermal management method for a motor controller, characterized in that, include: Obtain the temperature of the switching transistor corresponding to the motor controller and the temperature of the cooling medium used to cool the switching transistor; When at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than the corresponding temperature threshold, the flow rate of the cooling medium is regulated. If the temperature of the switching transistor continues to rise after adjustment, the motor controller will perform torque control based on the cumulative three-phase current heat of the switching transistor. The regulation of the flow rate of the cooling medium includes: The target flow rate of the cooling medium is determined based on the temperature of the switching transistor and the temperature of the cooling medium. The final target flow rate is determined based on the target flow rate and the corresponding cooling medium flow coefficient. The flow rate of the cooling medium is regulated according to the final target flow rate; The step of determining the target flow rate of the cooling medium based on the temperature of the switching transistor and the temperature of the cooling medium includes: The target flow rate of the cooling medium is determined based on the temperature of the switching transistor, the temperature of the cooling medium, and a preset relationship, wherein the preset relationship includes the correspondence between the temperature of the switching transistor, the temperature of the cooling medium, and the target flow rate.

2. The motor controller thermal management method according to claim 1, characterized in that, The step of regulating the flow rate of the cooling medium when at least one of the temperature of the switching transistor and the temperature of the cooling medium is greater than a corresponding temperature threshold includes: Determine the temperature of the switching transistor and the magnitude of the first temperature threshold; Determine the temperature of the cooling medium and the magnitude of the second temperature threshold; If the temperature of the switching transistor is greater than the first temperature threshold, and / or the temperature of the cooling medium is greater than the second temperature threshold, then the flow rate of the cooling medium is regulated.

3. The thermal management method for a motor controller according to claim 1, characterized in that, The regulation of the flow rate of the cooling medium also includes: The cooling medium flow coefficient is determined based on the vehicle controller's required torque for the electric drive system and the rate of change of required torque.

4. The motor controller thermal management method according to claim 2, characterized in that, After regulating the flow rate of the cooling medium, the method further includes: The temperature of the switching transistor and the third temperature threshold are compared. If the temperature of the switching transistor after adjustment is greater than the third temperature threshold, it is determined that the temperature of the switching transistor will continue to rise, wherein the third temperature threshold is greater than the first temperature threshold.

5. The thermal management method for a motor controller according to claim 1, characterized in that, The torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor includes: The heat accumulation difference is determined based on the three-phase current heat accumulation value and the preset heat accumulation upper limit value; The degradation coefficient is determined based on the accumulated heat difference and the corresponding difference threshold. The control torque is reduced according to the degradation factor.

6. The thermal management method for a motor controller according to claim 5, characterized in that, The torque control of the motor controller based on the three-phase current thermal accumulation value of the switching transistor also includes: The cumulative thermal value of the three-phase current is determined based on the effective value of the three-phase current and the resistance of the motor stator winding.

7. A vehicle, characterized in that, The method includes a computer-readable storage medium storing a computer program and a processor, the computer program being read and executed by the processor to implement the motor controller thermal management method as described in any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when read and run by a processor, implements the motor controller thermal management method as described in any one of claims 1 to 6.

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