Cooling control method and device of oil-cooled motor and medium

Abstract

The invention relates to the technical field of motor cooling, in particular to a cooling control method and device for an oil-cooled motor and a medium. The method comprises the following steps: acquiring a motor working condition; different branch cooling oil spraying strategies are adopted according to different motor working conditions, so that the temperature of the motor is increased to a designed temperature limit value. And branch cooling oil spraying strategies corresponding to different motor working conditions are optimized and obtained by adopting a particle swarm optimization algorithm. The motor can work in the optimal temperature interval, compared with a traditional cooling mode, the average efficiency of the working condition of the motor is improved from 95.21% to 95.64%, the overall efficiency is improved by 0.43%, and then the endurance mileage is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor cooling, and in particular to a cooling control method, device and medium for an oil-cooled motor. Background Art

[0002] Compared with the water cooling solution, the oil cooling design has better cooling effect and is therefore widely used in the field of electric vehicle drive motors.

[0003] The traditional oil cooling design does not take into account the operating conditions of the motor during operation, and the cooling oil inside the motor is always in a spraying state. Figure 1 As shown in the figure, Map_1 area is the typical working range distribution of the motor, where the horizontal axis represents the motor speed, and n_max represents the maximum operating speed of the motor. The vertical axis represents the motor output torque, and Trq_max represents the maximum output torque of the motor. Map_2 area represents the common working condition area of ​​the motor, such as the CLTC working condition. In this area, the motor torque and speed are low, and the motor thermal load is small. Figure 2 It is the temperature change curve of the hottest point of the stator assembly and rotor assembly when the motor runs in the Map_2 area for a long time. Figure 2 It can be seen that the motor operating temperature is far from reaching the design temperature limit.

[0004] Therefore, the cooling oil inside the motor is always in a spraying state, which reduces the working efficiency of the system and causes energy waste. Summary of the invention

[0005] The invention discloses a cooling control method, a device and a medium for an oil-cooled motor, which can improve the working efficiency of the motor.

[0006] In order to achieve the above object, on the one hand, a method is provided in which the cooling oil of each branch is in a spraying and cooling state when the motor is working, and the specific method is as follows:

[0007] Get the motor working condition;

[0008] According to different motor operating conditions, different branch cooling oil spray strategies are adopted to increase the motor temperature to the design temperature limit.

[0009] Furthermore, the motor operating condition includes: rotation speed or torque.

[0010] Furthermore, the motor operating conditions include: rotation speed and torque.

[0011] Furthermore, different branch cooling oil spraying strategies include:

[0012] The stator branch flow is set to zero, and / or the rotor branch flow is set to zero, and / or the bearing branch flow is set to zero.

[0013] Furthermore, different branch cooling oil spraying strategies are adopted for different motor working conditions, including:

[0014] When the speed is less than or equal to the first speed threshold, and the torque is less than or equal to the second torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero;

[0015] When the speed is less than or equal to the first speed threshold, and the torque is greater than the second torque threshold, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero;

[0016] When the speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the torque is less than or equal to the second torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero;

[0017] When the speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the torque is greater than the second torque threshold, the cooling oil flow of the bearing branch is set to zero;

[0018] When the speed is greater than the second speed threshold and less than or equal to the third speed threshold, and the torque is less than or equal to the first torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero;

[0019] When the speed is greater than the second speed threshold and less than or equal to the third speed threshold, and the torque is less than the first torque threshold, the cooling oil flow of the bearing branch is set to zero;

[0020] When the combination of speed and torque is in other working areas, keep the cooling oil in each branch in a spraying and cooling state.

[0021] Furthermore, according to different motor operating conditions, an optimization algorithm is used to determine the branch cooling oil spraying strategy corresponding to the different motor operating conditions.

[0022] Furthermore, the optimization algorithm is a particle swarm optimization algorithm, and the specific method is as follows:

[0023] The motor speed, torque, stator branch cooling oil flow, rotor branch cooling oil flow and bearing branch cooling oil flow are used as particles;

[0024] Determine the motor cooling boundary based on the thermal safety value under the motor operating conditions;

[0025] Under the motor cooling boundary, the average efficiency of the motor operating condition is used as the adaptation value;

[0026] Through iteration, until the average efficiency of the motor operating condition reaches the optimal level, the corresponding stator branch cooling oil flow, rotor branch cooling oil flow and bearing branch cooling oil flow are output at different speeds and torques of the motor.

[0027] To achieve the above object, on the other hand, a cooling control device for an oil-cooled motor includes: a motor operating condition acquisition module, a control strategy acquisition module and an execution module;

[0028] The motor operating condition acquisition module acquires the motor operating condition;

[0029] The control strategy acquisition module queries the branch cooling oil spray strategy according to different motor working conditions;

[0030] The execution module executes the branch cooling oil spraying strategy to increase the motor temperature to the designed temperature limit.

[0031] To achieve the above object, on the other hand, a storage medium stores a plurality of instructions, and a processor loads the instructions to execute the above oil-cooled motor cooling control method.

[0032] To achieve the above object, on the other hand, a vehicle controller adopts the cooling control device of the oil-cooled motor and / or the storage medium.

[0033] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0034] The present invention can make the motor work in the optimal temperature range. Compared with the traditional cooling method, the average efficiency of the motor working condition is increased from 95.21% to 95.64%, an overall increase of 0.43%, thereby achieving an increase in cruising range.

[0035] It should be noted that the terms "first", "second" and similar terms used in this article are only for describing the various components in the technical solution, and do not constitute a limitation of the technical solution, nor can they be understood as an indication or suggestion of the importance of the corresponding elements; elements with "first", "second" and similar terms indicate that the corresponding technical solution contains at least one of the element. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the present invention and facilitate further understanding of the technical effects, technical features and purposes of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The accompanying drawings constitute an essential part of the specification and are used together with the embodiments of the present invention to illustrate the technical solution of the present invention, but do not constitute a limitation to the present invention.

[0037] The same reference numerals in the accompanying drawings represent the same components, specifically:

[0038] Figure 1 This is a schematic diagram of the motor working range distribution.

[0039] Figure 2 This is a schematic diagram of the motor temperature rise curve.

[0040] Figure 3 This is a schematic diagram of the motor cooling oil branch structure.

[0041] Figure 4 Schematic diagram of the process of determining the branch cooling oil spray strategy using the particle swarm optimization algorithm.

[0042] Figure 5 It is a schematic diagram of the overall process of the present invention. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. Of course, the specific embodiments described below are only for explaining the technical solutions of the present invention, rather than for limiting the present invention. In addition, the parts described in the embodiments or the accompanying drawings are only examples of the relevant parts of the present invention, rather than the whole of the present invention.

[0044] Embodiment 1:

[0045] A cooling control method for an oil-cooled motor, such as Figure 5 As shown, the specific steps are as follows:

[0046] S1. Obtain the motor operating condition.

[0047] In this embodiment, the motor operating conditions include: rotation speed and torque.

[0048] Different branch cooling oil spraying strategies, specific methods include: setting the stator branch flow to zero, and / or setting the rotor branch flow to zero, and / or setting the bearing branch flow to zero.

[0049] S2. According to different motor working conditions, look up the table to obtain different branch cooling oil spray strategies.

[0050] In this embodiment, the inlet distribution of the motor cooling oil is as follows Figure 3 As shown, the cooling oil is divided into three main branches after being output by the oil pump: branch 1 cools the motor stator core; branch 2 cools the motor shaft; branch 3 cools the motor bearings.

[0051] Cooling oil flow control strategy query table, the specific contents are as follows:

[0052]

[0053] The contents of the cooling oil flow control strategy query table are obtained by particle swarm optimization algorithm, such as Figure 4 The specific setting method is as follows:

[0054] Particle Settings:

[0055] Motor speed Spd, for example, the value range of Spd is [0, 10000], and the speed step is 1000rpm;

[0056] Motor torque Trq, for example, Trq value range is [0, 200], and torque step is 10Nm;

[0057] Stator core cooling oil flow FL1, value 0, 6;

[0058] The shaft cooling oil flow rate FL2 takes values ​​of 0 and 4;

[0059] Bearing cooling oil flow FL3, value is 0, 2.

[0060] Adaptation value setting:

[0061] Meet the thermal safety requirements under motor operating conditions. For example, when the motor is under the cooling boundary, the maximum temperature Thot ≤ Tmax, that is, the allowable temperature;

[0062] The average efficiency of the motor in working condition is Eta.

[0063] Stop condition setting:

[0064] Under the premise of satisfying the adaptability value, the solution with the highest average efficiency Eta of the motor working condition is taken.

[0065] S3. Execute the branch cooling oil spray strategy.

[0066] Embodiment 2:

[0067] A cooling control device for an oil-cooled motor, comprising: a motor operating condition acquisition module, a control strategy acquisition module and an execution module;

[0068] The motor operating condition acquisition module acquires the motor operating condition;

[0069] The control strategy acquisition module queries the branch cooling oil spray strategy according to different motor working conditions;

[0070] The execution module executes the branch cooling oil spraying strategy to increase the motor temperature to the designed temperature limit.

[0071] It should be noted that the above embodiments are only for more clearly illustrating the technical solutions of the present invention. Those skilled in the art will understand that the implementation methods of the present invention are not limited to the above contents, and obvious changes, replacements or substitutions based on the above contents do not exceed the scope of the technical solutions of the present invention; other implementation methods will also fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A cooling control method for an oil-cooled motor, when the motor is working, the cooling oil in each branch is in a spraying and cooling state, characterized in that: The specific method is as follows: Get the motor working condition; According to different motor operating conditions, different branch cooling oil spray strategies are adopted to increase the motor temperature to the design temperature limit.

2. The cooling control method for an oil-cooled motor according to claim 1, characterized in that: The motor operating condition includes: rotation speed or torque.

3. The cooling control method for an oil-cooled motor according to claim 1, characterized in that: The motor operating conditions include: rotation speed and torque.

4. The cooling control method for an oil-cooled motor according to claim 3, characterized in that: Different branch cooling oil spray strategies include: The stator branch flow is set to zero, and / or the rotor branch flow is set to zero, and / or the bearing branch flow is set to zero.

5. The cooling control method for an oil-cooled motor according to claim 4, characterized in that: Different branch cooling oil spray strategies are used for different motor working conditions, including: When the speed is less than or equal to the first speed threshold, and the torque is less than or equal to the second torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero; When the speed is less than or equal to the first speed threshold, and the torque is greater than the second torque threshold, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero; When the speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the torque is less than or equal to the second torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero; When the speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the torque is greater than the second torque threshold, the cooling oil flow of the bearing branch is set to zero; When the speed is greater than the second speed threshold and less than or equal to the third speed threshold, and the torque is less than or equal to the first torque threshold, the stator branch cooling oil flow is set to zero, the rotor branch cooling oil flow is set to zero, and the bearing branch cooling oil flow is set to zero; When the speed is greater than the second speed threshold and less than or equal to the third speed threshold, and the torque is less than the first torque threshold, the cooling oil flow of the bearing branch is set to zero; When the combination of speed and torque is in other working areas, keep the cooling oil in each branch in a spraying and cooling state.

6. The cooling control method for an oil-cooled motor according to claim 1, characterized in that: According to different motor operating conditions, an optimization algorithm is used to determine the branch cooling oil spray strategy corresponding to different motor operating conditions.

7. The cooling control method for an oil-cooled motor according to claim 6, characterized in that: The optimization algorithm is a particle swarm optimization algorithm, and the specific method is as follows: The motor speed, torque, stator branch cooling oil flow, rotor branch cooling oil flow and bearing branch cooling oil flow are used as particles; Determine the motor cooling boundary based on the thermal safety value under the motor operating conditions; Under the motor cooling boundary, the average efficiency of the motor operating condition is used as the adaptation value; Through iteration, until the average efficiency of the motor operating condition reaches the optimal level, the corresponding stator branch cooling oil flow, rotor branch cooling oil flow and bearing branch cooling oil flow are output at different speeds and torques of the motor.

8. A cooling control device for an oil-cooled motor, characterized in that: include: Motor operating condition acquisition module, control strategy acquisition module and execution module; The motor operating condition acquisition module acquires the motor operating condition; The control strategy acquisition module queries the branch cooling oil spray strategy according to different motor working conditions; The execution module executes the branch cooling oil spraying strategy to increase the motor temperature to the designed temperature limit.

9. A storage medium, characterized in that: A plurality of instructions are stored, and a processor loads the instructions to execute the cooling control method for an oil-cooled motor as claimed in any one of claims 1 to 7.

10. A vehicle controller, characterized in that: Use the cooling control device for the oil-cooled motor as described in claim 8, and / or the storage medium as described in claim 9.

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