Heat dissipation method and system of motor stator

Abstract

The invention discloses a heat dissipation method and system of a motor stator, a threaded groove is carved in the surface of a stator assembly, the stator assembly is sleeved with a liquid cooling shell, a cooling channel is formed between the stator assembly and the liquid cooling shell through the threaded groove, and the liquid cooling shell is provided with a cooling liquid inlet and a cooling liquid outlet; an air cooling mechanism is arranged on the side, close to the stator assembly, in the motor shell. During heat dissipation, firstly, the temperature of a motor stator is collected according to a preset time interval, the temperature change trend of the motor stator is determined based on the temperature collected according to the preset time interval, a heat dissipation mode is determined based on the temperature and the temperature change trend, and heat dissipation is carried out according to the temperature of the motor stator and stator operation parameters. And determining the heating power, and determining the operation parameters of the air cooling mechanism and / or the liquid cooling mechanism according to the heating power and the heat dissipation mode. Through the method, efficient heat dissipation of the motor stator can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor stator heat dissipation, and particularly relates to a motor stator heat dissipation method and system. BACKGROUND

[0002] With the rapid development of the new energy vehicle market, the industry competition is increasingly fierce, and the related research on new energy vehicles has been highly valued by scientific research institutions and companies in various countries. As one of the three core systems of new energy vehicles, the driving motor provides the main driving power for vehicle running, and its characteristics determine the main performance indicators of the vehicle. The high efficiency and light weight of the driving motor are the inevitable requirements of the industry development. In order to meet the related requirements, the improvement of the power and efficiency of the driving motor is the top priority of the current development.

[0003] At present, the motors used for new energy vehicle driving systems mainly include DC motors, asynchronous AC motors and permanent magnet synchronous motors. Among them, the permanent magnet synchronous motor has been widely used due to its advantages of large power, high efficiency, small size and the like. In order to prevent dust, moisture and other foreign matters from entering the inside of the motor, the permanent magnet synchronous motor usually adopts a sealed structure to ensure the stable operation of the motor. However, the high power and the sealed structure will cause the motor to heat seriously. The temperature rise will cause the bearing life to be shortened, the mechanical strength of the key components to be reduced, the core loss to be increased and the like. Therefore, in order to ensure that the driving motor operates stably and efficiently for a long time, the motor needs to be cooled to reduce the temperature rise during operation.

[0004] The heat of the motor mainly comes from various losses generated during the operation of the motor. Among them, the core loss of the motor stator is the main source of heat. The research on the stator cooling has been the focus of the motor cooling research.

[0005] The cooling of the traditional motor stator mainly relies on the air cooling system or the simple liquid circulation cooling system. When the two cooling methods are used, the heat generated by the motor winding during operation cannot be dissipated through the shell in time because the stator core is located in the inside of the motor. At the same time, with the continuous improvement of the power of the motor, the traditional cooling method has low cooling efficiency and can hardly meet the demand of the normal operation of the motor stator.

[0006] In addition, in actual application, the actual power output by the permanent magnet motor will change, and thus the heat generated by the stator will also change. The use of fixed cooling method and power will result in the inability to effectively cool according to the actual situation. The cooling power is wasted when the heat generated is small, and the effective cooling cannot be performed when the heat generated is large. SUMMARY

[0007] The motor stator heat dissipation method and system effectively improve the motor stator heat dissipation efficiency, improve the motor performance, overcome the technical problems that the heat dissipation mode and power cannot be adjusted according to the actual heat generated by the motor stator in the prior art, and the heat dissipation efficiency and heat dissipation power consumption cannot be considered, and realize the motor stator.

[0008] To achieve the above object, the present application adopts the following technical solutions: A motor stator heat dissipation method, a threaded groove is formed on the surface of a stator assembly, a liquid cooling shell is sleeved outside the stator assembly, a cooling channel is formed between the stator assembly and the liquid cooling shell through the threaded groove, and a cooling liquid inlet and a cooling liquid outlet are arranged on the liquid cooling shell; a air cooling mechanism is arranged on the side of the motor shell body close to the stator assembly; the heat dissipation method comprises the following steps: S1, collecting the temperature of the motor stator at a predetermined time interval; S2, determining the temperature variation trend of the motor stator based on the temperature collected at the predetermined time interval; S3, determining the heat dissipation mode based on the temperature and the temperature variation trend; S4, determining the heat generation power according to the temperature of the motor stator and the stator operating parameters; S5, determining the air cooling mechanism and / or liquid cooling mechanism operating parameters according to the heat generation power and the heat dissipation mode.

[0009] Further, the heat dissipation mode is determined based on the temperature variation trend, which comprises calculating ΔT1= (T2- T1) / ( t2- t1) and ΔT2= (T3-T2) / ( t3- t2) according to the temperatures T1, T2 and T3 of the motor stator collected at t1, t2 and t3 respectively, when T3 is less than the first temperature threshold and ΔT1> ΔT2, the air cooling and liquid cooling mechanisms are closed at the same time, when T3 is less than the first temperature threshold and ΔT1< ΔT2, or T3 is between the first temperature threshold and the second temperature threshold and ΔT1> ΔT2, the air cooling mechanism is turned on, when T3 is greater than the second temperature threshold, or T3 is between the first temperature threshold and the second temperature threshold and ΔT1< ΔT2, the air cooling and liquid cooling mechanisms are turned on at the same time, wherein the second temperature threshold is greater than the first temperature threshold.

[0010] Further, the heat generation power is determined according to the temperature of the motor stator and the stator operating parameters, which comprises determining the stator core loss P Fe , the stator heat transfer power P w , and the stator radiation heat power consumption P f , wherein the stator core loss P Fe is calculated as follows: PFe = (P hys + P cur + P add )*V core = (k hys fB 2 + k cur f 2 B 2 + k add f 1.5 B 1.5 )*V core P hys for hysteresis loss, P cur for eddy current loss, P add for additional loss, k hys for hysteresis loss coefficient, k cur for eddy current loss coefficient, k add for additional loss coefficient, f for alternating current frequency, B for generator air gap magnetic density amplitude, V core for iron core volume; Stator heat transfer power P w is calculated in the following way: P w = (T3+T1-2T4) / R+ (T3-T1) Cm / (t3-t1) Wherein, T4 is the temperature inside the motor shell, R is the thermal resistance of the stator core itself, C is the specific heat capacity, and m is the mass of the stator core.

[0011] Heat radiation power P f is calculated in the following way: P f = δAε(T3 4 +T1 4 -2T4 4 ) / 2 Wherein, δ is the blackbody radiation constant, A is the surface area of the iron core, and ε is the blackbody degree of the surface of the iron core.

[0012] The active heat dissipation power is: P total = P Fe +3I 2 R2- P w - P f Wherein, I is the stator phase current, and R2 is the stator phase resistance.

[0013] Further, determining the operating parameters of the air cooling mechanism and / or liquid cooling mechanism includes P total= P1+ P2, wherein P1 is the heat dissipation power consumption of the air cooling mechanism, and P2 is the heat dissipation power consumption of the liquid cooling mechanism, the air cooling mechanism operation parameter is determined according to the heat dissipation power consumption P1 of the air cooling mechanism: P air = P1 / (c a ρ a Δt a ) P n = P air *P / (η1η2) Wherein, P air is the air volume required for heat dissipation, c a is the specific heat capacity of air, rho a is the density of air, Delta t a is the temperature difference between the outlet and the inlet of the cooling air, P n is the air cooling mechanism operation power, P is the air blowing pressure of the air cooling mechanism, eta1 is the air cooling mechanism efficiency, and eta2 is the mechanical transmission efficiency.

[0014] The liquid cooling mechanism operation parameter is determined according to the heat dissipation power consumption P2 of the liquid cooling mechanism: V f = P2 / (c f ρΔt) Wherein, V f is the cooling liquid flow, c f is the specific heat capacity of the cooling liquid, rho is the density of the cooling liquid, and Delta t is the temperature difference between the inlet and the outlet of the cooling liquid.

[0015] Further, the air volume flowing through the stator assembly is detected by the air cooling margin detection module to determine whether the heat dissipation requirement is met.

[0016] Compared with the prior art, the present application has the following beneficial effects: The present application directly forms the liquid cooling water channel on the surface of the stator assembly, avoids the process of additionally setting the liquid cooling water channel, can reduce the complexity and processing cost of the motor stator heat dissipation structure, and the cooling liquid can directly contact the stator assembly to accelerate the heat exchange efficiency between the cooling liquid and the stator and improve the heat dissipation efficiency.

[0017] The present application aims at the technical defect that the basic structure part of the motor shell and the stator assembly is relatively thick, and the heat in the stator cannot be completely transferred to the surface of the motor shell, and the heat generated in the stator assembly is brought into the motor shell by the liquid cooling heat dissipation mode, and then the heat is dissipated by air cooling, so that the heat is quickly transferred.

[0018] The application not only refers to the real-time working temperature of the motor stator when determining the heat dissipation mode, but also comprehensively considers the temperature change trend in the working process of the motor stator, when the real-time temperature of the motor stator is less than the first threshold value and the temperature change trend is rising, although the current temperature of the motor stator is low, the motor stator gradually heats up with the working process, and the temperature rising trend is fast, therefore, the heat dissipation system is started in advance, and overheating damage of components caused by untimely heat dissipation can be avoided.

[0019] Since the air cooling mechanism is arranged in the space, the air volume is lost in the heat dissipation process, which may cause that the actual air volume reaching the stator assembly is inconsistent with the theoretical calculation value, the air cooling flow detection module is further arranged to detect the air volume flowing through the stator assembly, to judge whether the actual air volume flowing through the stator assembly meets the heat dissipation requirement, when the requirement is not met, the power of the air cooling mechanism is increased, so that the heat dissipation effect is improved to meet the actual requirement. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 is a schematic diagram of the motor structure of the present application; Figure 2 is a schematic diagram of the stator assembly structure of the present application; Figure 3 is a flowchart of the motor stator heat dissipation method of an embodiment of the present application; Figure 4 is a schematic diagram of the air cooling flow detection module structure of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0023] Please refer to Figure 1 , Figure 1It is a motor structure schematic diagram of the application. As shown in the figure, the motor 1 is internally provided with a stator assembly 2, and the stator assembly side is provided with a wind cooling mechanism 3 for air cooling and heat dissipation of the heat generating stator assembly 2. The stator assembly air outlet side is provided with a wind cooling flow detection module 4 for detecting the air flow through the stator assembly to determine whether the actual refrigeration air volume meets the heat dissipation requirement.

[0024] Please refer to Figure 2 , Figure 2 It is a stator assembly structure schematic diagram of the application. Threaded grooves are engraved on the surface of the stator assembly 2, and a liquid cooling shell (not shown) is sleeved outside the stator assembly. The cooling channel is formed between the stator assembly and the liquid cooling shell through the threaded grooves, and the liquid cooling shell is provided with a cooling liquid inlet and a cooling liquid outlet.

[0025] Figure 3 It is a flow schematic diagram of the motor stator heat dissipation method of an embodiment of the application, and the specific steps are as follows: S1, collecting the temperature of the motor stator and the stator operating parameters at a predetermined time interval.

[0026] Specifically, a temperature sensor is arranged on the motor stator for detecting the real-time working temperature of the motor stator.

[0027] S2, determining the temperature variation trend of the motor stator based on the temperature collected at the predetermined time interval.

[0028] S3, determining the heat dissipation mode based on the temperature and the temperature variation trend.

[0029] When determining the heat dissipation mode based on the temperature variation trend, first, according to the temperatures T1, T2, T3 of the motor stator collected at t1, t2, t3 respectively, calculate ΔT1= (T2- T1) / (t2- t1), ΔT2= (T3- T2) / (t3- t2). When T3 is less than the first temperature threshold and ΔT1> ΔT2, the air cooling and liquid cooling mechanisms are closed at the same time. When T3 is less than the first temperature threshold and ΔT1< ΔT2, or T3 is between the first temperature threshold and the second temperature threshold and ΔT1> ΔT2, the air cooling mechanism is started. When T3 is greater than the second temperature threshold, or T3 is between the first temperature threshold and the second temperature threshold and ΔT1< ΔT2, the air cooling and liquid cooling mechanisms are started at the same time, wherein the second temperature threshold is greater than the first temperature threshold.

[0030] In the determination of the heat dissipation mode, not only the real-time working temperature of the motor stator is referred to, but also the temperature variation trend in the working process of the motor stator is considered comprehensively, so that the heat dissipation power can be adjusted in advance, instead of adjusting after the actual temperature exceeds the temperature control interval, resulting in delay of heat dissipation regulation and control.

[0031] S4, determining the active heat dissipation power according to the temperature of the motor stator and the stator operating parameters.

[0032] The heat generation of the motor stator is mainly caused by the stator core loss and the stator winding loss, and in the process of heat generation, the motor stator itself will generate heat and transfer heat to the outside, in addition, heat radiation is one of the main ways of heat transfer. Therefore, in this application, the core loss, stator winding loss, stator heat transfer power and heat radiation power are mainly considered to calculate the active heat dissipation power.

[0033] First, according to the temperature of the motor stator and the stator operating parameters, the stator core loss P Fe is determined. Fe P hys = (P cur + P add )*V core = (k hys fB 2 + k cur f 2 B 2 + k add f 1.5 B 1.5 )*V core P hys is the hysteresis loss, P cur is the eddy current loss, P add is the additional loss, k hys is the hysteresis loss coefficient, k cur is the eddy current loss coefficient, k add is the additional loss coefficient, f is the alternating current frequency, B is the generator air gap magnetic density amplitude, V core is the core volume. The stator heat transfer power P w is calculated as follows: P w =(T3+T1-2T4) / R+(T3-T1)Cm / ( t3-t1) Wherein, T4 is the temperature inside the motor shell, R is the thermal resistance of the stator core itself, C is the specific heat capacity, and m is the mass of the stator core.

[0034] The heat radiation power P f is calculated as follows: P f =δAε(T3 4 +T1 4 -2T4 4 ) / 2 ​Wherein, delta is blackbody radiation constant, A is core surface area, epsilon is core surface blackbody degree.

[0035] Therefore, the active heat dissipation power is: P total = P Fe +3I 2 R2- P w - P f Wherein, I is stator phase current, R2 is stator phase resistance.

[0036] S5, according to the active heat dissipation power and heat dissipation mode, determine the air cooling mechanism and / or liquid cooling mechanism operating parameters.

[0037] Further, the air cooling mechanism and / or liquid cooling mechanism operating parameters include, when only the air cooling mechanism is turned on, P total = P1, when the air cooling mechanism and liquid cooling mechanism are turned on simultaneously, P total = P1+ P2, wherein P1 is the air cooling mechanism heat dissipation power consumption, P2 is the liquid cooling mechanism heat dissipation power consumption. P1, P2 distribution ratio is not limited, only need to be able to meet P1+ P2=P total , can, for example, can be selected P1=P2=0.5*P total .

[0038] According to the air cooling mechanism heat dissipation power P1 determine the air cooling mechanism operating parameters: P air =P1 / (c a ρ a Δt a ) P n = P air *P / (η1η2) Wherein, P air is the air volume required for heat dissipation, c a is the specific heat capacity of air, rho a is the density of air, delta t a is the outlet and inlet temperature difference of cooling air, P n is the air cooling mechanism operating power, P is the air cooling mechanism blowing pressure, eta1 is the air cooling mechanism efficiency, eta2 is the mechanical transmission efficiency.

[0039] According to the liquid cooling mechanism heat dissipation power P2 determine the liquid cooling mechanism operating parameters: V f = P2 / (c f ρΔt) Wherein, V f is the flow rate of cooling liquid, c fis the specific heat capacity of the cooling liquid, p is the density of the cooling liquid, and At is the temperature difference between the cooling liquid inlet and the cooling liquid outlet.

[0040] Further, the air-cooling margin flow detection module is configured to detect the air flow through the stator assembly and determine whether the heat dissipation requirement is met.

[0041] The air-cooling margin flow detection module includes a vertical baffle plate, when the air flow is 0, the baffle plate is vertically downward, when the air flow is not 0, the baffle plate is rotated by an angle a due to the air pressure, thus, the air flow P can be calculated based on the gravity G of the baffle plate and the rotation angle a. a The specific calculation formula is as follows: P a =S*[2G*tan(α) / (C a *ρ*A f )] 1 / 2 Wherein, S is the cross-sectional area of the air duct, C a is the air resistance coefficient, p is the air density, and A f is the air receiving area of the baffle plate.

[0042] When P a is less than P air , it means that the actual air flow provided is less than the theoretical air flow, then the air-cooling mechanism operation power can be increased to meet the heat dissipation requirement.

[0043] According to another embodiment of the present application, a heat dissipation system of a motor stator is provided, which includes a temperature sensor, an air-cooling margin flow detection module, and a processor, the temperature sensor is configured to detect the real-time working temperature of the motor stator, the air-cooling margin flow detection module is configured to detect the air flow through the stator assembly, and the processor is configured to implement the heat dissipation method of the motor stator as described in the above embodiments.

[0044] The motor stator heat dissipation method and system of the present application can avoid the process of additionally setting up the liquid cooling water channel, reduce the complexity of the motor stator heat dissipation structure and the processing cost, and accelerate the heat exchange efficiency of the cooling liquid and the stator, thereby improving the heat dissipation efficiency. In addition, the liquid cooling water channel set on the outer surface of the stator assembly can bring the heat generated in the stator assembly to the motor housing, and then dissipate heat through air cooling, thereby realizing rapid heat transfer. Moreover, the liquid cooling system and the air cooling system are provided at the same time to dissipate heat for the motor stator, thereby further improving the motor stator heat dissipation efficiency and realizing rapid cooling. When determining the heat dissipation mode, the present application not only refers to the real-time working temperature of the motor stator, but also comprehensively considers the temperature change trend in the working process of the motor stator. When the real-time temperature of the motor stator is less than the first threshold value and the temperature change trend is rising, although the current temperature of the motor stator is low, the motor stator gradually heats up with the working process, and the temperature rising trend is fast. Therefore, the heat dissipation system is started in advance, which can avoid the damage of components caused by untimely heat dissipation. Preferably, the present application is also provided with an air cooling flow detection module for detecting the air flow through the stator assembly, judging whether the actual air flow through the stator assembly meets the heat dissipation requirement, and increasing the power of the air cooling mechanism when it does not meet the requirement, thereby improving the heat dissipation effect to meet the actual requirement.

[0045] The above is a description of the present disclosure and should not be considered as a limitation thereof. Although several exemplary embodiments of the present disclosure are described, those skilled in the art will readily understand that many modifications can be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure defined by the claims. It should be understood that the above is a description of the present disclosure and should not be considered as a limitation to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

[0046] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0047] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of the technical features is considered to be within the scope of the present application.

[0048] Finally, it should be noted that those skilled in the art readily understand that the above-described embodiments are only the preferred embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the present application, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for heat dissipation of an electric motor stator, characterized in that, The method includes: Threaded grooves are engraved on the surface of the stator assembly, and a liquid-cooled outer shell is fitted over the stator assembly. A cooling channel is formed between the stator assembly and the liquid-cooled outer shell through the threaded grooves. The liquid-cooled outer shell is provided with a coolant inlet and a coolant outlet. An air-cooling mechanism is provided inside the motor housing near the stator assembly. The heat dissipation method includes the following steps: S1. Collect the temperature of the motor stator at predetermined time intervals; S2. Based on the temperatures collected at predetermined time intervals, determine the temperature change trend of the motor stator; S3. Determine the heat dissipation method based on the temperature and temperature change trend; S4. Determine the active heat dissipation power based on the temperature of the motor stator and the stator operating parameters; S5. Determine the operating parameters of the air-cooled mechanism and / or liquid-cooled mechanism based on the active heat dissipation power and heat dissipation method.

2. The method according to claim 1, characterized in that, The process of determining the heat dissipation method based on the temperature change trend includes: Based on the motor stator temperatures T1, T2, and T3 collected at times t1, t2, and t3 respectively, calculate ΔT1 = (T2 - T1) / (t2 - t1) and ΔT2 = (T3 - T2) / (t3 - t2). When T3 is less than the first temperature threshold and ΔT1 > ΔT2, both the air cooling and liquid cooling mechanisms are turned off. When T3 is less than the first temperature threshold and ΔT1 < ΔT2, or when T3 is between the first and second temperature thresholds and ΔT1 > ΔT2, the air cooling mechanism is turned on. When T3 is greater than the second temperature threshold, or when T3 is between the first and second temperature thresholds and ΔT1 < ΔT2, both the air cooling and liquid cooling mechanisms are turned on. The second temperature threshold is greater than the first temperature threshold.

3. The method according to claim 1, characterized in that, The process of determining the active cooling power based on the temperature and operating parameters of the motor stator includes: Determine the stator core loss P Fe Stator heat transfer power P w Stator radiative heat dissipation P f Among them, the stator core loss P Fe The calculation method is as follows: P Fe = (P hys + P cur + P add )*V core = (k hys fB 2 + k cur f 2 B 2 + k add f 1.5 B 1.5 )*V core P hys For hysteresis loss, P cur For eddy current losses, P add For additional losses, k hys k is the hysteresis loss coefficient. cur K is the eddy current loss coefficient. add Here, f is the additional loss factor, f is the alternating current frequency, B is the generator air gap magnetic flux density amplitude, and V is the generator air gap magnetic flux density amplitude. core This refers to the volume of the iron core. Stator heat transfer power P w The calculation method is as follows: P w = (T3+T1-2T4) / R+ (T3-T1)Cm / ( t3-t1) Where T4 is the internal temperature of the motor housing, R is the thermal resistance of the stator core itself, C is the specific heat capacity, and m is the mass of the stator core. Thermal radiation power P f The calculation method is as follows: P f =δAε(T3 4 +T1 4 -2T4 4 ) / 2 Where δ is the blackbody radiation constant, A is the surface area of ​​the iron core, and ε is the blackbody degree of the iron core surface; The active cooling power is: P total = P Fe +3I 2 R2- P w - P f Where I is the stator phase current and R2 is the stator phase resistance.

4. The method according to claim 3, characterized in that, The determination of the operating parameters of the air-cooled mechanism and / or liquid-cooled mechanism includes, P total = P1 + P2, where P1 is the heat dissipation power of the air-cooled mechanism and P2 is the heat dissipation power of the liquid-cooled mechanism. The operating parameters of the air-cooled mechanism are determined based on the heat dissipation power P1 of the air-cooled mechanism: P air =P1 / (c a r a Δt a ) P n =P air *P / (η1η2) Among them, P air To provide the required airflow for heat dissipation, c a ρ is the specific heat capacity of air. a Let Δt be the density of air. a P represents the temperature difference between the outlet and inlet of the cooling air. n η1 is the operating power of the air-cooling mechanism, P is the blowing pressure of the air-cooling mechanism, η2 is the efficiency of the air-cooling mechanism, and η2 is the mechanical transmission efficiency. Determine the operating parameters of the liquid cooling mechanism based on the heat dissipation power consumption P2 of the liquid cooling mechanism: V f = P2 / (c f ρΔt) Among them, V f c is the coolant flow rate. f ρ is the specific heat capacity of the coolant, ρ is the density of the coolant, and Δt is the temperature difference between the coolant inlet and outlet.

5. The method according to claim 1, characterized in that, The airflow through the stator assembly is detected by the air-cooled excess flow detection module to determine whether the heat dissipation requirements are met.

6. A heat dissipation system for a motor stator, characterized in that, The device includes a temperature sensor, an air-cooled current detection module, and a processor. The temperature sensor is used to detect the real-time operating temperature of the motor stator, the air-cooled current detection module detects the airflow through the stator assembly, and the processor is used to implement the heat dissipation method for the motor stator as described in any one of claims 1 to 5.

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