A permanent magnet synchronous brushless DC motor

Abstract

The present invention relates to the technical field of motor cooling devices, and specifically to a permanent magnet synchronous brushless DC motor. The motor includes a water cooling controller to control the water flow of a water cooling heat dissipation device. During the control process, the environmental cooling effect in the current environment is first evaluated based on the real-time temperature state. The environmental severity index of the current underwater environment is further analyzed, and the corrected load intensity of the device at future times is evaluated in combination with the subsequent operating instructions of the motor application device. By quantifying and analyzing the above factors, the water flow adjustment value of the water cooling heat dissipation device is obtained. The present invention enables the water cooling heat dissipation device to adaptively adjust the water flow based on the underwater environmental state and the subsequent operating state of the motor application device, thereby adjusting the heat dissipation efficiency, thereby ensuring the scientific operation of the motor.

Description

Technical Field

[0001] The invention relates to the technical field of motor cooling devices, and in particular to a permanent magnet synchronous brushless DC motor. Background Art

[0002] Underwater robots are common application devices of permanent magnet synchronous DC brushless motors. During operation, permanent magnet synchronous DC brushless motors will produce certain losses due to resistance, eddy current, hysteresis and other phenomena, and these losses are mainly dissipated in the form of heat energy. When the heat dissipated during operation is too high, it will reduce the life of the insulation material inside the motor, reduce the operating efficiency of the motor, and even cause permanent demagnetization or burn-in of the magnetic material inside the motor. Therefore, it is necessary to effectively dissipate the heat of the motor. Since the working scene of the underwater robot is underwater, it cannot be cooled by air cooling heat dissipation devices. Usually, water cooling combined with water in the environment is used for heat dissipation. However, due to the complexity of the underwater environment, the confusion of the water flow direction and the confusion of the water flow rate, the heat dissipation effect of the ambient water cannot be fixed. If the heat dissipation efficiency of the water cooling heat dissipation device cannot be adaptively adjusted, the heat dissipation effect will be poor, affecting the working efficiency of the motor. Summary of the invention

[0003] In order to solve the technical problem that the water cooling device of the motor in the underwater environment cannot adaptively adjust the heat dissipation efficiency, resulting in poor heat dissipation effect and affecting the working efficiency of the motor, the purpose of the present invention is to provide a permanent magnet synchronous brushless DC motor, and the technical solution adopted is as follows:

[0004] The present invention proposes a permanent magnet synchronous brushless DC motor, the motor comprising a water cooling device; during the underwater operation of the motor application device, the water cooling device is controlled by a water cooling controller to control the water flow; the method for the water cooling controller to control the water flow includes:

[0005] Acquire in real time a first temperature difference between the inside of the motor and the environment, and a second temperature difference between the inside of the motor and a preset standard temperature; obtain an environmental cooling effect according to the first temperature difference, the second temperature difference, and the direction of water flow in the environment;

[0006] The environmental severity index is obtained in real time according to the flow rate and pressure of the water flow in the environment; the operation complexity at a future moment is evaluated according to the preset operation instructions of the motor; the load change at a future moment is corrected according to the environmental severity index and the operation complexity to obtain a corrected load intensity; the cooling intensity adjustment coefficient is obtained according to the corrected load intensity and the real-time temperature of the motor;

[0007] The water flow adjustment value of the water-cooling heat sink is obtained according to the cooling intensity adjustment coefficient and the real-time environmental cooling effect, and a control command is fed back to the water-cooling heat sink.

[0008] Furthermore, the method for obtaining the environmental cooling effect includes:

[0009] The first temperature difference is the temperature difference between the inside of the motor and the environment, and the second temperature difference is the temperature difference between the inside of the motor and a preset standard temperature;

[0010] The inverse of the second temperature difference is multiplied by the first temperature difference in real time and normalized to obtain an initial environment cooling effect;

[0011] The angle difference between the direction of the ambient water flow and the forward direction of the motor application device is obtained in real time; the angle difference is negatively correlated and mapped, multiplied by the initial ambient cooling effect, and normalized to obtain the ambient cooling effect.

[0012] Furthermore, the method for obtaining the environmental severity index includes:

[0013] Count the external pressure on the motor application device at real time; count the water flow rate of the motor application device in various directions; accumulate the water flow rate in various directions and multiply it by the external pressure, normalize the product, and obtain the environmental severity index.

[0014] Furthermore, the method for obtaining the operation complexity includes:

[0015] Counting the working time of each motor start and stop in subsequent operations in the operation instructions of the motor application device, and the change characteristics of the power components in the motor application device;

[0016] The operation complexity is obtained according to the working time of each motor start and stop and the change characteristics of the power components.

[0017] Furthermore, the method for obtaining the modified load strength includes:

[0018] A correction coefficient is obtained according to the environmental severity index and the operation complexity; the correction coefficient is a normalized value; the load change at a future moment is obtained according to the operation instruction, the load change is normalized and multiplied by the correction coefficient to obtain the corrected load intensity.

[0019] Furthermore, the method for obtaining the cooling intensity adjustment coefficient includes:

[0020] The real-time temperature and operation duration of the motor are multiplied by the corrected load intensity and then normalized to obtain the cooling intensity adjustment coefficient.

[0021] Furthermore, the method for obtaining the water flow adjustment value includes:

[0022] A gain coefficient is obtained according to the environmental cooling effect and the cooling intensity adjustment coefficient, and the gain coefficient is multiplied by a preset maximum water flow adjustment value to obtain the water flow adjustment value.

[0023] Furthermore, the motor also includes an abnormal warning module, which is used to feedback a warning signal when the temperature of the motor is greater than a preset temperature threshold and the duration is greater than a preset duration threshold, and the water flow of the water cooling device is already maximum.

[0024] Furthermore, the water-cooling heat sink has a circulating pump that controls the water flow, the water-cooling heat sink surrounds the motor body, and the inside of the water-cooling heat sink shell includes a cooling trough for cooling water to flow; the application device of the motor includes a propeller, and the propeller controls the rotation of the blades through the motor for propulsion.

[0025] Furthermore, the control command includes a water flow adjustment value that needs to be adjusted for the circulation pump, and the water flow direction of the circulation pump is set as the propulsion direction of the propeller.

[0026] The present invention has the following beneficial effects:

[0027] The permanent magnet synchronous DC brushless motor proposed in the present invention includes a water cooling controller to control the water flow of the water cooling device. During the control process, the environmental cooling effect in the current environment is first evaluated according to the real-time temperature state. That is, the better the environmental cooling effect, the lower the heat dissipation efficiency of the water cooling device, thereby achieving energy saving and increasing the endurance of the device. The environmental harshness index of the current underwater environment is further analyzed, and the corrected load intensity of the device at future times is evaluated in combination with the subsequent operation instructions of the motor application device. That is, the greater the corrected load intensity, the higher the power required for the motor to work, and the greater the heat dissipation efficiency should be. By quantifying and analyzing the above factors, the water flow adjustment value of the water cooling device is obtained, so that the water cooling device can adaptively adjust the water flow based on the underwater environmental state and the subsequent operation state of the motor application device, and then adjust the heat dissipation efficiency, thereby ensuring the scientific operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of a permanent magnet synchronous brushless DC motor provided by an embodiment of the present invention;

[0030] Figure 2 for Figure 1 Disassembly diagram of .

[0031] Figure 3 A flow chart of a method for controlling water flow by a water cooling controller provided by an embodiment of the present invention.

[0032] Among them, 1. Motor; 2. Water cooling device shell; 3. Circulation pump; 4. Connecting pipe; 5. Cooling tank. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation, structure, features and effects of a permanent magnet synchronous DC brushless motor proposed according to the present invention in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0035] The permanent magnet synchronous brushless DC motor proposed in the embodiment of the present invention is mainly used in robot devices in underwater environments, and is collectively referred to as a motor application device in the subsequent description. When the motor application device moves underwater, it will rely on the motor to drive the blades to rotate, thereby pushing the water flow to generate thrust. The heat generated by the internal energy of the motor during operation will be dissipated through a water-cooled heat sink. The motor will be installed inside the water-cooled heat sink, and the heat generated by the motor will be taken away by the flow of cooling water. Please refer to Figure 1 and Figure 2 In the embodiment of the present invention, the water cooling device controls the water flow rate by the circulation pump 3 , the water cooling device surrounds the motor body, the water cooling device housing 2 includes a cooling tank 5 for cooling water to flow, and the circulation pump 3 delivers water to the cooling tank 5 through the connecting pipe 4 .

[0036] The water cooling device in the permanent magnet synchronous brushless DC motor proposed in the embodiment of the present invention controls the water flow rate by the water cooling controller, please refer to Figure 3 , which shows a flow chart of a method for controlling water flow by a water cooling controller provided by an embodiment of the present invention, the method comprising:

[0037] Step S1: obtaining in real time a first temperature difference between the inside of the motor and the environment, and a second temperature difference between the inside of the motor and a preset standard temperature; obtaining an environmental cooling effect according to the first temperature difference, the second temperature difference and the direction of water flow in the environment.

[0038] When the motor application device is working underwater, it will be affected by the heat dissipation of the ambient water and the heat dissipation of the water-cooled heat dissipation device. If the heat dissipation effect of the ambient water can already achieve good heat dissipation, the heat dissipation power of the water-cooled heat dissipation device can be reduced, which plays a role in energy saving. Therefore, in order to achieve scientific control of the heat dissipation of the water-cooled heat dissipation device, it is more important to evaluate the cooling effect of the underwater environment on the motor. According to prior knowledge, the lower the water temperature in the environment, the higher the motor temperature, which means that there is a sufficient temperature difference between the environment and the motor at this time. The ambient water can reflect a better heat dissipation effect through the transfer of temperature. Therefore, the water-cooled controller first obtains the first temperature difference between the inside of the motor and the environment in real time. Further considering that the more normal the motor runs, the more normal the heat dissipation can be carried out, the second temperature difference between the inside of the motor and the preset standard temperature is obtained, that is, the second temperature difference is used to characterize the degree of abnormality during the operation of the motor. The closer the motor is to the standard temperature when it is running, the more normal the motor is running at this time, and the better the heat dissipation effect can be achieved only through the heat dissipation of the ambient water. Further considering that the motor application device relies on the motor to move during underwater operation, the more consistent the movement direction of the device is with the water flow direction, the easier it is for the ambient water to take away more heat. Therefore, the ambient cooling effect can be obtained by combining the water flow direction, the first temperature difference and the second temperature difference.

[0039] Preferably, in one embodiment of the present invention, in order to accurately quantify the environmental cooling effect, the first temperature difference is defined as the temperature difference between the inside of the motor and the environment, that is, the first temperature difference is a positive number and a large value, indicating that the ambient water and the motor have a large temperature difference, and the ambient water has a good heat dissipation effect; the second temperature difference is defined as the temperature difference between the inside of the motor and the preset standard temperature, that is, if the second temperature difference is a positive number and a large value, it means that the motor is running abnormally at this time, and the ambient water cannot smoothly dissipate the heat, that is, the ambient water has a poor heat dissipation effect. Therefore, the embodiment of the present invention multiplies the opposite of the second temperature difference by the first temperature difference, and performs normalization processing to obtain the initial environmental cooling effect. That is, the smaller the second temperature difference, the more normal the motor operation is, and the better the heat dissipation effect of the ambient water; the larger the first temperature difference, the greater the temperature difference between the environment and the inside of the motor, and the better the heat dissipation effect of the ambient water.

[0040] The angle difference between the direction of the ambient water flow and the forward direction of the motor application device in the real-time state is further obtained. The smaller the angle difference, the more the motor application device works in accordance with the direction of the water flow, and the better the heat dissipation effect of the ambient water. Therefore, the angle difference is negatively correlated and then multiplied by the initial ambient cooling effect and normalized to obtain the ambient cooling effect.

[0041] It should be noted that the normalization process proposed in the embodiment of the present invention is a common technical means used by those skilled in the art to eliminate the influence of dimension and unify the numerical range. It can be implemented through basic mathematical means such as range normalization, hyperbolic function mapping method, exponential function mapping method, etc., which will not be elaborated here. As an example, the environmental cooling effect is expressed by the formula:

[0042] ;in is the ambient cooling effect at time t; is the angle difference, where the angle difference is the difference between the direction of the ambient water flow and the forward direction of the motor application device. Therefore, there are positive and negative cases, and the value needs to be quantified by finding the absolute value; is a preset anti-zero coefficient, which is set to 1 in the embodiment of the present invention; is the first temperature difference at time t, is the second temperature difference at the tth moment; norm() is a normalization function, and in the embodiment of the present invention, a hyperbolic tangent function is selected for normalization.

[0043] In the environmental cooling effect formula, the angle difference is negatively correlated in the form of an inverse number. At the same time, in order to avoid the denominator being 0, an anti-zero coefficient is introduced. The mapping of the normalized function makes the calculation process dimensionless, and the final environmental cooling effect value range is between 0 and 1.

[0044] It should be noted that the standard temperature of the motor can be set according to the model of the motor itself and the content of the operation performed, and the temperature inside the motor and the environment can be collected by temperature sensors. The direction of water flow and the forward direction of the motor application device can also be obtained by corresponding sensors, and the embodiments of the present invention will not be repeated.

[0045] Step S2: Obtain the environmental severity index in real time according to the flow rate and pressure of water in the environment; evaluate the operation complexity at future times according to the preset operation instructions of the motor; correct the load changes at future times according to the environmental severity index and the operation complexity to obtain the corrected load intensity; obtain the cooling intensity adjustment coefficient according to the corrected load intensity and the real-time temperature of the motor.

[0046] The embodiment of the present invention further takes into account the complexity of the underwater environment. When the motor application device is running underwater, it will be affected by water flows of different directions and sizes, and as the diving depth increases, the water pressure will gradually increase. These factors will cause resistance in the motor during operation, thereby generating more heat, requiring a stronger heat dissipation effect. Therefore, the embodiment of the present invention first obtains the environmental harshness index in real time based on the flow rate and pressure of the water flow in the environment. The larger the environmental harshness index, the more complex the underwater environment is, and the stronger the heat dissipation effect is needed.

[0047] When the motor application device is working underwater, it will perform the corresponding operation content according to the preset operation instructions. The more actions it performs, the greater the load of the motor. At the same time, the motor application device will undertake tasks such as transporting objects and carrying objects when working underwater. It will bear a certain workload, and the load will change during the work process. When the load becomes larger, the motor will need to output higher power, and it also needs higher heat dissipation efficiency. Therefore, the embodiment of the present invention evaluates the complexity of the operation at the future moment according to the preset operation instructions of the motor, and can determine the load intensity at the future moment, and further corrects the load intensity by combining the complexity of the operation with the environmental harshness index to obtain the corrected load intensity. On the basis of making the corrected load intensity include the original load intensity information, it further combines the complexity of the environment itself and the complexity of the operation required at the future moment to achieve accurate quantification of the heat dissipation effect required by the motor. Further combining the corrected load intensity and the real-time temperature of the motor, the cooling intensity adjustment coefficient can be obtained, that is, the cooling intensity adjustment coefficient represents the heat dissipation effect required by the motor itself. The larger the corrected load intensity, the more complex the working conditions will be during the operation of the motor, and the stronger the heat dissipation will be required to ensure the smooth operation of the motor. The larger the real-time temperature of the motor, the more likely the motor will overheat, and the more it needs to dissipate its temperature.

[0048] Preferably, a method for obtaining an environmental severity index in an embodiment of the present invention includes:

[0049] Count the external pressure on the motor application device at real time; count the water flow rate of the motor application device in all directions. It should be noted that the external pressure and the water flow rate in all directions can be obtained through existing sensor devices, which will not be described in detail here. Add up the water flow rates in all directions and multiply them by the external pressure, normalize the product, and obtain the environmental harshness index. The environmental harshness index is expressed by the formula: ;in is the environmental severity index at the tth moment, is the external pressure at time t, is the water flow velocity in the eth direction at the tth moment, and r is the number of directions. That is, the cumulative value of the water flow velocity in each direction represents the turbulence and eddy current intensity of the current device environment, and the external pressure represents the working water depth. The greater the external pressure, the greater the cumulative value of the water flow velocity, indicating that the environment in which the device is located is more complex and the environmental harshness index is greater.

[0050] Preferably, in one embodiment of the present invention, the method for obtaining the operation complexity includes:

[0051] The working time of each motor start and stop in the subsequent operation in the operation instructions of the motor application device and the change characteristics of the power components in the motor application device are counted. The longer the working time of the motor start and stop and the more times the motor starts and stops, the more complicated the operation is if the motor application device needs to make a special and delicate action; the greater the change characteristics of the power components in the motor application device, the more complicated the operation is if the motor application device needs to perform some special actions through the combination of power components. Therefore, the complexity of the operation can be obtained according to the working time of each motor start and stop and the change characteristics of the power components.

[0052] In the specific implementation of the embodiment of the present invention, the motor application device is an underwater robot, and its power component is mainly a propeller. Therefore, in the embodiment of the present invention, the frequency of change of the propeller combination and the degree of change of each change are counted, where the degree of change is the ratio of the number of propellers involved in the change to the total number of propellers. The average degree of change of all changes is obtained, and the average degree of change is multiplied by the change frequency to obtain the change characteristics of the power component. Further, the working time of all motor starts and stops is accumulated, multiplied by the change characteristics of the power component, and then normalized to obtain the complexity of the operation.

[0053] Preferably, in one embodiment of the present invention, the method for obtaining the modified load strength includes:

[0054] The greater the environmental severity index and the greater the complexity of the operation, the stronger the load that the motor application device will face in subsequent work. Therefore, a correction coefficient can be obtained based on the environmental severity index and the complexity of the operation. The correction coefficient is a normalized value. The load change at a future moment is obtained according to the operation instruction, and the load change is normalized and multiplied by the correction coefficient to obtain a corrected load intensity. The corrected load intensity obtained in the embodiment of the present invention is used to obtain a water flow adjustment value in subsequent steps. Therefore, it is only necessary to characterize the degree of load change, and there is no need to represent the load change of a specific physical quantity. Therefore, the load change is normalized and multiplied by the correction coefficient to obtain a corrected load intensity, that is, the corrected load intensity is also a coefficient used to characterize the degree of greater heat dissipation efficiency required by the motor application device at a future moment.

[0055] In the embodiment of the present invention, because the environmental severity index and the operation complexity are both normalized values, the product of the environmental severity index and the operation complexity is used as the correction coefficient.

[0056] Preferably, in an embodiment of the present invention, considering that the real-time temperature, operating time and corrected load intensity of the motor are all positively correlated with the heat dissipation effect required by the motor, the real-time temperature, operating time and corrected load intensity of the motor are multiplied and normalized to obtain the cooling intensity adjustment coefficient.

[0057] Step S3: obtaining a water flow adjustment value of the water-cooling heat sink according to the cooling intensity adjustment coefficient and the real-time environmental cooling effect, and feeding back a control command to the water-cooling heat sink.

[0058] Through step S1 and step S2, the ambient cooling effect representing the heat dissipation effect of ambient water and the cooling intensity adjustment coefficient representing the cooling effect required by the motor are obtained. By combining the two characteristics, the water flow adjustment value of the water-cooled heat dissipation device can be obtained, and the control command can be fed back. The heat dissipation capacity of the water-cooled heat dissipation device is increased by adjusting the water flow of the water-cooled heat dissipation device.

[0059] It should be noted that in the specific implementation of the embodiment of the present invention, in order to save control computing power and prevent energy waste caused by frequent control of the water cooling device, a control cycle can be set. After each control cycle, information on the current motor and the environment is collected in real time to determine the control command.

[0060] Preferably, in an embodiment of the present invention, the method for obtaining the water flow adjustment value includes:

[0061] A gain coefficient is obtained according to the ambient cooling effect and the cooling intensity adjustment coefficient, and the gain coefficient is multiplied by the preset maximum water flow adjustment value to obtain the water flow adjustment value. It should be noted that because the greater the ambient cooling effect, the less heat dissipation of the water-cooled heat sink is needed, so in the embodiment of the present invention, the ratio of the cooling intensity adjustment coefficient to the ambient cooling effect is used as the gain coefficient. The gain coefficient is a value ranging from 0 to 1. The larger it is, the more water flow is needed to improve the heat dissipation effect. After receiving the control command, the water-cooled heat sink can increase the water flow according to the water flow adjustment value on the basis of the original water flow to improve the heat dissipation effect.

[0062] Preferably, the embodiment of the present invention takes into account that when the water-cooled heat sink is dissipating heat, the circulating water flow generated by the circulating pump has a certain influence on the operation of the motor application device. When the propeller is running in the forward direction, if the water outlet of the water-cooled heat sink is opposite to it, it will cause convection, making the load of the motor greater and causing the difficulty of control to increase. On the contrary, if the water flow direction of the propeller is consistent with the water flow direction of the water-cooled heat sink, it can increase the travel speed of the robot, thereby reducing the load of the motor. Therefore, the control command fed back by the water cooling controller not only includes the water flow adjustment value that needs to be adjusted by the circulating pump, but can also be used to control the water flow direction of the circulating pump of the water-cooled heat sink. The water flow direction discharged by the circulating pump should be set to be consistent with the propulsion direction of the propeller.

[0063] Preferably, the permanent magnet synchronous brushless DC motor proposed in the embodiment of the present invention further includes an abnormal warning module, which is used to feedback a warning signal when the temperature of the motor is greater than a preset temperature threshold and the duration is greater than a preset duration threshold, and the water flow of the water cooling device is at its maximum. The setting of the abnormal warning module can assist the staff to promptly detect the abnormality of the working state of the motor, avoid further deterioration of the abnormal state, and ensure the service life of the motor and the motor application device.

[0064] It should be noted that the preset temperature threshold and the preset duration threshold need to be set according to the specific motor model and parameters, which will not be elaborated or limited here.

[0065] In summary, the permanent magnet synchronous DC brushless motor proposed in the embodiment of the present invention includes a water cooling controller to control the water flow of the water cooling heat dissipation device. In the control process, the environmental cooling effect in the current environment is first evaluated according to the real-time temperature state. That is, the better the environmental cooling effect, the lower the heat dissipation efficiency of the water cooling heat dissipation device, thereby achieving energy saving and increasing the endurance of the device. The environmental harshness index of the current underwater environment is further analyzed, and the corrected load intensity of the device at future times is evaluated in combination with the subsequent operation instructions of the motor application device. That is, the greater the corrected load intensity, the higher the power required for the motor to work, and the greater the heat dissipation efficiency should be. By quantifying and analyzing the above factors, the water flow adjustment value of the water cooling heat dissipation device is obtained, so that the water cooling heat dissipation device can adaptively adjust the water flow based on the underwater environmental state and the subsequent operation state of the motor application device, and then adjust the heat dissipation efficiency, thereby ensuring the scientific operation of the motor.

[0066] It should be noted that the sequence of the above embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0067] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A permanent magnet synchronous brushless DC motor, characterized in that: The motor includes a water cooling device; when the motor application device is running underwater, the water flow of the water cooling device is controlled by a water cooling controller; The method for controlling the water flow rate of the water cooling controller includes: Acquire in real time a first temperature difference between the inside of the motor and the environment, and a second temperature difference between the inside of the motor and a preset standard temperature; obtain an environmental cooling effect according to the first temperature difference, the second temperature difference, and the direction of water flow in the environment; The environmental severity index is obtained in real time according to the flow rate and pressure of the water flow in the environment; the operation complexity at a future moment is evaluated according to the preset operation instructions of the motor; the load change at a future moment is corrected according to the environmental severity index and the operation complexity to obtain a corrected load intensity; the cooling intensity adjustment coefficient is obtained according to the corrected load intensity and the real-time temperature of the motor; Obtaining a water flow adjustment value of a water-cooling heat sink according to the cooling intensity adjustment coefficient and the real-time environmental cooling effect, and feeding back a control command to the water-cooling heat sink; The method for obtaining the environmental cooling effect includes: The first temperature difference is the temperature difference between the inside of the motor and the environment, and the second temperature difference is the temperature difference between the inside of the motor and a preset standard temperature; The inverse of the second temperature difference is multiplied by the first temperature difference in real time and normalized to obtain an initial environment cooling effect; Obtaining the angle difference between the direction of the ambient water flow and the forward direction of the motor application device in real time; performing negative correlation mapping on the angle difference, multiplying the result with the initial ambient cooling effect, and normalizing the result to obtain the ambient cooling effect; The method for obtaining the environmental severity index includes: Counting the external pressure on the motor application device at real time; counting the water flow rate of the motor application device in various directions; accumulating the water flow rate in various directions and multiplying it by the external pressure, normalizing the product, and obtaining an environmental severity index; The method for obtaining the operation complexity includes: Counting the working time of each motor start and stop in subsequent operations in the operation instructions of the motor application device, and the change characteristics of the power components in the motor application device; The operation complexity is obtained according to the working time of each motor start and stop and the change characteristics of the power components.

2. A permanent magnet synchronous brushless DC motor according to claim 1, characterized in that: The method for obtaining the modified load strength includes: A correction coefficient is obtained according to the environmental severity index and the operation complexity; the correction coefficient is a normalized value; the load change at a future moment is obtained according to the operation instruction, the load change is normalized and multiplied by the correction coefficient to obtain the corrected load intensity.

3. A permanent magnet synchronous brushless DC motor according to claim 1, characterized in that: The method for obtaining the cooling intensity adjustment coefficient includes: The real-time temperature and operation duration of the motor are multiplied by the corrected load intensity and then normalized to obtain the cooling intensity adjustment coefficient.

4. A permanent magnet synchronous brushless DC motor according to claim 1, characterized in that: The method for obtaining the water flow adjustment value includes: A gain coefficient is obtained according to the environmental cooling effect and the cooling intensity adjustment coefficient, and the gain coefficient is multiplied by a preset maximum water flow adjustment value to obtain the water flow adjustment value.

5. A permanent magnet synchronous brushless DC motor according to claim 1, characterized in that: The motor also includes an abnormal warning module, which is used to feedback a warning signal when the temperature of the motor is greater than a preset temperature threshold and the duration is greater than a preset duration threshold, and the water flow of the water cooling device is at its maximum.

6. A permanent magnet synchronous brushless DC motor according to claim 1, characterized in that: The water cooling device controls the water flow by a circulating pump, the water cooling device surrounds the motor body, and the inside of the shell of the water cooling device includes a cooling groove for cooling water to flow; the application device of the motor includes a propeller, and the propeller controls the rotation of the blades through the motor to propel.

7. A permanent magnet synchronous brushless DC motor according to claim 6, characterized in that: The control command includes the water flow adjustment value that needs to be adjusted for the circulation pump, and the water flow direction of the circulation pump is set as the propulsion direction of the propeller.

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