Phase change heat dissipation method and system for propulsion motor

Abstract

The present invention relates to the technical field of motor heat dissipation, and specifically to a phase change heat dissipation method and system for a propulsion motor. The invention analyzes the data distribution of multiple curve segments in the temperature curve of each position, obtains the degree of fluctuation of each curve segment, and obtains the local heat dissipation degree of each curve segment corresponding to each position; screens out abnormal heat dissipation curve segments; obtains the overall heat dissipation degree of each position according to the time characteristics of the abnormal heat dissipation curve segments corresponding to each position, and the distribution of the local heat dissipation degree; obtains multiple heat dissipation similar position groups according to the difference in the overall heat dissipation degree between adjacent positions; obtains the flow rate control coefficient of each position at each moment, regulates the initial output power of the flow rate control device, and obtains the corresponding regulated output power; assists the propulsion motor in phase change heat dissipation. The present invention assists the phase change structure in more effective motor heat dissipation by appropriately adjusting the flow rate control device of the cooling liquid corresponding to each position.

Description

Technical Field

[0001] The present invention relates to the technical field of motor heat dissipation, and in particular to a phase change heat dissipation method and system for a propulsion motor. Background Art

[0002] Under high-power load conditions, the rotor and stator inside the propulsion motor will generate a large amount of heat loss. If the motor cannot dissipate heat in time, the temperature of various parts of the propulsion motor will rise rapidly, causing the motor energy consumption to increase, which may cause the internal components of the motor to burn out and cause the motor to fail. Therefore, it is very necessary to dissipate heat for the propulsion motor.

[0003] In the prior art, phase change heat dissipation technology is used to change the physical state of the phase change material medium through the change of the temperature around the medium, thereby releasing or absorbing heat, and using the latent heat storage of the phase change medium to passively control the temperature of the motor, so that the temperature change process of the propulsion motor is smoother; however, in actual work, the temperature of each part of the motor changes with the change of load, the temperature at different positions in the motor is uneven, and the response speed of the phase change material is different, so that the phase change structure has different effects on temperature regulation at different positions, and it is impossible to directly use the phase change structure to accurately regulate the temperature at different positions based on the heat dissipation capacity of the phase change structure, resulting in poor motor heat dissipation effect. Summary of the invention

[0004] In order to solve the technical problem that the phase change structure has different effects on temperature control at different positions, the purpose of the present invention is to provide a phase change heat dissipation method and system for a propulsion motor. The technical solution adopted is as follows:

[0005] The present invention proposes a phase change heat dissipation method for a propulsion motor, the method comprising:

[0006] Acquire temperature data of each position of the propulsion motor in time sequence to form a temperature curve of each position;

[0007] For any position, according to the volatility of the data in the temperature curve, multiple non-overlapping curve segments of the temperature curve are obtained; according to the distribution of the data in each curve segment, the degree of fluctuation of each curve segment is obtained, and the local heat dissipation degree of each curve segment corresponding to each position is obtained; according to the local heat dissipation degree of all curve segments, the abnormal heat dissipation curve segments are screened out; according to the time characteristics of the abnormal heat dissipation curve segments corresponding to each position, and the distribution of the local heat dissipation degree, the overall heat dissipation degree of each position is obtained; according to the difference in the overall heat dissipation degree between adjacent positions, multiple heat dissipation similar position groups are obtained;

[0008] According to the change trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups and the distribution characteristics of the positions, the flow rate requirement of the cooling liquid corresponding to each position is obtained; according to the local flow rate requirement distribution of each position and the local temperature distribution of each position at each moment, the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained;

[0009] According to the distribution of the local flow rate control coefficient of the cooling liquid corresponding to each position at real time, the initial output power of the flow rate control device corresponding to each position is regulated to obtain the regulated output power of each position at real time; based on the regulated output power, the flow rate control device is adjusted to assist the propulsion motor in phase change heat dissipation.

[0010] Furthermore, the method for obtaining the fluctuation degree includes:

[0011] For any position, obtaining a first mean value of all data in the temperature curve and a second mean value of all data in each curve segment;

[0012] According to the difference between the first mean and the corresponding second mean of each curve segment, the difference between each data in each curve segment and the second mean, and the duration of each curve segment, the fluctuation degree of each curve segment is obtained. The difference between the first mean and the corresponding second mean of each curve segment is positively correlated with the fluctuation degree, the difference between each data in each curve segment and the second mean is positively correlated with the fluctuation degree, and the duration is negatively correlated with the fluctuation degree.

[0013] Furthermore, the method for obtaining the local heat dissipation degree includes:

[0014] Obtaining the speed data and current data of the propulsion motor in time sequence; obtaining the average speed data and the average current data corresponding to all moments in each curve segment; calculating the ratio of the average current data to the average speed data as a first ratio;

[0015] Obtain the data difference between the maximum value of the data in each curve segment at each position and the minimum data at the moment in the temperature curve;

[0016] The ratio of the first mean to the second mean is obtained as the second ratio; the local heat dissipation degree of each curve segment at each position is obtained according to the fluctuation degree of each curve segment, the data difference, the first ratio and the second ratio, the first ratio and the second ratio are positively correlated with the local heat dissipation degree, and the fluctuation degree and the data difference are negatively correlated with the local heat dissipation degree.

[0017] Furthermore, the method for obtaining the abnormal heat dissipation curve segment includes:

[0018] The local heat dissipation degree of each curve segment is normalized. If the local heat dissipation degree of the normalized curve segment is less than a preset heat dissipation threshold, the corresponding curve segment is regarded as an abnormal heat dissipation curve segment.

[0019] Furthermore, the method for obtaining the overall heat dissipation degree includes:

[0020] Obtaining the average of the local heat dissipation degrees corresponding to all curve segments at each position as the local average heat dissipation degree;

[0021] Obtain the difference between the local heat dissipation degree and the local average heat dissipation degree of the heat dissipation abnormality curve segment corresponding to each position;

[0022] According to the duration, minimum value at the moment, degree difference and local average heat dissipation degree corresponding to each heat dissipation abnormality curve segment at each location, the overall heat dissipation degree at each location is obtained. The minimum value at the moment and the local average heat dissipation degree are positively correlated with the overall heat dissipation degree, while the duration and degree difference are negatively correlated with the overall heat dissipation degree.

[0023] Furthermore, the method for obtaining the heat dissipation similar position group includes:

[0024] The average value of the overall heat dissipation degree at all positions of the propulsion motor is obtained as the overall average heat dissipation degree;

[0025] Obtaining the difference in overall heat dissipation between adjacent positions; calculating the ratio of the overall average heat dissipation to the difference as the overall heat dissipation similarity between adjacent positions;

[0026] The overall heat dissipation similarity between all adjacent positions is normalized. If the overall heat dissipation similarity between adjacent positions after normalization is greater than the preset similarity threshold, the corresponding position is used as a similar marked position to obtain the similar marked position of each position to form multiple heat dissipation similar position groups.

[0027] Furthermore, the method for obtaining the flow rate requirement includes:

[0028] According to the changing trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups, the heat source position and the heat conduction straight line are obtained;

[0029] For any position, obtain the extreme value of the overall heat dissipation degree in the heat dissipation similar position group where the corresponding position is located; obtain the heat conduction straight line with the smallest distance from the corresponding position, and use the corresponding heat conduction straight line as the target heat conduction straight line; connect the line segment between the heat source position and the corresponding position to obtain the angle between the corresponding line segment and the target heat conduction straight line;

[0030] According to the extreme value of the heat dissipation similar position group where the corresponding position is located, the relative distance between the corresponding position and the heat source position, the angle, and the overall heat dissipation degree of the corresponding position, the flow velocity requirement of the corresponding position is obtained. The extreme value and the angle are positively correlated with the flow velocity requirement, and the relative distance between the corresponding position and the heat source position and the overall heat dissipation degree are negatively correlated with the flow velocity requirement.

[0031] The method for obtaining the heat source position and the heat conduction straight line includes:

[0032] The average of the overall heat dissipation degree of all positions in each heat dissipation similar position group is obtained as the overall heat dissipation level;

[0033] Select the position with the smallest overall heat dissipation level among all heat dissipation similar position groups, and the position corresponding to the smallest overall heat dissipation level among all heat dissipation similar position groups as the heat source position;

[0034] Traverse the heat dissipation similar position groups in all directions along the heat source position. If there are at least two heat dissipation similar position groups in a direction, the overall heat dissipation levels decrease successively. Connect the position with the largest relative distance to the heat source position in the corresponding direction with a straight line to serve as the heat conduction line.

[0035] Furthermore, the method for obtaining the flow rate control coefficient includes:

[0036] Obtain the ratio of the temperature data of each position at each moment to the previous adjacent moment as the local temperature variation degree;

[0037] The position with the smallest relative distance from the heat source position among the adjacent positions of each position is obtained as the target adjacent position; the difference in flow rate demand between each position and the target adjacent position is obtained, the ratio between the difference result and the average flow rate demand of all positions is calculated, and normalized as the local flow rate demand factor;

[0038] The rotation speed of the flow rate control device corresponding to each position is obtained, and the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained by combining the local flow rate demand factor of each position and the local temperature change degree at each moment. The local flow rate demand factor, local temperature change degree and rotation speed are all positively correlated with the flow rate control coefficient.

[0039] Furthermore, the method for obtaining the regulated output power includes:

[0040] Obtain the mean value of the flow rate control coefficients at all locations at the real time as the average flow rate control coefficient;

[0041] Obtain the difference in the flow rate control coefficient of the cooling liquid at each position between the real time and the previous adjacent time, calculate the ratio between the difference result and the average flow rate control coefficient, and normalize them as the normalized ratio; calculate the sum of the normalized ratio and the positive integer 1 as the local flow rate control weight;

[0042] The output power of the flow rate control device is weighted according to the local flow rate control weight to obtain the control output power of the flow rate control device corresponding to each position at the real time.

[0043] The present invention also proposes a phase change heat dissipation system for a propulsion motor, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any one of the steps of the phase change heat dissipation method for a propulsion motor.

[0044] The present invention has the following beneficial effects:

[0045] The present invention takes into account that different positions are affected by heat sources to different degrees and have different heat dissipation capabilities, and analyzes each position separately; for any position, according to the volatility of the data in the temperature curve, a plurality of curve segments of the temperature curve are obtained, which is helpful to analyze the heat dissipation characteristics of each stage more carefully; according to the distribution of temperature data in each curve segment, the degree of fluctuation of each curve segment is obtained, and the local heat dissipation degree of each curve segment corresponding to each position is obtained, so that the temperature fluctuation can be identified and the overall heat dissipation degree in different curve segments can be evaluated; according to the local heat dissipation degree of all curve segments, the heat dissipation abnormal curve segments are screened out, and representative heat dissipation abnormal curve segments are identified as references, so as to more accurately evaluate the overall heat dissipation degree of each position as a whole, and more accurately quantify the heat dissipation capacity of each position; according to the difference in the overall heat dissipation degree between adjacent positions, a plurality of heat dissipation similar position groups are obtained, and positions with similar heat dissipation characteristics are divided into groups; Being divided into the same group helps to analyze the heat dissipation situation in more detail; according to the change trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups and the distribution characteristics of the positions, the flow rate requirement of the cooling liquid corresponding to each position is obtained, and the difference in heat dissipation capacity of different positions under different conditions is considered to accurately analyze the flow rate requirement of the cooling liquid required; considering the temperature change over time, according to the distribution of the local flow rate requirement of each position and the local temperature distribution of each position at each moment, the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained; according to the distribution of the local flow rate control coefficient of the cooling liquid corresponding to each position at real time, the initial output power of the flow rate control device corresponding to each position is regulated, and the regulated output power of each position at real time is obtained, so as to quickly respond to the change of heat dissipation demand and ensure the maintenance of a stable heat dissipation state; assist the propulsion motor to perform phase change heat dissipation. The present invention assists the phase change structure to perform more effective motor heat dissipation by appropriately adjusting the flow rate control device of the cooling liquid corresponding to each position. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] 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.

[0047] Figure 1 A flow chart of a phase change heat dissipation method for a propulsion motor provided by one embodiment of the present invention;

[0048] Figure 2 A flow chart of a method for obtaining the overall heat dissipation degree provided by an embodiment of the present invention;

[0049] Figure 3 A flow chart of a method for obtaining a heat dissipation similar position group provided by an embodiment of the present invention;

[0050] Figure 4 A flow chart of a method for obtaining a flow rate control coefficient provided by an embodiment of the present invention;

[0051] Figure 5 A flow chart of a method for obtaining output power regulation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] 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 phase change heat dissipation method and system of a propulsion motor proposed by the present invention, its specific implementation, structure, characteristics and effects, 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.

[0053] 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.

[0054] The following is a detailed description of a phase change heat dissipation method and system for a propulsion motor provided by the present invention in conjunction with the accompanying drawings.

[0055] See also Figure 1 , which shows a flow chart of a phase change heat dissipation method for a propulsion motor provided by an embodiment of the present invention, and the specific method includes:

[0056] Step S1: Acquire the temperature data of each position of the propulsion motor in time sequence to form a temperature curve of each position.

[0057] In the process of heat dissipation of the propulsion motor using phase change heat dissipation technology, temperature control is achieved based on the characteristic that the temperature of the phase change material does not change when absorbing or releasing a large amount of heat energy. When the temperature of a certain position of the propulsion motor rises to exceed the phase change temperature, the material state of the phase change material itself will change. The process of material state transformation will absorb the heat of the position, thereby reducing the temperature of the position and achieving temperature control of the position; but in the actual working process, with the continuous operation of the motor, the temperature of some positions may continue to rise and the distribution of the phase change material may be uneven, which makes the ability of the phase change structure at this position to control the temperature limited; in the present invention, in order to improve the heat dissipation effect of the phase change heat dissipation system and enable the propulsion motor to dissipate heat in time, a liquid cooling system is covered on the outside of the phase change structure, and the liquid cooling system is designed A liquid cooling pipe for circulating cooling liquid is arranged, and the flow rate of the cooling liquid is adjusted by arranging flow rate control devices at different positions of the liquid cooling pipe, so that when the flow rate of the cooling liquid in the pipe increases, the rate of heat conduction with the phase change structure increases, thereby accelerating the absorption and release of heat by the phase change material, and realizing precise control of the temperature of the propulsion motor. Therefore, it is necessary to analyze the temperature change and adjust the flow rate control device to obtain a suitable flow rate of the cooling liquid; first, a plurality of temperature sensors are installed at different positions on the surface of the propulsion motor, and the temperature data of each position of the propulsion motor is obtained in time sequence to form a temperature curve for each position; wherein, the direction of time sequence increase is used as the positive direction of the horizontal axis of the temperature curve, and the direction of temperature increase is used as the positive direction of the vertical axis of the temperature curve.

[0058] It should be noted that, in one embodiment of the present invention, the timing interval is 1 minute, that is, the temperature data is obtained once every minute; in other embodiments of the present invention, the size of the timing interval can be set according to the specific situation, which is not limited or elaborated here.

[0059] It should be noted that in order to facilitate subsequent data processing and avoid differences in data units and numerical magnitudes, the data is standardized to eliminate the influence of dimensions in data calculations.

[0060] It should be noted that, in an embodiment of the present invention, the flow rate control device is a pressure pump for increasing the flow rate of the cooling liquid; in other embodiments of the present invention, the flow rate control device may also be a variable frequency pump.

[0061] Step S2: For any position, according to the volatility of the data in the temperature curve, multiple non-overlapping curve segments of the temperature curve are obtained; according to the distribution of the data in each curve segment, the degree of fluctuation of each curve segment is obtained, and the local heat dissipation degree of each curve segment corresponding to each position is obtained; according to the local heat dissipation degree of all curve segments, the abnormal heat dissipation curve segments are screened out; according to the time characteristics of the abnormal heat dissipation curve segments corresponding to each position, and the distribution of local heat dissipation degree, the overall heat dissipation degree of each position is obtained; according to the difference in overall heat dissipation degree between adjacent positions, multiple heat dissipation similar position groups are obtained.

[0062] Due to the influence of ambient temperature and load changes, the temperature of the propulsion motor varies in different time periods, and since the temperature attenuates during the transmission process, the temperature data at different positions also differ. Therefore, the temperature curve fluctuates. In order to analyze the temperature change trend and better identify and distinguish the different characteristics of the data, for any position, the APCA algorithm is used to segment the data according to the volatility of the temperature curve to obtain multiple non-overlapping curve segments of the temperature curve. It should be noted that the specific APCA algorithm is a technical means well known to technicians in this field and will not be elaborated here.

[0063] Ideally, a phase change cooling system with good heat dissipation capacity can effectively reduce the motor temperature and keep the temperature within a smaller temperature range, reduce the temperature shock to the propulsion motor components, and make the temperature distribution of various parts of the motor at different times more uniform, and the fluctuation degree of each curve segment is smaller. Therefore, according to the distribution of data in each curve segment, the fluctuation degree of each curve segment is obtained, and the local heat dissipation degree of each position corresponding to each curve segment is obtained.

[0064] Preferably, in one embodiment of the present invention, the method for obtaining the degree of fluctuation includes:

[0065] For any position, obtaining a first mean value of all data in the temperature curve and a second mean value of all data in each curve segment;

[0066] According to the difference between the first mean and the corresponding second mean of each curve segment, the difference between each data in each curve segment and the second mean, and the duration of each curve segment, the fluctuation degree of each curve segment is obtained. The difference between the first mean and the corresponding second mean of each curve segment is positively correlated with the fluctuation degree, the difference between each data in each curve segment and the second mean is positively correlated with the fluctuation degree, and the duration is negatively correlated with the fluctuation degree.

[0067] Among them, the positive correlation indicates that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases, that is, the greater the difference between the first mean and the corresponding second mean of each curve segment, the greater the change of each curve segment relative to the overall curve, the greater the difference between each data in each curve segment and the second mean, the more uneven the data distribution, and the greater the degree of fluctuation; the negative correlation indicates that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases, that is, the larger the time length, the more data there is in the curve segment. Since the data is divided according to volatility, the more data there is, the closer the data changes are, and the smaller the degree of fluctuation is.

[0068] In one embodiment of the present invention, taking any position as an example, the formula for the degree of fluctuation is expressed as:

[0069] ;

[0070] in, Indicates The degree of fluctuation of each curve segment; Represents the mean of all data in the temperature curve, that is, the first mean; Indicates The first individual data; Indicates The mean of the data in the curve segments is the second mean; Indicates The number of data in a curve segment; Indicates The duration of each curve segment; Indicates the average duration of all curve segments in the temperature curve.

[0071] In the formula for volatility, Indicates the mean of all data in the calculated temperature curve and the The difference between the means of the data in the curve segments is larger. The more the mean of the data in a curve segment deviates from the mean of all the data in the temperature curve, the greater the data level in the curve segment is than the overall data level, and the greater the degree of fluctuation; It represents the ratio between the calculated difference result and the first mean. The larger the ratio, the greater the difference and the greater the fluctuation. It means calculating the difference between each data in each curve segment and the second mean, and averaging the corresponding differences of all data in each curve segment. The larger the mean, the greater the difference between each data in each curve segment and the second mean, and the greater the fluctuation; Indicates the average and the first time length of all curve segments in the calculated temperature curve. The larger the ratio is, the shorter the duration of the corresponding curve segment is, the fewer data with similar temperature changes in the curve segment are, and the greater the fluctuation is.

[0072] Preferably, in one embodiment of the present invention, it is considered that current is a key factor in driving the operation of the motor and is also the main source of heat generation; since the motor, in actual application, is affected by the working state on the basis of the fixed load of the motor, a constantly changing power load is generated, the larger the current data, the smaller the motor speed, and there may be a larger power load generated during operation, and more torque needs to be generated by increasing the current, the internal loss of the motor increases, and the motor speed decreases, so that the heat is greater and the temperature rises, which can intuitively reflect the thermal state of the motor; therefore, the heat dissipation of the motor is evaluated by analyzing the changing trend of the motor temperature. When the temperature data tends to rise more and the fluctuation is greater, the heat dissipation effect is worse; the method for obtaining the local heat dissipation degree includes:

[0073] Obtaining the speed data and current data of the propulsion motor in time sequence; obtaining the average speed data and the average current data corresponding to all moments in each curve segment; calculating the ratio of the average current data to the average speed data as a first ratio;

[0074] Obtain the data difference between the maximum value of the data in each curve segment at each position and the minimum data at the moment in the temperature curve;

[0075] The ratio of the first mean and the second mean is obtained as the second ratio. The local heat dissipation degree of each curve segment at each position is obtained according to the fluctuation degree of each curve segment, the data difference, the first ratio and the second ratio. The first ratio and the second ratio are positively correlated with the local heat dissipation degree, and the fluctuation degree and the data difference are negatively correlated with the local heat dissipation degree.

[0076] Among them, the positive correlation indicates that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases, that is, the larger the first ratio is, the larger the current data of the corresponding curve segment is, and the smaller the speed data is, that is, there are more power loads generated during operation, which makes the motor generate more heat, and the greater the impact on the local heat dissipation degree; the larger the second ratio is, the smaller the second mean of the corresponding curve segment is, that is, the smaller the overall temperature of the corresponding curve segment is, and the better the local heat dissipation degree is; the negative correlation indicates that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases, that is, the greater the fluctuation degree, the more uneven the data distribution in the corresponding curve segment, the worse the local heat dissipation degree is, the greater the data difference is, the larger the maximum value of the data in the curve segment is, that is, the greater the temperature change is, the worse the local heat dissipation degree is.

[0077] In one embodiment of the present invention, taking any position as an example, the formula for the local heat dissipation degree is expressed as:

[0078] ;

[0079] in, Indicates The local heat dissipation degree of each curve segment; Indicates The degree of fluctuation of each curve segment; Indicates the minimum data at a certain moment in the temperature curve; Represents the mean of all data in the temperature curve, that is, the first mean; Indicates The maximum value of the data in the curve segment; Indicates The mean of all data in the curve segment, i.e. The second mean of the curve segments; It represents the adjustment parameter, which is set to 0.01 to avoid the denominator of the formula being 0; Indicates The mean value of the current data at all times in the curve segment; Indicates The average speed data corresponding to all moments in a curve segment.

[0080] In the formula for local heat dissipation, Indicates the minimum data and the first The difference in the maximum value of the data in the curve segments, the greater the difference, that is, the greater the temperature rise change, the worse the local heat dissipation; Indicates the calculation of the mean and the first value of all data in the temperature curve The ratio of the mean values ​​of the data in the curve segments is the second ratio. The larger the ratio, the The smaller the mean value of the data in the curve segment, the lower the temperature is and the better the local heat dissipation is. The greater the fluctuation of each curve segment, the more uneven the temperature distribution is, and the poorer the local heat dissipation is. Indicates the calculation The ratio between the mean value of the current data at all times in the curve segment and the mean value of the speed data at all times, that is, the first ratio. The larger the first ratio, the faster the motor is in the first The larger the mean value of the current data in the first curve segment, the smaller the mean value of the speed data, which means that the motor is more affected by the load and the heat generated by the motor increases. Therefore, the smaller the temperature rise change, the smaller the change in the first curve segment. The lower the temperature of a curve segment, the more uniform the temperature distribution and the greater the degree of local heat dissipation.

[0081] It should be noted that the data with the smallest moment is the first data in the temperature curve.

[0082] It should be noted that in order to avoid differences in units and numerical magnitudes between data, the current data and speed data are also standardized to eliminate the impact of dimensions in data calculations.

[0083] By analyzing the local heat dissipation degree of each curve segment, the heat dissipation situation in different time ranges of each location can be reflected, and the law and trend of heat dissipation performance changing over time can be identified. The greater the local heat dissipation degree, the more uniform the data of the corresponding curve segment, and the better the heat dissipation capacity. On the contrary, the smaller the local heat dissipation degree, the more uneven the data of the corresponding curve segment, and the worse the heat dissipation capacity. Therefore, representative heat dissipation abnormal curve segments can be identified as a reference, which is helpful for analyzing the overall heat dissipation capacity of each subsequent location; therefore, according to the local heat dissipation degree of all curve segments, the heat dissipation abnormal curve segments are screened out.

[0084] Preferably, in one embodiment of the present invention, the method for obtaining the abnormal heat dissipation curve segment includes:

[0085] The local heat dissipation degree of each curve segment is normalized. If the local heat dissipation degree of the normalized curve segment is less than a preset heat dissipation threshold, the corresponding curve segment is regarded as an abnormal heat dissipation curve segment.

[0086] Based on this, since the curve segment with a local heat dissipation degree less than a preset heat dissipation threshold is selected, the smaller the local heat dissipation degree, the worse the heat dissipation, that is, the abnormal heat dissipation curve segment is a curve segment with a poor local heat dissipation degree.

[0087] It should be noted that, in one embodiment of the present invention, the preset heat dissipation threshold is 0.5; in other embodiments of the present invention, the size of the preset heat dissipation threshold can be set according to specific circumstances, which is not limited or elaborated here.

[0088] In the actual working process, as the motor continues to run, the temperature of some positions may continue to rise, and the uneven distribution of phase change materials limits the ability of the phase change system at this position to control the temperature, resulting in low overall heat dissipation at the current position and the temperature may continue to rise. Therefore, analyzing the time characteristics helps to understand the heat dissipation performance of this position in different time periods. The local heat dissipation distribution reflects the ability of this position to dissipate heat to the surrounding environment within the heat dissipation abnormality curve segment. Therefore, the overall heat dissipation degree of each position is obtained according to the time characteristics of the heat dissipation abnormality curve segment corresponding to each position and the local heat dissipation distribution.

[0089] Preferably, in one embodiment of the present invention, the flowchart of the method for obtaining the overall heat dissipation degree can be found in Figure 2 , which shows a flow chart of a method for obtaining the overall heat dissipation degree, including:

[0090] Step S201: obtaining the average of the local heat dissipation degrees of all curve segments corresponding to each position as the local average heat dissipation degree;

[0091] In order to facilitate data comparison, the local heat dissipation degree corresponding to all curve segments at each position is quantified and statistically analyzed by averaging method, and compared by local average heat dissipation degree in subsequent calculation process.

[0092] Step S202: obtaining the difference between the local heat dissipation degree and the local average heat dissipation degree of the heat dissipation abnormality curve segment corresponding to each position.

[0093] The fluctuation is shown by calculating the cumulative value of the difference between the local heat dissipation degree and the local average heat dissipation degree of different heat dissipation abnormality curve segments. That is, the larger the cumulative value of the difference, the greater the difference between the local heat dissipation degree and the local average heat dissipation degree of different heat dissipation abnormality curve segments, the more uneven the distribution of local heat dissipation degrees of different heat dissipation abnormality curve segments, and the greater the heat dissipation fluctuation.

[0094] Step S203: According to the duration and the minimum value at the moment, the local average heat dissipation degree and the degree difference corresponding to each heat dissipation abnormality curve segment at each position, the overall heat dissipation degree of each position is obtained. The minimum value at the moment and the local average heat dissipation degree are positively correlated with the overall heat dissipation degree, and the duration and the degree difference are negatively correlated with the overall heat dissipation degree.

[0095] Among them, the positive correlation indicates that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases, that is, the larger the minimum value at the moment, the longer the time required to rise to the temperature corresponding to the abnormal heat dissipation curve segment, the slower the rising effect, the better the overall heat dissipation, and the larger the local average heat dissipation, that is, the better the overall heat dissipation corresponding to all curve segments; the negative correlation indicates that the dependent variable will decrease as the independent variable increases, and the dependent variable will increase as the independent variable decreases, that is, the larger the time length, the longer the time period of the abnormal heat dissipation curve segment, that is, the longer the time period of the local poor heat dissipation, the worse the overall heat dissipation, and the greater the degree difference, that is, the more inconsistent the local heat dissipation of the abnormal heat dissipation curve segment, and the worse the overall heat dissipation.

[0096] In one embodiment of the present invention, the formula for the overall heat dissipation degree is expressed as:

[0097] ;

[0098] in, Indicates the overall heat dissipation at each location; Indicates the duration of the temperature curve corresponding to each position; It represents the sum of the duration of all heat dissipation abnormality curve segments corresponding to each position; Indicates the number of abnormal heat dissipation curve segments corresponding to each position; Indicates The minimum value of the moment corresponding to each abnormal heat dissipation curve segment; It represents the mean of the local heat dissipation degree of all curve segments in the temperature curve corresponding to each position, that is, the local average heat dissipation degree; Indicates The local heat dissipation degree of each heat dissipation abnormality curve segment; It represents the adjustment parameter and takes 0.01 to avoid the denominator of the formula being 0.

[0099] In the formula for overall heat dissipation, It represents the ratio between the corresponding time of the calculated temperature curve and the sum of the corresponding time of all heat dissipation abnormality curve segments. The larger the ratio, the larger the sum of the corresponding time of all heat dissipation abnormality curve segments, that is, the longer the time occupied by the curve segment with poor local heat dissipation, the worse the overall heat dissipation at the corresponding position; It indicates calculating the cumulative sum of the minimum values ​​of all the heat dissipation abnormality curve segments at the time. The larger the cumulative sum, the larger the minimum value of the heat dissipation abnormality curve segment at the time, that is, the longer it takes to rise to the temperature corresponding to the heat dissipation abnormality curve segment, the slower the rising effect, and the better the overall heat dissipation degree; Indicates the calculation The difference between the local heat dissipation degree of each heat dissipation abnormality curve segment and the local average heat dissipation degree in the temperature curve, that is, the degree difference; It represents the cumulative value of all degree differences. The larger the cumulative value, the greater the deviation of the local heat dissipation degree of the abnormal heat dissipation curve segment relative to the local heat dissipation degree of the overall curve segment, and the worse the overall heat dissipation degree; the larger the mean value of the overall heat dissipation degree of all curve segments in the temperature curve, the better the overall heat dissipation degree corresponding to the position.

[0100] It should be noted that the minimum time value is the minimum time value among all times corresponding to the heat dissipation abnormality curve segment.

[0101] Since the temperature of the positions closer to the heat sources such as the stator and rotor in the propulsion motor is higher and the heating rate is faster, and vice versa is slower, the heat dissipation capacity of different positions is also different. During the operation of the propulsion motor, the possibility that the heating power of the position with faster temperature rise is higher than the heat dissipation power is greater, and the possibility of poor heat dissipation is also greater. In addition, the difference in the overall heat dissipation degree of areas with similar position distances is small, which is conducive to more targeted local analysis of the heat dissipation situation. Therefore, based on the difference in the overall heat dissipation degree between adjacent positions, multiple groups of positions with similar heat dissipation are obtained.

[0102] Preferably, in one embodiment of the present invention, the flowchart of the method for obtaining the heat dissipation similar position group can be found in Figure 3, which shows a flow chart of a method for obtaining a heat dissipation similar position group, including:

[0103] Step S301: obtaining the average value of the overall heat dissipation degree of all positions of the propulsion motor as the overall average heat dissipation degree.

[0104] In order to facilitate data comparison, the overall heat dissipation degree of all positions of the propulsion motor is quantified and statistically analyzed by averaging method to reflect the overall heat dissipation level of the propulsion motor. In the subsequent calculation process, the overall average heat dissipation degree is used for comparison.

[0105] Step S302: obtaining the difference in overall heat dissipation between adjacent positions; calculating the ratio of the overall average heat dissipation level to the difference as the overall heat dissipation similarity between adjacent positions.

[0106] Among them, the overall heat dissipation similarity can evaluate the correlation between the overall heat dissipation levels between adjacent positions; the more consistent the overall heat dissipation level, the greater the overall heat dissipation similarity.

[0107] In one embodiment of the present invention, the formula for the overall heat dissipation similarity is expressed as:

[0108] ;

[0109] in, Indicates The overall heat dissipation similarity between a position and its adjacent positions; Indicates The overall heat dissipation at each location; Indicates any one The overall heat dissipation degree of the adjacent positions of each position; It represents the mean of the overall heat dissipation at all locations, that is, the overall average heat dissipation; Indicates taking the absolute value; It represents the adjustment parameter and takes 0.01 to avoid the denominator of the formula being 0.

[0110] In the formula for overall heat dissipation similarity, Indicates the calculation position and any one The difference in the overall heat dissipation between adjacent positions is greater, and the more inconsistent the overall heat dissipation between adjacent positions is, and the lower the overall heat dissipation similarity is.

[0111] Step S303: normalize the overall heat dissipation similarity between all adjacent positions. If the overall heat dissipation similarity between adjacent positions after normalization is greater than a preset similarity threshold, take the corresponding position as a similar marked position, obtain the similar marked position of each position, and form multiple heat dissipation similar position groups.

[0112] It should be noted that, in one embodiment of the present invention, the preset similarity threshold is 0.7; in other embodiments of the present invention, the preset similarity threshold may be set according to specific circumstances, which will not be limited or elaborated herein.

[0113] Step S3: According to the changing trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups and the distribution characteristics of the positions, the flow rate requirement of the cooling liquid corresponding to each position is obtained; according to the local flow rate requirement distribution of each position and the local temperature distribution of each position at each moment, the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained.

[0114] In a group of similar heat dissipation positions, different positions may show different overall heat dissipation degree change trends due to the influence of factors such as heat source distribution, heat dissipation structure, and environmental conditions. Some positions may have a faster temperature rise due to being closer to the heat source or having a poor heat dissipation structure, while other positions may have a relatively stable temperature due to superior heat dissipation conditions. Therefore, based on the overall heat dissipation demand and the position distribution, the cooling liquid flow rate requirement is analyzed. In positions with poor overall heat dissipation, the heat exchange effect can be enhanced by increasing the cooling liquid flow rate. Therefore, the cooling liquid flow rate requirement corresponding to each position is obtained based on the overall heat dissipation degree change trend and the position distribution characteristics of different positions in different heat dissipation similar position groups.

[0115] Preferably, in one embodiment of the present invention, the method for obtaining the flow rate requirement includes:

[0116] According to the changing trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups, the heat source position and the heat conduction straight line are obtained;

[0117] For any position, obtain the extreme value of the overall heat dissipation degree in the heat dissipation similar position group where the corresponding position is located; obtain the heat conduction straight line with the smallest distance from the corresponding position, that is, draw a perpendicular line through this position to each heat conduction straight line, and the corresponding heat conduction straight line with the smallest distance from this position to the foot of the perpendicular is used as the target heat conduction straight line; connect the line segment between the heat source position and the corresponding position to obtain the angle between the corresponding line segment and the target heat conduction straight line;

[0118] According to the extreme value of the heat dissipation similar position group where the corresponding position is located, the relative distance between the corresponding position and the heat source position, the angle, and the overall heat dissipation degree of the corresponding position, the flow velocity requirement of the corresponding position is obtained. The extreme value and the angle are positively correlated with the flow velocity requirement, and the relative distance between the corresponding position and the heat source position and the overall heat dissipation degree are negatively correlated with the flow velocity requirement.

[0119] Methods for obtaining the heat source position and heat conduction straight line include:

[0120] The average of the overall heat dissipation degree of all positions in each heat dissipation similar position group is obtained as the overall heat dissipation level;

[0121] Select the position with the smallest overall heat dissipation level among all heat dissipation similar position groups, and the position corresponding to the smallest overall heat dissipation level among all heat dissipation similar position groups as the heat source position;

[0122] Traverse the heat dissipation similar position groups in all directions along the heat source position. If there are at least two heat dissipation similar position groups in a direction, the overall heat dissipation levels decrease successively. Connect the position with the largest relative distance to the heat source position in the corresponding direction with a straight line to serve as the heat conduction line.

[0123] In one embodiment of the present invention, the formula for flow rate requirement is expressed as:

[0124] ;

[0125] in, Indicates Flow rate requirements at each location; Indicates The maximum value of the overall heat dissipation degree in a group of positions with similar heat dissipation at each position; Indicates The minimum value of the overall heat dissipation degree in the group of positions with similar heat dissipation at the position; The vector representing the line segment between the heat source position and the corresponding position; Represents the vector corresponding to the target heat conduction line; Represents the vector corresponding to the line segment between the heat source position and the corresponding position And the target heat conduction straight line The angle between corresponding vectors; Indicates The relative distance between each position and the heat source position; Indicates The overall heat dissipation at each location; It represents the adjustment parameter and takes 0.01 to avoid the denominator of the formula being 0.

[0126] In the formula for flow rate requirement, Indicates the calculation The difference between the maximum and minimum values ​​of the overall heat dissipation degree in the group of similar heat dissipation positions at each position is the range value. The larger the range value, the larger the range of the overall heat dissipation degree, the more uneven the distribution, the more it is necessary to adjust the flow rate of the cooling liquid, and the greater the demand for the flow rate of the cooling liquid; The larger the value, the more heat source is transferred to the location that is not in the direction of heat conduction. As the temperature rises, the heat dissipation capacity will decrease. The more the flow rate of the cooling liquid needs to be adjusted, the greater the demand for the flow rate of the cooling liquid. The greater the relative distance between the first position and the heat source position, the less affected by the heat source. The greater the overall heat dissipation at each location, the less it is necessary to adjust the flow rate of the cooling liquid, and the smaller the flow rate requirement of the cooling liquid.

[0127] It should be noted that, in one embodiment of the present invention, the method for obtaining the relative distance is to calculate the Euclidean distance between the positions. In other embodiments of the present invention, the relative distance can also be obtained by using existing distance algorithms such as the Manhattan distance. The specific Euclidean distance and Manhattan distance are technical means well known to those skilled in the art and will not be described in detail here.

[0128] Since different locations may have different sensitivities to temperature changes and some locations are more susceptible to heat effects, the flow rate demand quantifies the adjustments that need to be made when different locations are affected by different heat effects. Therefore, by monitoring the flow rate demand in the local range of each location and the temperature changes at different times, the flow rate control coefficient of the cooling liquid at each location can be more accurately evaluated. Therefore, based on the local flow rate demand distribution of each location and the local temperature distribution of each location at each moment, the flow rate control coefficient of the cooling liquid corresponding to each location at each moment is obtained.

[0129] Preferably, in one embodiment of the present invention, the flow chart of the method for obtaining the flow rate control coefficient can be found in Figure 4 , which shows a flow chart of a method for obtaining a flow rate control coefficient, including:

[0130] Step S401: Obtain the ratio of the temperature data of each position at each moment to the previous adjacent moment as the local temperature variation.

[0131] The local temperature variation reflects the change in the thermal state of the propulsion motor at a certain position between adjacent moments. The greater the local temperature variation, the more likely it is that there is abnormal heat dissipation.

[0132] Step S402: Obtain the position with the smallest relative distance to the heat source position among the adjacent positions of each position as the target adjacent position; obtain the difference in flow rate demand between each position and the target adjacent position, calculate the ratio between the difference result and the average flow rate demand of all positions, and normalize it as the local flow rate demand factor.

[0133] Among them, different locations have different distances from the heat source, and the degree of heat and cooling requirements are also different. Determining the position with the smallest relative distance from the heat source can more accurately evaluate the cooling demand of this position; the change in flow rate demand reflects the response speed and adjustment ability to the cooling needs of different locations. The greater the flow rate demand at different locations, the greater the local flow rate demand factor, and the more abnormal the heat dissipation process is.

[0134] Step S403: Obtain the rotational speed of the flow rate control device corresponding to each position, combine the local flow rate demand factor of each position and the local temperature change degree corresponding to each moment, and obtain the flow rate control coefficient of the cooling liquid corresponding to each position at each moment. The local flow rate demand factor, local temperature change degree and rotational speed are all positively correlated with the flow rate control coefficient.

[0135] Among them, the flow rate control device corresponding to each position is the flow rate control device that is closer to the propulsion motor position. Among them, the positive correlation relationship means that the dependent variable will increase with the increase of the independent variable, and the dependent variable will decrease with the decrease of the independent variable, that is, the larger the local flow rate demand factor, the greater the local temperature change, the more likely the heat dissipation will have a large change, the more adjustment is needed, and the larger the flow rate control coefficient; the larger the speed of the flow rate control device, the larger the range of flow rate adjustment.

[0136] In one embodiment of the present invention, the formula of the flow rate control coefficient is expressed as:

[0137] ;

[0138] in, Indicates Position in The flow rate control coefficient at each moment; Indicates Flow rate requirements at each location; Indicates the target adjacent position Flow rate requirement; It represents the mean of the flow velocity requirements at all locations, i.e. the average flow velocity requirement; Indicates Position in The temperature at a given moment; Indicates Position in The previous adjacent moment Temperature; Indicates the speed of the flow rate control device; represents the linear normalization function.

[0139] In the formula of flow rate control coefficient, Indicates the difference in cooling liquid flow rate requirements between each position and the target adjacent position, It represents the ratio between the calculated difference result and the average flow rate requirement of all positions, and is normalized to 0-1 to obtain the local flow rate requirement factor. The larger the local flow rate requirement factor, the larger the ratio. The greater the difference in the cooling liquid flow rate requirement between each position and the target adjacent position relative to the overall average flow rate requirement, the more regulation is needed. It represents the ratio of the temperature data between each moment and the previous adjacent moment, that is, the local temperature variation. The greater the local temperature variation, the larger the temperature data at each moment, the smaller the temperature data between the previous adjacent moments, the more the temperature needs to be adjusted downward, and the larger the flow rate control coefficient; the greater the rotation speed of each flow rate control device, the larger the range of flow rate adjustment.

[0140] Step S4: According to the distribution of the local flow rate control coefficient of the cooling liquid corresponding to each position at the real time, the initial output power of the flow rate control device corresponding to each position is regulated to obtain the regulated output power of each position at the real time; the flow rate control device is adjusted based on the regulated output power to assist the propulsion motor in phase change heat dissipation.

[0141] Since the cooling liquid flow rate control coefficients at different motor positions are different, the greater the change in the local flow rate control coefficient of the cooling liquid at real time, the more uneven the heat dissipation is, and the more it is necessary to control the output power of the flow rate control device, which helps to improve the efficiency of the flow rate control device, increase the flow rate of the cooling liquid, and improve the heat dissipation capacity of the motor. According to the distribution of the local flow rate control coefficient of the cooling liquid corresponding to each position at real time, the initial output power of the flow rate control device corresponding to each position is controlled to obtain the controlled output power of each position at real time.

[0142] Preferably, in one embodiment of the present invention, the flow chart of the method for obtaining the output power regulation can be found in Figure 5 , which shows a flow chart of a method for obtaining output power regulation, including:

[0143] Step S501: Obtain the mean value of the flow rate control coefficients at all positions at the real time as the average flow rate control coefficient.

[0144] The average flow rate control coefficient reflects the general level of the cooling liquid flow rate control coefficient at all positions at the real time. The larger the cooling liquid flow rate control coefficient at each position, the larger the average flow rate control coefficient.

[0145] Step S502: Obtain the difference in the flow rate control coefficient between the real time and the previous adjacent time at each position, calculate the ratio between the difference result and the average flow rate control coefficient, and normalize it as the normalized ratio; calculate the sum of the normalized ratio and the positive integer 1 as the local flow rate control weight.

[0146] Among them, by analyzing the difference in the cooling liquid flow rate control coefficient between the real time and the previous adjacent moment at each position, and comparing it with the average flow rate control coefficient, the difference in each position relative to the overall effect is obtained. The greater the change in the flow rate control coefficient, the greater the normalized ratio, and the greater the local flow rate control weight.

[0147] Step S503: weighting the initial output power of the flow rate control device according to the local flow rate control weight to obtain the control output power of the flow rate control device corresponding to each position at the real time.

[0148] In one embodiment of the present invention, the formula for regulating the output power is expressed as:

[0149] ;

[0150] in, Indicates Position in Real-time control of output power, For the The initial output power at each position; Indicates Position in The flow rate control coefficient at a real-time moment; Indicates The position at the previous adjacent time The flow rate control coefficient; Indicates that all positions in The average value of the flow rate control coefficient at each real-time moment is the average flow rate control coefficient; represents the linear normalization function.

[0151] In the formula for regulating output power, It represents the difference of the flow rate control coefficient of the cooling liquid at each position between the real time and the previous adjacent time. It represents the ratio between the calculated difference result and the average flow rate control coefficient, and is normalized to 0-1; It means calculating the sum of the normalized ratio and the positive integer 1 to obtain the local flow rate control weight. The larger the local flow rate control weight, the larger the difference of the cooling liquid flow rate control coefficient between the real time and the previous adjacent time at each position relative to the overall average flow rate control coefficient, and the more adjustment is needed; The greater the initial output power at each position, the greater the regulated output power.

[0152] By adjusting the output power of the flow rate control device, the greater the output power, the greater the flow rate of the cooling liquid, which assists the phase change material in heat dissipation, thereby improving the heat dissipation capacity of the propulsion motor. Based on the output power, the flow rate control device is adjusted to assist the propulsion motor in phase change heat dissipation.

[0153] It should be noted that in other embodiments of the present invention, after obtaining the regulated output power of the flow rate control device, the flow rate control device can be adjusted to assist the propulsion motor in phase change heat dissipation, including: setting the regulated output power of the flow rate control device so that the flow rate of the cooling liquid in the hydraulic system changes. The greater the regulated output power, the greater the flow rate, and the greater the heat conduction efficiency between the phase change material and the phase change material, thereby accelerating the absorption and release of heat by the phase change material and improving the heat dissipation performance. In order to avoid equipment damage, if the regulated output power is adjusted in real time When the maximum output power of the flow rate control device is exceeded, the flow rate control device needs to restart and operate at the initial flow rate so that the liquid cooling system continues to work, thereby assisting the phase change heat dissipation system in regulating the temperature of the propulsion motor; in an embodiment of the present invention, the maximum output power of the flow rate control device is obtained by the implementer based on existing reference materials and will not be elaborated here.

[0154] In summary, the present invention analyzes the data distribution of multiple curve segments in the temperature curve of each position, obtains the degree of fluctuation of each curve segment, and obtains the local heat dissipation degree corresponding to each curve segment at each position; screens out abnormal heat dissipation curve segments; obtains the overall heat dissipation degree of each position according to the time characteristics of the abnormal heat dissipation curve segments corresponding to each position, and the distribution of local heat dissipation degree; obtains multiple heat dissipation similar position groups according to the difference in overall heat dissipation degree between adjacent positions; obtains the flow rate control coefficient of each position at each moment, regulates the initial output power of the flow rate control device, and obtains the corresponding regulated output power; assists the propulsion motor in phase change heat dissipation. The present invention assists the phase change structure in more effective motor heat dissipation by appropriately adjusting the flow rate control device of the cooling liquid corresponding to each position.

[0155] The present invention also proposes a phase change heat dissipation system for a propulsion motor, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any one of the steps of a phase change heat dissipation method for a propulsion motor.

[0156] It should be noted that the sequence of the above embodiments of the present invention is only for description 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.

[0157] 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 phase change heat dissipation method for a propulsion motor, characterized in that: The method comprises: Acquire temperature data of each position of the propulsion motor in time sequence to form a temperature curve of each position; For any position, according to the volatility of the data in the temperature curve, multiple non-overlapping curve segments of the temperature curve are obtained; according to the distribution of the data in each curve segment, the degree of fluctuation of each curve segment is obtained, and the local heat dissipation degree of each curve segment corresponding to each position is obtained; according to the local heat dissipation degree of all curve segments, the abnormal heat dissipation curve segments are screened out; according to the time characteristics of the abnormal heat dissipation curve segments corresponding to each position, and the distribution of the local heat dissipation degree, the overall heat dissipation degree of each position is obtained; according to the difference in the overall heat dissipation degree between adjacent positions, multiple heat dissipation similar position groups are obtained; According to the change trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups and the distribution characteristics of the positions, the flow rate requirement of the cooling liquid corresponding to each position is obtained; according to the local flow rate requirement distribution of each position and the local temperature distribution of each position at each moment, the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained; According to the distribution of the local flow rate control coefficient of the cooling liquid corresponding to each position at the real time, the initial output power of the flow rate control device corresponding to each position is regulated to obtain the regulated output power of each position at the real time; the flow rate control device is adjusted based on the regulated output power to assist the propulsion motor in phase change heat dissipation; The method for obtaining the fluctuation degree includes: For any position, obtaining a first mean value of all data in the temperature curve and a second mean value of all data in each curve segment; According to the difference between the first mean and the second mean corresponding to each curve segment, the difference between each data in each curve segment and the second mean, and the duration of each curve segment, the fluctuation degree of each curve segment is obtained, the difference between the first mean and the second mean corresponding to each curve segment is positively correlated with the fluctuation degree, the difference between each data in each curve segment and the second mean is positively correlated with the fluctuation degree, and the duration is negatively correlated with the fluctuation degree; The method for obtaining the abnormal heat dissipation curve segment includes: The local heat dissipation degree of each curve segment is normalized. If the local heat dissipation degree of the normalized curve segment is less than a preset heat dissipation threshold, the corresponding curve segment is regarded as an abnormal heat dissipation curve segment; The method for obtaining the overall heat dissipation degree includes: Obtaining the average of the local heat dissipation degrees corresponding to all curve segments at each position as the local average heat dissipation degree; Obtain the difference between the local heat dissipation degree and the local average heat dissipation degree of the heat dissipation abnormality curve segment corresponding to each position; According to the duration, the minimum value at the moment, the degree difference and the local average heat dissipation degree corresponding to each heat dissipation abnormality curve segment at each location, the overall heat dissipation degree at each location is obtained. The minimum value at the moment and the local average heat dissipation degree are both positively correlated with the overall heat dissipation degree, while the duration and degree difference are both negatively correlated with the overall heat dissipation degree. The method for obtaining the heat dissipation similar position group includes: The average value of the overall heat dissipation degree at all positions of the propulsion motor is obtained as the overall average heat dissipation degree; Obtaining the difference in overall heat dissipation between adjacent positions; calculating the ratio of the overall average heat dissipation to the difference as the overall heat dissipation similarity between adjacent positions; Normalize the overall heat dissipation similarity between all adjacent positions. If the overall heat dissipation similarity between adjacent positions after normalization is greater than a preset similarity threshold, take the corresponding position as a similar marked position, obtain the similar marked position of each position, and form multiple heat dissipation similar position groups; The method for obtaining the flow rate requirement includes: According to the changing trend of the overall heat dissipation degree of different positions in different heat dissipation similar position groups, the heat source position and the heat conduction straight line are obtained; For any position, obtain the extreme value of the overall heat dissipation degree in the heat dissipation similar position group where the corresponding position is located; obtain the heat conduction straight line with the smallest distance from the corresponding position, and use the corresponding heat conduction straight line as the target heat conduction straight line; connect the line segment between the heat source position and the corresponding position to obtain the angle between the corresponding line segment and the target heat conduction straight line; According to the extreme value of the heat dissipation similar position group where the corresponding position is located, the relative distance between the corresponding position and the heat source position, the angle, and the overall heat dissipation degree of the corresponding position, the flow velocity requirement of the corresponding position is obtained. The extreme value and the angle are positively correlated with the flow velocity requirement, and the relative distance between the corresponding position and the heat source position and the overall heat dissipation degree are negatively correlated with the flow velocity requirement. The method for obtaining the heat source position and the heat conduction straight line includes: The average of the overall heat dissipation degree of all positions in each heat dissipation similar position group is obtained as the overall heat dissipation level; Select the position with the smallest overall heat dissipation level among all heat dissipation similar position groups, and the position corresponding to the smallest overall heat dissipation level among all heat dissipation similar position groups as the heat source position; Traverse the heat dissipation similar position groups in all directions along the heat source position. If there are at least two heat dissipation similar position groups in a direction, the overall heat dissipation levels decrease in sequence. Connect the position with the largest relative distance to the heat source position in the corresponding direction with the heat source position as a heat conduction straight line. The method for obtaining the flow rate control coefficient includes: Obtain the ratio of the temperature data of each position at each moment to the previous adjacent moment as the local temperature variation degree; The position with the smallest relative distance from the heat source position among the adjacent positions of each position is obtained as the target adjacent position; the difference in flow rate demand between each position and the target adjacent position is obtained, the ratio between the difference result and the average flow rate demand of all positions is calculated, and normalized as the local flow rate demand factor; The speed of the flow rate control device corresponding to each position is obtained, and the flow rate control coefficient of the cooling liquid corresponding to each position at each moment is obtained by combining the local flow rate demand factor of each position and the local temperature change degree at each moment. The local flow rate demand factor, the local temperature change degree and the speed are all positively correlated with the flow rate control coefficient. The method for obtaining the regulated output power includes: Obtain the mean value of the flow rate control coefficients at all locations at the real time as the average flow rate control coefficient; Obtain the difference in the flow rate control coefficient of the cooling liquid at each position between the real time and the previous adjacent time, calculate the ratio between the difference result and the average flow rate control coefficient, and normalize them as the normalized ratio; calculate the sum of the normalized ratio and the positive integer 1 as the local flow rate control weight; The output power of the flow rate control device is weighted according to the local flow rate control weight to obtain the control output power of the flow rate control device corresponding to each position at the real time.

2. A phase change heat dissipation method for a propulsion motor according to claim 1, characterized in that: The method for obtaining the local heat dissipation degree includes: Obtaining the speed data and current data of the propulsion motor in time sequence; obtaining the average speed data and the average current data corresponding to all moments in each curve segment; calculating the ratio of the average current data to the average speed data as a first ratio; Obtain the data difference between the maximum value of the data in each curve segment at each position and the minimum data at the moment in the temperature curve; The ratio of the first mean to the second mean is obtained as the second ratio; the local heat dissipation degree of each curve segment at each position is obtained according to the fluctuation degree of each curve segment, the data difference, the first ratio and the second ratio, the first ratio and the second ratio are positively correlated with the local heat dissipation degree, and the fluctuation degree and the data difference are negatively correlated with the local heat dissipation degree.

3. A phase change heat dissipation system for a propulsion motor, the system comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the phase change heat dissipation method for a propulsion motor as described in any one of claims 1 to 2 are implemented.

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