A method and system for controlling the uniformity of the welding temperature field of a motor stator

Abstract

The present application relates to the technical field of welding control, in particular to a motor stator welding temperature field uniformity control method and system. The method comprises the following steps: S1, according to the circumferential position, axial position and weld position of the motor stator, the motor stator is divided into multiple temperature control areas, and one temperature control area is selected as the first welding area for welding; S2, the initial surface temperature and the environment temperature of each temperature control area are collected, and the surface temperature of each area is continuously collected after the first welding is completed; by constructing a space coordinate system suitable for the cylindrical rotation structure of the stator, the division of the temperature control area is completed according to the circumferential distribution and axial distribution of the weld, the grid discrete management and control of the stator welding temperature field are realized, and the heat propagation characteristics of each area are extracted through the online measurement of the first welding, so that the effective heat transfer range of the welding heat source is quantitatively calibrated.

Description

Technical Field

[0001] This invention relates to the field of welding control technology, and more specifically, to a method and system for controlling the uniformity of the temperature field during motor stator welding. Background Technology

[0002] Stator welding is a key process in motor manufacturing. Its core function is to achieve a fixed connection between the stator core and the frame, as well as between the core laminations, ensuring the overall structural strength, geometric accuracy, and electromagnetic performance stability of the stator.

[0003] Existing stator welding processes are mostly used in mass production of motors. They typically pre-set a fixed welding sequence based on industry experience and generally adopt mature process solutions such as symmetrical welding and segmented alternating welding. They are used in conjunction with special welding fixtures to complete the sequential welding of all stator circumferential and axial welds.

[0004] However, in actual production applications, the process scheme of using a fixed welding sequence cannot dynamically adjust the welding sequence according to the real-time temperature field distribution of the stator. The heat generated during the welding process is continuously conducted to the surrounding area and accumulates, which can easily cause the stator to have excessively high local temperature and uneven temperature field distribution. This can lead to defects such as stator core roundness deviation, uneven axial deformation, and residual thermal stress concentration, which directly affect the dimensional accuracy and electromagnetic performance of the stator. In severe cases, it can also cause thermal damage to the stator insulation layer, significantly reducing the operating safety and service life of the motor. Therefore, a method and system for controlling the uniformity of the welding temperature field of motor stator is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for controlling the uniformity of the welding temperature field of an electric motor stator, so as to solve the problems mentioned in the background art.

[0006] To address the aforementioned technical problems, one objective of this invention is to provide a method for controlling the uniformity of the welding temperature field in an electric motor stator, comprising the following steps: S1. Based on the circumferential position, axial position and weld position of the motor stator, the motor stator is divided into multiple temperature control zones, and one temperature control zone is selected as the first welding zone for welding. S2. Collect the initial surface temperature and ambient temperature of each temperature control zone. After the first welding is completed, continuously collect the surface temperature of each zone. Analyze the heat propagation based on the temperature rise value, temperature rise time and the distance between each zone and the first welding zone to obtain heat propagation data for zones at different distances. S3. Determine the effective heat transfer range based on heat transfer data. Sort the unwelded areas for non-heat transfer welding according to the area spacing and effective heat transfer range to form a basic welding sorting list, so that the spacing between adjacent sorted areas is greater than the effective heat transfer range. S4. After the area welding is completed, the current surface temperature of each unwelded area is collected. The area whose real-time surface temperature is within the preset pre-welding temperature window is determined as the initial candidate area. At the same time, based on the heat transfer data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. S5. Screen out the initial candidate areas where the predicted peak temperature exceeds the preset upper limit of temperature, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to weld in sequence until the welding of all areas is completed.

[0007] As a further improvement to this technical solution, in S1, a stator spatial coordinate system is established with the central axis of the motor stator as the reference, the circumferential angle of the stator represents the position of each weld in the circumferential direction, and the distance from each weld to the preset axial reference plane of the stator represents the position of each weld in the axial direction. Map each weld position to the stator space coordinate system, and determine the region boundary of each temperature control zone based on the circumferential spacing, axial spacing and weld length. One or more welds located within the same preset circumferential angle range and the same preset axial distance range are classified into the same temperature control zone, so that each weld corresponds to a temperature control zone. A temperature control zone is randomly selected as the initial welding zone, and the welding device is controlled to weld the initial welding zone.

[0008] As a further improvement to this technical solution, in S2, the surface temperature of each temperature control area is continuously collected, and the surface temperature before welding is used as the initial surface temperature. At the same time, the ambient temperature is collected by an ambient temperature sensor located on the periphery of the motor stator and not directly exposed to the welding heat source. After the initial welding of the welding area, the surface temperature of each temperature control area is extracted. The surface temperature of each temperature control area is arranged by time according to the sampling time. The initial surface temperature of the corresponding area is subtracted from the arranged temperature time series to obtain the temperature rise value of each temperature control area at different sampling times. The maximum temperature rise, the time corresponding to the maximum temperature rise, the maximum temperature rise per unit time, and the maximum temperature drop per unit time are determined from the temperature time series of the temperature control area. The time difference between the welding start time and the welding end time is determined as the heat propagation delay time. Based on the circumferential distance, axial distance, and spatial distance between the corresponding temperature control area and the first welding area, the heat transfer relationship between the spatial distance and the maximum temperature rise, heat propagation delay time, heating rate, and cooling rate is established as the heat propagation data from the first welding area to the temperature control area. Then, combined with the spatial distance between each temperature control area and the first welding area, the heat propagation data of different distance areas are obtained. The heat transfer data is only established in the region where the temperature rise value of the time series increases at the beginning of welding.

[0009] As a further improvement to this technical solution, in step S3, the maximum distance region is extracted from the heat transfer data, the distance from the first welding area to the maximum distance region is determined as the effective heat transfer distance, and an effective heat transfer range centered on the welding area is formed based on the effective heat transfer distance. The area where the first weld is performed is used as the current sorting area, and a set of unsorted areas containing all unwelded temperature control areas is established. Calculate the spatial distance between each temperature control area in the set of areas to be sorted and the currently sorted area, and determine the ratio of each spatial distance to the effective heat transfer distance corresponding to the currently sorted area. Temperature control regions with spatial distances greater than effective heat transfer distances are identified as candidate regions with no heat transfer. Select the temperature control region with the largest spatial distance from the current sorted region from the candidate regions without heat transfer, and use it as the next sorted region after the current sorted region. Then, delete the next sorted region from the set of regions to be sorted and update it as the current sorted region. Repeat the calculation, judgment, selection and deletion process until all unwelded temperature control regions are sorted to obtain the basic welding sorting list.

[0010] As a further improvement to this technical solution, in S4, during a preset judgment period after the welding of the current temperature control area is completed, multiple frames of surface temperature data of each unwelded temperature control area are continuously acquired. The surface temperature data of multiple frames are arranged according to the acquisition time, and the surface temperature difference between adjacent acquisition times is calculated. Based on the surface temperature difference and the corresponding acquisition time interval, the temperature change rate of each unwelded temperature control area is determined. Determine whether the current surface temperature of the unwelded temperature control area is not lower than the preset pre-welding temperature lower limit and not higher than the preset pre-welding temperature upper limit; Determine whether the rate of temperature change in the unwelded temperature control area is within the preset rate of temperature change range; When all the above judgment results are met, the corresponding unwelded temperature control area is determined as the initial candidate area; If any judgment result is not met, the corresponding temperature control area remains unwelded, and the judgment is re-performed in the next acquisition cycle.

[0011] As a further improvement to this technical solution, in step S4, the current surface temperature of each temperature control area at the prediction start time is combined according to the corresponding area position to form a prediction initial temperature field. Based on the welding power, welding speed, welding time, welding trajectory and welding heat source area used in the initial candidate area, the candidate welding heat input is determined. Based on the data corresponding to the spatial distance and propagation direction of each temperature control zone in the heat propagation data, the predicted temperature rise, predicted propagation delay and predicted heating process after the candidate welding heat input is transferred to each temperature control zone are determined. Based on the current surface temperature, ambient temperature, and cooling rate of each temperature control zone, the predicted heat dissipation temperature drop of each temperature control zone within the preset prediction period is determined. The predicted initial temperature field, predicted temperature rise, and predicted heat dissipation temperature drop are combined in chronological order to obtain the predicted temperature distribution at each prediction time, and the predicted temperature distribution at each prediction time forms the predicted temperature field.

[0012] As a further improvement to this technical solution, in step S4, the predicted surface temperatures of the initial candidate region, the welded region adjacent to the initial candidate region, and the unwelded region adjacent to the initial candidate region are extracted respectively during the prediction period, and the highest predicted surface temperature of each region during the prediction period is determined as the predicted peak temperature corresponding to the initial candidate region. Based on the predicted temperature field, determine the maximum predicted temperature difference between the highest and lowest surface temperatures of each temperature control area at the same predicted time, determine the dispersion of the predicted surface temperature of each temperature control area relative to the average predicted surface temperature of all temperature control areas, determine the predicted temperature difference between circumferentially symmetrical temperature control areas and the predicted temperature difference between axially corresponding temperature control areas based on the circumferential and axial positions of the motor stator, and determine the predicted temperature gradient between adjacent areas based on the spatial distance and predicted temperature difference between adjacent temperature control areas. The predicted maximum temperature difference, dispersion, temperature difference in circumferentially symmetrical regions, temperature difference in axially corresponding regions, and predicted temperature gradient are normalized and weighted, and the processing results are determined as the temperature field uniformity index.

[0013] As a further improvement to this technical solution, in step S5, the initial candidate region whose predicted peak temperature exceeds the preset temperature upper limit is removed from the candidate set; The remaining initial candidate regions in the candidate set are arranged in ascending order of temperature field uniformity index. The initial candidate region at the top of the list is determined as the next welding region, and the welding device is controlled to weld in sequence until all regions are completed.

[0014] The second objective of this invention is to provide a control system for the uniformity of the welding temperature field of an electric motor stator, including any one of the above-mentioned methods for controlling the uniformity of the welding temperature field of an electric motor stator, comprising a data acquisition module, an index determination module, and a welding control module. The data acquisition module is used to divide the motor stator into multiple temperature control zones based on the circumferential position, axial position and weld position of the motor stator, select one temperature control zone as the first welding zone for welding, collect the initial surface temperature and ambient temperature of each temperature control zone, continuously collect the surface temperature of each zone after the first welding is completed, and perform heat propagation analysis based on the temperature rise value, temperature rise time and the distance between each zone and the first welding zone to obtain heat propagation data of zones at different distances. The index determination module is used to determine the effective heat transfer range based on heat propagation data. It sorts the unwelded areas for non-heat transfer welding according to the area spacing and the effective heat transfer range, forming a basic welding sorting list. The spacing between adjacent sorted areas is greater than the effective heat transfer range. When an area is welded, the current surface temperature of each unwelded area is collected. Areas whose real-time surface temperature is within the preset pre-welding temperature window are determined as initial candidate areas. At the same time, based on heat propagation data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. The welding control module is used to screen out initial candidate areas where the predicted peak temperature exceeds the preset temperature upper limit, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to perform welding in sequence until the welding of all areas is completed.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. A method and system for controlling the uniformity of the welding temperature field of an electric motor stator. By constructing a spatial coordinate system adapted to the cylindrical rotating structure of the stator, the temperature control area is divided according to the circumferential and axial distribution of the weld, realizing the gridded discrete control of the stator welding temperature field. The heat propagation characteristics of each area are extracted through online measurement of the first welding, and the effective heat transfer range of the welding heat source is quantified and calibrated. Based on this, a basic welding sequence list without heat transfer interference is generated. From the spatial layout level, it is ensured that there is no heat superposition between adjacent welding areas, suppressing the problem of local heat accumulation from the source and effectively reducing the risk of local overheating of the stator.

[0016] 2. A method and system for controlling the uniformity of the temperature field during stator welding of an electric motor, which sets up a dual admission screening mechanism of pre-welding temperature window and temperature change rate to ensure that the thermal state of each area is stable and consistent before welding; at the same time, combined with measured and calibrated heat propagation law, real-time surface temperature and ambient temperature parameters, it realizes rapid prediction of the temperature field of the entire domain after welding in candidate areas. It does not rely on complex offline finite element calculations and can adapt to the material differences, clamping status and field environmental fluctuations of different stator workpieces. It not only ensures the accuracy of temperature field prediction, but also meets the real-time requirements of industrial online control, and provides reliable data basis for the dynamic optimization of welding sequence. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a method for controlling the uniformity of the welding temperature field of an electric motor stator according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, one of the objectives of this invention is to provide a method for controlling the uniformity of the welding temperature field of an electric motor stator, comprising the following steps: S1. Based on the circumferential position, axial position and weld position of the motor stator, the motor stator is divided into multiple temperature control zones, and one temperature control zone is selected as the first welding zone for welding. In S1, a stator spatial coordinate system is established with the central axis of the motor stator as the reference. The position of each weld in the circumferential direction is represented by the stator circumferential angle, and the position of each weld in the axial direction is represented by the distance from each weld to the stator preset axial reference plane. Using the central axis of the motor stator as the reference axis for spatial positioning, a fixed radial positioning structure on the stator frame is selected as the zero reference for the circumferential angle. The circumferential angle is measured along a single clockwise direction around the stator circumference to characterize the distribution position of each weld in the circumferential direction of the stator.

[0020] The core end face of the stator drive end is selected as the axial reference plane. The axial distance is measured along the direction extending from the stator central axis to the non-drive end. This is used to characterize the distribution position of each weld in the stator axial direction. The coordinate system adopts cylindrical positioning logic, which is fully adapted to the cylindrical shape of the stator. It can achieve unique and unambiguous position calibration for any position on the stator surface.

[0021] Map each weld position to the stator space coordinate system, and determine the region boundary of each temperature control zone based on the circumferential spacing, axial spacing and weld length. For all the welds to be welded on the stator, the physical positions of the start and end points of each weld are determined one by one. The two ends are mapped to the stator spatial coordinate system mentioned above to obtain the circumferential angle value and axial distance value corresponding to each end point.

[0022] Based on the position parameters of the two endpoints, the midpoint position, circumferential coverage area and axial coverage area of ​​each weld are calculated, and the position mapping of all welds in the spatial coordinate system is completed, so that each weld has quantifiable spatial position attributes, providing a positional basis for subsequent area division.

[0023] One or more welds located within the same preset circumferential angle range and the same preset axial distance range are classified into the same temperature control zone, so that each weld corresponds to a temperature control zone. Pre-set circumferential angle range thresholds and axial distance range thresholds as the maximum circumferential coverage scale and maximum axial coverage scale of a single temperature control area. Combined with the circumferential distribution spacing and axial distribution spacing of all welds and the length of a single weld, multiple continuous and non-overlapping temperature control areas are sequentially divided along the circumferential and axial directions, and the corresponding circumferential and axial boundaries of each area are determined.

[0024] After the division is completed, the midpoint position of each weld is checked one by one. One or more welds whose circumferential positions are within the same preset circumferential angle range and whose axial positions are within the same preset axial distance range are assigned to the same temperature control zone. After all welds are collected, the assignment status of each weld is verified to ensure that all welds correspond to a unique temperature control zone, and there are no cases of omissions or duplicate assignments.

[0025] The preset circumferential angle range threshold (15°~45°) can be adjusted according to the stator outer diameter, weld circumferential distribution density, and circumferential width of single weld heat-affected zone. The larger the stator outer diameter, the sparser the circumferential distribution of the weld, and the wider the heat-affected zone of a single weld, the higher the threshold can be; conversely, the threshold should be lowered.

[0026] The preset axial distance range threshold (20mm~80mm) can be adjusted according to the axial length of the stator core, the axial distribution density of the weld, and the axial width of the heat-affected zone of a single weld. The longer the stator core, the sparser the axial distribution of the weld, and the wider the heat-affected zone of a single weld, the higher the threshold can be; conversely, the threshold can be lowered.

[0027] A temperature control zone is randomly selected as the initial welding zone, and the welding device is controlled to weld the initial welding zone.

[0028] After completing the division of all temperature control zones and the collection of weld seams, one zone is randomly selected from all temperature control zones as the first welding zone. The location information and preset welding process parameters of the corresponding zone are sent to the welding device, which is then controlled to move to the weld seam position corresponding to that zone. The welding operation of all weld seams in that zone is completed according to the preset welding power, welding speed and welding trajectory, providing a standardized heat source input for subsequent heat transfer characteristic acquisition.

[0029] S2. Collect the initial surface temperature and ambient temperature of each temperature control zone. After the first welding is completed, continuously collect the surface temperature of each zone. Analyze the heat propagation based on the temperature rise value, temperature rise time and the distance between each zone and the first welding zone to obtain heat propagation data for zones at different distances. In S2, the surface temperature of each temperature control zone is continuously collected, and the surface temperature before welding is used as the initial surface temperature. At the same time, the ambient temperature is collected by an ambient temperature sensor located on the periphery of the motor stator and not directly exposed to the welding heat source. Surface temperature acquisition points are set at the geometric center of each temperature control zone. At the same time, ambient temperature acquisition points are arranged at locations around the motor stator that are far from the welding operation area and not affected by direct radiation and conduction of welding heat sources. Before the first welding start, multiple sets of surface temperature data for each zone are continuously collected. After the values ​​stabilize, the average value is taken as the initial surface temperature of the corresponding zone, and the current ambient temperature is recorded simultaneously as the ambient reference temperature.

[0030] After the initial welding is started, the surface temperature of all temperature-controlled areas is continuously collected at fixed time intervals, and the ambient temperature is collected simultaneously, until the surface temperature of all areas drops back to a stable state close to the initial temperature. During the collection process, all points strictly maintain the synchronization of sampling time to ensure that the time base of subsequent time series analysis is consistent.

[0031] The temperature sampling interval threshold (0.5s~2s) can be adjusted according to the amount of welding heat input and the thermal conductivity of the stator material. The larger the welding heat input and the faster the thermal conductivity of the stator material, the smaller the sampling interval should be to capture the complete temperature rise process, and vice versa to reduce the amount of data processing.

[0032] After the initial welding of the welding area, the surface temperature of each temperature control area is extracted. The surface temperature of each temperature control area is arranged by time according to the sampling time. The initial surface temperature of the corresponding area is subtracted from the arranged temperature time series to obtain the temperature rise value of each temperature control area at different sampling times. For each temperature control zone, the surface temperature data of all sampling times in that zone are arranged sequentially according to the order of sampling time to form the surface temperature time series of that zone.

[0033] Subtract the initial surface temperature value of the region from the surface temperature value at each sampling time in the time series to obtain the temperature rise value of the region at the corresponding sampling time. Arrange the temperature rise values ​​of all sampling times in chronological order to form the temperature rise value time series of the region, which fully characterizes the entire process of temperature change caused by the first welding heat source to the region.

[0034] The maximum temperature rise, the time corresponding to the maximum temperature rise, the maximum temperature rise per unit time, and the maximum temperature drop per unit time are determined from the temperature time series of the temperature control area. The time difference between the welding start time and the welding end time is determined as the heat propagation delay time. For the temperature rise time series of each temperature control zone, the maximum temperature rise value within the entire time period is extracted, and the sampling time corresponding to the maximum temperature rise value is recorded synchronously. The ratio of the temperature rise value difference between adjacent sampling times to the corresponding time interval is calculated to obtain the temperature change rate of each time period. The maximum rate of the heating phase is selected as the maximum temperature rise value per unit time, and the maximum rate of the cooling phase is selected as the maximum temperature drop value per unit time.

[0035] Record the start time of the first weld, and combine it with the end time of the temperature rise corresponding to the maximum temperature rise value in the region. The time difference between the two times is determined as the heat propagation delay time in the region, which is used to characterize the length of time it takes for heat to be conducted from the welded area to the region and reach the peak temperature rise.

[0036] Based on the circumferential distance, axial distance, and spatial distance between the corresponding temperature control area and the first welding area, the heat transfer relationship between the spatial distance and the maximum temperature rise, heat propagation delay time, heating rate, and cooling rate is established as the heat propagation data from the first welding area to the temperature control area. Then, combined with the spatial distance between each temperature control area and the first welding area, the heat propagation data of different distance areas are obtained. The heat transfer data is only established in the region where the temperature rise value of the time series increases at the beginning of welding.

[0037] Based on the established stator spatial coordinate system, the circumferential arc distance and axial straight-line distance between the center point of each temperature control zone and the center point of the initial welding zone are calculated separately. The spatial straight-line distance between the center points of the two zones is then calculated by combining these two measurements. The circumferential distance is calculated along the circumference of the outer cylindrical surface of the stator core, and the axial distance is calculated along a direction parallel to the stator central axis. The spatial distance, taking into account the positional deviations of the circumferential and axial directions, characterizes the actual heat transfer path length between the two zones.

[0038] For all temperature control zones, it is determined whether the temperature rise time series shows a continuous positive upward trend after welding starts. Only the zones with a significant increase in temperature rise are retained as effective heat transfer zones, and the zones that are not affected by the heat source of welding are eliminated.

[0039] For all effective heat transfer zones, the spatial distance between zones is used as the independent variable. A one-to-one correspondence is established with the maximum temperature rise, heat propagation delay time, maximum temperature rise per unit time, and maximum temperature drop per unit time for each zone. This forms a dataset of heat propagation characteristics under different spatial distances, i.e., heat propagation data, which is used to characterize the variation of the amplitude, time, and rate of heat propagation in the stator structure with distance.

[0040] The effective temperature rise determination threshold (0.5℃~2℃) can be adjusted according to the ambient temperature fluctuation range and the temperature sensor measurement accuracy. The greater the ambient temperature fluctuation and the lower the sensor measurement accuracy, the higher the threshold should be to eliminate interference. Conversely, the threshold should be lowered to ensure detection sensitivity. When the temperature rise value is greater than the threshold for no less than 3 consecutive sampling times, it is determined to be an effective heat transfer area with rising temperature value.

[0041] S3. Determine the effective heat transfer range based on heat transfer data. Sort the unwelded areas for non-heat transfer welding according to the area spacing and effective heat transfer range to form a basic welding sorting list, so that the spacing between adjacent sorted areas is greater than the effective heat transfer range. In S3, the maximum distance region is extracted from the heat transfer data, and the distance from the first welding area to the maximum distance region is determined as the effective heat transfer distance. Based on the effective heat transfer distance, an effective heat transfer range centered on the welding area is formed. From all effective heat transfer zones, select the zone with the largest spatial distance from the initial welding zone and denote it as the maximum distance zone.

[0042] The spatial distance from the center point of the first welding area to the center point of the maximum distance area is determined as the effective heat transfer distance. Using this distance as the radius of influence and the center point of the welding area as the center, the coverage area formed in the space of the stator column is the effective heat transfer range corresponding to the welding area.

[0043] Areas within the effective heat transfer range will be significantly affected by heat conduction after welding in those areas; In areas beyond the effective heat transfer range, the heat generated by welding will not cause observable temperature changes.

[0044] The first welded area is used as the current sorting area, and a set of unsorted areas containing all unwelded temperature control areas is established. The first welded area is used as the first area for welding sorting, i.e. the initial current sorting area. All temperature control areas other than the first welded area are included in the set of unsorted areas. The areas in the set are all unwelded areas whose welding order has not yet been determined, providing a candidate pool for subsequent iterative sorting.

[0045] Calculate the spatial distance between each temperature control area in the set of areas to be sorted and the currently sorted area, and determine the ratio of each spatial distance to the effective heat transfer distance corresponding to the currently sorted area. Temperature control regions with spatial distances greater than effective heat transfer distances are identified as candidate regions with no heat transfer. If the spatial distance between regions is greater than the effective heat transfer distance, it is determined that there will be no heat superposition effect when the region and the currently sorted region are welded sequentially, and it is included in the candidate region without heat transfer. If the spatial distance is less than or equal to the effective heat transfer distance, it will be temporarily retained in the unsorted set and will not be included in the candidate range of this round.

[0046] Select the temperature control region with the largest spatial distance from the current sorted region from the candidate regions without heat transfer, and use it as the next sorted region after the current sorted region. Then, delete the next sorted region from the set of regions to be sorted and update it as the current sorted region. Repeat the calculation, judgment, selection and deletion process until all unwelded temperature control regions are sorted to obtain the basic welding sorting list.

[0047] The process of calculating spatial distance, screening candidate areas without heat transfer, selecting the next welding area, and updating the status is repeated. Each time an area is selected, the current sorted area and the set to be sorted are updated until all areas in the set to be sorted are included in the basic welding sorting list. The final complete sorting list is the basic welding sorting list without heat transfer interference, ensuring that the distance between any two adjacent welding areas is greater than the effective heat transfer distance, and that no heat superposition occurs when welding sequentially.

[0048] S4. After the area welding is completed, the current surface temperature of each unwelded area is collected. The area whose real-time surface temperature is within the preset pre-welding temperature window is determined as the initial candidate area. At the same time, based on the heat transfer data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. In S4, during the preset judgment period after the welding of the current temperature control area is completed, multiple frames of surface temperature data of each unwelded temperature control area are continuously acquired. After the welding operation in the current temperature control area is completed, a preset judgment period is started. During this period, multiple frames of surface temperature data of all unwelded temperature control areas are continuously collected at fixed sampling intervals. The temperature collection of all areas is kept in time synchronization to ensure that the time base for subsequent rate calculation is consistent. The preset judgment period is used to reserve sufficient heat diffusion time to avoid candidate judgment during the stage of drastic fluctuation of welding residual heat.

[0049] The preset judgment time threshold (30s~120s) can be adjusted according to the amount of welding heat input and the thermal conductivity of the stator material. The larger the welding heat input and the slower the thermal conductivity, the longer the judgment time should be, and the judgment should be made after the temperature fluctuation tends to be flat. Conversely, the shorter the judgment time should be.

[0050] The surface temperature data of multiple frames are arranged according to the acquisition time, and the surface temperature difference between adjacent acquisition times is calculated. Based on the surface temperature difference and the corresponding acquisition time interval, the temperature change rate of each unwelded temperature control area is determined. According to the order of acquisition time, the multiple frames of surface temperature data of each unwelded area are arranged sequentially to form a temperature time series of a single area.

[0051] The surface temperature difference between two adjacent acquisition times is calculated successively, and the difference is divided by the time interval between the two corresponding times to obtain the temperature change rate in each time interval.

[0052] The average of the temperature change rates of the last few consecutive intervals within the judgment period is taken as the current temperature change rate of the region, which is used to characterize the real-time temperature change trend of the region.

[0053] Determine whether the current surface temperature of the unwelded temperature control area is not lower than the preset pre-welding temperature lower limit and not higher than the preset pre-welding temperature upper limit; Among them, the preset pre-welding temperature lower limit threshold (20℃~40℃) and the preset pre-welding temperature upper limit threshold (60℃~100℃) can be adjusted according to the stator base material, welding process requirements, and temperature resistance level of insulation material. The higher the preheating requirements of the base material and the higher the temperature resistance level of the insulation material, the higher the upper limit of temperature can be appropriately increased. When the ambient temperature is low, the lower limit of temperature can be appropriately increased.

[0054] Determine whether the rate of temperature change in the unwelded temperature control area is within the preset rate of temperature change range; The preset temperature change rate range threshold (-0.5℃ / s~0.5℃ / s) can be adjusted according to the temperature sampling accuracy and the amplitude of welding residual heat fluctuation. The lower the sampling accuracy and the greater the residual heat fluctuation, the wider the rate range can be. When the temperature stability requirement is higher, the rate range can be narrowed appropriately.

[0055] When all the above judgment results are met, the corresponding unwelded temperature control area is determined as the initial candidate area; If any judgment result is not met, the corresponding temperature control area remains unwelded, and the judgment is re-performed in the next acquisition cycle.

[0056] In S4, the current surface temperature of each temperature control area at the start of the prediction is combined according to the corresponding area position to form the initial temperature field of the prediction. Based on the welding power, welding speed, welding time, welding trajectory and welding heat source area used in the initial candidate area, the candidate welding heat input is determined. Using the prediction start time as the time reference, the current surface temperature data of all temperature control areas at that time are extracted and arranged according to the spatial location of each area to form the temperature distribution state of the whole domain, which serves as the initial temperature field for temperature field prediction. The initial temperature field fully reflects the thermal state of the stator at the prediction start point and is the basis for subsequent temperature rise and heat dissipation calculations.

[0057] For each initial candidate region, the heat density input to the region per unit time is calculated by combining the preset welding process parameters, including welding power, welding speed, welding time of a single weld, welding trajectory length, and the effective area of ​​the welding heat source. The total heat input of the region is obtained by combining the total welding time, which serves as the basis for the heat source input in subsequent heat transfer calculations.

[0058] Based on the data corresponding to the spatial distance and propagation direction of each temperature control zone in the heat propagation data, the predicted temperature rise, predicted propagation delay and predicted heating process after the candidate welding heat input is transferred to each temperature control zone are determined. Based on the obtained heat propagation data, the spatial distance and relative propagation direction between each initial candidate region and the other temperature control regions are calculated. The heat transfer characteristic parameters under the corresponding distance and direction are matched from the heat propagation data, including the maximum temperature rise ratio, heat propagation delay time, heating rate and cooling rate.

[0059] By combining the welding heat input magnitude of the candidate regions, the predicted temperature rise amplitude, temperature rise arrival time, and complete temperature rise process curve after the welding heat source is transferred to each region are calculated, characterizing the thermal impact of the welding heat source on all regions of the entire area. The formula is as follows: ; Where Q0 is the heat input for the first weld, c is the candidate weld area, and d c ,k is the spatial distance between the k-th region and candidate region c, ΔT max,ref (d c (k) represents the distance d obtained by matching the heat transfer data. c ,k corresponds to the maximum reference temperature rise value, T pred,kAs the reference thermal propagation delay time, T ref (d c (k) represents the predicted maximum temperature rise and predicted heat propagation delay time for the k-th region; Based on the current surface temperature, ambient temperature, and cooling rate of each temperature control zone, the predicted heat dissipation temperature drop of each temperature control zone within the preset prediction period is determined. Based on the current surface temperature and real-time ambient temperature of each temperature control zone, as well as the temperature drop rate characteristics of each zone measured by S2, and combined with the temperature difference driving characteristics of the heat dissipation process, the natural heat dissipation temperature drop process of each zone under the condition of no new heat source input is calculated within the preset prediction period. The heat dissipation temperature drop is positively correlated with the difference between the current temperature of the zone and the ambient temperature. The larger the temperature difference, the faster the heat dissipation rate and the greater the temperature drop.

[0060] The preset prediction time threshold (10s~60s) can be adjusted according to the welding duration of a single area and the temperature sampling cycle. The longer the welding duration of a single area, the longer the prediction time should be to cover the complete welding and temperature rise peak process, and vice versa.

[0061] The predicted initial temperature field, predicted temperature rise, and predicted heat dissipation temperature drop are combined in chronological order to obtain the predicted temperature distribution at each prediction time, and the predicted temperature distribution at each prediction time forms the predicted temperature field.

[0062] According to the chronological order, the predicted initial temperature field is used as the temperature reference for each moment. The predicted temperature rise value generated by the candidate welding heat source at the corresponding moment is superimposed, and the natural heat dissipation temperature drop value at the corresponding moment is deducted. The predicted surface temperature of each temperature control area at each predicted moment is calculated point by point. The global temperature distribution of all predicted moments is combined in chronological order to form the complete predicted temperature field corresponding to the welding of the initial candidate area.

[0063] In S4, the predicted surface temperatures of the initial candidate region, the welded region adjacent to the initial candidate region, and the unwelded region adjacent to the initial candidate region are extracted respectively within the prediction period. The highest predicted surface temperature of each region within the prediction period is determined and identified as the predicted peak temperature corresponding to the initial candidate region. For each initial candidate region, the predicted surface temperature data of three types of regions are extracted during the entire prediction period: the initial candidate region itself, the welded regions adjacent to the initial candidate region in the circumferential and axial directions, and the unwelded regions adjacent to the initial candidate region.

[0064] The highest predicted surface temperature of each type of region during the prediction period is determined, and the maximum value among the highest temperatures of the three types of regions is taken as the predicted peak temperature corresponding to the initial candidate region, which is used to characterize the highest temperature level that may be reached locally after welding.

[0065] Based on the predicted temperature field, determine the maximum predicted temperature difference between the highest and lowest surface temperatures of each temperature control area at the same predicted time, determine the dispersion of the predicted surface temperature of each temperature control area relative to the average predicted surface temperature of all temperature control areas, determine the predicted temperature difference between circumferentially symmetrical temperature control areas and the predicted temperature difference between axially corresponding temperature control areas based on the circumferential and axial positions of the motor stator, and determine the predicted temperature gradient between adjacent areas based on the spatial distance and predicted temperature difference between adjacent temperature control areas. For each prediction time within the prediction period, the maximum and minimum predicted surface temperatures of all temperature control areas at that time are statistically analyzed, and the difference between the two is calculated to obtain the global maximum temperature difference at that time. The maximum value of the global maximum temperature difference at all times throughout the entire prediction period is taken as the final predicted maximum temperature difference, which is used to characterize the overall deviation of the stator's global temperature distribution.

[0066] For each prediction time, first calculate the average predicted surface temperature of all temperature control areas at that time, then calculate the degree of deviation of the temperature of each area from the average value to obtain the temperature standard deviation at that time. Take the maximum value of the temperature standard deviation of all times in the entire prediction period as the global temperature dispersion, which is used to characterize the overall dispersion state of the temperature of each area relative to the average level.

[0067] Based on the stator spatial coordinate system, for each set of temperature control regions that are centrally symmetrical about the stator central axis, the predicted surface temperature difference between the two symmetrical regions at the same prediction time is calculated to obtain the circumferential symmetrical temperature difference.

[0068] For each group of corresponding regions located at the same circumferential angle but different axial positions, the temperature difference at the same moment is calculated to obtain the axial corresponding temperature difference. The maximum value of all circumferential symmetrical temperature differences and the maximum value of all axial corresponding temperature differences within the prediction period are taken as the temperature difference index of the circumferential symmetrical region and the temperature difference index of the axial corresponding region, which are used to characterize the temperature consistency of the symmetrical position of the stator structure.

[0069] For all temperature control regions that are adjacent in the circumferential or axial direction, the predicted surface temperature difference between two adjacent regions at the same prediction time is calculated. The difference is divided by the spatial distance between the center points of the two regions to obtain the temperature gradient of the adjacent region pair. The maximum value of the temperature gradient of all adjacent region pairs during the prediction period is taken as the predicted temperature gradient index, which is used to characterize the degree of temperature change between local regions. The larger the gradient, the higher the risk of local thermal stress.

[0070] The predicted maximum temperature difference, dispersion, temperature difference in circumferentially symmetrical regions, temperature difference in axially corresponding regions, and predicted temperature gradient are normalized and weighted, and the processing results are determined as the temperature field uniformity index.

[0071] Five indicators—predicted maximum temperature difference, temperature dispersion, temperature difference in circumferentially symmetrical regions, temperature difference in axially corresponding regions, and predicted temperature gradient—were normalized to map the values ​​of each indicator to the range of 0 to 1, eliminating the influence of different dimensions and numerical ranges. Based on the degree of influence of each indicator on the stator welding quality, corresponding weight coefficients were set. The five normalized indicators were multiplied by their corresponding weights and then summed to obtain a single temperature field uniformity index. The smaller the value of this index, the better the temperature field uniformity of the stator after welding.

[0072] The weighting coefficients for each indicator are: predicted maximum temperature difference (0.25~0.35), temperature dispersion (0.2~0.3), temperature difference in circumferential symmetrical region (0.15~0.25), temperature difference in axial corresponding region (0.1~0.2), and predicted temperature gradient (0.1~0.2). The sum of all weights is 1. These weights can be adjusted according to the focus of stator welding deformation control. When the overall deformation control requirements are high, the weights of predicted maximum temperature difference and dispersion are increased; when the symmetry accuracy requirements are high, the weights of circumferential and axial symmetrical temperature differences are increased.

[0073] S5. Screen out the initial candidate areas where the predicted peak temperature exceeds the preset upper limit of temperature, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to weld in sequence until the welding of all areas is completed.

[0074] In S5, the initial candidate regions whose predicted peak temperature exceeds the preset temperature upper limit are removed from the candidate set; A maximum allowable temperature limit for the stator surface during welding is pre-set as a safety threshold for judging local overheating. For each initial candidate region, the corresponding predicted peak temperature value is retrieved and compared with the preset temperature limit. If the predicted peak temperature of an initial candidate region exceeds the preset temperature limit, it is determined that welding in that region under the current thermal state will cause the local temperature to exceed the process allowable range, posing a risk of thermal damage to the insulation layer, deterioration of silicon steel sheet iron loss, changes in the microstructure and properties of the base material, or excessive welding deformation. The region is directly removed from the candidate set and is not included in the subsequent optimal region selection. After the screening is completed, the remaining candidate regions all meet the peak temperature safety constraints and can participate in the subsequent uniformity ranking.

[0075] The preset upper temperature limit (120℃~180℃) can be adjusted according to the temperature resistance level of the stator insulation material, the iron loss degradation temperature of the silicon steel sheet, and the maximum allowable welding temperature of the base material. The higher the insulation level, the better the heat resistance of the silicon steel sheet, and the stronger the high temperature mechanical properties of the base material, the higher the upper temperature limit can be appropriately increased. The higher the requirement for welding deformation control accuracy and the weaker the temperature resistance of the insulation material, the lower the upper temperature limit should be appropriately decreased.

[0076] The remaining initial candidate regions in the candidate set are arranged in ascending order of temperature field uniformity index. The initial candidate region at the top of the list is determined as the next welding region, and the welding device is controlled to weld in sequence until all regions are completed.

[0077] For all regions within the qualified candidate set, they are arranged in ascending order according to their respective temperature field uniformity index values. The smaller the temperature field uniformity index value, the more balanced the temperature distribution of the entire stator after welding, and the better the control effect of overall thermal deformation and residual thermal stress. The candidate region ranked first is determined as the next welding region, that is, the optimal welding position under the current thermal state.

[0078] After determining the next welding area, the location information and corresponding welding process parameters of the area are sent to the welding device. The welding device is then controlled to move to the target area and complete the welding operation of all welds in the area according to the preset welding power, welding speed and travel trajectory.

[0079] The second objective of this invention is to provide a control system for the uniformity of the welding temperature field of an electric motor stator, including a method for controlling the uniformity of the welding temperature field of an electric motor stator, comprising any one of the above-mentioned methods, including a data acquisition module, an index determination module, and a welding control module. The data acquisition module is used to divide the motor stator into multiple temperature control zones based on the circumferential position, axial position, and weld position of the motor stator. One temperature control zone is selected as the first welding zone for welding. The initial surface temperature and ambient temperature of each temperature control zone are collected. After the first welding is completed, the surface temperature of each zone is continuously collected. Heat propagation analysis is performed based on the temperature rise value, temperature rise time, and distance between each zone and the first welding zone to obtain heat propagation data for zones at different distances. The index determination module is used to determine the effective heat transfer range based on heat transfer data. It sorts the unwelded areas for non-heat transfer welding according to the area spacing and the effective heat transfer range, forming a basic welding sorting list. The spacing between adjacent sorted areas is greater than the effective heat transfer range. When an area is welded, the current surface temperature of each unwelded area is collected. Areas whose real-time surface temperature is within the preset pre-weld temperature window are determined as initial candidate areas. At the same time, based on heat transfer data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. The welding control module is used to screen out initial candidate areas where the predicted peak temperature exceeds the preset upper limit of temperature, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to perform welding in sequence until the welding of all areas is completed.

[0080] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the uniformity of the welding temperature field of an electric motor stator, characterized in that: Includes the following steps: S1. Based on the circumferential position, axial position and weld position of the motor stator, the motor stator is divided into multiple temperature control zones, and one temperature control zone is selected as the first welding zone for welding. S2. Collect the initial surface temperature and ambient temperature of each temperature control zone. After the first welding is completed, continuously collect the surface temperature of each zone. Analyze the heat propagation based on the temperature rise value, temperature rise time and the distance between each zone and the first welding zone to obtain heat propagation data for zones at different distances. S3. Determine the effective heat transfer range based on heat transfer data. Sort the unwelded areas for non-heat transfer welding according to the area spacing and effective heat transfer range to form a basic welding sorting list, so that the spacing between adjacent sorted areas is greater than the effective heat transfer range. S4. After the area welding is completed, the current surface temperature of each unwelded area is collected. The area whose real-time surface temperature is within the preset pre-welding temperature window is determined as the initial candidate area. At the same time, based on the heat transfer data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. S5. Screen out the initial candidate areas where the predicted peak temperature exceeds the preset upper limit of temperature, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to weld in sequence until the welding of all areas is completed.

2. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In S1, a stator spatial coordinate system is established with the central axis of the motor stator as the reference. The position of each weld in the circumferential direction is represented by the stator circumferential angle, and the position of each weld in the axial direction is represented by the distance from each weld to the stator preset axial reference plane. Map each weld position to the stator space coordinate system, and determine the region boundary of each temperature control zone based on the circumferential spacing, axial spacing and weld length. One or more welds located within the same preset circumferential angle range and the same preset axial distance range are classified into the same temperature control zone, so that each weld corresponds to a temperature control zone. A temperature control zone is randomly selected as the initial welding zone, and the welding device is controlled to weld the initial welding zone.

3. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In S2, the surface temperature of each temperature control area is continuously collected, and the surface temperature before welding is used as the initial surface temperature. At the same time, the ambient temperature is collected by an ambient temperature sensor located on the periphery of the motor stator and not directly exposed to the welding heat source. After the initial welding of the welding area, the surface temperature of each temperature control area is extracted. The surface temperature of each temperature control area is arranged by time according to the sampling time. The initial surface temperature of the corresponding area is subtracted from the arranged temperature time series to obtain the temperature rise value of each temperature control area at different sampling times. The maximum temperature rise, the time corresponding to the maximum temperature rise, the maximum temperature rise per unit time, and the maximum temperature drop per unit time are determined from the temperature time series of the temperature control area. The time difference between the welding start time and the welding end time is determined as the heat propagation delay time. Based on the circumferential distance, axial distance, and spatial distance between the corresponding temperature control area and the first welding area, the heat transfer relationship between the spatial distance and the maximum temperature rise, heat propagation delay time, heating rate, and cooling rate is established as the heat propagation data from the first welding area to the temperature control area. Then, combined with the spatial distance between each temperature control area and the first welding area, the heat propagation data of different distance areas are obtained. The heat transfer data is only established in the region where the temperature rise value of the time series increases at the beginning of welding.

4. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In step S3, the maximum distance region is extracted from the heat transfer data, the distance from the first welding area to the maximum distance region is determined as the effective heat transfer distance, and an effective heat transfer range centered on the welding area is formed based on the effective heat transfer distance. The area where the first weld is performed is used as the current sorting area, and a set of unsorted areas containing all unwelded temperature control areas is established. Calculate the spatial distance between each temperature control area in the set of areas to be sorted and the currently sorted area, and determine the ratio of each spatial distance to the effective heat transfer distance corresponding to the currently sorted area. Temperature control regions with spatial distances greater than effective heat transfer distances are identified as candidate regions with no heat transfer. Select the temperature control region with the largest spatial distance from the current sorted region from the candidate regions without heat transfer, and use it as the next sorted region after the current sorted region. Then, delete the next sorted region from the set of regions to be sorted and update it as the current sorted region. Repeat the calculation, judgment, selection and deletion process until all unwelded temperature control regions are sorted to obtain the basic welding sorting list.

5. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In step S4, during a preset judgment period after the welding of the current temperature control area is completed, multiple frames of surface temperature data of each unwelded temperature control area are continuously acquired. The surface temperature data of multiple frames are arranged according to the acquisition time, and the surface temperature difference between adjacent acquisition times is calculated. Based on the surface temperature difference and the corresponding acquisition time interval, the temperature change rate of each unwelded temperature control area is determined. Determine whether the current surface temperature of the unwelded temperature control area is not lower than the preset pre-welding temperature lower limit and not higher than the preset pre-welding temperature upper limit; Determine whether the rate of temperature change in the unwelded temperature control area is within the preset rate of temperature change range; When all the above judgment results are met, the corresponding unwelded temperature control area is determined as the initial candidate area; If any judgment result is not met, the corresponding temperature control area remains unwelded, and the judgment is re-performed in the next acquisition cycle.

6. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In S4, the current surface temperature of each temperature control area at the start of the prediction is combined according to the corresponding area position to form the prediction initial temperature field. The candidate welding heat input is determined based on the welding power, welding speed, welding time, welding trajectory and welding heat source area used in the initial candidate area. Based on the data corresponding to the spatial distance and propagation direction of each temperature control zone in the heat propagation data, the predicted temperature rise, predicted propagation delay and predicted heating process after the candidate welding heat input is transferred to each temperature control zone are determined. Based on the current surface temperature, ambient temperature, and cooling rate of each temperature control zone, the predicted heat dissipation temperature drop of each temperature control zone within the preset prediction period is determined. The predicted initial temperature field, predicted temperature rise, and predicted heat dissipation temperature drop are combined in chronological order to obtain the predicted temperature distribution at each prediction time, and the predicted temperature distribution at each prediction time forms the predicted temperature field.

7. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In step S4, the predicted surface temperatures of the initial candidate region, the welded region adjacent to the initial candidate region, and the unwelded region adjacent to the initial candidate region are extracted during the prediction period, and the highest predicted surface temperature of each region during the prediction period is determined as the predicted peak temperature corresponding to the initial candidate region. Based on the predicted temperature field, determine the maximum predicted temperature difference between the highest and lowest surface temperatures of each temperature control area at the same predicted time, determine the dispersion of the predicted surface temperature of each temperature control area relative to the average predicted surface temperature of all temperature control areas, determine the predicted temperature difference between circumferentially symmetrical temperature control areas and the predicted temperature difference between axially corresponding temperature control areas based on the circumferential and axial positions of the motor stator, and determine the predicted temperature gradient between adjacent areas based on the spatial distance and predicted temperature difference between adjacent temperature control areas. The predicted maximum temperature difference, dispersion, temperature difference in circumferentially symmetrical regions, temperature difference in axially corresponding regions, and predicted temperature gradient are normalized and weighted, and the processing results are determined as the temperature field uniformity index.

8. The method for controlling the uniformity of the welding temperature field of an electric motor stator according to claim 1, characterized in that: In step S5, the initial candidate regions whose predicted peak temperature exceeds the preset temperature upper limit are removed from the candidate set; The remaining initial candidate regions in the candidate set are arranged in ascending order of temperature field uniformity index. The initial candidate region at the top of the list is determined as the next welding region, and the welding device is controlled to weld in sequence until all regions are completed.

9. A temperature field uniformity control system for motor stator welding, used to implement the temperature field uniformity control method for motor stator welding as described in any one of claims 1-8, characterized in that: It includes a data acquisition module, an indicator determination module, and a welding control module; The data acquisition module is used to divide the motor stator into multiple temperature control zones based on the circumferential position, axial position and weld position of the motor stator, select one temperature control zone as the first welding zone for welding, collect the initial surface temperature and ambient temperature of each temperature control zone, continuously collect the surface temperature of each zone after the first welding is completed, and perform heat propagation analysis based on the temperature rise value, temperature rise time and the distance between each zone and the first welding zone to obtain heat propagation data of zones at different distances. The index determination module is used to determine the effective heat transfer range based on heat propagation data. It sorts the unwelded areas for non-heat transfer welding according to the area spacing and the effective heat transfer range, forming a basic welding sorting list. The spacing between adjacent sorted areas is greater than the effective heat transfer range. When an area is welded, the current surface temperature of each unwelded area is collected. Areas whose real-time surface temperature is within the preset pre-welding temperature window are determined as initial candidate areas. At the same time, based on heat propagation data, real-time surface temperature, ambient temperature and preset welding parameters, the temperature field after welding of each initial candidate area is predicted, and the predicted peak temperature and temperature field uniformity index are determined. The welding control module is used to screen out initial candidate areas where the predicted peak temperature exceeds the preset temperature upper limit, select the area with the smallest temperature field uniformity index from the remaining areas as the next welding area, and then control the welding device to perform welding in sequence until the welding of all areas is completed.

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