Magnetizing system of permanent magnet motor rotor

Abstract

The magnetizing system comprises a tray, a positioning chuck, a tip cone piece and a magnetizing head, a magnetic induction unit is arranged in the magnetizing head, the rotor is driven by the positioning chuck to rotate, the tip cone piece abuts against the other end of the rotor, the system comprises a parameter initialization module, a magnetizing parameter database is loaded, and initial parameters are preset; the magnetizing simulation calculation module is used for obtaining pre-estimated parameters such as magnetizing time through finite element simulation based on the magnetic induction intensity; the magnetic uniformity detection module is used for monitoring and calculating the magnetizing uniformity in real time; and the parameter dynamic regulation and control module is used for regulating the rotating speed of the rotor according to the uniformity and regulating and controlling the magnetizing current through a temperature sensor and a mapping model. The problems that in the magnetizing process of an existing permanent magnet motor rotor, magnetizing uniformity is insufficient, a real-time monitoring and dynamic adjusting mechanism is lacked, and the magnetizing quality is unstable and positioning precision is poor due to the fact that the magnetizing quality is prone to being affected by temperature are solved.

Description

TECHNICAL FIELD

[0001] The application relates to the magnetizing and detecting field of a permanent magnet motor rotor, in particular to a permanent magnet motor rotor magnetizing system. BACKGROUND

[0002] With the rapid development of permanent magnet motor technology, the requirements for rotor magnetizing systems are increasing. At present, there is still a lack of effective real-time detection means in the rotor magnetizing process. Only the overall magnetic flux detection is carried out after magnetizing is completed, and the magnetizing uniformity of different points on the rotor circumferential surface cannot be accurately evaluated. This limitation may lead to insufficient or over-magnetization in some areas, thereby affecting the overall performance and reliability of the motor.

[0003] After searching, a permanent magnet motor rotor automatic magnetizing and detecting system (CN106602807B) was disclosed on September 12, 2023. The patent combines a stacking robot and multiple magnetizing and detecting tables to realize automatic magnetization and surface magnetic detection of the rotor, and places the rotor according to the detection results. However, this technical solution mainly focuses on the overall surface magnetic detection of the rotor by a magnetic flux measuring instrument after magnetization is completed, and fails to realize real-time monitoring during the magnetizing process. Therefore, it cannot timely adjust the magnetizing parameters to ensure the magnetizing uniformity.

[0004] After searching, a permanent magnet motor rotor magnetizing device and method (CN115346755B) was disclosed on March 31, 2023. The patent designs a magnetizing winding composed of multiple sub-windings in series to realize the simultaneous generation of a multi-pole magnetic field, and reduces mechanical stress by designing adjacent magnetic fields with opposite directions. Although this technical solution can effectively reduce demagnetization risk and improve magnetizing efficiency, it does not involve real-time monitoring function during the magnetizing process, and it is difficult to ensure that the magnetizing state of each magnetic pole reaches the ideal level. At the same time, the control accuracy of the pulse current of the device is relatively high, and improper control may lead to uneven local magnetic field distribution, thereby affecting the motor performance.

[0005] In summary, the existing permanent magnet motor rotor magnetizing system still has certain deficiencies in real-time detection, magnetizing uniformity guarantee, and equipment cost control. Therefore, the present application provides a new permanent magnet motor rotor magnetizing system, which aims to optimize the magnetizing process by introducing real-time detection and dynamic regulation mechanisms, improve the magnetizing uniformity and motor performance, simplify the equipment structure to reduce production costs, and meet the needs of modern industry for efficient and reliable permanent magnet motors. SUMMARY

[0006] In view of the deficiencies of the prior art, the permanent magnet motor rotor magnetizing system aims to provide a permanent magnet motor rotor magnetizing system, which solves the problems of insufficient magnetizing uniformity, lack of real-time monitoring and dynamic adjustment mechanism, unstable magnetizing quality caused by temperature influence, and poor positioning accuracy in the existing permanent magnet motor rotor magnetizing process through the connection of modules and sensors.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A permanent magnet motor rotor magnetizing system, comprising a tray, a positioning chuck and a top cone, the tray is fixedly connected with a magnetizing head, the magnetizing head is placed with a rotor, one shaft end of the rotor passes through the magnetizing head and the tray and is connected with the positioning chuck located on the side of the tray away from the magnetizing head, the top cone is pressed on the other shaft end of the rotor, the positioning chuck can rotate to drive the rotor to rotate, and the magnetizing head is further provided with a magnetic induction unit;

[0009] Further comprising:

[0010] A parameter initialization module loads a magnetizing parameter database corresponding to the rotor model, and presets initialization parameters, the initialization parameters including a magnetizing target magnetic flux, a rotor initial rotation rate and a magnetizing current initial value;

[0011] A magnetizing simulation calculation module acquires the magnetic induction intensity collected by the magnetic induction unit, calculates a magnetic flux change rate according to the magnetic induction intensity, and obtains estimated parameters by precomputing the magnetizing process through a finite element simulation model with the magnetic flux value and the magnetizing target magnetic flux, the estimated parameters including a magnetizing time, a magnetizing current output and a rotor rotation rate matching value;

[0012] A magnetic uniformity detection module monitors the magnetic induction intensity in the magnetizing process with the estimated parameters as a reference in real time, calculates a real-time magnetic flux through the magnetic induction intensity, and calculates the uniformity according to the magnetic flux distribution;

[0013] A parameter dynamic regulation module dynamically regulates the rotor rotation rate according to the uniformity.

[0014] Further, the magnetizing head is provided with a temperature sensor, the parameter initialization module further comprises a temperature safety threshold, and further comprises a mapping model construction module and a temperature processing module,

[0015] The mapping model construction module loads a magnetizing historical current data set and a corresponding temperature data set corresponding to the current rotor model in the magnetizing parameter database, and constructs a current-temperature mapping relationship model based on the historical current data set and the temperature data set;

[0016] The temperature processing module acquires a real-time temperature value inside the magnetizing head collected by the temperature sensor, compares the real-time temperature value with a temperature safety threshold, and outputs an adjusted magnetizing current value through a mapping relationship model if the real-time temperature value is greater than the temperature safety threshold.

[0017] Further, the mapping model construction module includes a construction strategy, which includes constructing an initial current-temperature relationship model by polynomial regression algorithm from the historical current data set and the corresponding temperature data set, solving the regression coefficients of the initial relationship model by least square method to obtain a minimization objective function, and synchronously introducing a regularization term to correct the objective function to obtain the mapping relationship model.

[0018] Further, the magnetic uniformity detection module includes a uniformity calculation strategy, which includes defining the magnetic induction unit setting position as a monitoring point, calculating the average value and standard deviation of the detection point magnetic flux in the rotor circumferential direction, and evaluating the magnetizing uniformity by the coefficient of variation.

[0019] Further, the magnetizing simulation calculation module includes a simulation strategy, which includes calling the B-H curve of the rotor material, inputting the initial magnetic flux and the magnetizing target magnetic flux, calculating the magnetizing time through current-magnetic flux conversion, calculating the magnetizing current output through the magnetic circuit Ohm's law and the coil voltage formula, calculating the rotor rotation rate matching value according to the number of rotor magnetic poles, and correcting the magnetizing time, magnetizing current output and rotor rotation rate matching value through the finite element simulation model.

[0020] Further, the parameter dynamic adjustment module further includes a dynamic adjustment strategy, which includes a to-be-compensated area positioning step and a rotation speed adjustment step.

[0021] The to-be-compensated area positioning step regards the area between two adjacent magnetic induction units on the rotor as a magnetizing area, determines that a region is a substandard region when the magnetic flux difference between adjacent magnetizing regions or the magnetic flux of a certain region does not reach a preset threshold, obtains the current angle position of the rotor through the encoder, and calculates the angle range corresponding to the substandard region.

[0022] The rotation speed adjustment step reduces the rotation speed according to the magnetic flux of the region when the rotor rotates to the angle range, and the rotation speed reduction amplitude is positively correlated with the substandard degree, and restores to the initial rotation speed when the rotor rotates out of the substandard range.

[0023] Further, the dynamic adjustment strategy further includes a current adjustment step.

[0024] The current adjusting step calculates the magnetizing time prolonged due to the reduced speed of the non-standard area, determines the magnetizing time shortened for other standard areas according to the prolonged magnetizing time, and increases the magnetizing current output in the standard area to shorten the magnetizing time of the area to the magnetizing time estimated by the magnetizing simulation calculation module.

[0025] Further, the rack is vertically arranged, the vertical slide is arranged on the rack, the tray is slidably connected to the vertical slide, the horizontal slide is arranged on the rack, and the top cone is slidably connected to the horizontal slide.

[0026] Further, the top cone comprises a top cone head and a visual sensor, and further comprises an image acquisition module and a top cone positioning module.

[0027] The image acquisition module acquires an image of the rotor shaft end face collected by the visual sensor as a top image.

[0028] The top cone positioning module performs image preprocessing on the top image, identifies the center point of the rotor shaft end face, constructs a space coordinate system with the center point in the top image, calculates the moving position of the top cone head in the space coordinate system according to the visual sensor and the vertex point of the top cone head, and makes the vertex point of the top cone head located directly above the center point of the rotor shaft end face.

[0029] The beneficial effects of the present application are as follows: 1. By integrating the magnetic induction unit and the magnetic uniformity detection module, the system can monitor the magnetic flux change in the magnetizing process in real time, combine the parameter benchmark pre-calculated by the finite element simulation model, realize dynamic evaluation of the magnetic flux distribution on the rotor circumferential surface, solve the problem of relying on post-detection and failing to timely find local uneven magnetization in traditional magnetizing technology, and the parameter dynamic regulation module can adjust the rotor rotation rate in real time according to the uniformity, prolong the magnetizing time by reducing the speed for the non-standard area, and simultaneously adjust the current in the standard area to balance the overall magnetizing efficiency, which not only ensures the magnetizing uniformity, but also avoids the redundant time consumption of the overall process.

[0030] 2. The present application has comprehensive self-adaptive adjustment capability and can effectively cope with the interference of complex working conditions. The temperature processing module can dynamically adjust the current when the temperature of the magnetizing head exceeds the limit by constructing a mapping relationship model of current and temperature, thereby avoiding the influence of high temperature on the performance of the magnetizing head and the magnetic performance of the rotor. The visual positioning system of the top cone realizes the precise alignment of the top cone head and the rotor shaft end through image recognition and space coordinate calculation, guarantees the stability of the rotor in high-speed rotation, and the cooperation of software and hardware not only improves the consistency of magnetizing quality, but also enhances the adaptability of the system to different types of rotors, so that the diversified production demands can be met without frequent tool replacement. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 This is a system module connection diagram in this invention;

[0032] Figure 2 This is a structural diagram of the magnetization mechanism in this invention;

[0033] Figure 3 This is a flowchart of the overall workflow of this invention.

[0034] Auxiliary markings: 1. Frame; 2. Tray; 3. Positioning chuck; 4. Top cone; 5. Magnetizing head; 6. Rotor; 7. Vertical slide; 8. Horizontal slide. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0036] Existing permanent magnet motor rotor 6 magnetization systems still have certain shortcomings in terms of real-time detection, magnetization uniformity assurance, and equipment cost control. Therefore, this invention provides a novel permanent magnet motor rotor 6 magnetization system, which aims to optimize the magnetization process by introducing a real-time detection and dynamic control mechanism, improve magnetization uniformity and motor performance, and simplify the equipment structure to reduce production costs, thereby meeting the needs of modern industry for high-efficiency and reliable permanent magnet motors.

[0037] Specifically, such as Figure 2 As shown, the device includes a frame 1, a tray 2, a positioning chuck 3, and a top cone 4. The frame 1 is vertically arranged and has a vertical slide rail 7. The tray 2 is slidably connected to the vertical slide rail 7. The frame 1 also has a horizontal slide 8, and the top cone 4 is slidably connected to the horizontal slide 8. The horizontal slide 8 is slidably connected to the vertical slide rail 7. A magnetizing head 5 is fixedly connected to the tray 2. The rotor 6 of the permanent magnet motor is placed vertically in the positioning hole of the magnetizing head 5. One shaft end of the rotor 6 passes through the magnetizing head 5 and the tray 2, and is magnetized against the tray 2. The positioning chuck 3 is connected to one side of the head 5. The top cone of the top cone 4 presses against the other shaft end of the rotor 6. It needs to press against the center point of the shaft end face of the rotor 6. The pressure is monitored in real time by a pressure sensor to ensure that the pressure is maintained within the preset range, so as to avoid excessive pressure causing deformation of the rotor 6 or excessive looseness causing rotational deviation. The positioning chuck 3 can rotate to drive the rotor 6 to rotate. A circular grating encoder can be set on the positioning chuck 3 to realize the angular positioning of the rotor 6. The magnetizing head 5 is also equipped with a magnetic induction unit for detecting the magnetic flux of the internal rotor 6.

[0038] Top cone component 4 includes a top cone head and a vision sensor, such asFigure 3 As shown, the system includes an image acquisition module and a apex cone positioning module.

[0039] The image acquisition module acquires images of the rotor's 6-axis end face captured by the vision sensor as the images to be displayed.

[0040] The top cone positioning module performs image preprocessing based on the image to be topped and identifies the center point of the rotor's 6-axis end face. It constructs a spatial coordinate system based on the center point in the image to be topped and calculates the movement position of the top cone head in the spatial coordinate system based on the vision sensor and the apex point of the top cone head, so that the apex point of the top cone head is located directly above the center point of the rotor's 6-axis end face.

[0041] like Figure 1 As shown, the system also includes:

[0042] The parameter initialization module loads the magnetization parameter database corresponding to rotor model 6, and presets initialization parameters, including the target magnetization flux φ. target The initial rotational speed ω0 of rotor 6 and the initial value of magnetizing current I0.

[0043] The magnetization mechanism is started according to the initialization parameters. Specifically, the magnetization mechanism's IPC sends a start command, and the positioning chuck 3 is driven by a servo motor to rotate the rotor 6. The rotor 6 speed is collected in real time by a circular grating encoder, and a PID closed-loop control algorithm is used to maintain the target speed. The PID control algorithm is as follows:

[0044]

[0045] Where u(t) is the output voltage of the servo motor, and e(t) = ω target -ω(t) represents the rotational speed deviation, K p K is the proportionality coefficient. i K is the integral coefficient. d The coefficient is the differential coefficient; at the same time, the top cone 4 maintains stable pressure through pressure feedback closed-loop control, avoiding displacement caused by axial force fluctuations when the rotor 6 rotates.

[0046] The magnetization simulation module simulates the magnetization process based on a finite element model (FEM). The model is grounded in Maxwell's equations and incorporates the magnetic properties of the rotor 6 material (such as the BH curve, remanence, and coercivity) and the structural parameters of the magnetizing head 5 (coil turns, geometric dimensions, and core permeability) to construct a three-dimensional electromagnetic field simulation space. Specifically, the model discretizes the physical structures of the magnetizing head 5 and rotor 6 into a finite number of mesh elements. By solving for the distribution of magnetic field strength H, magnetic induction intensity B, and magnetic flux Φ in each element, the dynamic changes of the magnetic field with time and current during magnetization are reproduced. The simulation cycle is synchronized with the actual magnetization process, providing data support for parameter pre-calculation. The magnetic induction unit inside the magnetizing head 5 (composed of three sets of Hall sensors and a magnetic flux coil) is activated, and the magnetization process is pre-calculated based on the finite element simulation model. First, based on the target magnetic flux Φ... target The magnetization time is calculated using the rate of change of magnetic flux dΦ / dt. The initial magnetic flux is Φ0, which is typically 0. Therefore, the magnetization time t... re The pre-calculation formula is:

[0047] Secondly, the magnetizing current is calculated. Based on Ohm's law for magnetic circuits, the magnetomotive force (F = N·I) generated by the magnetizing coil needs to overcome the total magnetic reluctance R of the magnetic circuit, that is: N·I = R m ·Φ target The total magnetic reluctance R of the magnetic circuit consists of the rotor 6 reluctance, the core reluctance of the magnetizing head 5, and the air gap reluctance (R = R). r otor+R c ore+R g ap), combined with the target magnetic flux Φ target The required magnetizing current can be deduced from this: In actual calculations, the magnetic circuit efficiency coefficient k needs to be introduced, i.e., the current formula is:

[0048] Finally, the rotational speed of rotor 6 is matched. To ensure uniform magnetization of each pole of rotor 6, the rotational speed must be precisely matched with the magnetization pulse period to avoid pole misalignment. Regarding the correlation between the number of pole pairs and the pulse period, assuming the number of pole pairs of rotor 6 is n (e.g., 4 pole pairs n=4), then rotor 6 needs to complete one pole magnetization cycle for every 1 / n revolutions. The magnetization pulse period T (the duration of the current for a single magnetization cycle) must be synchronized with the rotation angle of rotor 6, that is: ω is the rotor's angular velocity. The relationship between the rotational speed ω0 and the angular velocity ω is ω=ω0×π / 30, that is: For example, if n = 4 and the magnetization pulse period T = 0.01s, then ω0 = 400r / min.

[0049] The magnetic uniformity detection module performs real-time magnetic flux detection through the magnetic induction unit built into the magnetizing head 5. Its core objective is to accurately collect the changes in magnetic flux during the magnetization process of the rotor 6, providing a data basis for uniformity judgment and parameter control. The magnetic induction unit includes three sets of Hall sensors and one set of magnetic flux coil. The three sets of Hall sensors are evenly distributed along the inner circumference of the magnetizing head 5, with an angle of 120° between adjacent sensors, corresponding to the three magnetic pole regions of the rotor 6 (or three evenly divided detection areas). The magnetic flux coil is set around the central axis of the magnetizing head 5, covering the entire magnetization range of the rotor 6, and is used to collect the total magnetic flux.

[0050] First, raw data is acquired. The Hall sensor outputs the magnetic induction intensity B in real time with a sampling frequency of 1kHz. The magnetic flux coil outputs the induced electromotive force E through the principle of electromagnetic induction. According to Faraday's law of electromagnetic induction, E=-N·dΦ / dt (N is the number of turns of the coil). The magnetic flux Φ(t) is calculated in real time through the integrator circuit.

[0051] Noise filtering is performed: The Kalman filter algorithm is used to reduce noise in the original magnetic flux data and eliminate errors caused by electromagnetic interference. The filtering formula is as follows: Where Φ(t) is the filtered magnetic flux at time t, and Φ(t-1) is the predicted magnetic flux at time t-1. meas (t) represents the measured magnetic flux at time t, and Kg is the Kalman gain (dynamically adjustable from 0.1 to 0.3; the greater the noise, the larger the value of Kg, thus enhancing the weight of the measured data).

[0052] Secondly, regional magnetic flux calculation is performed, with each Hall sensor acquiring the magnetic induction intensity B of the corresponding region. i (i = 1, 2, 3, corresponding to 3 regions), combined with the effective area S of this region i (Calculated based on rotor diameter 6 and region angle, S) i =π · D · L · (120° / 360°), D is the rotor diameter (6), L is the magnetization length), calculate the magnetic flux in the region: Φ i (t)=B i (t)·S i Then, the total magnetic flux is calculated: Before each power-on, a calibration coefficient is calculated using a standard magnet, which serves as the basis for all subsequent magnetic flux data.

[0053] Finally, the magnetization uniformity is judged and evaluated, using the coefficient of variation (CV) as a quantitative index of uniformity. The calculation formula is as follows: Where μ is the average magnetic flux in the three regions, i.e. σ is the standard deviation of the magnetic fluxes in three regions, that is (when n = 3, the denominator is n - 1);

[0054] Judgment of uniformity: Qualified standard: The preset uniformity threshold CV0 = 5%. When CV ≤ 5%, it is judged that the magnetization of the rotor 6 is uniform and no adjustment is required; slightly non-uniform: 5% < CV ≤ 8%, slight parameter adjustment is required (such as fine-tuning the magnetization current of a certain region or the rotation speed of the rotor 6); severely non-uniform: CV > 8%, emergency intervention is required.

[0055] Parameter dynamic regulation module, step 1: Monitoring point layout and uniformity judgment. Set three monitoring points (P1, P2, P3) in the circumferential direction of the magnetization head 5. The included angle between adjacent monitoring points is 120°, corresponding to three magnetization regions (A1, A2, A3). Each region covers a range of 120°. Real-time collect the magnetic flux data Φ1, Φ2, Φ3 of each region, and calculate the uniformity index of each region: Coefficient of variation of uniformity of region i: where, σ i is the standard deviation of the magnetic fluxes of three sampling points in region i, μ i is the average value of the magnetic fluxes in region i, i = 1, 2, 3; in addition, if the magnetic fluxes of two adjacent magnetization regions are different, it means that the overall magnetization uniformity of the rotor 6 does not meet the requirements, and separate uniformity judgment needs to be carried out for each magnetization region.

[0056] Step 2: Angle positioning of the region to be compensated. Real-time collect the current angle θ(t) of the rotor 6 through the circular grating encoder at the shaft end of the rotor 6. Combine the preset angle coordinates of the monitoring points (such as P1 corresponding to 0°, P2 corresponding to 120°, P3 corresponding to 240°) to determine the angle range of the region i to be compensated: The angle interval of region i is where is the angle coordinate of the monitoring point Pi.

[0057] Step 3: Rotation speed adjustment when the rotor 6 enters the region to be compensated. When the angle θ(t) of the rotor 6 ∈ [θ i_start , θ i_end , reduce the rotation speed of the rotor 6 to extend the magnetization time of this region and compensate for the insufficient magnetic flux: Calculate the uniformity deviation: ΔCV i = CV i - CV0, the target rotation speed ω i of the region to be compensated is: ω i = ω0 × (1 - k ω × ΔCV i ), where ω0 is the initial rotation speed, k ω is the rotation speed adjustment coefficient. The greater the uniformity deviation, the more the rotation speed decreases.

[0058] Step 4: Calculate the magnetic flux in the region to be compensated. Extend the magnetization time to increase the magnetic flux, ensuring that the magnetic flux in region i after compensation reaches the target value Φ. target,i The simulation prediction parameters include the time it takes for rotor 6 to pass through region i. During compensation, the actual time it takes for rotor 6 to pass through region i is: The difference in magnetic flux that needs to be compensated: ΔΦ i =Φ target,i -μ i ,in, μ0 is the average magnetic flux of the three regions. The magnetic flux of region i is monitored in real time by the magnetic induction unit. When μ i ′≥Φ target,i Time (μ) i ′ is the average magnetic flux of region i after compensation, and the compensation is determined to be complete.

[0059] Step 5: Current adjustment. In order to keep the total magnetization time constant, the magnetization current is increased in the non-compensated area to shorten its magnetization time. That is, after the compensation area is fully compensated, all three magnetization areas can be identified as non-compensated areas. At this time, the magnetization current output will be increased to shorten the magnetization time.

[0060] Step 6: Temperature feedback and parameter correction. Since it is necessary to increase the output of the magnetizing current, the temperature of the magnetizing head 5 may rise. The data is corrected by combining the temperature sensor and temperature processing module installed in the magnetizing head 5.

[0061] Because the magnetization head 5 generates heat during the magnetization process, a temperature safety threshold T is also included in the parameter initialization module. ax The system also includes a mapping model construction module and a temperature processing module.

[0062] The mapping model construction module loads the historical magnetization current data set I1, I2, ..., I and the corresponding temperature data set T1, T2, ..., T corresponding to the current rotor model 6 from the magnetization parameter database. Based on the historical current data set and the temperature data set, a polynomial regression model is constructed using the least squares method with a regularization term as the mapping relationship model between temperature and current. The expression of the polynomial regression model is: I = p0 + p1T + p2T 2 +…+p k T k Where p0, p1, ..., p are regression coefficients, and k is the order of the polynomial, determined to be 3-5 through cross-validation; the objective function of the least squares method with regularization is:

[0063]

[0064] Wherein, λ is the regularization parameter; the parameter initialization module also includes a temperature warning threshold Tpre and a temperature danger threshold Tdanger; the current adjustment value output by the mapping model can be directly used as the input for dynamic control of magnetization parameters, forming a synergy with magnetic flux monitoring and speed control. For example, when the magnetic flux does not reach the target, the system can combine the upper limit of the current output by the model (based on the current temperature) to increase the current within a safe range, avoiding temperature over-limit caused by blind parameter adjustment, and achieving coordinated optimization of multiple parameters.

[0065] The temperature processing module collects real-time temperature data inside the magnetizing head 5. It obtains the real-time temperature T(t) of the magnetizing head 5 through a temperature sensor. When T(t) < Tpre, the magnetizing current remains constant at its initial value I0. When Tpre ≤ T(t) < Tpre... ax When the real-time temperature T(t) is substituted into the above mapping model, the adjusted current I′ is calculated, that is: I′=p0+p1T(t)+p2T(t) 2 +…+p k T(t) k When T ax When ≤T(t)<T, the adjustment current I″ is obtained through the mapping relationship model, and I″ must satisfy I″<I′.

[0066] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A magnetization system for a permanent magnet motor rotor, characterized in that: The device includes a tray (2), a positioning chuck (3), and a top cone (4). A magnetizing head (5) is fixedly connected to the tray (2). A rotor (6) is placed on the magnetizing head (5). One shaft end of the rotor (6) passes through the magnetizing head (5) and the tray (2) and is connected to the positioning chuck (3) located on the side of the tray (2) opposite to the magnetizing head (5). The top cone (4) presses against the other shaft end of the rotor (6). The positioning chuck (3) can rotate to drive the rotor (6) to rotate. A magnetic induction unit is also provided inside the magnetizing head (5). Also includes: The parameter initialization module loads the magnetization parameter database corresponding to the rotor (6) model and presets the initialization parameters, including the magnetization target magnetic flux, the initial rotational speed of the rotor (6) and the initial value of the magnetization current. The magnetization simulation calculation module acquires the magnetic induction intensity collected by the magnetic induction unit, calculates the magnetic flux change rate based on the magnetic induction intensity, and uses the magnetic flux change rate and the magnetization target magnetic flux to perform parameter pre-calculation of the magnetization process through the finite element simulation model to obtain the estimated parameters. The estimated parameters include magnetization time, magnetization current output and rotor (6) rotation speed matching value. The magnetic uniformity detection module monitors the magnetic induction intensity in real time during the magnetization process based on the estimated parameters, calculates the real-time magnetic flux through the magnetic induction intensity, and calculates the uniformity based on the magnetic flux distribution. The parameter dynamic control module dynamically controls the rotation speed of the rotor (6) according to the uniformity.

2. The magnetization system for a permanent magnet motor rotor according to claim 1, characterized in that: The magnetizing head (5) is equipped with a temperature sensor. The parameter initialization module also includes a temperature safety threshold, a mapping model construction module, and a temperature processing module. The mapping model construction module loads the magnetization historical current data set and the corresponding temperature data set corresponding to the current rotor (6) model into the magnetization parameter database, and constructs a mapping relationship model between current and temperature based on the historical current data set and the temperature data set. The temperature processing module acquires the real-time temperature value inside the magnetizing head (5) collected by the temperature sensor, compares the real-time temperature value with the temperature safety threshold, and outputs the adjusted magnetizing current value through the mapping relationship model if the real-time temperature value is greater than the temperature safety threshold.

3. The magnetization system for a permanent magnet motor rotor according to claim 2, characterized in that: The mapping model construction module includes a construction strategy, which includes constructing an initial model of the relationship between current and temperature using a multinomial regression algorithm based on historical current data sets and corresponding temperature data sets, then solving the regression coefficients of the initial model using the least squares method to obtain a minimized objective function, and simultaneously introducing a regularization term to modify the objective function to obtain a mapping relationship model.

4. The magnetization system for a permanent magnet motor rotor according to any one of claims 1-3, characterized in that: The magnetic uniformity detection module includes a uniformity calculation strategy, which includes defining the magnetic induction unit setting position as the monitoring point, calculating the average value and standard deviation of the magnetic flux at the detection point in the circumferential direction of the rotor (6), and evaluating the magnetization uniformity through the coefficient of variation.

5. The magnetization system for a permanent magnet motor rotor according to claim 4, characterized in that: The magnetization simulation calculation module includes a simulation strategy, which includes calling the BH curve of the rotor (6) material, inputting the initial magnetic flux and the target magnetic flux for magnetization, calculating the magnetization time by converting current and magnetic flux, calculating the output of the magnetization current by Ohm's law of magnetic circuit and the coil voltage formula, calculating the rotor (6) rotation speed matching value according to the number of magnetic pole pairs of the rotor (6), and then correcting the magnetization time, the output of the magnetization current and the rotor (6) rotation speed matching value by the finite element simulation model.

6. The magnetization system for a permanent magnet motor rotor according to claim 3, characterized in that: The parameter dynamic control module also includes a dynamic adjustment strategy, which includes a compensation area positioning step and a speed adjustment step. The compensation area positioning step takes the area between two adjacent magnetic induction units on the rotor (6) as the magnetization area. When the difference in magnetic flux between adjacent magnetization areas or the magnetic flux of a certain area does not reach the preset threshold, the area is determined to be a non-compliant area. The current angular position of the rotor (6) is obtained through the encoder, and the angular range corresponding to the non-compliant area is calculated. In the speed adjustment step, when the rotor (6) rotates to the angle range, the speed is reduced according to the magnetic flux in that area, and the speed reduction is positively correlated with the degree of non-compliance. When the rotor (6) rotates outside the non-compliance range, it is restored to the initial speed.

7. The magnetization system for a permanent magnet motor rotor according to claim 6, characterized in that: The dynamic adjustment strategy also includes a current adjustment step; The current adjustment step calculates the extended magnetization time due to the reduced rotation speed in the non-compliant area, determines the shortened magnetization time for other compliant areas based on the extended magnetization time, and increases the magnetization current output in the compliant areas to shorten the magnetization time in that area to the magnetization time estimated by the magnetization simulation calculation module.

8. The magnetization system for a permanent magnet motor rotor according to claim 1, characterized in that: It also includes a frame (1), which is vertically arranged and has a vertical slide rail (7) on it. The tray (2) is slidably connected to the vertical slide rail (7). The frame (1) is also provided with a horizontal slide (8), and the top cone (4) is slidably connected to the horizontal slide (8). The horizontal slide (8) is slidably connected to the vertical slide rail (7).

9. The magnetization system for a permanent magnet motor rotor according to claim 8, characterized in that: The top cone component (4) includes a top cone head and a vision sensor, and also includes an image acquisition module and a top cone positioning module. The image acquisition module acquires the image of the rotor (6) shaft end face acquired by the vision sensor as the image to be topped; The top cone positioning module performs image preprocessing based on the image to be topped and identifies the center point of the rotor (6) shaft end face. It constructs a spatial coordinate system based on the center point in the image to be topped and calculates the moving position of the top cone head in the spatial coordinate system based on the visual sensor and the apex point of the top cone head, so that the apex point of the top cone head is located directly above the center point of the rotor (6) shaft end face.

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