Method and System for Predicting Performance after Expansion of Motors on the Same Platform

Abstract

The present invention provides a method and system for predicting the performance of a motor after extension on the same platform, belonging to the technical field of predicting the extended performance of a motor, including: obtaining the no-load loss-speed test data of the motor before stack height extension, the stack height of the motor before extension and the stack height of the motor after extension, and obtaining the windage and friction loss of the motor after extension; according to the test results of the motor no-load loss, performing simulation to obtain the mechanical loss of the motor, and then based on the rotor weight before stack height extension, the rotor weight after stack height extension and the mechanical loss of the motor, obtaining the mechanical loss of the motor after extension; based on the fact that the DC copper loss of the motor before extension is a function of speed and torque, the total copper loss of the motor before extension, and obtaining the copper loss of the motor after extension based on the DC resistance of the motor before extension, the total copper loss of the motor before extension and the DC resistance after stack height extension; obtaining the output power and input power of each measurement point, and calculating the efficiency of each measurement point by using the output power / input power of each measurement point, which is the efficiency of the motor after extension.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor extended performance prediction, and particularly relates to a method and system for predicting the performance of motors after extension on the same platform. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Motors play an extremely important part in people's daily life and production. Due to its high slot fill factor and large power density, flat wire motors have been widely used in different application scenarios.

[0004] Same-platform extension means: keeping the stator and rotor lamination types of the motor different, and realizing the deformation of motors with different powers and torques by adjusting materials, stack heights, and winding parameters, etc.

[0005] Due to the relatively complex stator trial production process and poor flexibility of the production line of flat wire motors, when performing same-platform extension, it is necessary to ensure that the lamination types of the stator and rotor remain unchanged and perform stack height extension. Therefore, it is very important to accurately predict the performance of the motor after extension. The stack height specifically refers to the stack height of the stator and rotor cores, that is, the stack length of the cores.

[0006] Currently, there are some studies on the winding arrangement and performance analysis of flat wire motors. However, the performance of motors on the same platform after different stack height extensions is very beneficial for improving the motor optimization efficiency and optimization degree. Generally speaking, for motors with the same lamination type undergoing different stack height changes, it is necessary to predict in advance whether the performance indicators of the motor after the change meet the requirements. The indicators of the motor include many aspects, such as dynamic, economic, cost, NVH, and temperature rise. Different performances of the motor can be achieved by changing the stack height, material grades, winding parameters, etc., which can reduce the number of motor mold openings and other costs. However, in the prior art, the prediction of the performance of motors on the same platform after different stack height extensions mainly relies on subjective judgment or simple indicators, which is not objective enough and has a large error. Summary of the Invention

[0007] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a method for predicting the performance of motors after extension on the same platform, which provides technical support for the design of motors with differential advantages by calculating the external characteristics and efficiency of the same-platform extension of the motors.

[0008] To achieve the above object, one or more embodiments of the present invention provide the following technical solutions:

[0009] In the first aspect, a method for predicting the performance of motors after extension on the same platform is disclosed, including:

[0010] Obtain the no-load loss - speed test data of the motor before stack height expansion, the stack height of the motor before expansion and the stack height of the motor after expansion, and obtain the windage and friction loss of the motor after expansion;

[0011] According to the no-load loss test results of the motor, conduct no-load iron loss simulation to obtain the mechanical loss of the motor, and then based on the rotor weight before stack height expansion, the rotor weight after stack height expansion and the mechanical loss of the motor, obtain the mechanical loss of the motor after expansion;

[0012] Based on the fact that the DC copper loss of the motor before expansion is a function of speed and torque, the total copper loss of the motor before expansion, and based on the DC resistance of the motor before expansion, the total copper loss of the motor before expansion and the DC resistance after stack height expansion, obtain the copper loss of the motor after expansion;

[0013] Use electromagnetic simulation to calculate the external characteristics of the motor after expansion: respectively take the basic iron loss and DC copper loss at all speed - torque points, the windage and friction loss, mechanical loss, and copper loss at the corresponding measurement points;

[0014] Obtain the output power and input power at each measurement point. The input power is the sum of the output power, iron loss, copper loss, mechanical loss, and windage and friction loss;

[0015] Calculate the efficiency at each measurement point using the output power / input power at each measurement point, which is the efficiency of the motor after expansion.

[0016] As a further technical solution, the calculation process of the windage and friction loss of the motor after expansion is as follows:

[0017] Fit the no-load loss P0 - speed test data of the motor before stack height expansion, and extract the value P1 of the no-load loss varying with the third power term of speed;

[0018] Obtain the stack height L1 of the motor before expansion and the stack height L2 of the motor after expansion;

[0019] Calculate the windage and friction loss of the motor after expansion 。

[0020] As a further technical solution, the process of obtaining the mechanical loss of the motor after expansion is as follows:

[0021] According to the no-load loss test results of the motor, conduct no-load iron loss simulation to obtain P3;

[0022] The mechanical loss of the motor is P4 = P0 - P1 - P3;

[0023] Obtain the rotor weight m1 before stack height expansion and the rotor weight m2 after stack height expansion;

[0024] Calculate the mechanical loss of the motor after expansion 。

[0025] As a further technical solution, the process of obtaining the copper loss of the expanded motor is as follows:

[0026] The DC resistance of the motor before expansion is R1, and the DC resistance after expanding the stack height is R2;

[0027] Test the AC / DC resistance ratio of the motor before expansion, and the AC power frequency , where p is the number of pole pairs, n is the rotational speed, and R3 is the AC / DC resistance ratio of the motor, specifically the ratio of the total resistance to the DC resistance;

[0028] For any working condition, the current of the motor before expansion is I i， related to the rotational speed and torque, and the DC copper loss P6 = I i 2 R1, then the total copper loss of the motor before expansion is ;

[0029] Calculate the copper loss of the expanded motor .

[0030] As a further technical solution, it also includes the process of obtaining the iron loss coefficient of the expanded motor:

[0031] Use the total loss, wind friction loss, mechanical loss, copper loss, and efficiency calibrated by the performance of the motor before expansion to calculate the actual iron loss of the motor;

[0032] Calculate the basic iron loss using electromagnetic simulation;

[0033] The iron loss coefficient K of the motor = actual iron loss / basic iron loss;

[0034] The iron loss coefficient of the expanded motor is the same as that of the motor before expansion.

[0035] As a further technical solution, it also includes that when analyzing the external characteristics of the expanded motor, the expanded motor uses electromagnetic simulation to predict the peak torque of the motor in the constant torque section;

[0036] In the field-weakening speed expansion section of the motor before expansion, due to the certain difference between the corresponding relationship on the external characteristics and the inductance parameters of the simulated motor and the actual motor, adjust the voltage utilization rate of the motor. The specific adjustment process is as follows:

[0037] Extract the torque at the same current and the same rotational speed, and when the sum of the absolute values of the torque differences from the torque of the measured motor in the field-weakening speed expansion section is the smallest, the voltage utilization rate x of the motor is set as the voltage utilization rate of the expanded motor.

[0038] In the second aspect, a performance prediction system for the expanded motor of the same platform is disclosed, including:

[0039] The extended motor windage and friction loss acquisition module is configured to: obtain the no-load loss - speed test data of the motor before stack height extension, the stack height of the motor before extension, and the stack height of the motor after extension, so as to obtain the windage and friction loss of the motor after extension;

[0040] The mechanical loss acquisition module of the motor after extension is configured to: based on the no-load loss test result of the motor, conduct no-load iron loss simulation to obtain the mechanical loss of the motor, and then based on the rotor weight before stack height extension, the rotor weight after stack height extension, and the mechanical loss of the motor, obtain the mechanical loss of the motor after extension;

[0041] The copper loss acquisition module of the motor after extension is configured to: based on the fact that the DC copper loss of the motor before extension is a function of speed and torque, then the total copper loss of the motor before extension, and obtain the copper loss of the motor after extension based on the DC resistance of the motor before extension, the total copper loss of the motor before extension, and the DC resistance after stack height extension;

[0042] The efficiency calculation module of the motor after extension is configured to: use electromagnetic simulation to calculate the external characteristics of the motor after extension: respectively take the basic iron loss and DC copper loss at all speed - torque points, the windage and friction loss, mechanical loss, and copper loss at the corresponding measurement points;

[0043] Obtain the output power and input power at each measurement point, and the input power is the sum of the output power, iron loss, copper loss, mechanical loss, and windage and friction loss;

[0044] Calculate the efficiency at each measurement point using the output power / input power at each measurement point, which is the efficiency of the motor after extension.

[0045] The above one or more technical solutions have the following beneficial effects:

[0046] The technical solution of the present invention uses the measured data of the motor before change to reverse - deduce and calibrate the simulation model of the motor, and then uses the simulation model to predict the performance of the motor after change. For the measured data of the motor before extension, various losses are reasonably analyzed and the output is determined. The influence of parameters such as the inductance of the actual motor and the simulation motor is analyzed using the voltage utilization rate and corresponding adjustments are made.

[0047] The technical solution of the present invention uses the measured data of the motor before change to reverse - deduce and calibrate the simulation model of the motor, and then uses the simulation model to predict the performance indicators of the motor after change. The characteristics of the external characteristic curve of the permanent magnet synchronous motor can be checked. The front section is called the constant torque section and the rear section is called the constant power section. In the constant power section, due to the presence of field - weakening, it is difficult to predict the dynamic performance and efficiency of this section. Therefore, with the existence of the measured results of the motor before change, a relatively accurate prediction and analysis of the external characteristics of the constant power section can be made.

[0048] The technical solution of the present invention is an external characteristic and efficiency calculation method for motor platform expansion, providing technical support for the design of motors with differential advantages.

[0049] Advantages of additional aspects of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0051] Figure 1 is a flowchart of the external characteristic and efficiency calculation method for motor platform expansion provided by an embodiment of the present invention;

[0052] Figure 2 , is a schematic diagram of the simulation results provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention.

[0055] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0056] Embodiment 1

[0057] Referring to the attached Figure 1 As shown, this embodiment discloses a method for predicting the performance of motors after platform expansion, specifically including:

[0058] S1: Before the stack height expansion, the test data of the no-load loss and speed of the motor are obtained through the bench test of the motor. P0 is the no-load loss of the motor, with the unit of kW. The test data is fitted to extract the value P1 that changes with the third power term of the speed. P1 is the windage and friction loss of the motor before expansion. The stack height of the motor before expansion is L1, and the stack height of the motor after expansion is L2. According to common knowledge, increasing the stack height will cause an increase in the iron core volume, thereby increasing the magnetic resistance and eddy current loss. The windage and friction loss are linearly related to the stack height, that is, P1 = μL1, where μ = P1 / L1, and μ is used to represent the ratio of the linear relationship. The stack height is changed to L2, that is, the windage and friction loss P2 of the motor after expansion = μL2. Substituting μ = P1 / L1 into it, the windage and friction loss of the motor after expansion can be calculated accordingly. 。

[0059] In this embodiment, polynomial fitting is performed using Matlab to distinguish losses of different orders, and losses of different orders represent different types of losses. The no-load loss includes the mechanical loss of the bearing, the windage and friction loss of the rotor, and the iron loss of the iron core. The iron loss of the iron core includes hysteresis loss and eddy current loss. Only the windage and friction loss among these losses is of the third order. Therefore, it is necessary to first deal with the windage and friction loss and then continue to disassemble other losses.

[0060] In this embodiment, based on the measured results of a motor with a stack height of L1, the performance of the motor after being expanded to a stack height of L2 is judged to determine whether it meets the requirements. Based on the expansion formula of the windage and friction loss for different stack heights, the windage and friction loss of the expanded motor is predicted.

[0061] S2: According to the no-load loss test results of the motor, no-load iron loss simulation is carried out. When simulating, the temperature is set at 25°C, the current is 0.001 A, and the current lead angle is 45°. The iron loss P3 can be directly obtained by the software. By simulating the no-load iron loss at different speeds, the mechanical loss of the motor is P4 = P0 - P1 - P3, where P1 is the mechanical loss of the corresponding bearing in the no-load loss of the motor; before the stack height expansion, the rotor weight is m1, and after the stack height expansion, the rotor weight is m2. According to common knowledge, the mechanical loss is linearly related to the rotor weight, and based on this, the mechanical loss of the expanded motor is calculated. 。

[0062] Based on the influence law of the radial force of the bearing on the bearing loss, this embodiment can calculate the mechanical loss of the bearing of the motor after being expanded to a stack height of L2 more accurately.

[0063] S3: The DC resistance of the motor before expansion obtained by measuring the motor with a multimeter is R1, and the stack height is expanded: the calculated DC resistance is R2. The AC-DC resistance ratio of the motor before expansion and the AC power frequency are measured. , where p is the number of pole pairs and n is the motor speed in rpm. Then the AC-DC resistance ratio of the motor is the measured relationship. The DC copper loss P6 of the motor before expansion is related to the speed and torque. Then the total copper loss of the motor before expansion is , where R3 is the AC-DC resistance ratio of the motor, specifically the ratio of the total resistance to the DC resistance; according to common knowledge, the copper loss of the motor is linearly related to the DC resistance, and based on this, the total copper loss of the expanded motor is calculated. , based on the total loss of the motor before expansion, calculate the total copper loss of the expanded motor, including DC copper loss and AC copper loss.

[0064] Regarding the function of rotational speed and torque, when the motor is at different rotational speeds and torques, due to the existence of the control strategy, the intensity of the current passing through is different, and the Joule heat caused by the current is also different. P6 represents the DC copper loss of the motor before expansion. The current distribution of the motor at different rotational speeds and torques is also called the current MAP.

[0065] It should be noted that the AC / DC resistance ratio = total resistance / DC resistance. When the frequency of the current passing through the conductor changes, the resistance will change. By measuring the DC resistance, the AC resistance of the motor at different frequencies can also be tested with an LCR meter, and the AC / DC resistance ratio can be directly calculated.

[0066] S4: Using the efficiency MAP (contour map, isogram) calibrated by the performance of the motor before expansion, the total loss, windage and friction loss, mechanical loss, copper loss, and efficiency are used to calculate the actual iron loss of the motor (total loss - windage and friction loss - mechanical loss - copper loss = actual iron loss). The basic iron loss can be calculated by electromagnetic simulation. The iron loss coefficient of the motor K = actual iron loss / basic iron loss. The iron loss coefficient of the motor after expansion remains unchanged. The iron loss coefficient is related to the processing and manufacturing of the motor. For the same product expansion, the general process will not change.

[0067] S5: For the external characteristics of the motor after expansion, in the constant torque section, the motor after expansion uses electromagnetic simulation to predict the peak torque of the motor in the constant torque section. For the field weakening speed expansion section of the motor before expansion, the n-T-I correspondence relationship on the external characteristics. Because there are certain differences between the parameters such as the inductance of the simulated motor and the actual motor, the voltage utilization rate needs to be adjusted: adjust the voltage utilization rate of the motor, extract the torque at the same current and the same rotational speed, and compare it with the torque of the measured motor in the field weakening speed expansion section. When the sum of the absolute values of the torque differences is the smallest, the voltage utilization rate x of the motor before expansion is set as the voltage utilization rate of the motor after expansion. Based on this voltage utilization rate, the external characteristics of the motor after expansion are calculated by electromagnetic simulation.

[0068] The simulation process here is a common simulation technology of the Motor-cad software, which belongs to the prior art and will not be elaborated in detail here.

[0069] Among them, n-T-I is the current corresponding to the motor at different rotational speeds and torques, which is related to the parameters and control strategy of the motor. Generally, in the motor bench test, it is obtained by the test engineer through testing.

[0070] The voltage utilization rate is the actual line voltage of the motor (expressed in amplitude) / rated voltage.

[0071] S6: From the lowest rotational speed to the highest rotational speed, intervals n1 - nm are taken in sequence, and from the smallest torque to the largest torque, T1 - Tt are taken. The basic iron loss P9 at all rotational speed and torque points is taken respectively. The basic iron loss is obtained through simulation, and the windage and friction loss at the corresponding measurement points are calculated through the formula The mechanical loss is calculated through the formula , the total copper loss is calculated by the formula , the iron loss is calculated by the formula . K is the iron loss coefficient of the motor. The output power P11 at each measurement point (n, T) is , with the unit of kilowatt. The input power P12 = P11 + P10 + P8 + P5 + P2. The efficiency MAP of the motor is calculated by P11 / P12. At different points, the efficiency of the motor is different. The above obtained is the efficiency of the extended motor.

[0072] See the appendix Figure 2 As shown, the electromagnetic simulation of this embodiment is carried out using the Motor-cad software of Ansys Corporation. The simulation process includes:

[0073] Based on Motor-cad, fill in the outer diameter of the stator, inner diameter of the stator, air gap, number of slots, number of poles, slot depth and width, length and width of the permanent magnet, included angle of the permanent magnet, pole arc coefficient of the permanent magnet, and stack height in the geometric parameter setting module; fill in the number of phases, number of turns, number of parallel branches, number of parallel strands, pitch, and wire diameter in the winding parameter setting module; assign the stator core and rotor core to silicon steel material, the winding to pure copper, and the permanent magnet to rare earth permanent magnet in the material selection module; set the winding temperature and permanent magnet temperature in the solution setting module; after clicking to build the model in the efficiency solution module, set the voltage and voltage utilization rate, and click to generate the efficiency Map diagram and data in the efficiency Map calculation module. The generated data includes: information such as rotational speed, torque, efficiency, copper loss, iron loss, inductance, resistance, current, and voltage. This simulation process is a common simulation technology of the Motor-cad software and belongs to the prior art, so it will not be elaborated in detail here.

[0074] In the above process of simulating and obtaining the motor efficiency MAP, this step is to calculate different losses at different points in sequence, then calculate different efficiencies, and finally form the efficiency MAP of the extended motor to determine whether the extended requirements meet the development requirements.

[0075] Among them, Figure 2 the abscissa in is the rotational speed, the left ordinate is the torque, and the efficiency MAP diagram is obtained after simulation. Different colors represent different efficiencies on the right.

[0076] Embodiment 2

[0077] The purpose of this embodiment is to provide a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the above method are implemented.

[0078] Embodiment 3

[0079] The purpose of this embodiment is to provide a computer-readable storage medium.

[0080] A computer-readable storage medium has a computer program stored thereon, and when the program is executed by a processor, it performs the steps of the above method.

[0081] Embodiment 4

[0082] The purpose of this embodiment is to provide a performance prediction system for a motor after expansion on the same platform, including:

[0083] A module for obtaining the windage and friction loss of the expanded motor, configured to: obtain the no-load loss - speed test data of the motor before stack height expansion, the stack height of the motor before expansion, and the stack height of the motor after expansion, so as to obtain the windage and friction loss of the expanded motor;

[0084] A module for obtaining the mechanical loss of the expanded motor, configured to: perform no-load iron loss simulation according to the no-load loss test result of the motor to obtain the mechanical loss of the motor, and then based on the rotor weight before stack height expansion, the rotor weight after stack height expansion, and the mechanical loss of the motor, obtain the mechanical loss of the expanded motor;

[0085] A module for obtaining the copper loss of the expanded motor, configured to: based on the fact that the DC copper loss of the motor before expansion is a function of speed and torque, then the total copper loss of the motor before expansion, and obtain the copper loss of the expanded motor based on the DC resistance of the motor before expansion, the total copper loss of the motor before expansion, and the DC resistance after stack height expansion;

[0086] An efficiency calculation module for the expanded motor, configured to: use electromagnetic simulation to calculate the external characteristics of the expanded motor: respectively obtain the basic iron loss and DC copper loss at all speed-torque points, the windage and friction loss, mechanical loss, copper loss, and iron loss at the corresponding measurement points;

[0087] Obtain the output power and input power at each measurement point, and the input power is the sum of the output power, iron loss, copper loss, mechanical loss, and windage and friction loss;

[0088] Calculate the efficiency at each measurement point by using the output power / input power at each measurement point, which is the efficiency of the expanded motor.

[0089] Embodiment 5

[0090] The purpose of this embodiment is to provide a computer program product containing instructions, which when running on a computer, enables the computer to execute the methods and functions involved in any one of the above embodiments.

[0091] In the devices of the above embodiments, the steps involved correspond to those of the first method embodiment. For specific implementation details, please refer to the relevant description part of the first embodiment. The term "computer-readable storage medium" should be understood to include a single medium or multiple media containing one or more instruction sets; it should also be understood to include any medium that can store, encode, or carry an instruction set for execution by a processor and cause the processor to execute any method of the present invention.

[0092] Those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computer device. Optionally, they can be implemented by program codes executable by a computing device, so that they can be stored in a storage device for execution by the computing device, or they can be separately fabricated into individual integrated circuit modules, or multiple of them can be fabricated into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0093] Although the specific implementation manners of the present invention have been described above in conjunction with the accompanying drawings, this is not a limitation on the protection scope of the present invention. Those skilled in the art should understand that, based on the technical solutions of the present invention, various modifications or deformations that can be made without creative efforts by those skilled in the art are still within the protection scope of the present invention.

Claims

1. A method for predicting the performance of motors after expansion on the same platform, characterized in that: include: Obtain the no-load loss-speed test data of the motor before stacking height expansion, the stacking height of the motor before expansion and the stacking height of the motor after expansion, and obtain the wind friction loss of the motor after expansion; According to the no-load loss test results of the motor, the no-load iron loss simulation is performed to obtain the mechanical loss of the motor. Then, based on the rotor weight before stacking and expansion, the rotor weight after stacking and expansion, and the mechanical loss of the motor, the mechanical loss of the motor after expansion is obtained. Based on the DC copper loss of the motor before expansion as a function of the speed and torque, the total copper loss of the motor before expansion is obtained, and the copper loss of the motor after expansion is obtained based on the DC resistance of the motor before expansion, the total copper loss of the motor before expansion, and the DC resistance after expansion and stacking; Use electromagnetic simulation to calculate the external characteristics of the expanded motor; Obtain the basic iron loss and DC copper loss of all speed and torque points, the expanded motor wind friction loss of the corresponding measuring points, the expanded motor mechanical loss, and the expanded motor copper loss and iron loss; Obtain the output power and input power of each measuring point. The input power is the sum of the output power, iron loss, copper loss of the motor after expansion, mechanical loss of the motor after expansion, and wind friction loss of the motor after expansion. The efficiency of each measuring point is calculated using the output power / input power of each measuring point as the efficiency of the expanded motor.

2. The method for predicting the performance of a motor after expansion on the same platform as claimed in claim 1, characterized in that: The calculation process of the expanded motor wind friction loss is: The no-load loss P0-speed test data of the motor before stacking and expansion is fitted, and the value P1 of the no-load loss changing with the third-order term of speed is extracted. P1 is the wind friction loss of the motor before expansion. The stack height of the motor before expansion is obtained as L1, and the stack height of the motor after expansion is obtained as L2; Calculate the motor wind friction loss after expansion .

3. The method for predicting the performance of a motor after expansion on the same platform as claimed in claim 2, characterized in that: The process of obtaining the mechanical loss of the expanded motor is: According to the no-load loss test results of the motor, the no-load iron loss simulation is performed to obtain the iron loss P3; The mechanical loss of the motor is P4=P0-P1-P3, P0 is the no-load loss, and P1 is the wind friction loss of the motor before expansion; Obtain the rotor weight m1 before stacking height expansion and the rotor weight m2 after stacking height expansion; Calculate the mechanical losses of the motor after expansion .

4. The method for predicting the performance of a motor after expansion on the same platform as claimed in claim 1, characterized in that: The process of obtaining the copper loss of the expanded motor is: The DC resistance of the motor before expansion is R1, and the DC resistance after expansion and stacking is R2; Test the AC / DC resistance ratio of the motor before expansion, AC frequency , where p is the number of pole pairs and n is the rotation speed; For any working condition, the current of the motor before expansion is I i Related to speed and torque, DC copper loss P6=I i 2 R1, the total copper loss of the motor before expansion is , R3 is the AC / DC resistance ratio of the motor, specifically the ratio of the total resistance to the DC resistance; Calculate the copper loss of the motor after expansion .

5. The method for predicting the performance of a motor after expansion on the same platform as claimed in claim 1, characterized in that: It also includes the process of obtaining the iron loss coefficient of the expanded motor: The actual iron loss of the motor is calculated by using the efficiency MAP total loss, wind friction loss, mechanical loss, copper loss, and efficiency of the motor's performance calibration before expansion; Calculate the basic iron loss using electromagnetic simulation; The iron loss coefficient K of the motor = actual iron loss / basic iron loss; The iron loss coefficient of the motor after expansion is consistent with that before expansion.

6. The method for predicting the performance of a motor after expansion on the same platform as claimed in claim 1, characterized in that: It also includes the analysis of the external characteristics of the expanded motor, and the use of electromagnetic simulation to predict the peak torque of the motor in the constant torque section of the expanded motor; The corresponding relationship between the external characteristics of the motor in the weak magnetic field speed expansion section before expansion is based on the difference between the inductance parameters of the simulated motor and the actual motor. The voltage utilization rate of the motor is adjusted. The specific adjustment process is as follows: The torque under the same current and the same speed is extracted, and the torque in the weak magnetic expansion section of the measured motor is compared. When the absolute value of the torque difference is the smallest, the voltage utilization rate of the motor is x. After expansion, the voltage utilization rate of the motor is set to x.

7. The motor performance prediction system after expansion on the same platform is characterized by: include: The motor wind friction loss acquisition module after expansion is configured to: acquire the no-load loss-speed test data of the motor before stacking height expansion, the stacking height of the motor before expansion and the stacking height of the motor after expansion, and obtain the motor wind friction loss after expansion; The mechanical loss acquisition module of the motor after expansion is configured to: perform no-load iron loss simulation according to the no-load loss test result of the motor to obtain the mechanical loss of the motor, and then obtain the mechanical loss of the motor after expansion based on the rotor weight before stacking and expansion, the rotor weight after stacking and expansion, and the mechanical loss of the motor; The copper consumption acquisition module of the motor after expansion is configured to: acquire the total copper consumption of the motor before expansion based on the DC copper consumption of the motor before expansion as a function of the speed and torque, and acquire the copper consumption of the motor after expansion based on the DC resistance of the motor before expansion, the total copper consumption of the motor before expansion, and the DC resistance after expansion stacking; The efficiency calculation module of the expanded motor is configured to: calculate the external characteristics of the expanded motor by using electromagnetic simulation; Obtain the basic iron loss and DC copper loss of all speed and torque points, the expanded motor wind friction loss of the corresponding measuring points, the expanded motor mechanical loss, and the expanded motor copper loss and iron loss; Obtain the output power and input power of each measuring point. The input power is the sum of the output power, iron loss, copper loss of the motor after expansion, mechanical loss of the motor after expansion, and wind friction loss of the motor after expansion. The efficiency of each measuring point is calculated using the output power / input power of each measuring point to obtain the efficiency of the motor after expansion.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method described in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 6 are performed.

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