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CN-121980708-A - Method and device for calculating wind friction loss of motor air gap domain

CN121980708ACN 121980708 ACN121980708 ACN 121980708ACN-121980708-A

Abstract

The invention relates to a motor air gap domain wind friction loss calculation method and a motor air gap domain wind friction loss calculation device, belonging to the technical field of motor loss calculation, wherein the method comprises the steps of determining an air gap ratio of a target motor based on the air gap length and the rotor radius of the target motor; the method includes the steps of determining a first friction coefficient based on air density, angular speed of a target motor, rotor radius, air gap length, air gap ratio and aerodynamic viscosity when the air gap ratio is less than or equal to 0.05, determining a first correction factor based on air axial flow rate, determining a second correction factor based on surface roughness of an air gap side of the rotor, correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain a second friction coefficient, and determining air gap domain wind friction loss of the target motor based on the second friction coefficient, air density, air gap axial length, angular speed of the target motor and rotor radius. The invention ensures the accuracy of calculation of the wind friction loss of the motor and improves the efficiency of calculation of the wind friction loss.

Inventors

  • YIN YI
  • WANG QING
  • YANG GAO
  • ZONG YUN

Assignees

  • 武汉船用电力推进装置研究所(中国船舶集团有限公司第七一二研究所)

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. The method for calculating the wind friction loss of the motor air gap domain is characterized by comprising the following steps of: Determining an air gap ratio of the target motor based on the air gap length and the rotor radius of the target motor, wherein the air gap ratio is used for representing a proportional relationship between an air gap between a stator and a rotor of the motor and the motor size; determining a first coefficient of friction based on an air density, an angular speed of the target motor, a rotor radius, an air gap length, an air gap ratio, and an aerodynamic viscosity, if the air gap ratio of the target motor is less than or equal to 0.05; Determining a first correction factor based on the axial flow velocity of air, determining a second correction factor based on the surface roughness of the air gap side of the rotor, and correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain a second friction coefficient; The air gap domain wind friction loss of the target motor is determined based on the second coefficient of friction, the air density, the air gap axial length, the angular velocity of the target motor, and the rotor radius.
  2. 2. The method of claim 1, wherein determining the first coefficient of friction based on the air density, the angular velocity of the target motor, the rotor radius, the air gap length, the air gap ratio, and the aerodynamic viscosity comprises: the first coefficient of friction is determined based on the following equation: Wherein, the A first coefficient of friction is indicated and, The rotational reynolds number is indicated, Indicating the air gap ratio of the target motor, The air density is indicated as such, Indicating the angular velocity of the target motor, Representing the radius of the rotor of the target motor, Representing the air gap length of the target motor, Representing aerodynamic viscosity.
  3. 3. The method of calculating air gap domain wind friction loss in a motor of claim 2, wherein said determining a first correction factor based on an air axial flow rate comprises: determining a first correction factor based on the following formula: Wherein, the A first correction factor is indicated and is indicated, Representing the axial reynolds number, The rotational reynolds number is indicated, The air density is indicated as such, Representing the air gap length of the target motor, Indicating the axial flow rate of the air, Representing aerodynamic viscosity.
  4. 4. The method of calculating wind friction loss in an air gap region of a motor according to claim 2, wherein the determining a second correction factor based on the rotor air gap side surface roughness comprises: determining a second correction factor based on the following formula: Wherein, the A second correction factor is indicated and is indicated, Representing the rotor air gap side surface roughness, Representing the radius of the rotor of the target motor, The rotational reynolds number is indicated.
  5. 5. The method for calculating the wind friction loss of the air gap domain of the motor according to claim 1, wherein the correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain the second friction coefficient comprises: And determining the product of the first correction factor, the second correction factor and the first friction coefficient as a second friction coefficient.
  6. 6. The method of claim 1, wherein determining the air gap domain wind friction loss of the target motor based on the second coefficient of friction, the air density, the air gap axial length, the angular velocity of the target motor, and the rotor radius comprises: And determining the air gap domain wind friction loss of the target motor based on the following formula: Wherein, the Represents the air gap domain wind friction loss of the target motor, A second coefficient of friction is indicated and is indicated, The air density is indicated as such, Indicating the axial length of the air gap, Indicating the angular velocity of the target motor, Representing the rotor radius of the target motor.
  7. 7. The method of claim 1, wherein determining the air gap ratio of the target motor based on the air gap length and the rotor radius of the target motor comprises: The ratio of the air gap length of the target motor to the rotor radius of the target motor is determined as the air gap ratio of the target motor.
  8. 8. A motor air gap domain wind friction loss calculation device, comprising: A first determining module for determining an air gap ratio of the target motor based on an air gap length and a rotor radius of the target motor, the air gap ratio being used to represent a proportional relationship between an air gap between a stator and a rotor of the motor and a motor size; a second determining module for determining a first friction coefficient based on an air density, an angular speed of the target motor, a rotor radius, an air gap length, an air gap ratio, and an aerodynamic viscosity, if the air gap ratio of the target motor is less than or equal to 0.05; The correction module is used for determining a first correction factor based on the axial flow velocity of the air, determining a second correction factor based on the surface roughness of the air gap side of the rotor, and correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain a second friction coefficient; and a third determination module for determining an air gap domain wind friction loss of the target motor based on the second friction coefficient, the air density, the air gap axial length, the angular speed of the target motor, and the rotor radius.
  9. 9. A lossy computing device comprising a memory and a processor, wherein, The memory is used for storing programs; The processor, coupled to the memory, is configured to execute the program stored in the memory to implement the steps in the motor air gap domain wind friction loss calculation method according to any one of the preceding claims 1 to 7.
  10. 10. A computer readable storage medium storing a computer readable program or instructions which when executed by a processor is capable of carrying out the steps of the method for calculating wind friction loss in an air gap domain of a motor as claimed in any one of claims 1 to 7.

Description

Method and device for calculating wind friction loss of motor air gap domain Technical Field The invention relates to the technical field of motor loss calculation, in particular to a method and a device for calculating wind friction loss of an air gap domain of a motor. Background For a permanent magnet motor, particularly a high-speed motor, wind friction loss caused by rotor rotation accounts for a larger proportion of total loss of the motor, so that on one hand, the motor efficiency is reduced, on the other hand, the internal heating of the motor rotor is increased, and the risk of motor performance reduction and even loss of magnetism caused by high-temperature demagnetization of the permanent magnet is brought. Accurate assessment of such losses is critical to motor design. The current motor wind friction loss mainly comprises two methods of empirical formula calculation and computational fluid mechanics simulation. The simulation method has high calculation precision, complex pretreatment and long calculation time, and the empirical formula method has high calculation speed, meets the requirement of rapid iterative calculation for motor early-stage design, and has larger error when evaluating small air gap wind friction loss with the air gap ratio not more than 0.05. Therefore, how to ensure the accuracy of calculation of the wind friction loss of the motor and improve the calculation efficiency at the same time becomes a technical problem to be solved urgently. Disclosure of Invention In view of the foregoing, it is necessary to provide a method and a device for calculating the wind friction loss in the air gap of a motor, which are used for solving the problem that the accuracy and efficiency of the existing calculation scheme of the wind friction loss of the motor are difficult to be compatible. In order to solve the above problems, in a first aspect, the present invention provides a method for calculating wind friction loss in an air gap domain of a motor, including: Determining an air gap ratio of the target motor based on the air gap length and the rotor radius of the target motor, wherein the air gap ratio is used for representing a proportional relationship between an air gap between a stator and a rotor of the motor and the motor size; determining a first coefficient of friction based on an air density, an angular speed of the target motor, a rotor radius, an air gap length, an air gap ratio, and an aerodynamic viscosity, if the air gap ratio of the target motor is less than or equal to 0.05; Determining a first correction factor based on the axial flow velocity of air, determining a second correction factor based on the surface roughness of the air gap side of the rotor, and correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain a second friction coefficient; The air gap domain wind friction loss of the target motor is determined based on the second coefficient of friction, the air density, the air gap axial length, the angular velocity of the target motor, and the rotor radius. In one possible implementation, the determining the first coefficient of friction based on the air density, the angular velocity of the target motor, the rotor radius, the air gap length, the air gap ratio, and the aerodynamic viscosity includes: the first coefficient of friction is determined based on the following equation: Wherein, the A first coefficient of friction is indicated and,The rotational reynolds number is indicated,Indicating the air gap ratio of the target motor,The air density is indicated as such,Indicating the angular velocity of the target motor,Representing the radius of the rotor of the target motor,Representing the air gap length of the target motor,Representing aerodynamic viscosity. In one possible implementation, the determining the first correction factor based on the air axial flow rate includes: determining a first correction factor based on the following formula: Wherein, the A first correction factor is indicated and is indicated,Representing the axial reynolds number,The rotational reynolds number is indicated,The air density is indicated as such,Representing the air gap length of the target motor,Indicating the axial flow rate of the air,Representing aerodynamic viscosity. In one possible implementation, the determining the second correction factor based on the rotor air gap side surface roughness includes: determining a second correction factor based on the following formula: Wherein, the A second correction factor is indicated and is indicated,Representing the rotor air gap side surface roughness,Representing the radius of the rotor of the target motor,The rotational reynolds number is indicated. In one possible implementation manner, the correcting the first friction coefficient based on the first correction factor and the second correction factor to obtain the second friction coefficient includes: And determin