Interior magnet machine design with low core losses

Patent metadata

Field	Value
Publication number	US-2018322231-A1
Application number	US-201615772041-A
Country	US
Kind code	A1
Filing date	Oct 27, 2016
Priority date	Oct 30, 2015
Publication date	Nov 8, 2018
Grant date	—

Abstract

Methods and apparatus for estimating and minimizing core losses in interior magnet machines are disclosed. Methods can include creating, modifying, or receiving a finite element analysis (FEA) model to represent at least one portion of an motor in a computer system, placing at least one coil at a first location within the rotor iron or stator iron of the motor in the FEA model, calculating a time-domain flux density B of the at least one coil, converting the calculated flux density function to a frequency-domain spectrum, receiving material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum, and determining a core loss of the at least one portion of an electric motor by a weighted combination of the material core loss parameters. Coils may be placed manually by a user through a user interface, or may be placed automatically.

First claim

What is claimed is:

1 . A method of estimating core loss in an electric motor using a finite element analysis (FEA) simulation, comprising the acts of:
creating, modifying, or receiving a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor; placing, with the user interface, at least one coil at a first location around at least one portion of the rotor iron or stator iron of the motor in the FEA model, the coil comprising a wire loop; calculating a time-domain flux density B of the at least one coil as a function of time; converting the calculated flux density function to a frequency-domain spectrum; receiving material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and determining a core loss of the at least one portion of an electric motor by a weighted combination of the received material core loss parameters according to the relative magnitudes of the peaks in the discrete frequency-domain spectrum.

2 . The method of claim 1 , further comprising the act of modifying, adjusting, or redesigning a FEA model based on the estimated core loss so as to minimize core loss.

3 . The method of claim 2 , further comprising manufacturing an electric motor based on the modified, adjusted, or redesigned FEA model.

4 . The method of claim 1 , wherein the at least one portion of an electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

5 . The method of claim 1 , further comprising executing a time-stepped FEA simulation of the FEA model.

6 . The method of claim 1 , further comprising receiving an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or flux density of the at least one coil as a function of time.

7 . The method of claim 1 , wherein converting the calculated flux density function to a frequency-domain spectrum comprises computing a discrete Fourier transform (DFT) of the time-domain flux density function.

8 . The method of claim 1 , wherein the material core loss parameters comprise B-P curves.

9 . An apparatus for estimating core loss in an electric motor using a finite element analysis (FEA) simulation, the apparatus comprising:
means for creating, modifying, or receiving a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor; means for placing at least one coil at a first location within the rotor iron or stator iron of the motor in the FEA model, the coil comprising a wire loop; means for calculating a time-domain flux density B of the at least one coil as a function of time; means for converting the calculated flux density function to a frequency-domain spectrum; means for receiving material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and means for determining a core loss of the at least one portion of an electric motor by a weighted combination of the received material core loss parameters according to the relative magnitudes of the peaks in the discrete frequency-domain spectrum.

10 . The apparatus of claim 9 , wherein the at least one portion of an electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

11 . The apparatus of claim 9 , further comprising means for executing a time-stepped FEA simulation of the FEA model.

12 . The apparatus of claim 9 , further comprising means for receiving an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or flux density of the at least one trivial coil as a function of time.

13 . The apparatus of claim 9 , wherein converting the calculated flux density function to a frequency-domain spectrum comprises computing a discrete Fourier transform (DFT) of the time-domain flux density function.

14 . The apparatus of claim 9 , wherein the material core loss parameters comprise B-P curves.

15 . A computer program product for processing data for a program configured to estimate core loss in an electric motor using a finite element analysis (FEA) simulation, the computer program product comprising:
a non-transitory computer-readable medium having stored thereon code for causing processing circuitry to:
enable a user to create, modify, or receive a FEA model to represent at least one portion of an electric motor in a computer system, the computer system comprising a user interface and a processing circuit configured for FEA simulations, the electric motor comprising at least one rotor capable of rotation about a rotational axis and a stator having at least one pole pair disposed radially about the rotational axis of the rotor;
enable placement, with the user interface, of at least one coil at a first location within the rotor iron or stator iron of the motor in the FEA model, the coil comprising a wire loop;
calculate a time-domain flux density B of the at least one coil as a function of time;
convert the calculated flux density function to a frequency-domain spectrum;
receive material core loss parameters for at least some frequencies indicated by the frequency-domain spectrum; and
determine a core loss of the at least one portion of an electric motor by a weighted combination of the received material core loss parameters according to the relative magnitudes of the peaks in the discrete frequency-domain spectrum.

16 . The computer program product of claim 15 , wherein the at least one portion of an electric motor comprises at least one portion of the at least one rotor and at least one portion of the stator.

17 . The computer program product of claim 15 , wherein the code stored on the non-transitory computer-readable medium further causes processing circuitry to execute a time-stepped FEA simulation of the FEA model.

18 . The computer program product of claim 15 , wherein the code stored on the non-transitory computer-readable medium further causes processing circuitry to receive an output from the processing circuit configured for FEA simulations, the output comprising a flux linkage or flux density of the at least one trivial coil as a function of time.

19 . The computer program product of claim 15 , wherein the code for causing processing circuitry to convert the calculated flux density function to a frequency-domain spectrum comprises code for causing processing circuitry to compute a discrete Fourier transform (DFT) of the time-domain flux density function.

20 . The computer program product of claim 15 , wherein the material core loss parameters comprise B-P curves.

Assignees

• Faraday&Future Inc

Inventors

• Campbell Mengwei Li
• Dang Jie

Classifications

• G01R31/34 Primary

  Testing dynamo-electric machines · CPC title

• G01R33/02

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G06F2119/18

  Manufacturability analysis or optimisation for manufacturability · CPC title

• G06F30/23 Primary

  using finite element methods [FEM] or finite difference methods [FDM] · CPC title

• G06F2217/12

  Physics · mapped topic