Low-iron-loss variable flux permanent magnet memory motor robustness design method for electric automobile

Abstract

The invention relates to a low-iron-loss variable flux permanent magnet memory motor robustness design method for an electric automobile. The method comprises steps that a variable flux permanent magnet memory motor structure for the electric vehicle is determined; an air magnetic isolation groove structure of an improved variable flux permanent magnet memory motor is improved, air magnetic isolation groove expansion structures are added to air magnetic isolation grooves on two sides of a U-shaped permanent magnet cavity close to a surface of a rotor core, and sharp points of the air magneticisolation groove expansion structures in a rotor pole shoe are defined as vertexes of the expansion structures; a distance from the vertex of the air magnetic isolation groove expansion structures tothe circle center of the rotor, an included angle between the vertex of the air magnetic isolation groove expansion structure and a center line of a magnetic pole, the width of an edge opposite to thevertex of the air magnetic isolation groove expansion structure and the position of the edge opposite to the vertex of the air magnetic isolation groove expansion structure serve as optimization variables. The method is advantaged in that the minimum flux linkage and the minimum iron loss under the action of demagnetizing current pulses and the minimum iron loss under the action of magnetizing current pulses are taken as optimization objectives, and the improved structures of the air magnetic isolation grooves are optimized by using a Taguchi method.

Description

[0001] Technical field [0002] The invention belongs to the field of motor robustness design, and in particular relates to the robustness design of a low iron consumption variable flux permanent magnet memory motor for an electric vehicle. Background technique [0003] The permanent magnet synchronous motor used in electric vehicles requires the motor to have a wide operating speed range. For ordinary permanent magnet synchronous motors, in order to make the motor run at a higher speed, it is necessary to apply a higher negative d-axis current to the motor to weaken the flux linkage of the permanent magnet. The higher the running speed of the motor, the greater the negative d-axis current that needs to be applied. On the one hand, the permanent magnet in the motor is prone to irreversible demagnetization. In addition, the larger negative d-axis current also causes the copper loss and iron loss of the motor Increase, reduce the operating efficiency of the motor. To avoid the...

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Problems solved by technology

[0005] At present, the methods of optimizing the motor are divided into global optimization design method and local optimization design method. The global optimization design method includes genetic algorithm, simulated annealing method and tabu search and other intelligent optimization algorithms. The global optimization design method can eliminate all uncertain factors. Included in the optimization objective, but the establishment of the specific objective function is very complicated, the cost of calculation is very large, and the calculation time is very long; local optimization design methods include deterministic methods such as compound shape method, simplex method, and mountain climbing method. The linear optimization design method has a good convergence effect for single-objective optimization, but it cannot achieve multi-objective optimization design.

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