Meng Xiaoli

Magnetic field analysis and structure optimization of high speed EEFS machine

The structure of the motor and the pattern of windings have great influence on the electrical excitation flux-switching (EEFS) motor. This paper developed a 200KW EEFS machine in the light of drive motors of the high power air conditioning compressor, and introduced the operate principle and basic parameters of the motor. The EEFS machine was optimized through FEM analysis and simulated with Maxwell 2D in a comprehensive consideration of performance indexes such as rated voltage and power. By changing basic sizes of the motor, electromagnetic performances, loss and efficiency of different structures of EEFS machine were compared to get the most suitable structure, and a proposal of radial distribution was given. The performance included the phase flux-linkage, back electromotive force (EMF) waveforms, no load characteristics and load characteristics, etc. The results provided theoretical basis of the development of high reliability of the doubly salient motor.

Analysis of DC output voltage ripple in an electromagnetic doubly salient brushless DC generator

Considering the salient pole and high magnetic nonlinearity of the electromagnetic doubly salient (EMDS) DC generator, a 12/8 pole prototype EMDS generator is designed and calculated using a 2-D finite element method (FEM). The phenomenon is analyzed and that the phase voltage wave changes between 120° and 180°. The influence of the exciting current and armature reaction on the DC voltage ripple of the generator is discussed in detail, and the nonlinear rules are gained that DC voltage ripple changes accordingly. The theoretical analysis is verified by the simulation and experimental results. The results are helpful for the optimal design of the generator and the optimal control of exciting-winding. We conclude that the filter-capacitance of the rectifier can be designed.