永磁无刷电机对拖系统仿真分析

针对两台结构相同分别作为电动机和发电机的永磁无刷电机进行研究,两台电机对拖运行,电动机由PWM型逆变器驱动,发电机以三相Y形联接电阻箱为负载,仿真了三种等效电压相同,不同PWM占空比情况下的电动机和发电机的电流。发电机电流通过有限元法仿真得到,电动机电流利用反电势查表法通过有限元和MAT-LAB的联合仿真得到。仿真结果与实验结果相吻合,并在此基础上对对拖系统进行了损耗分析。通过研究发现,电动机和发电机的损耗并不相同,造成对拖运行的两台相同的电机发热不同。

Simulation Analysis of Permanent Magnet Brushless Machine Towing System

Two identical permanent magnet brushless machines were analyzed,when they were back-to-back connected and used as motor and generator.The motor was driven by pulsewidth modulation(PWM) inverters and the generator was connected to the 3-phase,Y-connected resistance load.Phase currents of both motor and generator under the same equivalent voltage but different PWM duty ratios were simulated.The generate current was simulated using finite element analysis(FEA) and the motor current was obtained using FEA and MATLAB combined simulation based on the table look-up method.Good agreement between simulation and measurement was achieved,and loss calculation of machines was performed based on the derived current.The analysis revealed that the reason causing the difference in temperature rises of the two identical machines of the towing system was the loss difference between motor and generator.