Although permanent magnet starting motor is a kind of pm dc motor , its performance requirements and performance calculating method are not the same as the latter , because it works at transient state . before the computer aided design software of pm starting motor is developed , the performance calculating method is given from the view of cad . the validity and correctness of the software are illustrated by test results 从计算机辅助设计的角度出发，首先给出了永磁起动机工作瞬态的性能计算方法，然后开发了永磁起动机计算机辅助设计软件，最后利用试验结果对计算方法进行了全面考核，证明了方法的正确性和有效性。
