说明：  根据永磁同步电机数学模型建立的电机仿真模型，并使用PI控制器进行双环控制，达到调节永磁同步电机转速的目的。
(According to the permanent magnet synchronous motor mathematic model of motor simulation model, and use the PI controller 2-ring control, to adjust the purpose of permanent magnet synchronous motor speed.)