说明：  三相异步电机变频调速仿真模型 仿真目的：改变三相异步电机的定子电源频率，观察电机定子电流，转速的变化规律。
(Three-phase induction motor speed regulation simulation model simulation purpose: to change the three-phase induction motor stator power frequency, and observe the variation of the stator current, speed.)