三相异步电机切换过程的动态分析与系统仿真

Three-phase Asynchronous Motor Dynamic Analysis and System Simulation of Switching Process

根据感应电动机的定子电压方程和相量图,对大功率电机动态切换过程存在的问题进行了理论分析,然后建立Matlab数学模型,采用变频器输出电压和工频电压不同的初始相位之差对切换过程进行系统仿真,结果表明初始相位相差越小,电流冲击越小,电机越容易进入稳定状态。因此大功率电机切换过程最有效方式是在切换的瞬时,变频器输出电压和工频电压相位尽量保持一致,这样有效地论证了电机同步切换时转换电流小,电机无冲击的理论分析。

According to an induction motor stator voltage equation and phase diagram,the theoretical analysis about the problem that exists in the dynamic switching course of high-power motor was given.Then a Matlab mathematical model was created to simulate the system by using the different initial phase between the converter output voltage and power frequency voltage in the course of switching.The result shows that the smaller the initial phase difference is,the lesser the current impact to motor is,and motor easily accesses to a stable state.Therefore,the most effective switching way to high-power motor is that phase should keep consistent possiblily between the converter output power and network power in the instantaneous of switching.So the theoretical analysis that the conversion current is small and current impact is very less in the course of motor synchronous switching is effectively demonstrated.