异步电动机软起动过程中的振荡

Oscillation in Soft-Starting of Induction Motor

针对异步电动机软起动过程中出现的电流、电磁转矩以及转速振荡问题,建立了其软起动通用仿真模型,分析了异步电动机软起动过程中引起振荡的影响因素及其产生原因,提出用控制关断角的方法,即以电流关断时刻为基准,在电机软起动过程中使关断角逐渐减小为零来抑制振荡。通过仿真验证了该控制方法的正确性,并在此基础上研制了基于关断角控制的异步电动机软起动装置并进行了样机试验,实验结果验证了理论分析的正确性。

Oscillation of current, electromagnetic torque and speed appears during soft-starting of three-phase induction motor. According to the mathematical model of the induction motor, a common simulation model of induction motors is established. Some influencing factors of the oscillation are analyzed and the cause of oscillation is derived. In addition, a method of controlling hold-off angle is proposed. This method makes the current zero-crossing as the reference. During the starting process of induction motor, the hold-off angle of current has gradually decreased from initial value to zero. This paper verifies the correctness of the method by simulation. Furthermore, it presents experimental facility based on hold-off angle control and experiments on a prototype induction motor. Then experiment results validate the correctness of theory analyses.