基于功率因数闭环控制的异步电动机软起动器的研究

Soft-starter of Asynchronous Motor Based on Power Factor Closedloop Control

异步电动机起动电流过大将对电网造成很大的冲击,本文在分析异步电动机功率因数角特性的基础上,以电机的功率因数角作为系统的反馈量进行闭环控制,避免了在电机起动过程中,由于电机端口输入电压的变化引起的电磁转矩振荡及电流振荡,保障了电机电压按预期的规律进行调节。实验结果证明了该方法的有效性。

The large starting current of asynchronous motor may bring about great impact to electric network. According to the analysis of power factor characteristic in asynchronous motors, Ibis paper brings lbrward a closed-loop control method using the power factor angle as the feedback variable of the system, avoiding the vibration ot＂ electromagnetic torsion and currents by variation of input-voltage during the starting process of motors. The above strategy ensures the voltage regulation according to the expected rules. The experiment results prove the availability of the method,