摘要
该文研究了三相异步电动机功率因数角随转速的变化规律,根据晶闸管调压电路的工作特点,分析了电机在调压起动过程中产生电流振荡的原因。提出了在电机软起动控制系统中应实施电机功率因数角闭环控制的观点,通过分析指出:晶闸管调压电路中可控的晶闸管触发角应该由两部分组成,一部分是按预定规律调整的角度,另一部分是跟随电机功率因数角的变化而增加的动态调整角度。实验证明,该闭环控制方法有效地解决了电机软起动过程中的电流震荡问题。同时,利用实时检测到的功率因数角信息,可以实现电机的轻载节能运行功能。
In this paper, the rule of displacement angle vs. speed in a three-phase induction motor is investigated. Based on the operating principle of thyristor voltage controller, the cause of phase current oscillation during soft starting with a voltage regulator, is analyzed. It is proposed that the displacement angle closed loop control should be introduced in induction motor soft starter. Through analyzing, it is pointed out that the thyristor firing angle should be composed of two parts. One is obtained from the predetermined voltage control rule, and the other is the increase of dynamic regulating angle with the variation of displacement angle. The experiments prove that the proposed closed loop control method can avoid current oscillation during soft starting, and energy saving operation of the motor under light load can be realized by using the displacement angle detection in real time.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2002年第8期82-87,共6页
Proceedings of the CSEE
