摘要
对三相交流异步电动机的缺相保护,传统的方法是采用热继电器。但在生产实践过程中,笔者发现由于热继电器主双金属片受热膨胀的热惯性及动作机构传递信号的惰性原因,导致其缺相保护动作不够灵敏,对故障电流响应慢,往往导致电动机误操作,或不起保护作用,造成电动机烧毁。交流接触器本身并没有缺相保护功能,但该文利用交流接触器对缺相保护线路进行重新设计,巧妙地利用交流接触器的欠压、零压保护功能,对三相电动机实现了电源缺相的瞬时保护。
Thermal relay is always adopted for phase break protection of three-phase AC induction motor. But in the engineering application, this paper finds that the thermal inertia of main bimetal heat expansion of thermal relay, and the inertia causes of action agencies sending signals will result in phase break protection to lack enough sensitivity and slow response to fault current. It consequently leads to motor misoperation or malprotection, resulting in motor to be burned. However, AC contactor itself lacks phase break protection. This paper uses AC contactor to redesign the line of phase break protection and cleverly uses the under-voltage and zero-voltage protection functions of the AC contactor to make the three-phase motors to realize the transient protection of power shortage phase.
出处
《继电器》
CSCD
北大核心
2008年第2期85-87,共3页
Relay
关键词
电源缺相
电动机
热继电器
交流接触器
烧毁
缺相保护
power phase shortage motor thermal relay AC contactor burn phase break protection
