负序保护在低压隔爆电动机综合保护中应用

通过分析低压隔爆电动机的主要故障类型,针对不对称性短路故障和断相故障提出了采用负序保护原理进行保护的方案。从电源电压严重不平衡故障、断相故障和两相短路故障三方面介绍了负序保护方案设计;采用滤序算法对采样得到的瞬时值进行处理得到序分量;并通过试验方法模拟了发生不对称性短路故障及断相故障时产生的负序电流,试验所得到的实测值和要求值基本吻合,从而验证了保护方案的正确性。将负序保护应用于低压隔爆电动机综合保护中,不仅可以降低保护装置的成本,还能提高保护装置的可靠性。

Negative sequence protection in comprehensive protection of LV flameproof motor

Based on the analysis of main fault types of LV(Low Voltage) flameproof motor,the negative sequence protection principle is proposed for its asymmetric short circuit fault and open phase fault.The design of negative sequence protection is mainly introduced with seriously unbalanced power supply voltage fault,open phase fault and two-phase short circuit fault.The strain sequence arithmetic is used to deduce sequence components from instantaneous samples.Negative sequence currents generated in asymmetric short circuit fault and open phase fault are simulated by experiments and the measured experimental results coincide with the requested values,which proves the correctness of protection scheme.The application of negative sequence protection in LV flameproof motor comprehensive protection reduces equipment cost and improves its reliability.