线路保护中PT断线判据的分析和改进

Analysis and improvement of PT breaking criterion in line protection

PT断线作为电力系统中一种常见的故障,能否及时有效地进行判别,是继电保护装置正确动作的前提条件。针对PT断线的特点,在对不同厂家的判据进行了分析后,结合一次现场实例,指出了目前判据中存在的不足之处,给出了一种PT断线的实用判据。根据该判据开发的线路保护装置已经在现场投入使用,证明了该判据的工程实用价值。

It is the precondition for protection's correct operation to verify PT breaking in time,which is a common fault in power system.Based on the characteristics of PT breaking and analysis of the criteria of different manufacturers,this paper points out the disadvantages of current PT breaking criterion.At last, it provides a practical criterion which has been applied to line protection,and the results reveal its usefulness in engineering.