关键词: 关键词：火电机组, 正向低功率保护, 程序跳闸, 逆功率保护, 整定原则

Abstract:

Abstract:This paper first introduced the principle,role and electrical process of programmable trip.And then it compared the differences of positive low power protection and reverse power protection for programmable trip on the aspects of logical configuration,role,trip mode and special working conditions such as load rejection.After that,it highlighted the differences of the two protection modes during load rejection
period and pointed out the feasibility and advantages of the application of positive low power protection in coal fired power unit.At last,it proposed the setting principle of positive low power protection and verified its action logic combining with engineering example.

Key words: ">Keywords:">coal ">fired power unit, positive low power protection, programmable trip, reverse power protection, setting principle