Method of Prevention from Expansion of Phase-segregated Circuit Breaker Malfunction in Manual Tripping
There have been reported several on-site instances of one-or two-phase circuit breaker malfunction during man-ual tripping of phase-segregated circuit breakers,but the current regulations do not require to activate protection against manual tripping circuit breaker malfunction.Hence if under this situation the load current is cut off by zero-sequence over-current protection,the accident may expand.At present the protection of 220 kV lines in Southern Power Grid has a-chieved remote tripping to line's opposite side after three-phase inconsistency and single-phase operation with three trip-ping actions through software modification.However,some areas of State Grid and Southern Power Grid do not have the conditions for software upgrade for protection.A method has been proposed working by connecting the manual tripping relay contacts and the three-phase position inconsistency state contacts of the circuit breaker in series and connecting them to other protection actions of longitudinal current differential protection.This method is simple,reliable,and easy to im-plement.
万方数据
维普
