500kV罐式断路器电流互感器二次回路接线错误的分析及对策

介绍了一起因500 kV罐式断路器电流互感器二次回路接线错误而产生的重大隐患,当500 kV罐式断路器本体发生故障时,由于线路保护与母线保护使用的电流互感器绕组接线未实现交叉,使得两者的保护范围没有交叉,存在保护死区,从而会导致主保护拒动。通过对全站500 kV系统保护用电流互感器绕组接线的检查和分析,发现造成保护死区主要是设计和安装两方面的原因,针对这两方面原因,提出了加强规范管理,在设计施工阶段加强一二次施工人员的配合以及施工、验收和日常维护时注重对该部分的检查等一系列具体的反事故措施,为今后罐式断路器继电保护用电流互感器绕组的设计、安装调试以及现场验收及维护提供了借鉴。

Analysis on Connection Error in Current Transformer Secondary Circuit of 500 kV Tank Circuit Breaker with Countermeasures

A hidden danger owing to connection error in the current transformer secondary circuit of 500 kV tank circuit breaker is introduced.When the 500 kV tank circuit breaker went wrong,the main protections did not trip to clear the fault because current transformer windings for respective line protection and bus protection had not been cross-connected hence two protection ranges did not overlapped and main protection did not work.The protection dead zone is found to be due to some problems in both design and installation of the current transformer through checking and analyzing the current transformer winding.Consequently,some countermeasures for avoiding the protection dead zone are suggested,such as strengthening cooperation between primary and secondary builders during design and installation stage,and paying more attention to examinations in construction,acceptance and daily maintenance stages.