The Analysis of One Protection Action Caused by 110kV Line Break Fault

Combined with the 110KV line breaking protection action, this paper pointed out the main problems is that the switch of 110KV side is not disconnected. It leaded to protection action of T type transformer in 110KV line. Because of the problem in switch operating of 110KV line, the three phases are not disconnecting all. It caused insulation damage of the 110KV main transformer that the 110KV line is non-phase, and then it caused tripping main transformer protection. This paper proposes improvement measures and precautions for such situations.