Analysis of 500 kV Line Grounding Switch Miss Operation Blocking in Ultra-high Voltage Power Grid

The correctness of miss operation blocking for grounding switch, is important to ensure the safety of switching-operation in power grid. This paper focuses on the problem of miss operation blocking for grounding switch in ultra high voltage power grid substation, and the principle of the logic blocking and electrical blocking for line grounding switch, under different conditions. Finally, the solutions are proposed to improve the reliability of miss operation blocking, such as series electrical circuit of voltage transformer, upgrade measurement-control device, and other measures.