Abstract:The circuit breakers of 10kV compensation capacitor banks have too many times of opening and closing, and faults emerge in endlessly. Due to the complexity of the open phase opening fault of 10kV compensation capacitor bank circuit breaker, it is still impossible to effectively judge it. In view of this, this paper develops a 10kV compensation capacitor bank circuit breaker non-full-phase opening monitoring system. By analyzing the logic values of capacitor bank bus voltage, any phase current and neutral point current when this type of circuit breaker is three-phase equally open, one phase is not open, two phases are not open, and three phases are closed, the type of non-full-phase opening of the circuit breaker is judged according to the display of the live display indicator connected to the logic circuit. During the trial operation of 51C capacitor bank circuit breaker in 110kV Yannian Station, the monitoring system is verified to be effective and feasible, which can help staff determine the opening type of the circuit breaker more quickly according to the live display and take corresponding measures to eliminate faults, thus avoiding accidents caused by incorrect operation methods when equipment defects occur and ensuring the safe operation of the power system.