Cause analysis of abnormal system voltage caused by phase absence of circuit breaker parallel capacitor

Based on Kirchhoff's current law, this paper calculated and analyzed a fault that the shunt capacitor of generator circuit breaker phase loss. The reasons causing abnormal condition of generator outlet voltage and low voltage side voltage of main transformer are analyzed. It is concluded that the fault of the shunt capacitor of the circuit breaker may cause the imbalance of the capacitance to earth of each phase of the system, and thus lead to the abnormal voltage of the system. And on this basis, combined with the author's work experience, give preventive measures for such abnormal situations for reference.