Analysis and Measures of 10kV Bus PT Breakdown Accident

A 10kV bus PT breakdown accident caused by two-phase grounded is mainly introduced in this paper. Firstly, the bus voltage variation is analyzed when two-phase grounded occurs. Then, the ferromagnetic resonance mechanism and the reason of PT magnetic saturation are introduced in neutral point ungrounded system. The function of PT primary side resonance elimination device is analyzed. At last, the management and technology problem exposed by the accident is analyzed, and the preventive measures suitable for the company are put forward in order to reduce the occurrence of such accidents.