Fault analysis of a grounding transformer

The grounding transformer is a transformer intended solely for establishing a neutral connection point on an ungrounded power system. Then grounded with the Petersen-coil or the low resistance. This paper makes the depth analysis of the structure principle of the grounding transformer and its electromagnetic relation. Then a zigzag grounding transformer is modeled in MATLAB simulator with the single-phase 5 winding transformer. It could realize the phase-to-phase faults and interterm faults simulation of the grounding transformer´ any point. The simulation results prove the analysis´ correctness and validity, which provide the theoretical basis for the grounding transformer´s protection device.