Research on the mechanism and restraining measures of ferroresonance in distribution network based on ATP-EMTP

•In this paper, the mechanism and the main suppression measures of ferroresonance were described.•A typical substation was taken as the research object, and the simulation models were established by using the electromagnetic transient analysis software ATP-EMTP.•Two measures to suppress ferromagnetic resonance are discussed, which can provide reference for the power sector to control ferromagnetic resonance.•When the neutral point of voltage transformer is grounded by resonance eliminator or the arc suppression coil, the ferroresonance of the system can be effectively suppressed. In order to monitor the three-phase voltage of the busbar to ground, the substation bus is usually connected to the electromagnetic voltage transformer by YN connection in the distribution network. Under certain conditions, the excitation characteristics are easy to saturate, and the inductance parameters match the system capacitance, excite ferromagnetic resonance, cause damage to fuses or voltage transformers, and seriously affect the safe and stable operation of the power system.By analyzing typical single-phase ground faults, this paper introduces the generation mechanism of ferromagnetic resonance and the main suppression measures at this stage. The electromagnetic transient analysis software ATP-EMTP is used to analyze the operation of a typical transformer, and the change of ferromagnetic resonance waveform after the neutral point of the voltage transformer is replaced by resonant eliminator and arc suppression coil grounding. The results show that when eliminating the single-phase ground fault, it is easy to cause the frequency division resonance of the system, and the use of these two measures can effectively suppress the ferromagnetic resonance of the system.