| Ferroresonance overvoltage is one of the inner overvoltage that always occurring in neutral isolated system and sometimes in neutral grounded system. The overvoltage and overcurrent of Ferroresonance does great harm to stable and safe running of power system. For keeping the transmission and distribution equipments out of damage, it is very important to research the Ferroresonance simulation model and detection method.Aim at one 110 kV power substation, considering the asymmetry of the power distribution system resulting from the non-transposed transmission lines, the ATP-EMTP simulation program is used to research the substation Ferroresonance simulation model, and the Ferroresonance situation on this substation 35kV bus PT is simulated. The simulation results indicate that the moment of the single phase grounding fault disappearing is a key factor to excite Ferroresonance. Various suppression measures such as connecting nonlinear resistance to the neutral point of three-phase PT high-voltage side, connecting an arc-extinguishing winding to the neutral point of power system, connecting damping resistance to the broken delta winding of three-phase PT are researched and compared.In the Ferroresonance detection area, due to the shortcomings of comparative counting method and the symmetry method, wavelet transform is widely used nowadays. Because of frequency aliasing resulting from wavelet transform, wavelet transform may causes misjudgment on Ferroresonance detection, at present the wavelet analysis on Ferroresonance detection is restricted to neutral isolated system. This paper solves this wavelet's frequency aliasing using combination of Fourier transform and wavelet transform. The results of simulation analysis comparison show this method is effective both in neutral isolated system and neutral grounded system.
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