Study on Ferroresonance Over-Voltage Based on Harmonic Elimination Device

The paper calculated the accident of the voltage transformer caused by the ferromagnetic resonance over-voltage in Hunan power grid, and analyzed the generation principle of the ferromagnetic resonance over-voltage. The simulation model of 10kV distribution line was established through ATP, and the ferromagnetic resonance over-voltage caused by single-phase ground and two-phase in the system was simulated and analyzed. Aiming at the generation principle of ferromagnetic resonance over-voltage, The paper proposed the measures of harmonic resonance elimination of the voltage Transformer, and analyzed the protection effect through simulation model. The research showed that the measure of neutral earthing via suppression coil is most effective for eliminating ferromagnetic resonance.For the second side loading harmonic resistance, the smaller the resistance, the more obvious of elimination effect, but the resistance is too small can cause TV overload, need to pay attention to the capacity of the TV.