Study on Line-Break Ferro-Resonance Over-voltage of 35kV Power System and Its Suppression Methods

There are a lot of inductance component and capacitance component in 35kV system, including transformer, current and voltage transformer, generators, arc suppression coil, transmission line´s direct-to-ground capacitance and phase-to-phase capacitance, condenser in parallel and series, stray capacity from all kinds of high voltage equipments. Under certain conditions, these elements can form different resonant circuit, cause resonance over-voltage phenomenon, endanger the insulation of the system. In this paper, on the basis of one copper mining company 35kV power supply system, it´s carried out the resonance over-voltage studies, reach conclusion about the general rules of how ferromagnetic resonance arises. Finally, corresponding suppression methods are raised.