Research Of Darat Power Plant High Voltage Bus Ferromagnetic Resonance

The 220KV step-up substation of Darat power plant is a central transformer substation in Inner Mongolia Power Grid, The ferroresonance problems in the substation seriously affect the network security, Studing and resovling the ferroresonance problem have important theoretical significances and practical values. There are many factors that effect the ferroresonance problem, it is difficult to find the optimal solution in both theory and actual application, in this paper, a method that instantaneously access a resistance at the primary side side of the voltage transformer neutral point is put forward.Based on Darat power plants actual situations the several ferroresonance problems are studied, ferroresonance phenomenon caused by the pressure capacitor at circuit breaker fracture is described, the cause is analyzed, numerical simulation and experimental methods are use to anlyze the effects of fracture pressure capacitance, bus-to-ground capacitance, ferromagnetic components and component dynamic hysteresis characteristics on ferroresonanc.Measures for restricting ferroresonance are discussed, and various measures are compared, finally the effective restrictive measures is proposed.The on-site field measurement for the proposed new method has got a more satisfactory result, which validate that the proposed harmonic elimination method is correct and effective.