Research on the Influence of Closing Resistor inside Circuit Breaker on Magnetizing Inrush Current of UHV Transformer

Using Matlab/Simulink software established the simulation model of UHV transformer and UHV power grid.The characteristic of magnetizing inrush current for UHV transformer was obtained by simulation.The paper also analyzed the impact on differential protection from it. Closing resistor inside circuit breaker method was proposed to restrain magnetizing inrush current.The method cuts down the amplitude and accelerated the attenuation speed of it, so as to restrain it. The simulation analysis verified the effectiveness of the method.