HHT based adaptive re-closure method

Automatic reclosure is widely used in power system which can effectively reduce the influence of transient fault and improve power supply reliability. But, when re-closure is closed at the line which have permanent fault, the power system can be affected by the impulse fault current. The paper analyses transmission character of traveling wave generated by breaker and presents a method to judge fault type based on the traveling wave generated by breaker. Because of the reflection and refraction, the amplitude and phase angle have a big change. So the variable quantity of amplitude and phase angle can be set criterion of adaptive re-closure method. HHT can be used to exact the instantaneous frequency of traveling wave. The simulation result shows the method can judge transient fault and permanent fault effectively.