Reserch on Extracting the Features at Relay Protection Based on Wavelet Transform Modulus Maximum

In electrical power systems, relay protection is an important protection method. In this paper, according to the theory of detecting abrupt signals with wavelet transformation, we make full use of wavelet transforms modulus maximum technique, the abrupt current signals can be detected quickly when faults occur. At the same time, we also study how to choice a appropriate wavelet for power relay protection. Simulation shows that the proposed method can effectively improve the sensitivity. Also shows the method has a wide range of application for fault diagnosis and extracting signal features.