Recognizing the Transformer Inrush Current by FPGA Based on Energy Components

Transformers are the main devices in substations, and the inrush current restricts the accuracy movements of protection device. According to the feather that lots of high harmonic are contained at the current mutation points, the high-frequency components could be obtained by wavelet transform. And the distribution of current mutation points is used to identify the inrush current. At the same time, from the aspect of saving the logic circuits resources in FPGA, the high-frequency energy ratio of adjacent windows is deeply analyzed, and the use of logic circuits has been optimized. Real-time identification of transformer inrush current is achieved on cheap chip EP2C35. The designed inrush current identifier is experimented by RTDS, and the results show that the proposed method is effective.