Analysis and identification method of transient overvoltage coupling characteristics of secondary equipment in substation caused by induced lightning

The induction lightning stroke over-voltage which is arising near Lightning substation is one of the important reasons to the secondary equipment damage. So the research and the identification, which are about the induction lightning stroke transient coupling characteristics of the substation secondary side equipment, have the great significance in transient protection and improvement of its reliability. This paper simulates the transient process which is arising from the of the induction lightning stroke impact to the substation secondary side cable using the laboratory equipment, analyzes the transient radiation signal which is arising from the induction lightning stroke impact coupling the shielded cable, and proposes a recognition of the induction lightning stroke based on wavelet packet energy spectrum characteristics entropy. Decompose the monitored transient disturbance signal into the reconstruction signals of different frequency bands by wavelet transform, construct high-band and low-band wavelet energy feature vector by wavelet energy spectrum method, and use it as the input of the recognition system. So the proposed method can better response the transient process characteristics which is arising by the induction lightning stroke, ensure the reliability of the identification results, and have certain theory and engineering applications value.