Lightning-induced Overvoltage Analysis of Wind Turbines Based on Integrated Wave Impedance Model
Lightning-induced transient overvoltage is an important factor affecting safe and stable operation of wind tur-bines.This paper analyzes dependences of overvoltage level on signal cable shielding layer,soil resistivity,and lightning current waveform based on integrated wave impedance model of wind turbines encountering lightning strikes,and reports a study on overvoltage suppression measures.It can be concluded that that the application of double shielding layers for signal cables and a good grounding system for wind turbines can better reduce overvoltage.The two ends of signal cables are more prone to breakdown.Amplitude and crest time of lightning current curve impact largely on overvoltage of signal cables.Moreover,installation of SPD(surge protective device)on top of the signal cable can effectively suppress its over-voltage.