Analysis and suppression measures of lightning transient overvoltage in the signal cable of wind turbines. Issue 4 (6th December 2017)

• Record Type: Journal Article
• Authors: Yang, Qing; Tao, Jiayuan; He, Yanxiao; Zhang, Bo
• Is Part Of: Wind energy. Volume 21:Issue 4(2018)
• Page Start: 211
• Page End: 225
• Publication Date: 2017-12-06
• Subjects: comprehensive surge impedance model -- lightning strike -- signal cable -- suppression measure -- transient overvoltage -- wind turbine; Wind power -- Periodicals; 621.312136
• DOI: 10.1002/we.2156
• Languages: English
• ISSNs: 1095-4244

Abstract

Abstract: Lightning strikes are a major threat to the secure operation of wind turbines. When lightning strikes a wind turbine, the lightning current flows through the blade and the tower and then the induced overvoltage will damage sensors and signal cables. In this study, a comprehensive transient surge impedance model of a wind turbine was built to analyze the causes of the overvoltage in the signal cable. The model that studies the overvoltage caused by both capacitive coupling and electromagnetic induction included the blade, nacelle, tower, signal cable, power cable, and grounding system using π networks. The influences of the cable shielding layer, soil resistivity, and lightning current waveform on the overvoltage were also analyzed. Then, 2 overvoltage suppression measures, ie, grounding at 2 ends of the outer shielding layer and installation of a surge protective device, were tested. Results show that a signal cable with double shielding layers reduced the overvoltage in the signal cable, and higher soil resistivity resulted in increased voltage on the tower base. In addition, the peak and the front time of the lightning current significantly influenced the overvoltage on the tower and the cable. The effectiveness of the 2 suppression measures was also verified. The calculation results will provide guidance for a reasonable lightning protection design.