Assessing the Effect of the Interconnecting Electrode Length on the Ground Potential Rise of Wind Turbines Subject to Representative Currents of First and Subsequent Strokes

• Published in: Journal of control, automation & electrical systems Vol. 32; no. 6; pp. 1728 - 1734
• Main Authors: Passos, Lucas S., Conceição, Daiane, Alípio, Rafael, Guimarães, Miguel, de Barros, Maria Teresa Correia
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2021; Springer Nature B.V
• Subjects: Conductors; Control; Control and Systems Theory; Electrical Engineering; Electrodes; Engineering; Mechatronics; Robotics; Robotics and Automation; Wind power; Wind turbines; Wind farms; Interconnected grounding systems; Lightning; Impulse response
• ISSN: 2195-3880; 2195-3899
• DOI: 10.1007/s40313-021-00746-5

An evaluation of the influence of the interconnecting electrode’s length on the ground potential rise developed in wind turbines is performed, by means of the injection of currents representative of first and subsequent strokes in a wind farm composed of five turbines. Typical interconnecting bare conductor lengths, as well as a wide range of soil resistivities (300, 600, 1 k, 3 k, 5 k and 10 kΩm), are considered (80 m, 160 m and 240 m). It is shown that for first strokes, the maximum GPR is modified only for the case of high-resistivity soils, still in a low degree. For subsequent strokes, the maximum GPR of the considered configurations is insensitive to the interconnecting electrode length. Even so, the observed voltage reductions at the GPR tail, especially for subsequent strokes, may decrease the electrical stress of the wind turbine. As opposed to the transient stage, the low-frequency resistance is strongly influenced by the interconnecting electrode: as the length of this element is increased, a corresponding reduction in the resistance is observed.