An EMTP Model for Lightning Surge Analysis of Wind Farms

Abstract

Wind farms usually occupy large areas with high wind incidence, which often coincide with high keraunic levels and high relative soil resistivity (often in excess of several thousand Ωm in parts of southern Europe). Additionally, wind farms present complex mutually interconnected electrical system, consisted of wind turbines (with their earthing system), cable networks, transformer station (with earthing grid and high voltage apparatus) and high voltage overhead transmission network. High lightning strike incidence, combined with high soil resistivity, can have adverse effects on performance of individual wind turbines, other electrical equipment and on the wind farm as a whole. Whence, lightning induced overvoltage analysis of the involved electrical system, carried out with a sophisticated software package such as EMTP, is often regarded as the best approach in the course of the overvoltage protection selection for wind farms. Application of the appropriate model for each individual electrical system component, in the course of the lightning surge analysis, is a major topic of concern among researchers and engineers involved in this field. This paper will present propositions of components modelling as well as comparison of several possible models for each of the components of the associated electrical system of the wind farm.

Petar Sarajčev

Full Professor | Department of Power Grids and Substations

Ranko Goić

Full Professor | Department of Power Grids and Substations

Full professor at the Faculty of Electrical Engineering, Mechanical Engineering, and Naval Architecture in Split exeperienced in transmission and distribution networks, renewable energy sources (RES), power system planing and economics