New lightning current arrester design for onshore and offshore wind turbines

This paper describes the challenging operating conditions of onshore and offshore wind turbines and the requirements for the design of surge-protective devices - which result from these operating conditions. To meet these operating conditions and the requirements derived from standards and guidelines for wind turbines, a new hybrid design of varistor-based and spark-gap-based IEC Class I lightning current arresters had been designed. This paper also describes the design principles and the operational behavior of this new arrester for wind turbines.

I. Introduction

Wind turbines are usually installed at exposed locations, and sometimes at very remote locations - e.g. offshore or in the middle of a desert. Especially at remote locations, the operational reliability of wind turbines is of the utmost importance for the operators of wind turbines. Wind turbines are easy targets for high-energy lightning strikes. Therefore IEC Class I surge-protective devices (SPDs) - for the diversion of lightning currents - are frequently used for the protection of low-voltage AC power systems in wind turbines.