How to design a wind turbine earthing system?

The design of the earthing system shall correspond to the lightning protection level (LPL) for which the wind turbine protection system is designed. The minimum radius of the ring conductor or the foundation earth electrode (re) is 5 meters for a system designed to meet lightning protection Class III or IV.

What are the requirements for a wind turbine earthing system?

Wind turbine manufacturers typically prescribe an earthing system design that exceeds the minimum requirements of IEC 61400-24 (and IEC 62305-3) for added protection and personal safety. A typical local WTG earthing arrangement is shown in the figure below.

What is the typical electrical system of a wind farm?

The typical electrical system of a wind farm consists of three main areas for design consideration the wind turbine generators (WTGs), the collector system of cables and/or overhead lines, and the substation for utility power interconnection.

Do offshore wind turbines need earthing?

For offshore wind turbines compliance with steel concrete reinforcement being used as the earthing electrode, then the maximum grid resistance requirements are assumed (due to the low resistivity of seawater), and no additional earthing is required.

What is a wind farm earthing system?

The typical earthing system for a wind farm is a single integrated (combined) structure suitable for all purposes, including lightning protection, power system fault protection, and telecommunication systems. The WTGs are earthed locally, and a ring electrode is installed for controlling the ground surface voltage gradients close to the foundation.

Why do wind farms need soil resistivity tests?

For a wind farm, it is imperative to perform extensive soil resistivity tests prior to the construction to achieve accurate analysis and a cost-effective design. This is due to the sheer size of a wind farm and the fact the soil resistivity is not consistent across the site due to geological variations.