It may be shown that lightning strikes are the cause of a
disproportionately large loss of kWh generation. Consequently the objectives of the project are the investigation and the development of a general methodology for the protection of wind turbine generator systems from lightning strikes. The project will provide practical assistance and guidance to the designers and operators of wind turbines to put in place cost-effective lightning protection systems providing a to-be-determined level of protection so that the effects of lightning can be minimised. Experimental work will examine the effect of lightning on blades and bearings. Various protection measures will be assessed. Computer analysis and simulation will be used to investigate induced voltages in control circuits and to model the response of wind farm earthing systems to lightning.
The project will consist of a number of phases.
- Recorded strike data will be collated by a questionnaire survey and a document search from published data.
- Estimates will be made of the level of protection required for different geographical locations using available data.
- Testing will be used to estimate the susceptibility of blade structures to lightning damage and to investigate the effects of lightning strikes on the rotating bearings in the wind turbine drive train.
- The guidelines of existing good lightning protection practice will be reviewed for their relevance to wind turbines and wind farms. Case studies will be made of existing wind turbine nacelle and tower designs to demonstrate the likely distribution of severe strike current and the consequent effects in generating induced voltages in wiring. - An analysis of the problem of maintaining the safety of the operators on wind farm sites will be made to establish the scale of the hazard. - The response of wind farm earthing to lightning will be investigated using computer simulation.
- A best practice guide will enable designers to assess the risk from lightning arising from their design, manufacture and siting of their turbines and assist them in appropriate protection measures.
Expected Achievements and Exploitation
A designers guide will be made available to European industry so that wind turbines and wind farms are designed and constructed with a level of protection that makes the risk of lightning strikes acceptable. The research carried out in the project will be included to illustrate the philosophy used in determining the recommendations made:
- Support the move toward the increase in size of wind turbines. - Reduction in power losses due to lightning strikes.
- Improved public perception of wind energy.
- Increased utilisation of wind energy within the EU resulting in reduced fossil-fuel emissions.
Funding SchemeCSC - Cost-sharing contracts
OX14 3DB Abingdon