Study On Lightning Protection Of Wind Turbines

In recent years,environmental pollution caused by the energy is becoming more and more severe,so the development of renewable energy is necessary.During this period,wind energy has developed rapidly with its own advantages.With increasing the capacity and height of wind turbines,lightning stroke in the wind field is becoming more and more obvious,which has to make people concern it.Currently,the lightning protection in the wind industry is designed on the basis of simple lightning protection standards,which obviously cannot satisfy domestic requirements.This paper takes 2MW wind turbine as research subject and makes further studies of lightning protection for wind turbines.This paper studies the lightning protection mainly from the blade,hub,nacelle,tower and surge protector to provide a relatively complete lightning protection system for wind turbines.Firstly,three mathematical models of lightning current are compared and analyzed by Matlab in order to determine the current model of simulation.And then the shortcomings of previous method which is used for calculating the lightning transient electromagnetic field are pointed out and Ansoft Maxwell is proposed to simulate the tower.The reliability of this method is verified by a simple model.The lightning transient characteristics of tower are analyzed according to the simulation results and the influence of lightning current amplitude and waveform on the electromagnetic field is further analyzed.Then the lightning electromagnetic interference on the electronic equipment and the transient overvoltage induced in the loop are calculated according to the law of electromagnetic induction.And the lightning protection of tower is designed and the simulation analysis and calculation results provide reliable theoretical basis for the lightning protection.Besides,the lightning protection of other components is also studied in this paper.The blades are one of the components that are subjected to direct lightning,so the lightning protection zone is divided more carefully.The lightning protection of the receptors is designed from the position,the number and the sectional area.The Faraday cage in the nacelle is designed by calculating the lightning electromagnetic field under the following three circumstances: without shielding,shielding but striking near the turbines,shielding and striking the Faraday cage.The surge protector is designed according to the rules of lightning protection standard: IEC61400-24.And the detailed scheme of SPD is provided.The design of wind turbine lightning protection in this paper has been applied in the wind industry.And the effectiveness of lightning protection designed in this paper is verified by the detailed statistics of lightning accidents in 2015 and 2016.