Lightning Protection And Grounding Of Wind Turbines And Its Application In Ruyuan Wind Farm

Due to many factors such as surrounding terrain,climate hydrology,soil conditions and its own height,wind turbines are greatly affected by lightning.If a direct lightning strike is encountered,the lightning flow will flow down the blade from the blade through the whole surface of the fan,and the main components of the fan in this process.The weak current system inside the blower will be seriously disturbed or even damaged.In the context of the expansion of the global wind power installed capacity and the construction scale of wind farms year by year,it is of great necessity and urgency to study how to maintain the safe and stable operation of the fan and to highlight its social and economic value.This paper analyzes the subjective and objective reasons for the lightning disaster of the wind turbine.Based on the existing results of the study on the discharge process of the wind turbine,the paper analyzes the many aspects of the lightning characteristics of the wind turbine,and focuses on the danger and prevention measures of the different parts of the wind turbine by the direct lightning and the non direct strike mine,and in the wind turbine unit.In the earthing study,the impact characteristic mechanism of the ground unit in the lightning strike is analyzed,and the change law of the ground resistance of grounding grid under different conditions is studied.At the same time,the typical design structure of the fan grounding device,the main measures of reducing the resistance and the principle are introduced.In order to further study the lightning protection grounding of wind turbines and grasp the distribution of transient overvoltage in different parts of the wind blower,the electric model of the fan must be simulated.The paper is based on the general modeling mathematical method of the fan,and calculates the parameters in the actual model according to the rigorous calculation formula,and uses the international system.The general electromagnetic transient analysis simulation software ATP-EMTP built the main component model of the single typhoon machine,including fan blade,engine room,tower tube,cable,grounding device,lightning arrester and other related components.The lightning transient response analysis model of single typhoon machine was established,and the lightning overvoltage distribution on part of the components was studied.The influence of the grounding resistance of the fan on the transient effect of lightning is analyzed,and the actual effect of the surge protector is simulated.At last,in the grounding project of Ruyuan big cloth fan,according to the actual measurement value of the project,three groups of soil resistivity are set up to each typhoon machine.According to the type of ground network of the wind farm,the type of three types of grounding grid of A,B and C type is designed,which is effective by using appropriate bentonite to reduce the antiseptic.The grounding resistance value of the grounding grid is reduced,and the multifaceted performance of the three types of grounding grids is verified by demonstration and calculation,which all meet the design requirements of the relevant regulations of the state.According to the actual situation of the wind farm,the lightning occurrence rate is high,so the paper puts forward some suggestions and suggestions respectively from two aspects of internal protection and external protection.