Research On Lightning Characteristics And Protection Measures Of Large Offshore Wind Turbines

Wind energy is one of the most widely used energy sources with the most rapid development momentum.Its extensive application is of great significance to reduce carbon emissions and improve energy structure.In recent years,with the strong support of the national energy department for green energy and the positive response of the industry to the early realization of "carbon peak,carbon neutral",compared with onshore wind power,offshore wind power naturally attracts more and more people’s attention.However,the complex weather conditions and hydrological environment at sea gradually become an important factor limiting the development of offshore wind power.In this paper,according to the characteristics of marine environment,the grounding resistance model of jacket foundation of offshore fan is established and the calculation method is proposed.The influence of seawater depth,seawater resistivity and seabed resistivity on grounding resistance is quantitatively analyzed by CDEGS software.In addition,the formulas for calculating inductance and capacitance parameters of fan blades are derived by using Neumann integral method and mean potential method.On this basis,a blade wave impedance model considering the rotation characteristics of fan blades and the change law of spatial position is established,and the numerical calculation formula of tower drum wave impedance is derived smoothly by using the theory of conical antenna.By means of ATP-EMTP software,an integrated model of offshore fan is established,and the transient process after lightning strike is successfully simulated.The voltage waveform of high voltage side and low voltage side of transformer is obtained,and the influence law of various factors on the transient process of lightning is discussed.Finally,this paper also studies the insulation protection measures and lightning protection schemes focusing on tower barrel,transformer and submarine cable.The research content of this paper can provide scientific theoretical basis and practical guidance for the safe and stable operation of offshore wind turbines,which is conducive to promoting the sustainable utilization and development of wind energy resources.