Research On The Noise Propagation Characteristics And The Reduction Scheme Of Wind Turbine

In the green development of energy transformation,the advantages of wind power generation are becoming more and more obvious,and the investment in wind power technology by various countries is also increasing.The total installed capacity of wind turbines is increasing year by year.At the same time that the wind turbine develops toward large size and large capacity,the noise generated by the impeller during the rotation process is also getting larger and larger,which has brought a great influence to the life of the residents near the wind farm to a certain extent.Therefore,it is of great significance to study the outdoor noise propagation characteristics and noise reduction schemes of wind turbines.Firstly,this thesis studies the influence factors of wind turbine noise in outdoor transmission,and proposes a wind turbine noise propagation calculation model which covers the effects of atmospheric absorption and ground absorption.In addition,the noise reduction scheme of wind farm is also studied.The maximum sound power level of wind turbine is optimized by particle swarm optimization algorithm.Finally,the noise reduction scheme of wind farm is given.The thesis has carried out research from the following three aspects:(1)Based on the IEC 61400-11-2012 noise measurement standard,the noise test of a 2.5MW wind turbine is carried out,and the noise characteristics of the wind turbine are analyzed.The noise test results provide real data for the research of noise propagation characteristics and noise reduction schemes of wind turbines.(2)When analyzing the influence of atmospheric absorption and ground absorption on the noise propagation of wind turbines,it is found that the variation of temperature,humidity and ground hardness will attenuate the noise propagation of wind turbines.Then,various influencing factors are revised to the noise propagation calculation model of wind turbines,and a noise propagation calculation model of wind turbines covering the influence of atmospheric absorption and ground absorption is proposed.Through the analysis of the noise sensitive points of 2.5MW wind turbines,it is concluded that the noise propagation calculation model of wind turbines covering the influence of atmospheric absorption and ground absorption can more accurately evaluate the noise level of wind turbines,and has practical application value in the environmental noise assessment of wind turbines.(3)Particle swarm optimization algorithm is applied to the noise reduction of wind turbines in wind farms.The algorithm is used to optimize the maximum sound power level of wind turbines,and the noise reduction scheme of wind farms is given.Taking a distributed wind farm as an example,the noise reduction schemes of conventional methods and particle swarm optimization are compared.When the environmental noise limit is satisfied,the noise reduction scheme given by particle swarm optimization algorithm can further improve the economic benefits of wind farms,which has practical guiding significance in noise reduction of wind farms.