为分析风荷载作用下的海上风机结构动力响应特性,提出采用数值仿真的方法模拟其空间域内的随机风场.利用MATLAB软件编制基于ARMA(autoregressive moving average)模型的脉动风速时程模拟程序,并嵌入AIC(Akaike's information theoretic)准则以判定ARMA模型的最优阶数,最终,针对江苏黄海某海上风机项目进行数值仿真分析,将模拟脉动风速功率谱与目标Davenport谱进行对比.计算结果表明:根据AIC准则确定的ARMA模型最优阶数可兼顾模型模拟精度和计算成本;模拟脉动风速时程功率谱函数在0.3 Hz以下的低频区间波动较大,与目标谱函数存在一定差距,在中高频段两者规律差距较小,整体模拟精度较高.
Simulation of stochastic wind field of offshore wind turbines based on ARMA model
A numerical simulation method for the stochastic wind field in a certain spatial domain was proposed to analyze the dynamic response characteristics of offshore wind turbines under wind loads.The simulation program for the time-history series of fluctuating wind speed was compiled by using the MATLAB software based on ARMA(autoregressive moving average)model.The optimal order of the ARMA model was determined through embedding the AIC(Akaike's information criterion).Finally,a numerical simulation analysis was carried out for an actual offshore wind turbine project in the Yellow Sea of Jiangsu Province,and the power spectrum of the simulated fluctuating wind velocity was compared with the target Davenport spectrum.The calculation results show that the optimal rank of the ARMA model determined according to the AIC can take into account the simulation precision and computation cost.The power spectrum function of simulated fluctuating wind speed fluctuates greatly in the low frequency range below 0.3 Hz,and there is a certain gap with the target spectrum function.The two laws are consistent,and the gap is small in the medium and high frequency ranges.The overall simulation accuracy is high.
offshore wind turbinesARMA modelAkaike's information criterionDavenport power spectrumMATLABfluctuating wind speed time series
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维普
