基于CFD和NCPSO的复杂地形风电场微观选址优化

OPTIMIZATION OF WINDFARM MICROSITTING IN COMPLEX TERRAIN BASED ON CFD AND NCPSO

针对复杂地形条件下风电场微观选址技术难度大的问题,提出一种基于数值计算结果和高效优化方法的微观选址优化算法。将测风数据按风向等分成12个扇区,并利用平均风速和CFD对复杂地形的每个扇区进行数值模拟,得到风电场各扇区的风资源分布,提取轮毂高度处的风速和风向分布。优化中风力机的尾流影响采用Jensen尾流模型,风电场风能计算中风速按照威布尔分布处理,并考虑每个扇区风速的大小、概率密度。目标函数为整个风电场的输出功率倒数的对数,自变量为风力机在给定风电场中的位置坐标,约束条件为地形边界和风力机之间的最小距离,优化算法采用该文提出的改进小生境粒子群算法(NCPSO),优化风力机组微观选址的最优解。该文提出优化算法得到的结果与基于高度的经验布置方法(EX-TH)、基于风能密度的经验布置方法(EX-PH)以及普通粒子群算法(PSO)进行比较,证明在复杂地形条件下所提出方法的可靠性与有效性,并可应用于工程实践。

Wind farm micro-sitting selection in complex terrain is challenging in the development of onshore wind farms. This paper presents a method for optimizing wind farm layout in complex terrain. In this method the wind direction is divided into twelve sections, and CFD is used to make numerical simulationswithwind speed averaged in each section. When the wind resource of each section is determined, the wind speed and wind direction at the hub height are extracted. The Jensen wake model is used to calculate the wake effects between wind turbines. To calculate the annual wind energy distribution, the wind speed is processed withthe Weibull distribution which takesboth wind speed and probability density into consideration. The optimal objective is the maximization of the whole wind farmpower output＇ s logarithm of reciprocaland the design variables are the wind turbines＇ coordinates which subject to boundary conditions and minimum distance conditions. A traditional Particle Swarm Optimization （PSO）and an improved Niching Particle Swarm Optimization （NCPSO）are used to search the optimal result. Finally, the optimized results are compared to the resultsobtained with the terrain highs based engineering method （EX-TH）and the power density highs based engineering method （EX-PH）, indicating that terrain high points are not necessarily the best positions for wind farm micro-sitting, convinced the availability of the method that this paper engineering practice. presented in the complex terrain, and can be practiced in the engineering practice.