Research On Onshore Wind Farm Layout Optimization And Control Strategy Optimization

With the rapid development of the wind energy and wind farm technology,in addition to increasingly large scales of wind farms,wind farms have been building in more complex scenes,which also poses new challenges to the planning and operation of wind farms.Under the new economic needs,building an environmentally friendly and adaptable wind farm has become a long-term development direction and also challenges for wind power companies.The traditional layout designs of onshore wind farms typically base on the empirical data of engineers instead of the heoretical basis,and there are not enough fast and accurate optimization methods under different scenarios to effectively guide engineering practice.In addition,the control strategies of onshore wind farms are usually based on the simple objective of maximizing power production,and rarely considers other factors such as environmental factors.Compared with offshore wind farms,the optimization of onshore wind farms should also consider the impact of topography on the wake model and the impact of wind farm noise on the environment.These all increase the complexity of wake modeling,wind farm layout optimization methods,and control strategy optimization in different wind farm scenarios.Wind farms have some characteristics such as the expensive investment costs,a long construction period and also are greatly affected by topography,environmental factors etc.In order to ensure the economic benefits of onshore wind farms and meet the new requirements of environmentally friendly wind farms,it is necessary to consider some practical factors for optimizing the wind farm layout and control strategies in the initial planning stage,thereby reducing the investment costs,increasing wind farm production efficiency,and making a good balance between economic and environmental aspects.Therefore,this dissertation is supported and guided by the National Natural Science Foundation of China's "Research on Overall Optimization of Wind Turbine Layout and Collection System of Large-scale Onshore Wind Farms"(51707029),then focuses on wind farm layout optimization and control strategies of onshore wind farms as the main research content,and wind farm modeling methods,wind turbine sittings optimization methods and control strategy design in different scenarios are fully considered.The main research content contains the following four parts:(1)A three-dimensional wake model suitable for onshore wind farm optimization is proposed,which provides a mathematical basis for the layout optimization of onshore wind farms considering topography.A wake model considering forest plantations of onshore wind farms is proposed to provide the model basis for onshore wind farm optimization work considering this factor.The power generation and investment costs of onshore wind farms are modeled,and the calculation method of onshore wind farm power production considering the wake effect is proposed.Considering the influence of topography and various constraints of wind farms,the layout optimization problem of onshore wind farms is established using the established three-dimensional wake model combined with the coordinate system method and the height matrix method.Then,the layout optimitzation is solved using the heuristic algorithm,and the case results under different terrains are compared with the reference wind farm to verified that the proposed models and methods are effective and practical.(2)Based on the three-dimensional wake model of onshore wind farms established above,the wake interaction between different types of wind turbines in onshore wind farms is analyzed in depth,and the geometric analysis and related formulas for the actual wake area are given.Then,the models of mixed wind farms are further introduced.In order to take the topography and different types of wind turbines into account,the evaluation method for the power generation of mixed wind farms considering different types of wind turbines is proposed.The objective function and constraints of the mixed wind farm layout problem are given and solved usding the heuristic algorithm and two simulation cases of mixed wind farms on different terrains are compared with the standard layout to verify the feasibility of the proposed method.(3)The wind farm noise models for onshore wind farms including its propagation and noise evaluation method are proposed.According to different actual conditions,two different strategies for taking into account the benefits of wind farm power generation and solving the noise problem of onshore wind farms are proposed.Starting from the economic and environmental perspectives,the wind farm layout optimization considering noise issues is solved.Considering a variety of constraints,the penalty function method and a novel particle swarm algorithm are chosen to solve the objective,then the computational costs of the classic particle swarm algorithm and the novel particle swarm algorithm on this problem are compared.Cases based on two different strategies prove that the proposed optimization method can effectively reduce wind farm noise and increase wind farm productivity.(4)Based on the above wind farm noise model,the cable loss model considering topography is established,and the noise interference problem of onshore wind farms to the surrounding area is analyzed.Two control strategies for dealing with wind farm noise are proposed according to different actual needs.Based on these two different strategies,the corresponding onshore wind farm control methods are proposed,and case results are compared with two traditional control strategies,which proves that the proposed control strategies can simultaneously fix the wind farm noise problem and increase the wind farm power production.