Research On Microgrids Load Frequency Control Considering Uncertainties Of Wind Power

Compared to traditional large power grids,microgrids have some obvious ad-vantages,such as the ability to bring together a variety of renewable energy and en-ergy storage devices,and to provide specific solutions for specific areas of power supply problems.The paper notes that some of the characteristics of microgrids can bring some obvious difficulties to their load frequency control problems.For example,because the proportion of renewable energy in the microgrid is large,the power gen-eration of the microgrid has strong uncertainty;due to the smaller size of the mi-cro-network,the structure is relatively simple,making its frequency inertia smaller.In the paper,a new "feedforward and feedback" load frequency control method is pro-posed,and the related power supply capacity allocation is discussed in order to im-prove the frequency control performance of microgrids.The main contents of this paper are as follows:1.The paper analyzes the difference between microgrids and large power grids,and proposes a kind of frequency control method of "feedforward and feedback" for the particularity of microgrids.Feedforward part is to arrange the relevant unit output,in order to compensate the load disturbance in advance.New energy generation fore-casting and load forecasting are based on the ARMA model.The principle of using renewable energy first is adopted in power generation allocation.The role of the feedback part is to quickly eliminate the imbalance caused by the prediction error.At the same time,considering the different adjustment performance and the adjustment cost between energy storage battery and traditional units,this paper establishes the optimization model of the output distribution coefficient,and obtains the optimal con-trol strategy based on the PSO algorithm.2.Based on the above "feedforward and feedback" frequency control scheme,this paper further studies the optimal configuration of power supply in feedforward and feedback parts.In the feedforward part,the paper first analyzes and summarizes the selection requirements of power supply,and puts forward a method of allocating the total capacity of this part by satisfying the load demand according to the actual history distribution of the load and history renewable energy.Then,the optimization model of the lowest cost is built to obtain the optimal capacity ratio between different power supplies.The genetic algorithm is designed to solve the problem.In the feedback part,the relationship between the load forecasting error and the renewable energy fore-casting error is analyzed,and then the size of the total error is determined.The proba-bility distribution of the total error is obtained.A method of configuring the total ca-pacity of this part by covering the forecasting error with a certain probability is pro-posed.Then,the optimization model of the lowest cost is built to obtain the optimal capacity ratio between different power supplies.The genetic algorithm is designed to solve the problem.