Research On Optimal Dispatch Model Based On Source-load Coordination For Power System With Large-scale Wind Power Integrated

With the rapid development of wind power in China,the contradiction between demand of large-scale wind power connected to power grid and operation security of power grid is becoming more and more highlighted.On the one hand,large-scale wind power can significantly increase power generation and reduce the contradiction between power supply and load demand.On the other hand,the character of wind power caused a lot of problems to the security and stability of power grid operation,such as intermittent and randomness,and uncontrolled.For disadvantage of wind power randomness cannot held accurately,power grid control department increase the risk of wind power for security operation.Accordingly,the energy efficiency of wind power must be reduced.Traditional power dispatching model with conventional generation source cannot solve the problem of cluster wind power acceptance in power system,the new control method and theory are urgently needed to study.Therefore,this paper analysis the characteristics of wind power operation and its influence to power grid dispatching and operation,discuss the positive effects of high energy load for wind power accommodation by interactive with power grid operation.Present the dispatch mode of source-load coordination for power system with large-scale wind power integrated.Study response capacity model of high energy load,multi-objective optimal model of source-load coordination and dispatch strategy on multiple time.The innovative achievements are as follow:Study operation characteristics of generate and load about the accommodation of wind power,and discusses the coordination relationship between conventional generation and high energy load on regulating wind power output;The characteristics are analyzed,as follow:distribution and peak shaving and fluctuation of wind power,regulation speed and capacity of high energy load and conventional generation,etc.With these characteristics,the response mechanism which make generation and load interactive with power grid can became the mathematical model.According to characteristics of wind turbine generator,the equivalent model of wind power cluster output characteristics is established.According to characteristics of high load c response,the mathematical model of high energy load in power grid dispatch is established.Finally,source-load coordination dispatching mode is presented.This paper analysis the regulation speed and capacity of high energy load,and establishes the response model of source-load coordination.This model considers the interactions influence between incentive measures of power grid and response behavior of high energy load.The decision maker of Upper model and lower model are power grid dispatch department and high energy load.By select the optimal incentive scheme and optimal participation pattern,both of them will achieve their own goals.According to different characteristics of upper model and lower model,this paper presents a hybrid algorithm for model solving.It can improve the solving calculation speed and convergence,which consisted by improved particle swarm optimization(PSO)algorithm and niche nonlinear forecast and correcting the original dual interior point method.Based on response capacity of high energy load,this paper study multi-objective optimization model of source-load coordination which consider accommodation benefit of wind power and operation economy of power system.In this model,object functions are maximum of wind power accommodation energy and minimum of power system operating cost.And its constraint conditions include balance of active power,start-stop and climbing of conventional generation,regulating of high energy load.Also present an improved difference evolution algorithm to solve multi-objective optimal model of source-load coordination by Pareto optimal method.In order to make the algorithm apply for solving multi-objective optimization problem of source-load coordination effectively,improved difference evolution algorithm includes:use binary encode for discrete variables of conventional generation start-stop and high energy load adjustment,and difference vector perturbation for disturbance of discrete variables.An index is used to make the infeasible solution slack,which means degree of constraints violated.It can add some excellence and constraints violated individual into evolution process,and also improve search ability of algorithm.Choose a compromise solution from Pareto optimal solution set by fuzzy satisfaction evaluating,and assist decision maker to select the best dispatch scheme by their own preference.With uncertainty error of wind power prediction,this paper considers the response characteristics of high energy load and conventional generation source which shown coordination and differences on the time dimension,presents a dispatch strategy about source-load coordination on multiple time including coordinate control among several grades and separate into each grade.In the strategy,day-ahead schedule grade will make decision based on multi-objective optimization model of source-load coordination,which supply the dispatch scheme of high energy load and conventional generation source for day dispatch and real-time dispatch.By wind power forecast information updated,both of day dispatch and real-time dispatch will rotational correct the deviation of conventional generation output and high energy load,and achieve optimal dispatch scheme of source-load coordination in multiple time dimension.