Robust Real-time Dispatch Considering Probabilistic Distribution Of Wind Generation

Compared with conventional power,wind power is not controllable.Large-scale wind power integration will further increase the uncertainty and the requirement of reserve in the operation of the electric power system.Meanwhile,when the active power dispatch problem including wind power solved by the uncertainty optimization method,it may face the contradictions between the practicality of the algorithm and the optimality of the results.These issues need to be further studied.Robust optimization,as one of the optimization method under uncertainty utilizing disturbance molded by interval,aims to find optimal decision under the worst-case disturbance conditions,and it can be applied to power system dispatch and decision-making for its advantages,such as data availability,computing efficiency and applicability of large-scale systems,etc.First of all,in chapter 1,on the basis of illustrating the characteristics of robust optimization itself,this paper introduces the applications of robust optimization to unit commitment problems in power system,expounds the law of model-building under continuity and accidental disturbance,discusses the commonly used uncertainty sets and ways to limit the degree of conservatism.Secondly,this paper describes the current researches of robust optimization to economic dispatch problems,presents the characteristics of three kinds of typical methods,including adaptive robust optimization,robust optimization considering affine policy and robust optimization with the objective to maximum the acceptable range of deviations.Finally,the key problems and future direction in this field of research are discussed and analyzed.In view of the above problems,for the specific issue of high levels of wind power generation,this paper proposed a robust real-time dispatch method which considered probability distribution characteristics of wind power in chapter 2.Based on both the index of the total operating cost of power system and the total conditional value-at-risk(CVaR)cost of wind power,the optimization model was constructed according to the theory of robust optimization.The operating point and the reserve capacity of each automatic generation control(AGC)unit were decided to obtain the range of wind power accepted by each node with statistical significance.The method embodies the combination of the robust optimization method and the stochastic programming method,and its results show the optimal probability,which can improve the efficiency of power system and the computing efficiency.Then,in order to make the dispatch strategies more realistic,the participation factors are taken into consideration as a variable.In chapter 2,the heuristic alternating iterative algorithm and the Big-M method are used to deal with the nonlinear problem(bilinear terms),realizing the coordinated decision between base points and participation factors quickly and effectively.Finally,the validity of the proposed method is verified by the calculation and analysis of a simple 6-bus system and the IEEE 118-bus system.