Study Of Scenario Reduction Based On PSO In The Stochastic Unit Commitment Problem

In solving the traditional UC problem and the price based unit commitment(PBUC) problem, electrical load and price is generally given in advance, the solution results usually can't reflect the influence of the uncertainties. Therefore, the stochastic unit commitment(SUC) problem and the SPBUC problem began to get attention.Generally, scenario analysis is used to model and solve the uncertainty in the SUC problem. When modeling the uncertainty to scenarios, a large number of scenarios will be generated to reflect the uncertainty adequately and represent the distribution properly. The quantity and quality of generated scenarios will affect the amount of computation and quality of solution of the SUC problem directly. Due to the complexity of computation and time constraints, the initial scenarios need to be reduced to obtain a scenario set with suitable quantity and quality in the practical application.This paper focuses on the scenario reduction methods of the SUC problem:Firstly, it introduces the research background and development of the UC problem, gives the model and constraints of the traditional UC problem,the SUC problem and the SPBUC problem, summarizes the solutions to the UC problem, introduces the current research status of scenario generation and reduction problem, then gives a detailed description of the research ideas and arrangements of the article.Secondly, based on the introduction of scenario, scenario analysis and scenario generation methods, it uses the Monte Carlo simulation method to generate a small initial price scenario set and a large-scale initial price scenario set, then introduces the theory basis of scenario reduction,describes the theory of BR and FS and defines a relative accuracy index to verify their effectiveness.Thirdly, it analyzes the background, research status, basic principles and convergence of the PSO. It puts forward a new scenario reduction method based on PSO, and presents the detailed steps of solving the scenario reduction problem in SUC problem.Finally, it gives an example test of the scenario reduction methodbased on PSO, uses this method to reduce the small price scenario set and large-scale price scenario set generated above respectively. It compares the reduction results of this method with the reduction results of BR and FS, the compared results indicate the effectiveness of the method. Test results show that the scenario reduction method based on PSO can reduce the initial scenarios quickly and efficiently, and solve the scenario reduction problem in SUC excellent.