Correlation Analysis of Wind Power Based on Mixed Copula Model and Its Application into Stochastic Dispatch

摘要

There is a strong correlation among wind power outputs within the same area. However, the correlation is not considered in traditional error scenario generation methods. This paper analyzes characteristics of four Copulas based on the correlation theory, and build a mixed Copula function model according to a linear combinations of four Copulas. A new error scenario generation method is proposed using this mixed Copula function model. Also, it is verified that the mixed Copula function has better performance than the single Copula function in fitting accuracy. To further testify the utility of this method, we compare the solutions obtained from two different stochastic economic dispatch models. Furthermore, stochastic dispatch simulation on IEEE 39-bus system and a real provincial power system is performed and the results obtained are analyzed according to evaluation indices including accessible wind energy, conventional units' outputs and the objective value. The simulation results on two systems with different sizes show the proposed method is beneficial to accommodate more wind energy through dispatching.