Credibility Theory Based Research On Unit Commitment With Large Scale Wind Farm

The wind power has become one of the most important ways to cope with the worldwide increasing environmental and energy problems,and the capacity of wind power incorporated into the gride is incraesing rapidly regardless of concentrated or dispersed.The unit commitment(UC) problem with wind power integrated is not a traditional certain problem because of the uncertainty of the wind power and the solution which is economic and reliable is difficult to attain by traditional ways.Considering the present wind power prediction level and the prediction error, the credibility theory accomplished in 2004 is introduced here,the trapezoidal fuzzy numbers which represent the uncertainty of the wind output is used here.The credibility distribution function of the wind output in each period is caculated,The chance constrained programming model of the unit commitment with wind power is well established based on credibility theory in this paper,the credibility indexes are used here to evaluate the fuzzy constraint conditions.Based on the fuzzy simulation-particle swarm optimization method,this problem is decomposed to two levels programming,while the outer level is unit commitment,and the inner level is the economic load dispatching.The 10 units testing case with different scales of wind farm proves the validity of the model and algorithm proposed,and provides a new way to research on the system dispach and operation with large scale wind farm.