Research On Multi-time Scale Optimal Dispatching Of Island Microgrid With Desalination

As the mainstream way for distributed power sources to connect to the power grid,microgrids have many advantages like reduce power generation costs,reduce environmental pollution,improve user satisfaction,improve renewable energy utilization and so on,through optimize the various types of power sources and loads.Therefore,it is of great significance to carry out research on the optimized operation of microgrids.In this regard,in this thesis,the island microgrid includes random wind,solar power and controllable diesel generators,storage batteries and seawater desalination loads are taken as an example,combined with the fuzzy chance constrained programming and multi-time scale method to study the island microgrid optimal scheduling problem.In order to analyze the impact of uncertain power access on the operation of the microgrid,this thesis establishes the wind power forecast error model and the photovoltaic power forecast error model;in order to analyze the impact of the load side before and after dispatch on the microgrid optimal dispatch,this thesis establishes controllable seawater desalination load model and uncontrollable conventional load model.Combined with the uncertainty of wind and solar and controllable seawater desalination load model,and the fuzzy chance constrained planning based on credibility measure,an island microgrid optimal scheduling model considering both operation economics and user satisfaction is established.This thesis puts forward two optimization goals:system comprehensive cost and user water supply satisfaction for the operation economics and user satisfaction of the island microgrid.Combined with the characteristics of prediction accuracy and decision makers' expectation of system reliability increasing with the shortening of time scale,a multi-time scale optimal scheduling method for island microgrid is proposed.Based on the optimal scheduling model of microgrid based on the fuzzy chance constraint programming,the fuzzy confidence in the constraint condition is set as increasing vector,according to the time scale refinement,a multi-time scale optimization scheduling model is established,and the cost deviation between different scheduling stages is added to the objective function of the scheduling model,so as to achieve the purpose of using multi-level coordination to improve the overall economics of scheduling decisions.In these examples,the rationality of the proposed optimal scheduling model and the effectiveness of the controllable seawater desalination load in scheduling have been analyzed and verified;and that the established multi-time scale fuzzy chance constrained programming model can effectively reduce the impact of forecast uncertainty has been verified,there realize the gradual consumption of power deviation value and improve the accuracy of scheduling results.