Research On Economic Optimal Operation Strategy For Micro-grid Based On Demand Side Management

Nowadays,energy shortage and environmental pollution restrict the further development of human society.Therefore,the reasonable development and utilization of renewable energy are the development trends of national new energy strategy.By integrating various types of distributed generators,micro-grid(MG)can effectively solve the problems along with distributed generators(DG)connected to grid.As one of the key issues in energy management of MG,the economic operation of MG is an important research direction.Combined with power demand-side management(PDSM)technology,the power side resources and demand-side resources in MG can be so fully considered that the integrated optimization of generators-grid-loads in MG operation can be realized.First of all,this thesis gives a brief introduction to the demand side management.Aiming at the MG characteristics of islanding and grid-connected operation modes,the real-time price scheme based on load rate and the transferable load scheme based on time-of-use price are both introduced,and corresponding mathematical models for optimized load are established respectively.Secondly,for a structure of MG containing photovoltaic power generation system,wind power generation system,fuel cell,micro-turbine and energy storage system,the steady-state operation active output model and economic cost model of MG are established by combining its electrical characteristics with economic operation theory,and a MG operation strategy based on PDSM is proposed.Accordingly,the MG economic operation model is built with the minimum daily operating costs as goal.Then,the chaotic fireworks algorithm(C-FWA)is used to solve the economic operation model of MG,combining the good randomness,ergodicity and sensitivity of initial value to improve the optimization ability of the fireworks algorithm.The logic self-mapping function is utilized to improve the traditional fireworks algorithm,and the flow steps of C-FWA are described.Finally,according to different PDSM models,the MG calculation example under islanding or grid-connected operation is selected respectively and verified through MATLAB simulation with the fusion of the proposed operating strategy and solution algorithm.Solution of the model can obtain the output of different distributed power sources at different time during the operation cycle and the optimal daily operating costs.The results show that the introduction of PDSM technology into general optimal operation strategy can not only effectively improve the stability and economy of MG operation,but also improve the absorption capacity of renewable energy and the ability of cutting peak and filling valley in MG.Meanwhile,the rationality of the economic optimization operation strategy based on PDSM and the validity of the algorithm are verified.