Economic And Environmental Dispatch Of Microgrid Using Co-evolutionary Genetic Algorithm

To meet the increasing demand of power load, we must make full use of all the clean and renewable energy and develop the distributed power generation technology. It is the micro-grid that solves the problem of existing energy gap and environmental pollution. We pay a lot of attention to the micro-grid economic scheduling due to its economic benefits. But micro power generation has characteristics of intermittent, complexity, diversity, instability and volatility which brings new problems and challenges to the micro-grid operating of economic, reliable, and environmentally friendly. Distributed power supply in micro-grid power grid has certain fluctuation due to the influence of the weather condition, the raw material price and other factors. Besides, the power characteristics and cost of respective powers are different and some micro-grid has Combined Cooling Heating and Power system. So how to optimize the scheduling of distributed generation to ensure the economy and environmental protection of the micro-grid is a very complicated problem of multi-objective optimization.Based on the analysis of the steady-state model and scheduling features of the micro-power, this article established a micro-grid system including wind power, solar photovoltaic, micro-turbines, fuel cells and battery energy storage unit. Also this article proposed the objective function which aimed at the lowest cost of generation and the minimum pollutant emissions and considered the cost of cutting load, earnings of cooling and heating and revenues of the renewable energy. On the basis of this objective function,a environmental economic dispatch model including CCHP system was established considering corresponding constraints limit.Combined with co-evolutionary genetic algorithm, multistage objective function was established, and the virtual charging and discharging price of the battery were included in the population optimization objective function to seek the best individuals from the population. The dispatching policies in grid-connected operation and isolated-connected operation were given in this article and then the effectiveness of scheduling model, strategies and algorithms were verified through numerical examples. Finally, economic dispatch of the micro-grid smooth switching was studied based on the N-1 security constraints, and the comparison of the optimized results before and after switching were given.