Research On Multi-objective Optimal Dispatch Of Microgrid

Distributed generation has attracted more and more social attention because of its advantages of integrating and utilizing renewable energy resources.Microgrid is an effective organization form of distributed generation.Microgrid can improve the utilization efficiency by stabilizing the fluctuation of renewable energy power generation,and can also ensure the continuous supply of important internal load in the case of power grid failure.The advantage of microgrid depends largely on its energy management system.Microgrid energy management system can dispatch internal distributed generators,energy storage equipments and controllable load.Optimization of microgrid energy management can improve the efficiency of energy utilization,and can realize the safe and economical operation of microgrid.The optimal dispatch of microgrid is a nonlinear programming problem with multiple objectives and constrains,and it is difficult to solve the problem.This paper focuses on the methods to solve the multi-objective optimization scheduling of microgrid.Firstly,the development status of microgrid and the research status of its optimal scheduling were introduced.The mathematical model of grid-connected microgrid day-ahead optimal scheduling was established.The total cost of fuel cost,power purchase cost,operation maintenance cost,depreciation cost of battery and environmental cost of microgrid was considered as the total operating cost.Under the condition of meeting system constraints and equipment operation constraints,the minimum total operating cost was taken as the optimization objective.The scheduling time scale was reduced to 15 minutes on the basis of 1 hour,and the improved black hole algorithm was used to solve the problem.This method can reduce the operating costs of microgrid.Considering the demand response,the dynamic optimization model was established for the grid connected microgrid.To solve the multi-objective optimization model of microgrid,the weight of each objective was determined firstly using analytic hierarchy process.Then the two important objectives were optimized using the non-dominant sorting genetic algorithm(NSGA-?).The optimal solutions obtained by optimizations were taken as the candidate solutions.Then the objective function values of the candidate solutions were evaluated.The final solution was determined by the method of multiple attribute decision making based on evidence reasoning.The results show the effectiveness of the proposed method.The optimized results can be used as a guide for the charge and discharge power of the battery and the output power of the fuel cells in the next day.It provides a new way to solve the problem of multi-objective optimal operation of microgrid.