Multi Objective Stochastic Optimization Methods And Their Applications In Economic Operation Of Microgrid

Multi-objective optimization problems are common.Intelligent algorithm and other related theories are developing rapidly.In fact,most multi-objective optimization problems are random more or less.But in traditional optimization methods,for the convenience of solving,these randomness are often ignored.This is unscientific,especially in the case of randomness is obvious.Therefore,how to solve the multi-objective optimization problem in uncertain environment caused attention of domestic and foreign scholars.Based on multi-objective optimization and stochastic programming,the method for solving multi-objective stochastic optimization problems is proposed and applied to the economic operation of micro grid optimization problem.Firstly,some basic concepts of multi-objective optimization and stochastic programming are systematically summarized.The concept and mathematical expressions of multi-objective stochastic optimization problems are proposed.In particular,a framework for solving multi-objective stochastic chance constrained optimization problems is proposed.some simple multi-objective stochastic chance constrained optimization problems in particular form can be solved by deterministic transformation method.For other complex multi-objective stochastic chance constrained optimization problems,an algorithm of stochastic chance constrained optimization problem based on NSGA2 is proposed.The algorithm includes chance constraint test based on stochastic simulation.Improved methods of penalty function and initial population generating are proposed.The efficiency of the algorithm is verified by simulation.Secondly,a multi-objective stochastic chance constrained optimization model of a micorgrid containing wind farm and energy storage devices is established.The model takes the minimum operating cost and the minimum pollution gas emissions as objective functions.Due to the constraints of energy storage element and equipment ramp rate,there are some problems in solving continuous hour optimization.To solve these problems,some methods are proposed.The whole optimization process is determined.The ideal point method is proposed to select the satisfactory solution from Pareto solutions.Concerned the characteristics of economic operation optimization of microgrid problem,the concept of economic optimal solution and environmental protection optimal solution is defined.Finally,a typical microgrid is established.The equipment parameters are given.The optimization problem is solved with the algorithm proposed.The results of simulation proved the feasibility of the multi-objective stochastic chance constrained optimization model and the effectiveness of the improved NSGA2 algorithm.