Research On Optimal Operation Of Micro-grid Based On Multiple Distributed Generation

With the development and progress of social economy,the contradiction between environmental protection and energy demand has become prominent increasingly.Exploitation and utilization of solar and wind energy and other clean energy has become an important component of energy supply.In resent years,in order to improve the utilization efficiency of energy,the distributed generation technology based on renewable energy has become a hot research topic.However,with the increase of the permeability of the distributed power supply,the disadvantages such as high cost,control difficulty and so on are becoming more and more.Micro-grid can make full use of the clean energy such as solar and wind energy,enhance the reliability and flexibility of power grid,and reduce pollution emissions.Due to the flexibility and diversity of the distributed power supply,it is necessary to study the optimal operation of micro-grid.This paper firstly introduces the background and significance of the development of micro-grid,and expounds the working principle and structural characteristics of various types of micro-grid.Under the premise of the mathematical model of the distributed power supply,this paper set up the scheduling strategy of economic and environment protection and the objective function including fuel cost,operation and maintenance cost and environmental penalty cost under the two mode of connected grid and isolated island.In addition,an improved particle swarm optimization algorithm is adopted to improve the performance of the weak and easy to fall into the premature defects.There are two aspects of the improvement:the one is that the strategy of linear differential and the learning factor of asynchronous change are introduced on the basis of the traditional particle swarm optimization algorithm;the two is the combination of particle swarm optimization algorithm and the natural selection mechanism of genetic algorithm.This improvement increases the randomness and ergodic property of the particles,and improves the diversity of the population,so that the optimal results can reach the best.Finally,the simplified model of distributed generation system is studied in the paper.According to the difference of daily load demand and environmental factors in different seasons in a year,the simulation analysis of fnicro-grid is carried out under the two operation modes of the grid connected and isolated island.This paper optimizes the output of the distributed power at different times,which makes the total power generation cost least.This will be able to get the optimal operation state of the micro-grid.The simulation results verify the validity of the model and the algorithm.