Research On Evaluation And Optimization Of Standalone Micro Grid Operation Performance

Micro grid is an effective organization form of the distributed power supply, it can not only give full play to the advantages of distributed generation in saving resources and protecting the environment, but also effectively solve the negative impact caused by the distributed power access to the large power grid.As an effective supplement to the large power grid, micro grid can play an important role in improving the stability of the power supply, energy efficiency and the rapid changes in the level of the load response. But the operating characteristics of different types of distributed power in micro grid are different,wind power and photovoltaic power generation are easily affected by external conditions,so the output power is intermittent and random.All of these cause some disturbance to the operation state of the micro grid,so it is of great significance to evaluate and optimize the micro grid operation performance,especially for independent micro grid.This paper aimed at this subject,mainly carried out the following research:Firstly,the mathematical model of each generating unit in micro grid is studied. In the light of PV-Wind-Diesel-Battery hybrid micro grid,this chapter analyzes its structure, main components and functions,and study on the working principle and power output model of photovoltaic arrays, wind turbines, diesel generators, batteries and other units.Secondly,fuzzy evaluation method of micro grid operation performance based on optimal membership degree is proposed. Based on the research and analysis of micro grid operation performance, the evaluation system of micro grid operation performance is put forward from the aspects of reliability, quality, economy and environmental protection, and the corresponding two level indicators are listed. Based on the optimal membership degree theory, a fuzzy comprehensive evaluation method for micro grid operation performance is proposed, and the G1 method is used to determine the weight of each index, and the specific process and steps of the evaluation are listed.Thirdly,the operation optimization of independent micro grid is studied. Above all, the operation optimization objective function of independent micro grid is established, and the optimization objective is to minimize the operating cost and the loss of electric energy cost,at the same time,the constraint conditions and strategies is given to optimize. This chapter chooses genetic algorithm as a tool to solve the optimization problem, the principle of genetic algorithm and the specific process of solving optimization are studied.According to the example of micro grid analysis, the effectiveness of the optimization method is verified.