The V2G Control And Operation Strategy In Micro-Grid

With the growing tension of fossil energy,energy storage battery technology continues to develop and the arrival of low-carbon era,electric vehicle has become an important development direction of new energy field and the means of solving energy and environmental problems.With the zero pollution and zero oil-consumption advantages,electric vehicle will be vigorously developed.However,the large-scale electric vehicle accessed and its random charging and discharging behavior,to the power system,especially the micro-grid,will bring a series of effects,making micro-grid security operation by greater uncertainty.The Vehicle to Grid(V2G)can effectively alleviate the problems caused by random charging and discharging.Its core idea is to use the electric vehicle energy storage as a buffer to the micro-grid,and use the bidirectional charger as the intermediate medium,take a reasonable converter control strategy and optimization operation mode to achieve micro-grid power balance.In this paper,electric vehicle is the research object,combined with micro-grid as the scene,the main research is as follow:1?This paper introduces the system structure of the V2 G bidirectional charger,describes in detail the working principle of the bidirectional charger and establishes the dynamic mathematical model of AC/DC and DC/DC.According to the mathematical model,designing the Linear Active Disturbance Rejection Controller(LADRC)as the voltage loop controller of the dual-loop control and adding the relevant model information.Because of LADRC strong anti-interference characteristics,so that it can ensure voltage stability in the process of charge switching and also it can provide the voltage and frequency support for isolation operation.The LADRC is a feedback system,and its nature is the stability of the system.To analysis the stability of a cascade system is very complex,in this paper,using the impedance ratio criterion and establishing the input and output impedance to discuss the impedance property of LADRC used in charger is superior to PI control.And then,the paper establishes the matlab simulation model and shows a comparison to verify the advantage of LADRC.2?The electric vehicles randomly access to charging will deteriorate equivalent load curve of the micro-grid and influence normal operation.In this paper,establishing the micro-grid operation dispatch model which regards and power fluctuation variance and the operation cost and the cost of the electric vehicle charging as the targets and using the multi objective particle swarm algorithm to solve the model.Through comparative analysis,it is concluded that the electric vehicles participate in the V2 G operation that can be used as a mobile energy storage and it can effectively to reduce the power fluctuation,and it is advantageous to improve reliability and economic operation of the micro-grid.