Research On Operation And Energy Management Of DC Micro Grid System

With the development of the economic,the environmental problems brought by economic development have become increasingly prominent,the scope of China’s haze is a concentrated expression of this problem in this few years. So changing the form of economic development and the development of new energy sources have become the most effective way to solve the problem of economic development and environmental problems.At present, the development of new energy resources in China is mainly solar photovoltaic(PV) and wind energy.Due to the randomness and intermittent of PV and wind energy, it will cause a great impact on the large power grid,limiting the use of a large number of new energy sources,and the micro grid is a good solution to this problem. Micro grid includes AC micro grid, DC micro grid and AC/DC micro grid.The DC micro grid has been focused on by the people because of its less energy flow, simple structure and flexible control. In this paper, the main content is based on PV, batteries and super capacitor independent DC micro grid.First, this paper analyzes the characteristics of PV, batteries and super capacitors, analysis and simulation of the working mode of PV, according to different charging and discharging characteristics of the battery and the super capacitor, different control methods are adopted to realize the stability of DC bus voltage.the content of the above model and verify the control results in Matlab/simulink.Secondly, according to the characteristics of PV, batteries and super capacitors,an energy control strategy for DC micro grid is adopted.Energy control system based on PV, batteries and super capacitors of different working conditions,control their respective converter to make it work in the appropriate mode of operation, so that the three kinds of micro source coordination work to ensure the stability of the DC micro grid operation. The feasibility of the control method is verified by modeling the whole DC micro grid system and control method in Matlab/simulink.Finally, the experimental platform of optical storage DC micro grid based on PLC is built,The stability and reliability of the system are verified by the variation of the load and the output power of the PV. The experimental results are compare with simulation results, the results prove the feasibility and effectiveness of the control technology of DC micro grid.