| Abstract:Today,in the pursuit of low-carbon society, solar energy as a clean distributed renewable energy is widely used, and with the. power electronics and energy storage technology continue to improve, the DC microgrid is being developed fast. The control of DC microgrid is simple, reliable and its energy loss is smaller, so it will become one of the major supply modes of remote villagesand home in the future.DC microgrid including distributed renewable energy generation module, the storage module and load module, must be in energy management control in order to improve the efficiency of the renewable energy utilization and stability of DC microgrid running. The object of this paper is a low-voltage miniature DC microgrid system with photovoltaic solar arrays, battery and controllable load. For the network operation mode and island operation mode, the improved master-slave control strategy and voltage droop control strategy are used respectively, to achieve the goal of DC microgrid stable operation.Firstly, with the modeling of solar cells and Boost converter, bidirectional DC/DC converter, three-phase full-bridge inverter and dual-switch Buck-Boost converter power electronics interface circuit, their output characteristics are analysed. Energy management strategy for the photovoltaic DC microgrid grid and island operation mode is proposed; and based on the strategy the control objectives under different operating modes are determined; and according to the characteristics of the control target requirements the reasonable controller is selected with the optimization design.Then, based on Matlab/Simulink simulation platform and photovoltaic DC microgrid experimental device, system simulation studies and experimental testing are completed, and simulation and experimental results can verify the rationality and correctness of the system energy management control strategy. Finally, for Inadequate of the common voltage droop control method of current DC microgrid, a novel voltage droop control is proposed. This method, compared with the conventional droop control method, can improve the characteristics of the voltage adjustment and energy management. Finally, the feasibility of the method is verified by simulation results. |
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