Research On Control Strategy For Smooth Transition Of Micro-grid Operation Modes

At present, the conventional energy consumption is over and the natural environment pollution is also more and more serious. In the face of these circumstances, many countries in the world put forward to solve these problems by using the distributed new energy generation system. Micro grid system which consists of the distributed new energy generation system, energy storage system and the local load and control protection device subsystem has become the focus of the study at home and abroad. One of the micro-grid system’s key technologies is how to realize the control strategy of grid-connected and stand-alone two operation modes and the smooth switching between the two operation modes.Firstly, this paper establishes the mathematical model of the micro-grid system consisting of a single dual-mode inverter device and analyzes the control algorithm in different operation mode based on research object of dual-mode inverter device for micro-grid model. In addition, the mathematical model and control strategy of micro grid system composed of two inverters are analyzed in detail. It mainly includes the control method of the master slave structure and the control mode of the peer to peer structure.Secondly, the operation mode of micro-grid system mainly includes grid-connected mode and stand-alone mode and two mode switching state. The paper has mainly analyzed the micro-grid system consist of the single inverter and two inverters smooth switching control strategy in the conversion of the two operation modes. In order to ensure and realize the smooth switching between different modes, ensure the smooth switching process and not have a greater impact on the load and the power grid.Finally, this paper simulates for the smooth switching of micro-grid system operation mode based on Matlab/Simulink, and analysis and research for the experimental part of micro-grid inverter control system. The experimental platform of the control system of the micro grid inverter based on TMS320F28335 is built and the control algorithm in different operation mode is verified by experiment, and the corresponding control algorithm is completed. Finally, the simulation results are consistent with the theoretical analysis, which verifies the effectiveness of the control strategy.