Research On Microgrid Inverter Based On Virtual Synchronous Generator Control

With drawbacks of the traditional power grid system highlighting distributedgeneration system has become a new direction leading the development of the powersystem. Micro-grid control technology can run the distributed generation as a micro-gridsystem. In this way, the advantages of distributed generation have been fully exerted, andthe disadvantages have been effectively avoided.Firstly, in this paper the summary of research status on micro-grid related technologyhave been completed reaching the conclusion that the control of micro-grid inverter wasthe key problem of the development of micro-grid. Then, based on comparative analysisof the traditional control methods of the inverter, in which the disadvantage of traditionalcontrol has been pointed out, and combined with the operation characteristics andtechnology requirements of micro-grid, the paper focused on a new control strategy, whichis the virtual synchronous generator (VSG) control strategy. Micro-grid inverter whichapplied VSG control strategy imitated the output characteristics of synchcronous generatorand solved the power sharing problem effectively, in addition through imitating the inertiaof synchcronous generator, the frequency stability of the traditional control methods hasbeen well improved. The theoretical basis of the control strategy has been analyzed indetail, and emphasized the design of the virtual governor, virtual excitation controller andvirtual synchronous generator algorithm in the paper. The simulation results of thisstrategy by MATLAB/Simulink proved that the inverter which applied VSG controlstrategy imitated the function characteristics of synchcronous generator as well as aperfect steady and dynamic response, which well met the operational requirements of themicro-grid. And then, aimed at the problem in parallel control of the micro-grid inverter,the control strategy is applied to micro-grid inverter parallel control in this paper,simulation results proved that the system could stably and reliably operate as well as meetthe requirements of load balancing.Finally, the experimental platform that three-phase inverter of3kW has been builtwhich was controlled by TMS320F2812and the control program was completed in CCStudio v3.3. At last, the effectiveness and the feasibility of the VSG control strategyhas been verified through the open-loop and closed-loop experiments on the experimentalplatform.