The Control Strategy of Virtual Synchronous Generator Based on Three-order Model

A control method of grid-connected inverter of distributed generations is presented based on virtual synchronous generators (VSG). The control strategy of inverter is built by utilizing the classical three-order model of an actual synchronous generator and the governing and excitation system models, which make the inverter have such functions as power following, primary frequency regulation and voltage regulation. The control parameters of the overall schemes are corresponding to that of synchronous generator, which is good for the compatibility between inverters, the traditional utility and the analysis and control methods. In addition, the small-signal model of the whole system is built, and the impacts of important control parameters on system stability are discussed according to the eigenvalue analysis method. The simulation results of PSCAD/EMTDC and real-time digital physical close-loop experiments based on RTDS verify the accuracy of proposed control strategy.