The Control Strategy Based on Improved Droop Method of Microgrid-Connected Inverters

A control strategy of inverters is proposed based on the control requirements of the distributed power sources in the microgrid, which realizes the seamless transition between the grid-connected mode and islanding mode. When the microgrid is connected with the main grid, the PQ control based on the improved droop method is used so that each DG dispatch their energy according to reference energy to realize the function of PQ independent control; When the microgrid is in the islanding mode, the V/f control based on traditional droop method is adopted to share the load power with function of providing reference voltage. With the PSIM software, the operation features are analyzed under different conditions of the mode transition and the variation of DGs and loads. The simulation results show the correctness and validity of the control strategy.