Droop control strategy of the AC/DC hybrid micro-grid based on quasi-PR control

With the developments of renewable energies and integrations of new loads into distribution system, the hybrid of AC and DC has been becoming the typical existing form of the micro-grid. Studying on the droop control strategy will be very important for improving the safe and economic operation of micro-grid. Therefore, this study aims at thoroughly analysing a novel droop control strategy of the hybrid AC/DC micro-grid. First of all, the analysis model of the hybrid AC/DC micro-grid is built by connecting the traditional AC and DC micro-grid. Next, the typical droop control strategy of AC and DC micro-grid is introduced, respectively. Then, the voltage outer loop of quasi-proportional resonance (PR) control strategy and its optimal parameters are presented based on the analysis of the voltage–current double-loop control strategy. Finally, the simulation model of AC/DC micro-grid in Matlab/Simulink is utilised to compare the performances of the Proportional Integral (PI) and quasi-PR droop control strategies. The results show that the proposed quasi-PR has better performances in control accuracy and harmonic suppression.