A PSO solution for improved voltage stability of a hybrid ac-dc microgrid

The stability of dc and ac bus voltage is of the most important issues in all microgrids including ac, dc or ac/dc hybrid microgrids. In this paper, a hybrid ac/dc microgrid is proposed to reduce processes of multiple reverse conversions in an ac or dc microgrid and to facilitate the connection of various renewable ac and dc sources and loads to power system. Also, all control schemes used among all converters will be developed in order to improve the voltage stability of hybrid microgrid. To give robustness to improved dynamic voltage stability of the microgrid, a voltage stabilizer is proposed and applied to the doubly fed induction generator (DFIG) installed in ac part. Furthermore, a particle swarm optimization (PSO) solution is proposed to optimize the various control gains among various converters in order to quickly restore and stabilize the voltage of both ac and dc parts under the different disturbances. The achieved results verify the controllers robustness and optimization algorithm efficiency.