A novel distributed secondary voltage control method for AC microgrids based on voltage observer

Abstract Since the islanded AC Microgrid is affected by impedance of line, it difficult to coordinate voltage regulation and reactive load distribution. A distributed secondary controller based on observer proposed for isolated Microgrids, does not need more communications. This method can guarantee estimated average equals actual output voltages that converge nominal values, realize accurate proportional sharing in a microgrid. Then, convergence proved. Finally, control verified time-domain simulation.