An autonomous controller for improved dynamic performance of parallel-connected,single-phase inverters

A new control technique is presented for the parallel connection of distributed generation inverters. The proposed control technique is based on a modification of the power angle droop control method, and uses only locally measured feedback signals. An improvement in transient response is achieved because the real and imaginary components of the output current are used when deriving the power angle droop controller. The method achieves good active and reactive power sharing and minimises circulating current between parallel connected units. Improved transient response is obtained whilst maintaining power sharing precision or output voltage and frequency accuracy. Simulation and experimental results validate that performance is better than that attained with conventional droop-based approaches.