Power quality improvement in grid connection of three-phase inverters

This paper addresses connection of distributed resources to an electric power system using three-phase inverters. Both voltage and current mode inverter control techniques for connection are critically compared in terms of power quality requirements where harmonic content of exported power is of particular interest. The impact of an isolating transformer is discussed and its role in harmonic filtering is examined. A new approach to inverter filter design that maintains high power quality is proposed. Experimental results are used to show the obtained power quality in both methods.