Steady state analysis of three phase unbalanced distribution systems with interconnection of photovoltaic cells

With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adapting Distributed Generation (DG) into their existing infrastructure. In this paper photovoltaic (PV) systems are modeled to study the effects of their interconnection in a distribution system. The system is a combination of the PV array, DC-DC boost converter with Maximum Power Point Tracking (MPPT) control and DC-AC inverter. With increasing penetration of PV, reverse power may flow on the grid which is associated with voltage rise that may lead to violation of various standards. The impact depends upon the size and location of the PV system. Studies are conducted on the real time data obtained from DTE Energy utility. Voltages of the feeder, two way flow of power and the voltage regulation under various levels of PV penetration are analyzed for an IEEE test system utilizing unbalanced power flow solution.