Abstract— This paper proposes a single stage three-phase four-wire grid-connected photo voltaic (PV) system, operating with a dual compensating strategy. The DC-bus voltage at the dc-link is improved by the PV system. Since the UPQC system is based on a dual compensation strategy. The parallely connected inverter operates as a sinusoidal voltage source, whereas the seriesly connected inverter operates as a sinusoidal current source. This project proposes, an improvement in the real power and reactive power flow through the transmission line with UPQC using PID controller when compared to the system without UPQC.
Index Terms— DG-Distributed Generation, NPC- Neutral Point Clamped Inverter, PCC- Point of Common Coupling, PLL-Phase Locked Loop, PQ-Power Quality, PV-Photo Voltaic, RES-Photo Voltaic, SSSC-Static Synchronous Series Compensator, STATCOM-Static Compensator, UPQC-Unified Power Quality Conditioner