Investigation on the performance of PV-UPQC under distorted current and voltage conditions

The design, configuration and control of photovoltaic interfaced unified power quality conditioner (PV-UPQC) is discussed in this paper. PV-UPQC is employed to maintain power quality under various current and voltage distortion. PV-UPQC is a multi objective type power conditioning device, which has both shunt and series voltage source converter with a common DC-link. Moreover the photovoltaic system is connected at the DC-link of UPQC to provide power to the load. This paper also proposes a modified synchronous reference frame scheme with an improved phase locked loop (PLL) for control of the UPQC to eliminate power quality issues like unbalanced grid voltage with harmonics, load step change and load harmonics. The dynamic behavior of PV-UPQC under irradiance change is also investigated. The system is simulated and results are presented to validate the efficiency and performance of PV-UPQC.