Power Quality Improvement Utilizing PV-UPQC Based on PI-SRF and PAC Controllers

Abstract

This paper presents enhanced control schemes for a photovoltaic system with a Unified Power Quality Conditioner (PV-UPQC) for a distribution system. The main goal of the integration of PV with the UPQC is mitigating power quality issues, particularly, current and voltage harmonics, and voltage fluctuations. This paper proposes a shared reactive power compensation algorithm to support the load reactive power. A Moving Average (MA) block is attached to the Proportional-Integral (PI) controller to avoid second-order harmonic ripple circulation in the DC-link due to unbalanced conditions. The Shunt Active Power Filter (Sh-APF) employs a Synchronous Reference Frame (SRF) technique to compensate for current distortion issues. The Series Active Power Filter (Se-APF) utilizes a Power Angle Control (PAC) approach to compensate grid side voltage quality issues. The results show an effective utilization of the inverters to share the reactive power compensation for distortion conditions to meet the requirements of the IEEE-519 and IEC 61000-3-6 standards.