Design and Performance Analysis of Three-Phase Solar PV Integrated UPQC Technique

The increasing integration of renewable energy sources and nonlinear loads in modern power distribution systems has introduced significant power quality challenges such as voltage sag, harmonic distortion, voltage imbalance, and reactive power demand. These disturbances adversely affect the performance, reliability, and efficiency of electrical equipment connected to the grid. To address these issues, the Unified Power Quality Conditioner (UPQC) has emerged as an effective custom power device capable of simultaneously compensating both voltage and current related power quality problems in distribution networks. This work presents the design and performance analysis of a three-phase Solar Photovoltaic (PV) integrated Unified Power Quality Conditioner (PV-UPQC) for improving power quality and enhancing the utilization of renewable energy in power systems. The proposed system integrates a solar PV generation unit with a UPQC configuration consisting of series and shunt voltage source converters connected through a common DC link. The solar PV array supplies real power to the system while the UPQC performs harmonic mitigation, reactive power compensation, and voltage regulation. In the proposed configuration, the series converter is responsible for mitigating supply-side disturbances such as voltage sag, swell, and imbalance by injecting compensating voltages in series with the supply. Meanwhile, the shunt converter eliminates current harmonics, compensates reactive power, and maintains the DC link voltage. The integration of the solar PV system into the DC link not only improves the energy efficiency of the UPQC but also enables the utilization of renewable power for local load demand and grid support.