SPV-Based UPQC with Modified Power Angle Control Scheme for the Enhancement of Power Quality

Unified Power Quality Conditioner (UPQC) with a modified Power Angle Control (PAC) scheme is presented for effective interconnection of renewable energy system into the grid. The UPQC consists of both shunt and series Active Power Filters (APFs). The shunt and series APF is one of the most effective custom power devices, which provides compensation for current and voltage-based disturbances, respectively. The shunt APF supplies active power to the load from the Distributed Generation (DG) in addition to reactive power demand supplied by it. Because of this functionality, the Volt-Ampere (VA) burden increases along with the rating of the shunt inverter. The PAC scheme aims to effective utilization of series and shunt APFs through sharing of reactive power to reduce VA burden on shunt APF. The PAC scheme is based on Synchronous Reference Frame (SRF) theory, which has simple computations, is robust and uses existing measurements of Solar Photovoltaic (SPV)-integrated UPQC. The performance of the proposed SPV-integrated UPQC is verified with the manifestation of nonlinear loads and reactive burdens with the SPV power generating system. The dynamic performance of the PV-UPQC is verified under the grid disturbances such as voltage sag, swell, varying load and change in solar irradiation. The effectiveness of the proposed control scheme is evaluated through the digital simulation and hardware experimental prototype model.