Enhancement of power quality with UPQC in grid integrated and battery assisted PV system

Abstract

The scope of work is the power quality improvement by utilizing the Unified Power Quality Conditioner (UPQC). The UPQC is integrated with the Photovoltaic (PV) and Battery Energy Storage System (BESS) in this system. In General, the PV system is capable of delivering the active power to loads. However, if this PV system is not able to deliver the power then the battery system activates and supports the power especially during the longer-term voltage interruption. The PV-UPQC without storage system is less reliable compared to a PV-Battery system because of its environment-dependency. So, battery system will enhances the voltage support continuously in the longer-duration disturbances, reduces the complexity in DC-link voltage control algorithm, and keep producing the clean energy. The synchronization operation of the UPQC system is directed by a self-tuning filter (STF) combined with the unit vector generation technique. Implementation of this phase synchronisation method will make sure the UPQC can operate under unbalanced and distorted grid voltage conditions also. Therefore, the need of a phase-locked loop (PLL) is avoided and the proposed unit vector generator is utilized to produce the synchronization phases for the series and shunt active power filter (APF) compensator in UPQC system. So, the proposed synchronisation method is compared with the regular synchronous references frame (SRF-PLL) method for controlling UPQC to show the importance of the proposed technique. To have comparative analysis study in MATLAB-Simulink software, different case studies are considered.