Photovoltaic System Enhancing Power Quality of Electrical Network

Abstract

This paper focuses on the power quality improvement with active power filter supplied by a photovoltaic system which consists of a conventional DC/DC boost converter for the impedance matching between the PV array and DC link, a  conventional DC/AC inverter and a power grid model with a non-linear load. A three-phase grid connected photovoltaic generation system for improving the power factor taking into account the influence of variable solar radiation is presented. Using the instantaneous power theory (p-q), a reduced inverter model and different control strategies are proposed and compared such as conventional PID controller, Fuzzy logic controller and hysteresis current controller. It is shown that with an extended P&O maximum power extraction algorithm, the hardware required to achieve performance improvement can be reduced to few components such as a single inverter and a boost converter. In this paper, the solution to improve the power quality, in particular the harmonic reduction through active power filters, passive power filters and hybrid power filters, is carefully studied and implemented in a fully scaled three-phase simulation environment. Extensive simulations show how the harmonics from a solar power generation system can be eliminated and how a stable steady state is rapidly achieved after an asymmetrical grid fault (opened phase fault in the point of common coupling) is occurred.