LMF Based Control of Single Stage Dual Purpose Three-Phase Four-Wire Grid Connected SPV System with Reduced Rating VSC

Abstract: A three-phase four wire grid connected Solar Photovoltaic (SPV) system consisting of a three leg voltage source converter (VSC) and a star/delta transformer is proposed. This topology provides injection of real power from PV panel as well as mitigate various power quality problems. The proposed topology uses a star/delta transformer hence the ratings of VSC reduced. It provides power factor correction by reactive power compensation along with harmonic elimination, load balancing and neutral current compensation in three phase four wire distribution system. The neutral point of load is connected to the neutral of star winding so that it provides a path to the zero sequence fundamental as well as harmonic neutral currents. It doesn't use additional DC-DC conversion stage and hence having higher efficiency as compared to double stage topology. The proposed grid interfaced SPV system consists of a SPV array, Voltage Source Converter, Star/Delta transformer, three phase grid and linear/nonlinear loads. The DC bus voltage of a three phase VSC is regulated for Maximum Power Point Tracking (MPPT) from the PV array. In this paper, a LMF (Least Mean Fourth) based control of a single stage dual purpose grid connected SPV system is proposed and simulation based on MATLAB and Simpower System Blockset demonstrates the dual purpose of the system. Keywords: Solar photovoltaic, MPPT, voltage source converter, Star/delta Transformer, Neutral Current Compensation, UPF operation, harmonic elimination.