Harmonic and Reactive Power Compensation of Grid Connected Photovoltaic System

Distributed Generation (DG) is predicted to play an important role in the electric power system in near future. It is widely accepted that photo voltaic generation is currently attracting attention to meet users' need in the distributed generation market. In order to investigate the ability of photo voltaic (PV) units in distribution systems, their efficient modeling is required. This paper presents a dynamic model of a PV generation system. The increasing application of nonlinear loads may cause distribution system power quality issues. In order to utilize distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced control approach. In this paper, synchronous reference frame strategy has been chosen and a grid connected photo voltaic generation system (PVG) can send the active power to the grid, compensate harmonics and absorb the reactive power that the local loads generated. The converter controller models are implemented in the MATLAB / SIMULINK. The performance of the implemented PV model is studied with an isolated load. Synchronous reference frame strategy is used to generate current reference for compensation and conventional PI controllers are used for control. The strategy utilizes co-ordinate transformations to separate the reactive and harmonic content in the load current. The design of the closed loop controllers is kept simple by modelling them as first order systems. The simulation studies showed good results with the reactive current compensation giving almost ideal result of near unity power factor and harmonic currents getting compensated to a larger extent. (C) 2015 Published by Elsevier Ltd.