Performance Analysis of Grid Connected SPCS under Unbalanced Grid Voltage, Frequency Deviation and Harmonics

Abstract

This paper presents the performance analysis of double stage solar power conversion system (SPCS) connected to the grid via three-phase voltage source inverter (VSI). Integration of large numbers of solar photovoltaic (PV) system has raised the power quality issues under various operating environment. Accurate grid synchronization, current reference generation for the controller and reducing the harmonics contents has become factor of concern for electrical power quality. The functionality of power controller, double second order generalize integrator (DSOGI)-phase locked loop (PLL) and proportional resonator-harmonic compensator <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(PR+HC)$</tex> is verified under unbalanced grid voltage, frequency deviation and load current harmonics. The simulation results shows the active power from SPCS is injected into the grid at unity power factor and grid current profile is improved with THD of 2.55%. The proposed system incorporating <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$PR+HC$</tex> controller, tracks the reference signal and removes the dominant 5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> and 7 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> harmonics from the load current.