Power Quality Improvement in Fifteen Level PUC Converter for Solar PV Grid-Tied Applications

Abstract

A fifteen-level packed U cell (FLPUC) converter with eight active switch counts for the grid-connected solar photovoltaic (GCSPV) application is introduced in this work. This converter has eight active switches with a PV source and two floating capacitors. This topology takes an edge over conventional configurations in terms of components required to achieve fifteen levels in converter output voltage. The mode of operation and switching states of the fifteen-level PUC converter are presented in detail. The active and reactive powers (PQ) control is incorporated for a grid-connected PV configuration, which in turn helps in an independent control over power injection into the grid. The maximum power operation is achieved for the first source connected to the PV array with the perturb and observe (P&O) MPPT technique and unity power factor is attained at the AC side. The voltages of floating capacitors are balanced at reference values using proportional-integral (PI) controllers to attain proper achievement of desired output voltage levels. Performance of the FLPUC based single-phase grid-tied system is analyzed under a constant and variable solar environment. This topology is modeled in MATLAB/Simulink, and test results are validated using real-time emulator to meet the IEEE-519 standard for power quality improvement.