Power Quality Improvement in Single Phase AC-DC Three Level Boost Converter Using PI and SMC

Abstract

This paper proposes the single phase ac-dc three-level boost converter with controller circuit such as sliding mode controller, proportional integral controller and employs three-level pulse width modulation technique. Solid state switched mode three-level boost converter along with the control methods achieve unity power factor, high efficiency, precisely regulated dc output in boost converter, reduced output voltage ripple and less than 5% of total harmonic distortion with unidirectional power flow. The outstanding feature of proposed control scheme is line current is driven to follow sinusoidal reference current command which is in phase with sinusoidal input voltage and guaranteeing dc-link capacitor voltage balance in every switching cycle. Comparative analysis of PI controller and sliding mode controller is carried out. The performances of converter under load variation, unbalanced load condition and sudden change in load condition for various control strategies were verified.