A high step-up partial power processing dc/dc t-source converter for ups application

Abstract

In this paper, a new modified structure of a DC/DC T-source converter is proposed. Since the proposed converter provides high voltage gain, it is suitable for photovoltaic integration into uninterruptible power supply (UPS) systems. The proposed structure employs partial power processing technique to increase the output voltage as well as efficiency without requiring new hardware. Partial power converters (PPCs) process only a fraction of flowing power while the remaining power directly flows through output. This generally causes an improvement in efficiency and output voltage. A total of two structures are presented: conventional partial power T-source converters and improved partial power T-source converters. The key advantage of the improved partial power converter is a higher voltage gain. Furthermore, it reduces the voltage and the current stresses on switches and diodes. The steady-state operation principles are described for both converters and the governed rules and equations are derived. The PPCs and full power converter are compared in terms of efficiency, voltage gain, voltage stress, and current stress of converter elements. The converter performance is evaluated through experimental and simulation studies. The presented results show good consistency with the theoretical analysis.