Methodology for Deriving High-Gain Step-Up DC-DC Converters With Partial Power Processing Based on Differential Connections

This article proposes a new methodology for deriving high-gain step-up DC-DC converters with partial power processing (PPP) based on differential connections. The differential connection between basic converters provides the feature of PPP only if the output voltages of both associated converters are negative with respect to a common input voltage. The methodology herein addressed proposes the insertion of an inverter cell (IC) in the basic converters with positive output voltage polarity (as boost, SEPIC, and zeta) to extend to them the feature of PPP when differentially connected. This article addresses the concept, theoretical analysis, and methodology applied to derive the differential converters with PPP from positive-group basic converters. Experimental results obtained from a differential converter composed of two boost converters and designed for an input voltage of 20 V, an output voltage of 180 V (gain of nine times), a duty cycle of 0.75, a switching frequency of 50 kHz, and a rated power of 100 W are presented to validate the proposal. The obtained peak efficiency is 95.5%.