Analysis and design of non-isolated inverting DC-DC converter for multi-port output applications

This study presents a hybrid multi-port DC-DC converter that enables a single negative voltage input and multiple positive voltage outputs, providing power to vehicle electronic devices with different voltage levels. The circuit uses multiple sets of switches in a shared configuration, featuring a simple circuit structure, fewer switches, and smaller inductors. This paper categorizes the operating modes and introduces the working principle of the stable operating mode. Through linear piecewise time-domain analysis, the circuit characteristics such as output power, current stress, and soft-switching range are analyzed in detail. For both single-branch and multi-branch modes, this work proposes corresponding optimized modulation strategies, which can reduce inductor current stress and expand the soft-switching range. In the experimental section, this work built a two-branch, four-port experimental prototype and conducted experimental tests under wide gain range and multiport output conditions. The experimental results validate the feasibility of the theoretical analysis.