New Five Level Resonant DC/DC Buck Converter

Abstract

This paper introduces a new five level resonant DC/DC converter and examines its operation in steady-state symmetrical conditions in discontinous current conduction mode. The converter has four outputs, which can provide four equivalent voltage levels or four different ones as well. It has several advantages such as improved performance at high efficiency and lower EMI. By using this converter, zero voltage and zero current switching is possible which helps reducing the swtiching losses. The most important relations among the input, output, and control variables will be derived and verified by simulation results. Three control variables will be examined in the paper, switching angle $\alpha_{p}[{}^{\circ}]$, capacitor peak voltage $V_{c}^{*}[pu]$ and switching frequency $f_{s}^{*}$ [pu]. Parameters $V_{c}^{*}$ and $\alpha_{p}$ are dependent variables, while $f_{s}$ is independent of them. This converter can be applied in UPS systems or in multi-level inverter drives as well.