Modulation and capacitor voltage balancing control of a four-level active-clamped dual-active-bridge DC-DC converter

This paper proposes and demonstrates the feasibility of a dual-active-bridge converter built upon four-level active-clamped legs. A suitable modulation pattern is defined. The dc-link capacitor voltage balancing is analyzed and a proper balancing control is designed. The topology, modulation, and balancing control performance are validated through the steady state and transient responses obtained with a set of simulation and experimental tests. An experimental prototype has been built for the experimental tests composed of four four-level active-clamped converter legs and controlled with a dSPACE control platform.