A Fully Balanced Vertically Stacked Multilevel Power Converter Topology with Linear Scaling using Dual Active Half Bridge Converters

This paper proposes a novel multilevel power converter topology that can be expanded to an arbitrary N number of levels. The topology is modular in nature, consisting of groupings of three degrees-of-freedom dual active half bridge (3D-DAHB) switching cells that can be stacked and reconfigured to achieve any desired number of levels. Each DAHB can move power between any of its four associated capacitors, allowing for stacked DAHBs to distribute voltages arbitrarily around all capacitors in the stacked configuration, resulting in a multilevel topology of arbitrary level voltages. Component quantities and component stresses scale linearly with the number of levels. Internal power flows are exclusively a product of input/output parameters and not the number of levels. Dynamic equations for the topology that can be used to determine the capacitor voltages and required capacitor power transfers are provided. A simplified circuit model is derived alongside methods of expanding this topology to N-levels. Functionality of the proposed converter is demonstrated through high-fidelity simulation of a 9-level converter.