Three-phase active bridge inverter — 3PAB

An Active-Bridge based, current-source, three-phase inverter (3PAB) is proposed. It is a single-stage, galvanically-isolated topology, which enables direct interface to a three-phase grid. Operation is similar to a Dual Active Bridge converter, in which the secondary side H-bridge is replaced with a three-phase bridge. A novel modulation technique presented in the paper enables unidirectional power flow from DC to AC side, while energizing all three output phases in one link cycle. Zero voltage, zero-current turn-on of all devices reduces switching losses and increases efficiency. The proposed topology is a viable solution for applications where a compact and lightweight, galvanically-isolated inverter is required such as roof-top photovoltaic installations.