Modulation Scheme Optimization for a Dual Three-Phase Active Bridge (D3AB) PFC Rectifier Topology

The recently presented Dual Three-Phase Active Bridge (D3AB) converter integrates a three-phase Power Factor Corrected (PFC) rectifier and a DC-DC converter stage with galvanic isolation, originating from the Dual Active Bridge converter, in a single converter unit, and accordingly features low complexity, high efficiency, and high power density. This paper proposes a multi-objective optimization procedure that considers the objectives of low RMS transformer currents and/or switching losses in order to identify Pareto-optimal low-loss modulation schemes for the D3AB rectifier that meet given specifications, prevent power pulsation, and facilitate interleaved operation. From the obtained results, which are verified by means of detailed circuit simulations, an improved modulation scheme is selected, which, compared to conventional modulation, reduces the primary-side switching losses by 54% and the total converter losses by 11%. Due to the general nature of the presented method, the application to other three-phase rectifier/inverter topologies is directly feasible.