Reactive current elimination in DC/DC DAB converters based on novel Equivalents Values Modulation (EVM)

Abstract

Actually the Dual Active Bridge converter (DAB) is emerging as a key technology for applications in systems with DC-DC conversion stages, such as; electric vehicles, solid state transformers, batteries charge and DC grids interconnection. In this paper a novel modulation method for Dual Active Bridge (DAB) Converters, called Equivalents Values Modulation (EVM) is proposed. The main characteristic of EVM is the bidirectional transfer flow of active current without generating reactive currents or return currents, in both DC ports and in all operation range of the converter. This characteristic allows overcoming the actual limitations of the most significant modulation techniques for DAB converters as SPCS, DSPCS and Independent Surfaces, thus deriving the following advantages: 1) reduce the stress of current semiconductor devices, 2) minimizes peak to peak currents at the ports of DC converter and 3) reduces the RMS current in the transformer. The Laboratory experimental results, mathematical models and simulations show that the modulation method EVM, is the most suitable for controlling the power flow between the two ports of DC.