Designing a Three-Phase Dual-Active Bridge for Water Electrolyzers Considering Voltage Variations

IEEE International Conference on Environment and Electrical Engineering and IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe), pp. 1–6

Abstract

The recognition of the importance of water electrolyzers in the context of the energy transition is strongly promoting their expansion. As a result, new technologies are being explored to ensure that the increasing number of systems can be powered in an efficient and grid-compatible manner. This paper presents the design method for a three-phase Dual-Active Bridge (DAB3) by minimizing the converter current ratings to supply a water electrolyzer from the Medium-Voltage DC (MVDC) grid. Taking into account possible voltage changes at the DAB3 input and output sides caused by grid fluctuations and electrolyzer aging, the AC link phase currents are minimized. The optimization procedure is demonstrated for the power supply design of a 22.5 MW water electrolyzer from the 30 kV MVDC grid and yields DAB3 core design parameters such as series inductance, phase angle and transformer turns ratio. In a subsequent design evaluation, it is shown how the soft-switching limits can be represented and interpreted for the different converter operating ranges.

Authors 2

1. Fabian Herzig

   Siemens (Germany) · Siemens Energy

   Affiliation as printed

   Sustainable Energy Systems, Siemens Energy,Erlangen,Germany

2. Rik W. De Doncker Aachen E.ON Energy Research Center

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University,E.ON Energy Research Center,Aachen,Germany