Evaluation of Bidirectional High-Power Converters for LVDC and MVDC Grids

For planning and design of future MVDC and LVDC grids, an evaluation and comparison of bidirectional, galvanically isolated, high-power dc-dc converters is essential. Prior publications reduce complexity by either focusing on predefined designs and subsequently multi-dimensional evaluation of multiple topologies or focusing on a multi-dimensional design of a preselected single topology. Both exclude potentially promising topologies or designs prematurely. In contrast, this paper abandons these simplifications by means of a multi-dimensional design algorithm of several topology candidates with the objectives of efficiency, cost, and material usage. For this, an efficient and uniform implementation of SPS is presented, which is independent of the used energy storages and switching frequency. Further the used analytical and empirical models based on approximately 40k components to estimate losses and weight of the energy storages are introduced. Finally, the application scenario of a DC-DC converter to interconnect a 2.5 kV MVDC and 760 V LVDC grid with a rated power of 100 kW has been studied.