The paper presents the findings of an R&D project connected to the development of 50 kW auxiliary power supply for the high‐voltage DC‐fed commuter trains. The aim was to introduce a new generation power converter utilizing high‐voltage insulated gate bibolar transistor (IGBT) modules, which can outpace the predecessors in terms of efficiency and power density, i.e. to provide more power for smaller volumetric space.
For development of the proposed converter, mathematical analysis and computer simulations were used. The software intended for simulations is Ansoft Simplorer, which is a mixed‐technology simulator for electrical, electromechanical, power electronic systems and drive applications. For the verification of theoretical results the full‐scale laboratory prototype of the proposed converter was developed and tested.
Thanks to increased switching frequency and current‐doubler rectifier (CDR) implemented in the proposed converter, the power dissipation of the isolation transformer was reduced by 30 percent as compared to earlier designs. Moreover, the 27 and 24 percent reductions in rectifier and inductor losses, respectively, led to approximately 1 percent efficiency rise of the proposed converter in comparison with its predecessors. Also, the proposed three‐level topology outpaces the two‐level one by more than 20 percent in terms of power density.
The proposed converter topology is aimed for the high‐voltage DC trains. With small modifications it also can be used in trams, trolleybuses as well as in some industrial applications.
The paper presents the novel DC/DC converter topology with 3.3 kV IGBT‐based three‐level neutral point clamped inverter, high‐frequency isolation transformer and the CDR.
