The presented work deals with different multilevel converter topologies for various low voltage applications (< 1 kV). Within the scope of the presented analyses, three novel technologies were investigated in more detail: the capacitor-based stepped EMMC, the battery cell-based BM3 and the capacitor-based magnetic stimulator. These are first presented from a historical perspective and then classified . In addition to their basic functionality, the selection and design of the power semiconductors and the passive energy storage for the investigated converter topologies is shown. Demonstrators were set up and evaluated, taking into account the different applications. Control procedures have been developed to ensure the proper operation of the inverters. For example, an optimum control approach was developed for the EMMC, which was tested in grid-tied operation utilizing a Proportional-Resonant controller. The three-phase operation was demonstrated for the BM3, using a resistive load, and the first stimulation pulses were tested for the presented magnetic stimulator. Furthermore, simulated drive cycles of different battery-based multilevel converters were compared for a small passenger car.
Fakultät für Elektrotechnik und Informationstechnik