Comparison of an Interleaved Multi-Branch Inverter and a Four-Level Inverter with Variable Voltage Levels for Emulation of Three-Phase Machines

Power-hardware-in-the-loop emulation of electrical machines is a useful tool to simplify the development and testing process of traction inverters and their control systems at different operating conditions. This requires two fundamental components: a real-time operating machine model and an applicable power electronic device, which adjusts the same currents and voltages as the surveyed machine would. This paper compares two different power electronic topologies regarding their suitability for emulation of three-phase machines. The surveyed topologies are on the one hand a multi-branch interleaved-switched inverter, which is a state-of-the-art solution and also used in commercial machine emulators. On the other hand, a four-level inverter topology with variable voltage levels is analyzed, which is custom-built for the purpose of emulating three-phase machines. Within this paper the setup of both topologies as well as the comparative analysis by measurement results are presented.