Power Semiconductor Loss Comparison of Low-Voltage, High-Power Two-Level and Three-Level Voltage Source Converters

For industrial low-voltage, high-power applications, the two-level voltage source converter (2L-VSC) is still the most common topology for machine-side and grid-side converters. With an ongoing development towards higher overall system efficiency, grid code requirements and the increasing availability of three-level low-voltage IGBT1-modules, three-level voltage source converter (3L-VSC) topologies become attractive as viable alternatives. As a first step towards a wider system-level comparison, this paper presents investigation results regarding the active power electronics part of the converter. This incorporates a deeper analysis and comparison of the IGBT-module losses and current capabilities of 400 V 2L- and 3L-VSCs for characteristic converter operating conditions and different modulation schemes (e.g. continuous and discontinuous space vector modulation).