Impact of Submodule Voltage Sensor Noise in 10 kV SiC MOSFET Modular Multilevel Converters (MMCs) under High dv/dt Environment

Medium voltage (MV) power converters using high voltage (HV) Silicon Carbide (SiC) power semiconductors result in great benefits in weight, size, efficiency and control bandwidth. However, HV SiC MOSFET based converters suffer from high dv/dt (>100 V/ns). Under high dv/dt environment, sensors are easily interfered due to the power electronic device’s fast switching. In this paper, the noise coupling mechanism in a submodule (SM) voltage sensor is analyzed, and the impact of SM voltage sensor noise on MMC phase-leg operation is discussed. A simulation model and a 10 kV SiC MOSFET based MMC prototype with 25 kV dc-link are built to validate the analysis of the impact.