Abstract

Multilevel converters uses a large amount of semiconductors. This allows to reconfigurate the converter to work even on internal fault condition. This paper presents a method to detect faulty cells in a cascaded multicell converter requiring just one voltage measurement per output phase. The method is based on high frequency harmonic analysis, using a dynamic prediction of their behavior, avoiding false detection on transients while keeps the precision under fault events. Once the faulty cell is detected, it can be shortcircuited allowing the converter to keep working according to previously reported techniques. © 2006 IEEE.