A Novel Seven-Level ANPC Converter Topology and Its Commutating Strategies

Traditional seven-level active neutral-point-clamped (ANPC-7L) converters suffer from the problems of dynamic voltage balancing in series switches and multilevel voltage jumping of phase output voltage during switching states transition. This paper presents a novel ANPC-7L topology with auxiliary commutating branches and elaborates on its commutating strategies. The presented topology and its commutating strategies completely resolve the two problems mentioned above. The validity of the presented topology and its commutating strategies are verified by experimental results from a 380 V/5 kW ANPC-7L converter.