Novel 3-level Hybrid Neutral-Point-Clamped Converter

This paper introduces a novel 3-level Voltage Source Converter (VSC) as an alternative to known 3-level topologies, including the conventional Neutral-Point-Clamped Converter (NPCC), many T-type VSCs, and Active NPCC. It is shown that operating in the low converter DC-link voltage range, this new solution can achieve not only higher efficiency than many typical 3-level structures, but can also overcome their drawback of unsymmetrical semiconductor loss distribution. The switching states and commutations of the new converter, named here as Hybrid NPCC, are analyzed and a loss balancing scheme is introduced. New 5- and 7-level VSC topologies with loss balancing features are also presented.