Nested Multilevel Topologies

This paper proposes multilevel topologies based on the concept of nested arrangement. Such topologies are called nested multilevel converters, since the central point of the legs are connected at the same point, with the external legs involving the internal ones. Nested configurations present advantages as compared to the equivalent NPC topologies in terms of reduced number of diodes and consequently higher efficiency. In addition to proposing a new family of power electronics converters, this paper presents an optimized pulse width modulation strategy that allows synthesizing voltage waveforms with higher quality, a losses comparison with the NPC topology, and a general comparison with other topologies proposed in the technical literature. Simulated and experimental results are presented to validate the theoretical expectations.