Robust control of extended commutation cell based converters

An extended commutation cell (ECC) is a four-port four-switch power processing cell that allows for bidirectional energy transport in two orthogonal directions throughout the structure. By cascading multiple cells a high-quality output voltage waveform can be constructed with a high number of levels. In this paper a model of the internal energy flow, together with a robust control structure is proposed. The proposed structure is analyzed, simulated and experimentally verified on an eight-level inverter prototype of 4.4 kW.