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In the paper, a new five-level (5L) converter is presented. It is called 5L-active-neutral-point-clamped with coupled-inductor (5L-ANPC-CI) and consists of a three-level bidirectional (3L-B) commutation cell connected to two parallel basic commutation cells. The proposed topology can be seen as two cascaded current stages controlled at different frequencies. The high-current stage is specific to the 3L-B cell controlled at low-frequency, while the low-current stage corresponds to the parallel cells with coupled-inductor controlled at high-frequency (HF). Due to this advantage, the new converter appears as a useful solution to increase the output current, while the switched current through the HF power devices is reduced. The operation principle of the new structure is verified by simulations both for single- and for three-phase topologies. Experimental results for single-phase 5L-ANPC-CI converter on a low-voltage test bench are also provided to validate the proper operation of this concept. [ABSTRACT FROM AUTHOR]

In this paper, a new three-level (3L) converter is presented. It is called 3L Vienna neutral-point-clamped (3L-VNPC) converter and consists of two stacked high-frequency (HF) commutation cells working with a shared power device. The HF cells are connected to a single-phase switched bridge controlled at low frequency. The 3L-VNPC topology is extended to 3L active VNPC (3L-AVNPC) concept, which is generalized for five levels (5L) and N odd voltage levels (N \L). The proposed multilevel converters can be seen as two cascaded voltage stages. The high-voltage stage is specific to the single-phase switched bridge, while the low-voltage (LV) stage corresponds to the stacked HF cells with shared power devices. The new concept AVNPC is a useful and suitable solution for medium-voltage applications, where small modulation index (M) is as crucial as large M. The analyses of the new converters are verified by simulations both for 3L and for 5L topologies, and their features are generalized for N\L. Experimental results for single-phase 3L-AVNPC converter on an LV test bench are also provided to validate the proper operation of the new concept. [ABSTRACT FROM AUTHOR]