A Single-Phase Hybrid Six-Leg AC-DC-AC Multilevel Converter

This article presents a single-phase hybrid six-leg ac-dc-ac multilevel converter. The configuration is composed of a three-leg neutral point clamped converter connected in series with a three-leg two-level converter. The proposed converter provides a sinusoidal input current with unitary input power factor and it feeds the load with a stable ac voltage. The system model, operation principles, and a control strategy are presented and discussed. Additionally, a space-vector puslewidth modulation technique is developed to control the dc-link capacitors, to produce optimal voltage waveforms, and to reduce the switching losses. The converter can generate 9-level and 11-level output voltages when operating with symmetrical and asymmetrical dc-link voltages. Experimental and simulation results are presented to validate the theoretical studies.

Automated summary

This article introduces a single-phase hybrid six-leg AC-DC-AC multilevel converter, providing discussions on the system model, control strategy, and space-vector pulse width modulation technique. The converter can generate 9-level and 11-level output voltages while feeding the load with stable AC voltage.