Analysis of modulation techniques for an alternative five-level NPC converter used on adjustable-speed drives

This paper intends to conduct a study of various modulation techniques applied to an alternative five-level NPC converter. The inverter is based on Neutral Point Clamped concept composed of five level bridges of three level legs in each inverter phase. This configuration presents as an advantage the synthesis of higher voltages compared to the classical three level structures. Modulation techniques implemented are detailed throughout the paper. The results are displayed and their analysis is performed considering the harmonic distortion and losses in the converter with a deep study of converter heating. Simulation will be presented and confirm the proposed ideas.