Inverter losses analysis for dual FED open winding machines with a novel modulation technique

With the progress in variable frequency power generation systems, and the increase of individual controlled power units in high power industrial processes, traditional two-level power converters began to operate very close to their physical limits. Therefore, more attention has been given to multilevel converters and they are increasingly being applied to high power systems. In this work, a structure is studied that uses two-level back-to-back converters connected to a squirrel cage rotor induction machine, operating with open windings. This structure results in a three-level behavior of the converter. A vector modulation technique was proposed to reduce the losses in the IGBT modules while producing a current with low harmonic distortion for this conversion topology. A comparison between this vector modulation technique and the level shifted modulation strategy is carried out through simulation results.