Space vector modulation of nine-phase voltage source inverters based on three-phase decomposition

A new space vector modulation (SVM) technique having a full and independent control of the multiple voltage space vectors of a nine-phase voltage source inverter (VSI) is presented in this paper. The proposed approach is based on the concept of system decomposition, leading to the modulation of three three-phase VSIs. The resulting SVM corresponds to standard SVM for each three-phase VSI in the case of a nine-phase load with three insulated central points, whereas the additional modulation of the zero-sequence component is introduced for each three-phase VSI in the case of a nine-phase load with a single central point. The modulation limits are investigated and the analytical developments are proved by a complete set of simulation results.