Commande DTC d’une propulsion moteur asynchrone/onduleur multiniveau asymétrique pour un véhicule électrique

Abstract

This paper deals with the DTC of an induction motor fed by an asymmetric multilevel inverter. This motor drive is used to propel an urban electric vehicle. For DTC purpose, the stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a hybrid cascaded H-bridge multilevel inverter, where each phase of the inverter can be implemented using a DC source, which would be available from the electric vehicle fuel cells, batteries, or ultracapacitors. This inverter provides nearly sinusoidal voltages with very low distortion, even without filtering, using less switching devices. In addition, the multilevel inverter can generate a high and fixed switching frequency output voltage with less switching losses, since only the small power cells of the inverter operate at high switching rate. Therefore a high performance and also efficient torque and flux controller is obtained, enabling a DTC solution for multilevel inverter powered motor drives.