Novel flux and torque control of induction motor drive using Four Switch Three Phase Inverter

This paper presents a novel control method for Four-Switch Three-Phase Inverter (FSTPI) suitable for low power applications. The method aims to apply the DTC technique using the FSTPI as a power circuit instead of conventional Six-Switch Inverter (SSTPI). A suitable switching table has been derived which selects the inverter switching states to fulfil the torque and flux requirements. The modulation strategy provides quick response and accurate control of both stator flux and motor torque. Simulation and experimental results have verified the validity and effectiveness of the proposed method to obtain a good performance AC drive with reduced initial cost. Moreover, Comparisons with DTC of induction motor fed by conventional SSTPI confirm that FSTPI topology can be alternative to the conventional topology for low power low cost induction motor drives.