Performance Analysis of a Novel Torque Controller in Direct Torque Control-Current Source Inverter Fed IM Drives at Low Speed with Minimum Ripple Torque

摘要

This paper proposes a novel torque estimator to improve the performance of DTC–CSI fed induction motor drive (IMD) and reduce the torque ripple during low speed operation. For effective operation of direct torque control method the electromagnetic torque and stator flux can beestimated from the stator quantities such as voltage and currents. The estimated stator flux can be affected by the parameter variation such as stator resistance due to temperature at low speed operation results torque ripples and the system become unstable. A modified torque estimator basedon MRAS principle implemented in this paper to overcome this problem and makes a system with dynamic performance. The effectiveness of proposed control method is verified using simulation and experimental results. The results prove that torque ripple has been significantly reduced and systemperformance improved at low speed operation.