Performance analysis of an advanced bus-clamping DTC strategy for IM drives

Abstract

This paper proposes a novel Bus-Clamping DTC strategy (BC-DTC strategy) dedicated to two-level three-phase inverter fed induction motor (IM) drives. This strategy consists in the synthesis of the vector selection table, suitably arranged considering the 60-Degree (60°) bus-clamping technique. Different from other 60-Degree Bus-Clamping based DTC (60° BC-DTC) strategies, the approach adopted in the selection of the clamped phase of the proposed strategy depends on the revolving reference stator current vector Is instead of the stator flux vector Φs. A comparison study between the classical DTC strategy and the proposed BC-DTC one is achieved. Simulation results have proven that the proposed BC-DTC strategy exhibits better performance during both transient and steady-state operations than the first one. Therefore, a reduction of the electromagnetic torque ripple amplitudes is gained. Extending the comparison to the converter operation, and through various comparison criteria, we have found that the considered 60° BC-DTC strategy offers the lowest average commutation frequency and the lowest average switching losses and the highest quality factor.