Design, Implementation and Control of a SiC-Based T5MLC Induction Drive System

This paper presents and evaluate a prototype of an advanced topology of five-level T-type MLC, namely “T5MLC”, implemented within a complete AC induction drive. The evaluation is based on the ability of balancing the converter DC link capacitor voltages, the torque and flux ripples reduction of the induction motor under control, the harmonic analysis and the efficiency of the inverter and the overall drive system. The converter implementation and design considerations using Silicon Carbide (SiC) discrete MOSFETs are discussed. The operation and the analytical model of T5MLC using switching-functions are presented. The model predictive control (MPC), as a preferred AC drive control approach, is selected to adapt the machine torque and flux, and to balance the DC link capacitor voltages. The T5MLC drive system is tested at different scenarios; i.e. suddenly load changing and speed reversal, to ensure the converter capability and excellent performance in AC drive applications. The experimental results show that the MPC could achieve an excellent performance in terms of low harmonic distortions, reduced flux and torque ripples and the ability of balanced DC link capacitors. In addition, the loss analysis showed that the T5MLC is 5.5 % to 24.8 % efficient compared to dual T-type MLC at different loading conditions.