Torque ripple comparison of a two-level and a three-level inverter fed brushless DC motor drives at different switching frequency

The conventional two-level inverter fed brushless DC (BLDC) motor drive generates high current ripple, which leads to torque ripple, speed ripple, and motor vibration. However, the three-level neutral-point-clamped (NPC) inverter fed BLDC motor drive would provide significant reduction in current ripple and torque ripple compared to the two-level inverter. This paper presents the performance comparison based on torque ripple and power loss of the two-level inverter and the three-level inverter fed BLDC motor drives under various switching frequencies. The simulation results show that the significant reduction in the toque ripple and the power losses in the BLDC motor fed by three-level NPC inverter when compared to the two-level inverter at high switching frequency.