A performance comparison study of space-vector and carrier-based PWM techniques for a 3-level neutral point clamped (NPC) traction inverter drive

This paper presents a performance comparison study between the space-vector and carrier-based PWM techniques used for neutral point clamped (NPC) 3-level inverter. A reduced switching loss based modulation technique is used for the SVPWM scheme and a third harmonic injected PWM technique is used for the carrier-based PWM scheme. A 110 kW surface-PMSM is used with the NPC inverter, as generally being used for electric vehicle propulsion applications. Detailed simulation studies are carried out to show the performance comparison between the two modulation techniques for the total harmonic distortion, torque ripple, total inverter losses, conduction and switching losses for each power switches, their antiparallel diodes, and for the two NPC diodes. Simulation studies are carried out in MATLAB/ SIMULINK platform and the power switches are modeled in PLACES. A scaled down laboratory prototype with a 6.0 kW SPMSM and a 3-level NPC inverter is built to show the performance of the system with both control strategies.