Optimal PWM for Three-Level Inverter fed High Speed Drives

Thanks to new field of applications, like high speed/high-pole drives with high rated fundamental frequency or multilevel converters powering medium or high voltage drive systems, optimized PWM techniques became again a hot topic of research interest. The current paper introduces an optimized PWM technique for three-level inverter, which can be applied to supply high speed drives at low pulse ratio. The optimization is done for the lowest loss-factor, which is proportional to the square of rms value of current harmonics. The performance of the optimal PWM technique is demonstrated by simulation and experimental tests by using a NPC type inverter