Recent advances and applications of power electronics and Motor Drives - Electric machines and motor drives

In this paper, current advances in electric motors and power converters for variable speed applications are presented. A short overview of both electric machines and power converters are given. Permanent magnet assisted synchronous reluctance motors (PMa-SynRM) are introduced and their effects are studied. Also, a novel soft switched AC-link buck-boost converter for AC-AC power conversion is presented. This configuration uses two bi-directional switches per leg of the converter resulting in a 12 bi-directional switch topology. Power transfer is accomplished via a link inductor which is first charged from the input, then discharged to the output with a precisely controllable current PWM technique which results in near zero harmonics at all frequencies below twice the link frequency, as there are two power transfers for each link cycle. Capacitance in parallel with the link inductor produces zero-voltage switching for both turn-on and turn-off.