Passive harmonic filtering systems for low power PWM ASDs: A comparative analysis and perspectives

The main goal of the paper is to discuss about usefulness, drawbacks and perspectives of single-phase PWM adjustable speed drives (ASDs) for low-power three-phase induction motors. Their positive impact on energy saving in large-scale residential house appliances is underlined. A great attention is devoted to the problem of generation of current harmonic components, both on the motor-side and on the supply-side. Two different passive filtering systems able to mitigate that problem are discussed, analyzed and compared, by means of a lot of numerical simulations performed by using Pspice under different working conditions. Finally, because of some evidenced drawbacks of both the considered schemes, the possibility of a introducing a new passive and simple filtering system is also briefly investigated.