Synchronous Reluctance Technology: Part I

Abstract

In recent years, the desire for high efficiency and high torque density electric motors has significantly increased. In the industrial arena, the EU Commission Regulation (EC) No 640/2009 implementing Directive 2005/32/EC has prompted the IEC to issue new energy efficiency standards (under IEC 60034-30) for electric motors, aimed at reducing energy consumption to help tackle greenhouse gas emissions (GHG) and climate change. Approximately 60% of all generated electricity in the EU and is fed into electric motors, whether this be to factories such as paper mills or plastic goods manufacturing, for common industrial fan and pump applications or consumer goods. Over 90% of these motors are of the induction type (IM), mostly three phase four pole, powered either direct on-line (DOL) or via a variable speed drive (VSD). These consume approximately 64,000 GWh of energy per annum [1], corresponding to approx. 35 Mt of GHG emissions [2]. The proposed IE4 super-premium efficiency standard, aims to increase machine minimum efficiency to help tackle the issue. We are already seeing the marketing of IE4 efficiency standard machines, both induction and synchronous reluctance, such as those in Fig. 1 by ABB.