Standards for Super-Premium Efficiency class for electric motors

Higher efficiency electric motors can lead to significant reductions in the energy consumption and also reduce the environmental impact. In order to promote a competitive motor market transformation, a new international standard, the IEC 60034-30 has been approved. This standard globally harmonizes motor energy-efficiency classes in general-purpose, line-fed, three-phase, squirrel-cage, induction motors (IMs). In this standard, four efficiency classes are proposed, namely Standard Efficiency (IE1), High-Efficiency (IE2) equivalent to EPAct, Premium Efficiency (IE3) equivalent to NEMA Premium and Super-Premium Efficiency (IE4). IE1, IE2 and IE3 classes were normative, and IE4 class was intended to be informative, since no sufficient market and technological information is available to allow IE4 standardization. The IE4 Super-Premium class, under discussion, can be applied both to line-fed motors and to inverter plus motor units. In fact, for low-power levels (up to 10 hp) it is clear that moving away from IM technology, and considering emergent or best-available technologies such as permanent-magnet synchronous motors (PMSMs) can achieve efficiency levels considerably significantly higher than those defined by Premium IE3 class. In this paper, feasible limits for IE4 class are analysed taking into account the efficiency levels of commercial and expected best available technology. The presented results can be useful to define future international standard ¿Super-Premium¿ or IE4-class levels as well as to set market transformation strategies.