Although an effective date isn’t expected before 2011控制工程网版权所有, mandatory minimum energy performance standards (MEPS) for electric Motors are coming to Europe in 2009. This will promote energy-efficient (EE) motor systems that can save up to 30% of the 70% of industrial electricity used by motorsCONTROL ENGINEERING China版权所有, according to Prof. Aníbal T. de Almeida, Electric Engineering Dept., University of Coimbra, Portugal.
　　At the recent Motor Summit `08 (Zurich, Switzerland), Prof. de Almeida presented details of a study prompted by the European Union’s Ecodesign Energy-using Products (EuP) directive, which has spurred the upcoming regulations. The study’s focus was to find ways to the lower life-cycle cost (LCC) and environmental impact of electric motors in the 0.75-375 kW (1-500 hp) range. Comprehensive analyses included material costsCONTROL ENGINEERING China版权所有, energy and other resources consumed during use-phase, and recycling/reuse requirements.
　　Key findings show significant environmental impact reduction from replacing IE1 motors with more efficient IE2 or IE3 class motors. This refers to new, globally harmonized motor efficiency classes defined in the IEC 60034-30 standard—namely, IE1-standard, IE2-high efficiency, and IE3-premium efficiency classes.
　　Lower life cycle cost would result at a relatively low number of annual motor operating hours. Depending on electricity costsCONTROL ENGINEERING China版权所有, this occurs around 2控制工程网版权所有,000 hr at 0.035  /kWh (lowest cost analyzed), and around 1控制工程网版权所有,000 hr at 0.075  /kWh (or 0.105 $/kWh). The latter is a more realistic figure given the upward trend of electricity costsCONTROL ENGINEERING China版权所有, and is more in line with U.S. electricity prices at current exchange rates.
　　Induction motors targeted
　　Induction motors are the main target of energy-efficiency efforts due to their huge installed base and production numbers. They represent 87% of ac motors sold in the EU, according to de Almeida. However, brushless permanent magnet (PM) electronically commutated motors were also analyzedwww.cechina.cn, he says, because of their much higher effi