Motor Summit 2014: Energy efficiency focus is on total motor systems
Motor Summit 2014, the 5th edition of this international conference dedicated to the promotion and development of efficient electric motor-driven systems, drew some 180 participants to Zurich, Switzerland, during Oct. 7-9, 2014. Energy requirements of motor-driven systems are estimated to be about 46% of total electric power generated worldwide—even substantially higher in some countries and in industrial sectors. That makes energy efficiency a topic of vital importance today and going forward. Motor Summit provided the platform for experts and interested parties to present and discuss technologies and strategies needed to make energy efficiency improvements possible.
Motor Summit was hosted by the Swiss Agency for Efficient Energy Use (SAFE) in collaboration with the Electric Motors Systems Annex (EMSA) of the International Energy Agency’s Implementing Agreement Energy Efficient Electrical End-Use Equipment (IEA 4E).
Co-host for the event was the National Electric Manufacturers Association (NEMA) www.nema.org of the U.S.
Motors and more
It has become increasingly evident over prior editions of Motor Summit that the "system" beyond the electric motor represents fertile ground for large energy efficiency gains. Here we are talking about pumps, fans, compressors, drives (the core motor system)-as well as gearboxes, piping/heating systems, and other motor-driven loads (the so-called total motor system). Several summit presentations stressed the need for efficiency improvement at the system level (see Refs. 1, 2, 3).
Reference 4 described efficiency assessment of motor systems including mechanical transmissions (drive belts, gearboxes with various gear types) and pump/fan loads where 30% or greater efficiency gains could be obtained. Ongoing work on efficiency measurements for combinations of motors and variable-speed drives (VSDs) was presented in Reference 5, including partial load results using a 20-point test regime. Three motors types and sizes (IE2, IE3, IE4-permanent magnet at 7.5 kW, 37 kW, 75 kW) and VSDs comprised a total of nine test elements or "power drive systems." Partial load motor system efficiency assessments are particularly important since information of this type remains scarce. Results can be shown as contour curves of torque-speed efficiency, which offers useful interpretation (see Figure 1). IE motor classifications are explained below.
Another common theme of the conference involved strategies needed to overcome market barriers holding back wider use of highly efficient motor systems. Barriers mentioned (Refs. 2, 6) included:
- OEMs’ exclusive concern for lower cost components
- Total cost of ownership not considered
- Motors often oversized, leading to low efficiency at partial loads
- Little influence of plant equipment users on management buying decisions.
Further barrier issues were mentioned for the China market, among them lack of awareness of system efficiency, lack of effective measurements and tools, and lack of trust for calculation of energy savings (Ref. 7).
The Oct. 2014 publication of "Toolkit for Policy Makers" from EMSA IEA 4E was made available at the conference. This significant milestone is Part 2 of an overall Policy Guidelines for Electric Motor Systems project-with Parts 3 to 6 under development. The report is available at www.motorsystems.org.
For their part, motors—particularly industrial workhorse ac induction machines—have made great strides in raising their efficiency through improved design and standardized testing, pushed by the enactment of mandatory minimum energy performance standards (MEPS). The U.S. has led the MEPS effort, followed by Australia and Canada, among others, with more nations heading to adopt MEPS. The types of motors currently covered under the amended U.S. regulation have been expanded to include virtually all categories of polyphase continuous-duty motors from 1 to 500 hp (0.75-375 kW).
In the European Union, stage 2 of a MEPS initiative will kick-in on Jan. 1, 2015, which makes mandatory the use of IE3 efficiency motors in the 7.5-375 kW power range. Stage 3 in January 2017 will extend the range of compliance down to 0.75 kW for IE3 motors. However, both stages allow an option to use IE2 motors if fitted with a variable speed drive. IE designation of motors refers to International Electrotechnical Commission (IEC) standard 60034-30 "International Efficiency (IE) Classes," which defines increasingly higher efficiency motor designs up to IE4 and makes provision for an IE5 class.
An IE3-class motor translates approximately to NEMA Premium efficiency level. For example, a 200 hp (150 kW), 4-pole 60 Hz NEMA Premium motor has a required nominal efficiency of 96.2% at full load. A comparable 160 kW, 4-pole 50 Hz IEC IE3 motor must provide 95.8% nominal efficiency. Motor designs of IE5 and even higher efficiency classes are under development.
While the progress to higher efficiency (IE3 class) motors outside the U.S. is a positive ongoing effect, global market transformation is expected to be slow due to the long life of electric motors and their huge installed base. This was made clear in the presentation "Motor market update" by Alex Chausovsky, manager and senior analyst, industrial automation, at IHS Technology in the U.S. (Ref. 8). IHS estimates that 60% of motor units in use worldwide in 2013 still remained IE1-a class no longer permitted for entry into the market in countries with mandatory MEPS in place.
As for current market size, IHS put the 2013 worldwide shipment of low voltage integral hp motors at 50 million units with average sale price of $300.
A regional breakdown of motor efficiency classes in use is summarized in the table below.
In addition, Ajit Advani of the CopperAlliance, India, added that the Indian motor market stands at about 12%-13% penetration for IE2 motors and less than 2% for IE3 motors. www.copperindia.org
Pursuing the course of mandatory MEPS in regions with small penetration of efficient motors makes economic sense. This approach will take considerable time. The start of mandatory IE3, scheduled for 2015 in Japan and for 2017 in China (Refs. 9 and 7, respectively), should lend impetus to the movement. Brazil expects to be on the IE3 MEPS track by 2018 (Ref. 10).
Retirement of old, inefficient motors presents another barrier to energy efficiency because of long product life and a large installed base. Figure 2 provides one glimpse of motor age from an analysis of 18 industrial plants in Switzerland (Ref. 2). The study found 56% of 4,142 motors older than their operating life expectancy. Similar findings are likely in other countries.
"The way forward" from this situation includes convincing upper management to invest in energy efficiency and promoting greater user awareness through education about potential savings, including life-cycle cost assessment, noted Rita Werle, representing the Swiss Agency for Efficient Energy Use and Topmotors, Switzerland.
For countries with established MEPS programs, such as the U.S., a different next phase of energy savings becomes practical. IE3 or higher class motors represent relatively "high-hanging fruit" with diminishing potential for further efficiency improvement. Instead an "extended motor product labeling initiative" (EMPLI) is being pursued in the U.S., according to Rob Boteler, Nidec Motor Corp. and chairman NEMA Energy Management Committee (Ref. 11). Boteler referred to this approach as the "move to managed kW."
Basis of EMPLI is a "motor coalition" of U.S. energy community stakeholders, and importantly includes fan, pump, and compressor associations. These three large "driven load" categories are now in the U.S. Dept. of Energy (DOE) rule-making process for energy regulations. Defining measurement and verification protocols—to be addressed by of each of the fan/pump/compressor product associations—and reaching agreement on performance metrics will be major steps forward.
The ultimate goal of EMPLI is the creation of labels or marks to identify highly efficient products. Labels could incorporate efficiency performance indicators and other metrics applicable to the product section (based on DOE rules) and amount of kW saved.
"Utilities will use the results to build unique incentive programs for respective service areas," Boteler explained.
"Results of this project can affect nearly 25% of the annual electric motor load in the USA [equivalent to 10 million connected hp]."
IEC standards progress
Meanwhile, other IEC standards are moving forward. A presentation by Martin Doppelbauer—Prof. Dr.-Ing. at Karlsruhe Institute of Technology, Germany, and Convener of IEC TC2 WG31—summarized relevant developments (Ref. 12). IEC 60034-30 (mentioned earlier) breaks down into two separate standards: 30-1 applies to grid-fed induction (and line-start synchronous) motors and covers efficiency values for class ratings IE1 through IE4. Standard 30-2 provides coverage for induction, PM-synchronous, and reluctance-synchronous motors under VSD control with ratings for the same IE classes. Applicable power range for both standards is 0.12 to 1,000 kW; however, 30-2 includes a motor speed specification range of 600 to 6,000 rpm, due to the different application. IEC 60034-30-1 was published as edition 1.0 in March 2014, while standard 30-2 is being readied for committee draft vote 2 in Q12015.
Energy efficiency is determined at six load-points in IEC 60034-30-2, and the weighted average of those points forms the basis of the IE classification. "An interpolation procedure is used to determine energy consumption at any load-point," Doppelbauer said.
Testing standards are associated with each of the above classification documents. IEC 60034-2-1 is a revised test standard with preferred test method specified for each motor type and size (grid-fed). Edition 2 was published in June 2014. IEC 60034-2-3 is a new test standard for motors under VSD control and is at the technical specification stage with verifications ongoing, according to Doppelbauer. Edition 1 was published in Nov. 2013.
A new "system efficiency standard" (IEC 61800-9) for motor and VSD combinations has just been started in Sept. 2014. IEC 61800-9 will cover test methods and efficiency classification; moreover, it will need to meet the challenge of developing a "reference" motor and drive since in practice these elements often come from different manufacturers.
Another new initiative on the conference agenda was a "global motor energy efficiency" (GMEE) program promoted through the collaboration of NEMA and IEC’s conformity assessment wing IECEE (Ref. 13). The initiative seeks to harmonize inconsistent differences among various national and regional MEPS regulations that hinder global market growth for efficient motor products.
Developing a common global MEPS registration process that includes test laboratory qualification and certification would be one of the program’s main goals, noted presenter Dan Delaney from Regal Beloit in the U.S. Another goal is the development of an enforcement/verification program to increase efficiency compliance in the global motor industry. The ultimate objective of the initiative is a globally recognized product efficiency label and one test certificate accepted by national regulators worldwide.
A two-phase approach is foreseen going forward. Phase 1, titled GMEE, would provide an IECEE "certification body test certificate," but would delay the labeling program. Phase 1 can be launched quickly and doesn’t need global regulatory approvals. Phase 2—"global motor labeling program" (GMLP)—would incorporate full labeling and regulatory participation, Delaney noted.
Typically, Motor Summit has a three-day format. Day 1 is structured around EMSA workshops. Four presentations on "policy" and three on "technology" aspects of motor system efficiency comprised the workshops on Oct. 7. International Strategy on day 2 (Oct. 8) covered a variety of topics that included energy strategies, global motor markets, energy efficiency policies around the world, test and measurement requirements, new technologies ahead, and a summary panel discussion.
"Swiss Implementation Day" concluded the conference on Oct. 9, with additional presentations that took place mainly in the German language. Motor Summit speakers represented Europe, Australia, Brazil, Canada, China, Japan, and the U.S. Principal moderator for the event was Conrad U. Brunner, operating agent for EMSA. Visit the Motor Summit 2014 website for more information on the program.
Control Engineering participated in Motor Summit 2014, also in the 2008 event, and provided reporting in 2010 and 2012.
The future of highly efficient electric motor systems rests on the ability to expand practical know-how into the total system beyond the motor itself. This is a task easier said than done, because full motor-driven systems are complex to analyze and have essentially an unlimited number of diverse applications. Analysis, verification testing, repeatability of results, etc., become more difficult and costly. However, talented, resourceful designers, engineers, and technology managers will surely bring new methods and tools into play to make a more energy-efficient future a reality.
– Frank J. Bartos, PE, is a Control Engineering contributing content specialist. Reach him at firstname.lastname@example.org
References cited from Motor Summit 2014
1) "Energy efficiency potentials for different motor system levels," Svetlana Paramonova and Patrik Thollander, Linköping, University, Sweden.
2) "Swiss audit program Easy," Rita Werle, Topmotors, Switzerland.
3) "Energy strategy 2050," Walter Steinmann, Swiss Federal Office of Energy.
4) "Total drive train optimization of industrial fans and pumps considering VFD driven motor, transmission and load," Steve Dereyne, University of Ghent, Belgium.
5) "Recent results of efficiency measurements of converters and motors," Pierre Angers, Hydro Quebec, Canada.
6) "Policy guidelines for efficient electric motor systems," Konstantin Kulterer, Austrian Energy Agency, Austria.
7) "Improving motor system efficiency in China," Zheng Tan, Topmotors China.
8) "Motor market update," Alex Chausovsky, IHS Technology.
9) "Japan starts with mandatory motor requirements," Takashi Obata, JEMA/Hitachi, Japan.
10) "Brazil moves ahead with MEPS for motors," George Alves Soares, Electrobras, Brazil.
11) "New U.S. MEPS for motors and applications," Rob Boteler, Nidec Motor Corp./NEMA, USA.
12) "New developments in IEC standards for motors driven by converters," Martin Doppelbauer, Karlsruhe Institute of Technology, Germany.
13) "IECEE global motor labeling program," Dan Delaney, Regal Beloit, USA.