Drives and Controls Magazine
US and EU motor-makers join forces on system efficiency
Published:  14 October, 2016

Electric motor manufacturers in North America and Europe are working together to develop efficiency standards for complete motor-driven systems, rather than focusing on motors in isolation.

The trade organisations that represent the manufacturers – Nema (the National Electrical Manufacturers Association) in the US, and Cemep (the Committee of Manufacturers of Electrical Machines and Power Electronics) in Europe – have set up a working group to develop a new direction for global motor efficiency standards based on a systems approach, which they say, will lead to bigger energy savings.

Originally, efficiency standards focused on isolated drive system components, but they are now evolving to encompass interconnected, multi-component systems.

“We believe the market will embrace a new systems approach to power drive standards that quantify total energy savings in place of efficiency for isolated components,” says Robert Boteler of Nidec Motor Corporation, who chairs Nema’s Motor and Generator Section Energy Management Committee. “This will enable us to measure and minimise power losses for all segments of the motor-driven market.”

Nema and Cemep have set up a joint working group and this week presented a white paper, called a New Systems Approach to Motor Efficiency Standards Promises Electrical Energy Savings in Practical Applications, at the Motor Summit 2016 conference in Switzerland. The paper outlines an extended product approach that moves beyond individual motors, inverters, and controls, to include electronic speed controls, power drive systems (PDSs), pumps, fans, compressors, and other auxiliary electronics that make up complete motor-driven systems.

“The motor is a critical part of any electronic system, but it only makes up a small percentage of the energy losses inherent in any electrical system,” points out Cemep president, Jurgen Sander. “Incorporating power drive systems can increase energy saved by as much as six times the amount that could be saved when relying solely on the motor component.”

Future efficiency standards will consider all of the components involved in motor-driven drivetrains

The Nema-Cemep working group is currently developing a new standard that uses loss reduction versus efficiency when considering total system energy savings. The group is also establishing the losses generated at various operating points and determining the savings in energy as a result of using a power drive system. The resulting standard will establish a series of points that can be used to evaluate and optimise energy savings.

Motor efficiency classification started in Europe in 1998. In 2001, US motor manufacturers raised efficiency levels above the minimum requirement that Congress had established in 1992. In 2010, this premium efficiency level was added to regulations, establishing it as the minimum requirement. This brought greater savings to a category of motors that make up about 40% of the motors sold every year.

In 2014, the most recent round of US regulations was released. It took effect June 1, 2016, and covers all polyphase motors from 1-500 horsepower (0.75–375kW).