IE6 hyper-efficiency motors are ready to roll
25 June 2024
Robert Chin, Global R&D Manager IEC LV Motors at ABB, explains that while IE5 is regarded as the current state-of-the-art in energy efficiency, motors that meet the anticipated IE6 “hyper-efficiency” level are already commercially available in the form of synchronous reluctance (SynRM) technology.
They offer a simple, cost-effective and magnet-free solution for the majority of applications.
In October 2023, the Energy Efficiency Movement (EEM) published its guide, “The Case for Industrial Energy Efficiency”. It explains that doubling energy efficiency by 2030 could cut greenhouse gas emissions by almost a third compared to today’s levels, according to the International Energy Agency (IEA). And for industrial players, the opportunity is immense.
One of the 10 simple measures outlined in the guide is to adopt higher-efficiency electric motors. This would yield an estimated saving of almost two billion metric tons (gigatons) of carbon dioxide (CO2) emissions a year by 2025, and more than four gigatons by 2030.
For an industrial enterprise, around two-thirds of its electricity consumption, and consequent electricity-related CO2 emissions, is most likely related to powering motors in pumps, fans, compressors and other equipment.
If the 300 million-plus industrial electric motor-driven systems operating today were replaced with optimised, high-efficiency versions, worldwide electricity consumption could be cut by up to 10 percent.
Many governments have responded to the urgent need to reduce global emissions by introducing efficiency regulations for motors. The EU has taken a leading role with the Ecodesign Directive, which since July 2023 has required IE4 “super-premium” energy efficiency for many common types of motor in the range of 75-200kW. Other countries and regions are following the EU’s lead.
However, implementing IE4 is just one step on the road. “Ultra-premium” energy efficiency IE5 SynRM motors have made a significant impact on the market since their launch in 2019, and now the anticipated IE6 “hyper-efficiency” level is available through the same well-proven technology.
What is IE6?
IE6 hyper-efficiency is the next logical step after IE5. But it is not yet specified by any standards. However, it is sensible to work on the basis that so far, each higher IE efficiency class has had 20 percent lower energy losses than the previous one. This “20 percent principle” is well-known among market participants. Therefore, the consensus is that IE6 is understood as offering 20 percent energy lower losses than IE5.
It should be noted that efficiency is not the sole factor in selecting the optimal type of motor for a specific application. Other important criteria can be power density, dynamic performance and sustainability.
Magnet-free IE6 SynRM
ABB has become the world’s first manufacturer to offer the anticipated IE6 hyper-efficiency in a magnet-free solution. This is made possible by the synchronous reluctance (SynRM) motor technology it pioneered in 2011.
It combines the performance of a permanent magnet (PM) motor with the simplicity and service-friendliness of an induction motor.
ABB launched IE5 ultra-premium efficiency SynRM motors in 2019 and they have proved themselves in thousands of applications all over the world.
The rotor has neither magnets nor windings and suffers virtually no power losses. And because there are no magnetic forces in the rotor, maintenance is as straightforward as with induction motors. Furthermore, the SynRM design does not require the use of rare earth metals.
SynRM motors have lower energy losses than induction motors and they run much cooler. Winding temperatures are up to 30°C lower and bearing temperatures up to 15°C lower. This means the insulation and bearings last longer, enhancing reliability, while longer greasing intervals for the bearings mean less maintenance.
To function, SynRM motors must be paired with a matching variable speed drive (VSD). That makes a SynRM package the ideal upgrade, especially as the motors are the same size as equivalent IE3 induction motors. This makes it easy to replace legacy motors with modern, high efficiency products.
According to the power rating, an IE6 SynRM motor will ensure more than 50 percent lower energy losses than an IE3 motor, enabling significant savings across a wide range of applications.
The SynRM motors are part of the ABB EcoSolutions product portfolio that enables customers and partners to make more sustainable choices by providing enhanced transparency about each product’s circularity value and environmental impact.
Products within the portfolio comply with a set of key performance indicators defined in ABB’s circularity framework and carry an external, third-party verified environmental product declaration (ISO 14025 Type III).
The importance of energy-efficient motors for optimised TCO
There can be a natural hesitation for operators to make an additional investment in the anticipated IE6 motor technology when IE4 will comply with current legislation. But it is vital to look beyond the upfront investment and to consider the motor’s total cost of ownership (TCO).
Over a long lifetime, the cost of the motor is far outweighed by the cost of the electricity to power it. For an IE6 SynRM, the upfront cost will be around two percent of its TCO, maintenance accounts for one percent and the remaining 97 percent is spent on electricity.
A more efficient motor will soon pay for itself, sometimes in only a few months when energy prices are high. It will then go on to generate annual savings for the rest of its working life.
Furthermore, saving energy has a dual benefit in helping existing generation capacity to go further while also reducing carbon emissions – when the motor uses power generated from non-renewable sources.
As a practical example of what is possible, it is useful to consider the case of a 55kW motor application operating under a regime where it runs for 6,500 hours a year at 75 percent power. We assume the energy cost to be €0,2/kWh. In this scenario, upgrading from an IE3 motor and VSD package to an IE6 SynRM package will yield annual cost savings of €1,772 and CO2 savings of 2,685kg. Over a service life of 25 years this will deliver a total saving of €44,295 while eliminating 66,000kg of CO2.
IE6 is also available in other motor technologies
The magnet-free SynRM motors are just one element in ABB’s comprehensive premium portfolio of high-performance motors that incorporates over 140 years of domain expertise to ensure maximum reliability combined with a commitment to sustainability.
ABB recognises that a single technology is not the answer to all customer needs, particularly when high power density is required to achieve a compact, lightweight solution. Therefore, in ABB’s effort to master all motor technologies, it has also achieved IE6 efficiency with permanent magnet (PM) and PMaSynRM technology – a hybrid technology launched in 2014 that pairs the SynRM design with a permanent magnet “boost”.
The table provides a useful comparison of the key features of motor technologies – Induction, SynRM and PM.
Innovation
“Innovation is in ABB’s DNA and we are constantly looking for ways to meet our customers’ needs for higher efficiency and lower emissions. As part of our continuous innovation in SynRM technology, we have achieved extremely compact IE6 motors and furthermore achieved high-speed SynRM rotor design,” says Robert Chin.
ABB has already delivered a prototype SynRM motor rated at 7.5kW that delivers IE6 in an extremely compact size. This is achieved by accurately modelling the material properties and the electromagnetic and thermal behaviour of the motor.
Additionally, improvements were made to the material characteristics, together with further enhancements in loss prediction. Compared with a regular IE3 induction motor, ABB has succeeded in reducing the volume by 40 percent – a reduction equivalent to two full frame sizes.
In terms of the material used to build the motors, the prototype SynRM has about 16 percent lower carbon footprint than the IE3. Furthermore, the switch from IE3 to IE6 efficiency reduces CO2 emissions during the use phase by about four percent.
Continuous innovation as highlighted above can provide hyper-efficiency in compact solutions using SynRM technology. ABB is continuing its efforts further to increase the power density.
“In our cutting-edge innovation activities to develop a customer solution, we have created a SynRM rotor design that achieves speeds up to 12,500rpm,” says Chin.
“Several rotor optimisation routines were conducted in order to reduce the stress levels and vibrations to come up with a unique rotor geometry that fits our manufacturing technology.
“We are extending the SynRM motors faster into broader product offerings, leveraging the technology platform for customer values.”
IE6 is ready to go with SynRM the best all-round technology
The anticipated IE6 hyper-efficiency is not a far-off motor technology. It is commercially available here and now. SynRM is a great all-round IE6 technology in terms of energy efficiency, power density, compact size, resource usage and maintenance needs.
Equivalent PM motors can be lighter and more compact, but in most industrial applications, the benefits of PM are outweighed by SynRM’s performance, robustness, lower cost and simplicity.
Learn more about ABB’s low-voltage motors here.
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