The global site of the UK's leading magazine for automation, motion engineering and power transmission
22 July, 2018

Product and Supplier Search

Facebook

PM electric motor comes top in Swedish efficiency tests

06 May, 2015

Tests performed by the Swedish Energy Agency have shown that a 15kW IE4 permanent magnet (PM) motor was 5.9% more efficient than an “IE0” induction motor of a similar rating, while a synchronous reluctance motor was 4.4% more efficient. Curiously, an IE3 induction motor delivered a smaller improvement in efficiency (1.8%) in the tests than an IE2 induction machine (2.4%).

The motors being tested were used to drive a pump operating with a constant pressure, from idling to peak load. The induction motors were run with and without drives, at six frequencies from 10–60Hz. The synchronous reluctance motor – an ABB SynRM model – operated with a dedicated drive.

The PM motor – a Leroy-Somer Dyneo LSRPM machine, tested with Control Techniques and ABB VSDs – was found to use almost 5,700kWh less over the course of a year than the IE0 motor. The Swedish Energy Agency points out that this saving is similar to the amount of electricity used by a typical Swedish four-person household over the course of a year.

The annual saving with the SynRM motor and drive was 4,285kWh, compared to the IE0 machine.

Effiency curves (%) for a Leroy-Somer PM motor driven by a Control Techniques VSD at different shaft power ratings (kW)
Graph: Swedish Energy Agency

For the IE2 induction motor – a Lönne machine tested with ABB and Yaskawa inverters – the annual saving was 2,336kWh, while for the IE3 motor – a VEM machine tested with the same VSDs – the saving was 1,703kWh.

Commenting on the results, Emerson (which owns Leroy-Somer and Control Techniques) says that they show that its PM motor was the equivalent of one IE class more efficient than the rival products, and close to three IE classes more efficient than the IE3 induction motor used in the tests. Emerson adds that in a compressor application, the PM efficiencies would be even higher because these motors retain their efficiencies across the entire speed and load ranges. 




Magazine
  • To view a digital copy of the latest issue of Drives & Controls, click here.

    To visit the digital library of past issues, click here

    To subscribe to the magazine, click here

    To see the latest Products & Services Directory, click here

     

Exhibition

Birmingham 2020The next Drives & Controls Exhibition and Conference will take place in Birmingham, UK, from 21-23 April, 2020. For more information on the event, visit the Show Web site

Poll

"Do you think that robots create or destroy jobs?"

Newsletter
Newsletter

Events

Most Read Articles