Almost all variable speed drives on the market easily reach IE2

The IEA 4E EMSA organised an international round robin testing programme for converters in cooperation with IEC SC22G/WG, to support the revision of IEC 61800-9-2 with science-based evidence.

The Report on Round Robin of Converter Losses summarises the results of the international testing programme. During the Round Robin, 8 laboratories performed a total of 179 tests on 57 different converters with a power range between 0.12 to 55 kW.

Some of the key findings:

  1. The measured converter losses were all less than 30% to 50% of the reference losses of IE1 and therefore well below the margin for the highest IE class for converters (IE2). Therefore, almost all converters on the market are within the IE2 class.
  2. The test results show a very good match between manufacturer catalogue data and measured data using the input-output method. Assuming that most manufacturer data are calculated and not measured such an alignment is to be judged positively.
  3. Modifications to eliminate the testing ambiguity in the second revision of IEC 61800-9-2 were based on the Uniform Testing Protocol, elaborated as part of the Round Robin.

Figure: IE-index for 3-phase Basic Drive Modules over nominal output current at (90:100) duty point.
Dotted line is the threshold between IE2 and IE1.  Red crosses: without filter, blue crosses: with filter.

Download report for the detailed results.