Reliable Power Transformer Efficiency Tests

Power transformer efficiency measurements are a crucial part of the acceptance tests of a power transformer. These tests have increased importance since the EU Ecodesign Directive per 1 July 2015 has put efficiency limits to power transformers that are sold on the European market. In this paper we present a series of measures to assure that power transformer efficiency tests performed by power transformer manufacturers are accurate and reliable. This includes the development of more accurate industrial loss measure­ment systems (LMS), optimized LMS calibration approaches, and a reference system for on-site LMS calibration. This research is performed within the “TrafoLoss” EU joint research project, which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. Additional funding is received from the Dutch Ministry of Economic Affairs and Climate. Author's accepted version of a paper presented at the 5th International Colloquium "Transformer Research and Asset Management" (ICTRAM), Opatija / Croatia, October 9 - 12, 201