Analysis of non-intrusive efficiency estimation of induction machines compared to the IEEE 112B and IEC 34-2-1 standards

International efficiency testing methods such as the IEEE 112-B and IEC 34-2-1 can determine an induction machine´s efficiency accurately at the cost of hindering the machine´s productivity. Alternatively, various methods used to determine a machine´s efficiency in-situ do so at the cost of accuracy. This paper proposes a method that determines an induction machine´s efficiency over a range of load conditions from tests conducted and centered around one thermally stable load point in the least intrusive manner possible. The results are then compared to IEEE 112-B and IEC 34-2-1 motor testing standards using segregated loss analysis. It was found that despite the proposed algorithm being unable to accurately determine core losses, the efficiency of a machine can be estimated to within 0.01-5.01% and 0.07-3.48% error when compared to the IEEE 112-B and IEC 34-2-1 standards respectively over a 25-150% machine load profile dependent upon the proposed method´s implementations.