Determination of the Measurement Uncertainty of Direct and Indirect Efficiency Measurement Methods in Permanent Magnet Synchronous Machines

The use of permanent magnet synchronous machines to achieve high performance and high efficiency in the modern motor and generator industries has increased rapidly in recent years. The existing efficiency determining methods and standards do not however consider measurement uncertainties during loss and efficiency calculations of such machines. In this paper, the determination of the efficiency of permanent magnet synchronous machines using direct and indirect methods is presented and the measurement uncertainty is determined using the software called GUM Workbench “Guide to the Expression of Uncertainty in Measurement” while assessing the results of efficiency measurements.