Estimation of PM Machine Efficiency Maps from Limited Data

Solmaz Kahourzade, Amin Mahmoudi, Wen L. Soong, Nesimi Ertugrul, Gianmario Pellegrino

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


This article investigates the accuracy of the estimation of efficiency maps for permanent magnet (PM) machines using the stator resistance, d- and q-axis flux-linkages versus the corresponding axis current and the iron loss versus the speed characteristic. The ultimate goal is to apply this approach to the experimental measurements, but this article performs initial investigation using only the finite-element (FE) data. Detailed FE data for 50-kW surface PM (SPM) and interior PM (IPM) machines are used to determine the 'actual' or exact efficiency map and, hence, the accuracy of using approximations. This article examines the effect on the torque-speed capability curve when ignoring cross-saturation effects. It also examines the modeling of the variation of iron losses as a function of load in the constant torque and power regions. A novel approach based on scaling the no-load (NL) losses as a function of load is proposed and shown to give promising results. FE results from two other machines are also provided, which show good correspondence.

Original languageEnglish
Article number9034083
Pages (from-to)2612-2621
Number of pages10
JournalIEEE Transactions on Industry Applications
Issue number3
Early online date24 Apr 2020
Publication statusPublished - May 2020


  • Efficiency map
  • flux linkage
  • loss modeling
  • no-load (NL) loss
  • permanent magnet (PM) machine


Dive into the research topics of 'Estimation of PM Machine Efficiency Maps from Limited Data'. Together they form a unique fingerprint.

Cite this