A stator-core quality-assessment technique for inverter-fed induction machines

Kwanghwan Lee, Jongman Hong, Kwang Woon Lee, Sang Bin Lee, Ernesto J. Wiedenbrug

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Localized heating caused by damage in the laminations or interlaminar insulation of the stator core increases the core losses and can lead to machine failure. Therefore, it is important to monitor the quality of the stator core for reliable and efficient operation of the machine. The methods currently available for core quality assessment are inconvenient since they require an outage and the machine to be disassembled or operated under no-load conditions. In this paper, a new method for monitoring the quality of the stator core for inverter-fed machines without motor disassembly or operation is proposed. The main concept is to use the inverter to apply a set of test signals to assess the quality of the core whenever the motor is at standstill. A set of high-frequency pulsating magnetic fields is produced using the inverter, and the power loss is observed as a function of field circumferential position to detect core problems. An experimental study on a 10-hp induction motor verifies that local interlaminar core faults can be detected with high sensitivity. The proposed technique is expected to provide a simple solution for frequent stator-core quality assessment without motor disassembly, motor operation, or additional hardware for reliable and efficient operation of inverter-fed induction machines.

Original languageEnglish
Article number5339137
Pages (from-to)213-221
Number of pages9
JournalIEEE Transactions on Industry Applications
Issue number1
Publication statusPublished - 2010 Jan


  • AC machine
  • Condition monitoring
  • Core loss
  • Diagnostics
  • Eddy-current loss
  • Hysteresis loss
  • Induction motor
  • Interlaminar-insulation failure
  • Inverter
  • Stator core

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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