AC motor instrumentation and main air gap flux measurement for fault diagnostics

This paper is related to the current research project “AC Meter Duty Meter” run by The University of Newcastle and ACARP¹. The main objective of the project is to develop an innovative condition monitoring tool for large industrial induction motors, which offers a superior fault prediction capability. The approach taken in the project has two distinctive features: it is based on measurement of main air gap flux and it relates motor condition to its duty. This paper will present an overview of the existing methods used in condition monitoring, especially those based on flux measurement. It will then explain about the advantages of the proposed main air gap measurement approach. Preliminary analysis of experimental data collected so far will be included to support the discussion. Finally, the findings of the paper will be summarised in conclusions.