Affiliations: School of Electrical Engineering and Automation, Hefei University of Technology, Hefei, Anhui, China
Correspondence:
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Corresponding author: Xiaohua Bao, School of Electrical Engineering and Automation, Hefei University of Technology, Hefei, Anhui 230009, China. Tel.: +86 055162905883; Fax: +86 055162904435; E-mail:sukz@ustc.edu
Abstract: Large submersible motors make a huge contribution to
national security prevention and control of water. But the eccentricity
fault has a strong impact on the operational reliability. Therefore, this
paper uses new diagnostic signals of air-gap magnetic field to detect
eccentricity fault in submersible motor. Compared with the previous papers,
this paper combines the effects of eccentricity and slotting. Firstly, a new
air-gap permeance model is established considering slotting effect aimed at
eccentric motor. Then the time harmonics of air-gap magnetic field are
obtained based on MMF and permeance wave approach. Compared with healthy
motor, the characteristic frequencies are chosen as diagnostic signals. The
air-gap magnetic field is measured by search coil placed around stator
tooth. The way is applied to detecting dynamic eccentricity and mixed
eccentricity. Finally, for validating the theoretical results, the induced
voltages of search coil are gained under different conditions in high
voltage submersible motor by finite element method. The simulation is
consistent with the theory in the process of data analysis.
