Open AccessElectromagnetic modelling and detection of buried stator core faults
Author(s) -
Bertenshaw David R.,
Ho Choon W.,
Smith A.C.,
Sasic Mladen,
Chan Trina
Publication year - 2017
Publication title -
iet electric power applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.815
H-Index - 97
eISSN - 1751-8679
pISSN - 1751-8660
DOI - 10.1049/iet-epa.2016.0470
Subject(s) - stator , fault (geology) , finite element method , electromagnetic coil , core (optical fiber) , transverse plane , yoke (aeronautics) , engineering , structural engineering , mechanical engineering , electrical engineering , geology , seismology , telecommunications , fly by wire , control system
Interlamination insulation faults in the stator cores of large electrical machines can damage both winding insulation and stator core, thus confidence in electromagnetic test results is important. They may be validated by finite element (FE) methods, however the 3D models required for short faults are computationally challenged by laminated structures, requiring approximations. A homogenised 3D FE model was used to model faults buried in the teeth and yoke of the core, with a new experimental methodology developed to calibrate fault currents. Limitations were identified in modelling just a core section due to images and the constraint of axial packet air gaps on fault flux dispersion. A system of transverse 2D FE models of the principal fault flux paths in the core were constructed to estimate the differential impact on fault signals by the air gap presence and applied to the 3D FE model. Together with corrections for images this gave close predictions of experimental results, supporting the validity of the model. The verified electromagnetic test results now permit assessment of the threat that a detected buried fault presents.