Open AccessInvestigation of scaling effect on power factor of permanent magnet Vernier machines for wind power application
Author(s) -
Kana Padinharu Dileep Kumar,
Li GuangJin,
Zhu ZiQiang,
Clark Richard,
Azar Ziad,
Thomas Arwyn
Publication year - 2020
Publication title -
iet electric power applications
Language(s) - English
Resource type - Journals
ISSN - 1751-8679
DOI - 10.1049/iet-epa.2020.0442
Subject(s) - vernier scale , power factor , armature (electrical engineering) , magnet , stator , flux linkage , electromagnetic coil , magnetic flux leakage , leakage (economics) , electrical engineering , scaling , engineering , materials science , control theory (sociology) , mechanics , physics , voltage , geometry , computer science , optics , mathematics , direct torque control , macroeconomics , control (management) , artificial intelligence , induction motor , economics
This study investigates the scaling effect on power factor of surface mounted permanent magnet Vernier (SPM‐V) machines with power ratings ranging from 3 kW, 500 kW, 3 MW to 10 MW. For each power rating, different slot/pole number combinations have been considered to study the influence of key parameters including inter‐pole magnet leakage and stator slot leakage on power factor. A detailed analytical modelling, incorporating these key parameters, is presented and validated with two‐dimensional finite‐element analysis for different power ratings and slot/pole number combinations. The study has revealed that with scaling (increasing power level), significant increase in electrical loading combined with the increased leakage fluxes, i.e. (i) magnet leakage flux due to large coil pitch to rotor pole pitch ratio, (ii) magnet inter‐pole leakage flux and (iii) stator slot leakage flux, reduces the ratio of armature flux linkage to permanent magnet flux linkage and thereby has a detrimental effect on the power factor. Therefore, unlike conventional SPM machines, the power factor of SPM‐V machines is found to be significantly reduced at high power ratings.