Automated Finite Element Aided Design of Skewed Rotor Induction Motors

This paper describes the way in which the 2D electromagnetic finite element analysis package OPERA-2d has been used, in conjunction with MATLAB programming language and Microsoft EXCEL, to perform automated simulation and performance analysis of induction motors as part of the design and optimisation process.  The objective of this work is to develop a practical tool for design purposes, where full 3D transient solutions are not acceptable due to excessive computing times.  However, it is a requirement that significant 3D effects, in particular those due to rotor bar skew, are taken into account.  A steady-state (single harmonic) FE solution at slip frequency is utilised for performance prediction, in place of the transient analysis.

The paper outlines how basic design data in parametric form is processed within the main controlling program, MATLAB, in an automated fashion, to generate data suitable for use in OPERA-2d (which is invoked as a subroutine from the main program).  The practical application of this combined use of the software employed and how the final routines evolved is discussed.  The discussion of practical aspects of 2D FE modelling is further developed to include the impact of 3D effects.  In particular the effect of skew is considered and the possibility of its inclusion within the 2D environment.  The multi-slice approach employed is set against the background of other similar techniques reported in literature since the early 1990’s.

Alex.Michaelides@vectorfields.co.uk

cpr@vectorfields.co.uk, kjh@vectorfields.co.uk, david.griffiths@fr-hitemp.co.uk