Improved air gap permeance model to characterise the transient behaviour of electrical machines using magnetic equivalent circuit method

Abstract

Transient analysis of electrical machines with mixed eccentricity requires dedicated, fast and accurate solvers. This paper proposes an improved air gap permeance expression which (i) is physically interpretable and (ii) can be easily derived based on the rotor position. This expression is very suitable for inclusion in a solver based on the magnetic equivalent circuit (MEC) method. This allows to e.g. calculate the torque and forces when vibrations act on the rotor. The results of the MEC solver agree very well with those obtained with a FEM solver, but are obtained with a fraction of the simulation time of the FEM solver.

A Review of Techniques Used for Induction Machine Fault Modelling

“…In the case of eccentricity, the authors of [ 3 ] propose the implementation of a modified expression for the air gap permeance and includes the effects related to eccentric rotor positions in the development of their MEC model. These air-gap permeances represent a continuously changing permeance as a function of the rotor position.…”

“…They are followed by those related to stator winding and external conditions damages, which each account for 16% of faults. Rotor-related failures represent 5% and other damages 12% [ 2 , 3 ]. Bearing- and stator-related faults are the most common type of faults, which together account for over 60% of the downtime of electrical machines.…”

A new hybrid analytical model for electromagnetic analysis of wound rotor induction motors

“…The MEC model is one of the famous techniques for analysis of electric machines, which acts based on the solving of permeance network of relevant electric machines 8–10 . The main capability of MEC model is to consider the magnetic saturation in iron parts, accurately.…”

“…To this end, hybrid analytical-FEM model has been presented in [3][4][5] for real time simulation, which previously prepares 3-D look-up tables for each element of inductance matrix through magneto-static analysis by FEM. different analytical techniques have been so far introduced such as winding function theory (WFT), 6,7 magnetic equivalent circuit (MEC) model, [8][9][10] conformal mapping (CM) method, 11,12 field reconstruction method (FRM), 13,14 and sub-domain (S-D) model. 15,16 FRM acts based on applying the law of superposition on the basis functions obtained through FEM.…”

Special Issue: The 11th International Symposium on Electric and Magnetic Fields (EMF 2018)

“…6,7 The third major topic concerns homogenization and reduced order models, with contributions to the time-domain homogenization of windings, 8 extraction of capacitance matrices 9 and lumped element modelling. 10 The fourth major topic concerns application-specific numerical techniques, with contributions to the modelling of synchronous reluctance machines, 11 graded surge arresters, 12 high voltage power cables 13 and DC-AC power converters. 14 We express our gratitude to all the members of the EMF scientific committee-P.…”