Minimization of a SynRel’s oscillating torque by calculation of the appropriate skew angle

Javier Martinez Garcia Tenorio, Klaus Krischan, Annette Mütze

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Purpose - Synchronous Reluctance (SynRel) motors are known to suffer from excessive torque ripples. The classical way to avoid this drawback of the motor is skewing the slots. This paper aims to provide an analytic estimation of the best skew angle to minimize the ripples in such SynRel motors with tooth windings. The approach used in this paper consists of the minimization of the spectral components of the magnetic energy that cause these oscillation torques. The method was validated by means of a multi-slice finite element model (FEM).
Design/methodology/approach - An analytic model, based on permeance theory, is derived to analyse the electromagnetic phenomena taking place inside of the motor. This model allows the identification of the causes underlying the torque ripple production. Based on this understanding, the most suitable skew angle can be determined. The analytic method, together with the best skew angle, is validated by means of an FEM of a SynRel machine.
Findings - A method to determine the optimum skew angle for a SynRel machine is presented. It depends on the wave-number of the magnetic waves producing the torque ripple. It is twice the one typically chosen for induction machines.
Practical/implications - The proposed approach allows improving on the design methodology for the production of smoothly running SynRel machines.
Originality/value - The methodology utilized in this paper is based on the relationship between the mechanical torque and the magnetic energy stored in the motor (virtual work law). From this, the best skew angle to eliminate the magnetic energy causing torque ripple can be determined. It, therefore, proposes an effective alternative to the common use of inductance models to determine such angles.
Original languageEnglish
Pages (from-to)824-835
Number of pages12
JournalCOMPEL - The international journal for computation and mathematics in electrical and electronic engineering
Volume36
Issue number3
DOIs
Publication statusPublished - 2017

Fingerprint

Skew
Ripple
Torque
Angle
Reluctance motors
Synchronous motors
Finite Element Model
Design Methodology
Energy
Induction Machine
Inductance
Slice
Identification (control systems)
Eliminate
Oscillation
Model-based
Minimise
Methodology
Alternatives
Model

Cite this

Minimization of a SynRel’s oscillating torque by calculation of the appropriate skew angle. / Martinez Garcia Tenorio, Javier; Krischan, Klaus; Mütze, Annette.

In: COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 36, No. 3, 2017, p. 824-835.

Research output: Contribution to journalArticleResearchpeer-review

@article{64f11784c71043fe8d5d11f8c6f028dc,
title = "Minimization of a SynRel’s oscillating torque by calculation of the appropriate skew angle",
abstract = "Purpose - Synchronous Reluctance (SynRel) motors are known to suffer from excessive torque ripples. The classical way to avoid this drawback of the motor is skewing the slots. This paper aims to provide an analytic estimation of the best skew angle to minimize the ripples in such SynRel motors with tooth windings. The approach used in this paper consists of the minimization of the spectral components of the magnetic energy that cause these oscillation torques. The method was validated by means of a multi-slice finite element model (FEM).Design/methodology/approach - An analytic model, based on permeance theory, is derived to analyse the electromagnetic phenomena taking place inside of the motor. This model allows the identification of the causes underlying the torque ripple production. Based on this understanding, the most suitable skew angle can be determined. The analytic method, together with the best skew angle, is validated by means of an FEM of a SynRel machine.Findings - A method to determine the optimum skew angle for a SynRel machine is presented. It depends on the wave-number of the magnetic waves producing the torque ripple. It is twice the one typically chosen for induction machines.Practical/implications - The proposed approach allows improving on the design methodology for the production of smoothly running SynRel machines.Originality/value - The methodology utilized in this paper is based on the relationship between the mechanical torque and the magnetic energy stored in the motor (virtual work law). From this, the best skew angle to eliminate the magnetic energy causing torque ripple can be determined. It, therefore, proposes an effective alternative to the common use of inductance models to determine such angles.",
author = "{Martinez Garcia Tenorio}, Javier and Klaus Krischan and Annette M{\"u}tze",
year = "2017",
doi = "10.1108/COMPEL-09-2016-0403",
language = "English",
volume = "36",
pages = "824--835",
journal = "COMPEL - The international journal for computation and mathematics in electrical and electronic engineering",
issn = "0332-1649",
publisher = "Emerald Group Publishing Ltd.",
number = "3",

}

TY - JOUR

T1 - Minimization of a SynRel’s oscillating torque by calculation of the appropriate skew angle

AU - Martinez Garcia Tenorio, Javier

AU - Krischan, Klaus

AU - Mütze, Annette

PY - 2017

Y1 - 2017

N2 - Purpose - Synchronous Reluctance (SynRel) motors are known to suffer from excessive torque ripples. The classical way to avoid this drawback of the motor is skewing the slots. This paper aims to provide an analytic estimation of the best skew angle to minimize the ripples in such SynRel motors with tooth windings. The approach used in this paper consists of the minimization of the spectral components of the magnetic energy that cause these oscillation torques. The method was validated by means of a multi-slice finite element model (FEM).Design/methodology/approach - An analytic model, based on permeance theory, is derived to analyse the electromagnetic phenomena taking place inside of the motor. This model allows the identification of the causes underlying the torque ripple production. Based on this understanding, the most suitable skew angle can be determined. The analytic method, together with the best skew angle, is validated by means of an FEM of a SynRel machine.Findings - A method to determine the optimum skew angle for a SynRel machine is presented. It depends on the wave-number of the magnetic waves producing the torque ripple. It is twice the one typically chosen for induction machines.Practical/implications - The proposed approach allows improving on the design methodology for the production of smoothly running SynRel machines.Originality/value - The methodology utilized in this paper is based on the relationship between the mechanical torque and the magnetic energy stored in the motor (virtual work law). From this, the best skew angle to eliminate the magnetic energy causing torque ripple can be determined. It, therefore, proposes an effective alternative to the common use of inductance models to determine such angles.

AB - Purpose - Synchronous Reluctance (SynRel) motors are known to suffer from excessive torque ripples. The classical way to avoid this drawback of the motor is skewing the slots. This paper aims to provide an analytic estimation of the best skew angle to minimize the ripples in such SynRel motors with tooth windings. The approach used in this paper consists of the minimization of the spectral components of the magnetic energy that cause these oscillation torques. The method was validated by means of a multi-slice finite element model (FEM).Design/methodology/approach - An analytic model, based on permeance theory, is derived to analyse the electromagnetic phenomena taking place inside of the motor. This model allows the identification of the causes underlying the torque ripple production. Based on this understanding, the most suitable skew angle can be determined. The analytic method, together with the best skew angle, is validated by means of an FEM of a SynRel machine.Findings - A method to determine the optimum skew angle for a SynRel machine is presented. It depends on the wave-number of the magnetic waves producing the torque ripple. It is twice the one typically chosen for induction machines.Practical/implications - The proposed approach allows improving on the design methodology for the production of smoothly running SynRel machines.Originality/value - The methodology utilized in this paper is based on the relationship between the mechanical torque and the magnetic energy stored in the motor (virtual work law). From this, the best skew angle to eliminate the magnetic energy causing torque ripple can be determined. It, therefore, proposes an effective alternative to the common use of inductance models to determine such angles.

UR - https://doi.org/10.1108/COMPEL-09-2016-0403

U2 - 10.1108/COMPEL-09-2016-0403

DO - 10.1108/COMPEL-09-2016-0403

M3 - Article

VL - 36

SP - 824

EP - 835

JO - COMPEL - The international journal for computation and mathematics in electrical and electronic engineering

JF - COMPEL - The international journal for computation and mathematics in electrical and electronic engineering

SN - 0332-1649

IS - 3

ER -