Computation of Torque of an Electrical Machine With Different Types of Finite Element Mesh in the Air Gap

Silwal, Bishal; Rasilo, Paavo; Perkkiö, Lauri; Oksman, Miika; Hannukainen, Antti; Eirola, Timo; Arkkio, Antero

doi:10.1109/tmag.2014.2333491

Cited by 16 publications

(11 citation statements)

References 13 publications

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“…where P in is the electric input power, P loss is the electromagnetic loss, W f is the magnetic energy and Tω m is the output power transmitted through the shaft. This expression was integrated over a time interval in order to obtain the average torque over the interval in [10]. As mentioned in the previous section, when the machine is under dynamic eccentricity, the force combines with the whirling motion to transfer some power, which is termed as the whirling power.…”

Section: Power Balance Approachmentioning

confidence: 99%

See 1 more Smart Citation

Prospects and Limitations of Power Balance Approach for Studying Forces and Electromagnetic Damping in Electrical Machines

Silwal¹,

Rasilo

Arkkio³

2018

IEEE Trans. Magn.

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Cage induction machine with dynamic rotor eccentricity is considered. In general, force and torque computation in the finite element analysis of electrical machines is done using conventional direct methods. Many methods have been put forward with a claim to be more accurate than one another. In this paper we assess the accuracy of the typical force computation method used in the finite element analysis of electrical machines, for various types of mesh used in the machine's air gap during simulations. The possibility of using the power balance of the machine to validate the force calculation and alternatively calculate the force is discussed. Besides, its applicability to study the electromagnetic damping of mechanical vibrations due to unbalanced magnetic pull is presented.Index Terms-Cage induction machine, eccentricity, finite element method (FEM), force computation, meshing, power balance.

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Section: Power Balance Approachmentioning

confidence: 99%

“…Recently, the authors studied comprehensively the influence of the air gap mesh on the calculation of the electromagnetic torque [10]. The authors also presented an approach to compute the average torque of the machine from the power balance.…”

Section: Introductionmentioning

confidence: 99%

Prospects and Limitations of Power Balance Approach for Studying Forces and Electromagnetic Damping in Electrical Machines

Silwal¹,

Rasilo

Arkkio³

2018

IEEE Trans. Magn.

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“…With a similar method described in [15], [16], the electromagnetic torque is computed in the air-gap with the method of virtual displacement with constant magnetic vector potential :…”

Section: Torque Calculationmentioning

confidence: 99%

“…With the method of virtual displacement described in II-C, it is important that the virtually moving elements remain the same for any rotor position, so the torque is computed in an annulus layer of the air-gap [16].…”

Section: B Electromagnetic Torquementioning

confidence: 99%

Homogenization Technique for Axially Laminated Rotors of Synchronous Reluctance Machines

et al. 2015

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In this paper, we propose a homogenization technique to model the axially laminated rotor of synchronous reluctance machines. Thus, the computational effort can be significantly reduced by replacing the laminated parts of the rotor by some equivalent anisotropic media. The proposed method is validated in terms of flux density and electromagnetic torque. Some small discrepancies can be noticed due to the air-gap fluctuations caused by the steel sheets and the interlaminar insulation sheets of the rotor. With the test machine, the homogenization method reduces by the number of elements to one fourth and the computation time to one third.

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“…This method is found to be accurate and insensitive to the type of mesh used in the air gap of the machine. Recently, a study compared the energy balance method and Coulomb's virtual work method based on the type of discretization used in the air gap [19]. The average torque calculated from Coulomb's virtual work method is dependent on the density of the mesh and the shape of the elements.…”

Section: Introductionmentioning

confidence: 99%

Influence of the rotor eccentricity on the torque of a cage induction machine

Silwal¹,

Rasilo

Belahcen³

et al. 2017

Archives of Electrical Engineering

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Abstract:The non-uniform air gap in an electrical machine caused by rotor eccentricity creates an asymmetrical flux-density distribution in the air gap. This can affect the nominal torque produced by the machine. Eccentricity also produces forces that act on the rotor which may also have an effect on the torque. Thus, it is important to know how the torque of the machine behaves. In this paper, the torque of a cage induction machine is studied when the machine has dynamic eccentricity. The study is performed using the finite element method and a magnetic vector potential formulation. The torque is calculated by the method of energy balance. The harmonic components of the torque are also analyzed. The results show that the machine under eccentricity does not exhibit the same torque as a normal healthy machine. The harmonic components around the first principal slot harmonic is most affected.

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Computation of Torque of an Electrical Machine With Different Types of Finite Element Mesh in the Air Gap

Cited by 16 publications

References 13 publications

Prospects and Limitations of Power Balance Approach for Studying Forces and Electromagnetic Damping in Electrical Machines

Prospects and Limitations of Power Balance Approach for Studying Forces and Electromagnetic Damping in Electrical Machines

Homogenization Technique for Axially Laminated Rotors of Synchronous Reluctance Machines

Influence of the rotor eccentricity on the torque of a cage induction machine

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