Bojan Štumberger, Gorazd Štumberger, Miralem Hadžiselimović, Ivan Zagradišnik, Anton Hamler and Mladen Trlep
The paper aims to present the comparison between the performances of the exterior‐rotor permanent magnet synchronous motors with distributed windings and the performances of the…
Abstract
Purpose
The paper aims to present the comparison between the performances of the exterior‐rotor permanent magnet synchronous motors with distributed windings and the performances of the exterior‐rotor permanent magnet synchronous motors with concentrated windings.
Design/methodology/approach
Finite element method is used for motors performance determination. The BLDC operation mode for the motors with different slot and pole number combination and concentrated windings was accounted for in the comparison.
Findings
In the BLDC operation mode motor structures with concentrated windings with similar slot and pole numbers exhibit at the same current density similar or even higher torque capability and lower electromagnetic torque ripple in comparison to the motor structure with distributed windings. Motor structures with 9‐slot/8‐pole, 9‐slot/10‐pole, 12‐slot/10‐pole slot and pole number combinations are the most appropriate for the BLDC operation.
Originality/value
The paper shows which motor structures with distributed or concentrated windings in the BLDC operation mode produce lower torque ripple and higher average torque per ampere.
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Keywords
Marko Jesenik, Anton Hamler, Miloš Beković and Mladen Trlep
The purpose of this paper is to find the geometry of a crack within a conductive plate and its parameters, on the basis of non-destructive testing, using eddy currents. The input…
Abstract
Purpose
The purpose of this paper is to find the geometry of a crack within a conductive plate and its parameters, on the basis of non-destructive testing, using eddy currents. The input data represents the measured values of magnetic flux density within the centre of the excitation coil.
Design/methodology/approach
The position of a crack can be determined by taking into consideration any change in the magnetic flux density between the measured points. The depth and width are determined through the use of a finite element model.
Findings
These calculations are the basis for determining a function that explains how magnetic flux density changes if the depth or width has changed. Jacobi's matrix is calculated using the determined functions’ analytical derivatives.
Originality/value
After wards, through the Newton-Raphson iterative procedure using the finite element method calculation results, the crack-depth and width can be obtained, this being one of the objectives in this paper. The suitability of the presented method was verified by the experimental example.
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Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines;…
Abstract
Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.