EPE Association: NORpie 2004 - Topic 06: Electrical Machines

NORpie 2004 - Topic 06: Electrical Machines
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2004 > NORpie 2004 - Topic 06: Electrical Machines

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   Genetic Optimization of Electric Machines, a State of the Art Study
By S. E. Skaar; R. Nilssen [View]
[Download]

Abstract: This paper presents a literature study of genetic algorithms (GA) in general and used in electrical machine optimization the recent years. Since Holland presented the first genetic algorithm in 1975 [1], GA has been used widely in optimization problems. The paper will summon up some of the work done using genetic optimization on electric machines the last years. An overview of methods used will be given and the conclusion of the different papers will be presented.

   Analysis of a PM Machine with Concentrated Fractional Pitch Windings
By F. Magnussen; D. Svechkarenko; P. Thelin; C. Sadarangani [View]
[Download]

Abstract: Permanent magnet machines with concentrated fractional pitch windings for servo and traction applications are growing in popularity. This paper deals with analysis of a novel synchronous permanent magnet machine using concentrated windings and grain-oriented and non-oriented silicon iron sheets for the teeth and yoke, respectively. Parasitic effects like unbalanced radial forces and alternating magnetic fields in the rotor, due to a non-symmetrical magnetic design of the presented machine, are described. Measurements on a laboratory prototype are performed and the results are compared to finite element method computation results to identify the heat transfer coefficients of the electrical machine.

   Iron Loss Calculation in a Claw-pole Structure
By A. Reinap; D. Martínez-Munoz; M. Alaküla [View]
[Download]

Abstract: The total core loss in a claw-pole structure has been calculated on the basis of the variation of the magnetic loading over the magnetization cycle in different parts of the machine. This variation has been estimated from a lumped parameter permeance network and 3D finite element simulations, studying the flux density waveform and loci in their elements. The results from the simulations are compared with the loss measurements in a single-phase claw-pole motor equipped with an outer permanent-magnet rotor. Results show that the static and dynamic losses are underestimated by 35% and up to 60% at 100Hz respectively. Finally, the results from an optimization process are presented, where the torque performance is evaluated as a function of the pole number and dimensions of the machine.

   Design Study of Different Direct-Driven Permanent-Magnet Motors for a Low Speed Application
By F. Libert; J. Soulard [View]
[Download]

Abstract: The goal of the study is to compare different designs of direct-driven Permanent Magnet (PM) motors that should replace an induction motor and its gearbox for an industrial application requiring 5 kW and 50 rpm. Motors with surface mounted PM, inset surface mounted PM or buried PM, with inner or outer rotor are investigated. The best design for the application is presented.

   A Study of the Research Activity in the Nordic Countries on Large Permanent Magnet Synchronous Machines
By Ö. Krövel; R. Nilssen; A. Nysveen [View]
[Download]

Abstract: This paper presents an overview of the activity on large Permanent Magnet Synchronous Machines (PMSM) in the Nordic countries. It is found that the Nordic countries are in the leading end of the development of large PMSM. This is much due long traditions of ship building, an important application for large PMSM, and pioneer work in wind conversion. The focus has mainly been on the radial flux permanent magnet machines, but in the later years also attentions has been given to axial and transverse flux permanent magnet machines. The industry has started to use large PMSM; e.g. ABB has their compact azipod® with radial flux machine, Siemens has a radial flux submarine motors and Jeumont uses axial flux generator in wind turbines. The impression is that at the time, the large machine manufacturers in Europe have radial flux machines in their assortment and are developing the axial flux technology. While the smaller and more specialised companies have already developed axial flux machines for their applications.

   High Power Linear Electric Machine - made possible by gas springs
By E. Hoff; J.E. Brennvall; R. Nilssen; L. Norum [View]
[Download]

Abstract: In some applications, such as compressors, free piston linear machines have several advantages compared to rotating machines. The power level of linear machines has been limited, mainly due to difficulties with the spring. A solution for this has now been found and will be described in this paper. It can open up new areas of applications, where the power level exceeds the present power limit of about 2kW. This machine needs special regulators in order to work efficiently. Two regulator algorithms for piston phase and one for position amplitude are therefore implemented for this prototype.

   Saliency Modeling in Radial Flux Permanent Magnet Synchronous Machines
By S. Ovrebo; R. Nilsen; R. Nilssen [View]
[Download]

Abstract: Sensorless control of Permanent Magnet Synchronous Machines is popular for several reasons: cost saving and system reliability. The basis for most low and zero speed sensorless control is that there exist a difference in the direct and quaderature inductance of the machines. This difference is also reefed to as saliency. In this paper the different contributors to the resulting saliency is modeled. This type of modeling is useful for several reasons: increased understanding of the fundamentals of sensorless control, incorporating the combined effects of leakage and main inductance variations, incorporating the effects of loading of the machine and finally it gives valuable insight when the saliency ratio is attempted increased by machine design.

   High frequency flux distribution in Permanent Magnet Synchronous Machines
By S. Ovrebo; R. Nilssen; R. Nilsen [View]
[Download]

Abstract: High frequency flux distribution is of great interest when working with low and zero speed Sensorless Control. The flux distribution determines what part of the machine structure that gives position dependent variations in the inductance. In induction machines the leakage inductance has been the source of the position dependent variation while for the IPMSM the rotor structure has been assumed as the source for the position dependent variations. In this paper the IPMSM flux distribution is discussed and inductance measurements are performed in order to verify the high frequency flux distribution.

NORpie 2004 - Topic 06: Electrical Machines
You are here: EPE Documents > 05 - EPE Supported Conference Proceedings > NORpie - Proceedings > NORpie 2004 > NORpie 2004 - Topic 06: Electrical Machines
	[return to parent folder]

	Genetic Optimization of Electric Machines, a State of the Art Study By S. E. Skaar; R. Nilssen	[View] [Download]
Abstract: This paper presents a literature study of genetic algorithms (GA) in general and used in electrical machine optimization the recent years. Since Holland presented the first genetic algorithm in 1975 [1], GA has been used widely in optimization problems. The paper will summon up some of the work done using genetic optimization on electric machines the last years. An overview of methods used will be given and the conclusion of the different papers will be presented.

	Analysis of a PM Machine with Concentrated Fractional Pitch Windings By F. Magnussen; D. Svechkarenko; P. Thelin; C. Sadarangani	[View] [Download]
Abstract: Permanent magnet machines with concentrated fractional pitch windings for servo and traction applications are growing in popularity. This paper deals with analysis of a novel synchronous permanent magnet machine using concentrated windings and grain-oriented and non-oriented silicon iron sheets for the teeth and yoke, respectively. Parasitic effects like unbalanced radial forces and alternating magnetic fields in the rotor, due to a non-symmetrical magnetic design of the presented machine, are described. Measurements on a laboratory prototype are performed and the results are compared to finite element method computation results to identify the heat transfer coefficients of the electrical machine.

	Iron Loss Calculation in a Claw-pole Structure By A. Reinap; D. Martínez-Munoz; M. Alaküla	[View] [Download]
Abstract: The total core loss in a claw-pole structure has been calculated on the basis of the variation of the magnetic loading over the magnetization cycle in different parts of the machine. This variation has been estimated from a lumped parameter permeance network and 3D finite element simulations, studying the flux density waveform and loci in their elements. The results from the simulations are compared with the loss measurements in a single-phase claw-pole motor equipped with an outer permanent-magnet rotor. Results show that the static and dynamic losses are underestimated by 35% and up to 60% at 100Hz respectively. Finally, the results from an optimization process are presented, where the torque performance is evaluated as a function of the pole number and dimensions of the machine.

	Design Study of Different Direct-Driven Permanent-Magnet Motors for a Low Speed Application By F. Libert; J. Soulard	[View] [Download]
Abstract: The goal of the study is to compare different designs of direct-driven Permanent Magnet (PM) motors that should replace an induction motor and its gearbox for an industrial application requiring 5 kW and 50 rpm. Motors with surface mounted PM, inset surface mounted PM or buried PM, with inner or outer rotor are investigated. The best design for the application is presented.

	A Study of the Research Activity in the Nordic Countries on Large Permanent Magnet Synchronous Machines By Ö. Krövel; R. Nilssen; A. Nysveen	[View] [Download]
Abstract: This paper presents an overview of the activity on large Permanent Magnet Synchronous Machines (PMSM) in the Nordic countries. It is found that the Nordic countries are in the leading end of the development of large PMSM. This is much due long traditions of ship building, an important application for large PMSM, and pioneer work in wind conversion. The focus has mainly been on the radial flux permanent magnet machines, but in the later years also attentions has been given to axial and transverse flux permanent magnet machines. The industry has started to use large PMSM; e.g. ABB has their compact azipod® with radial flux machine, Siemens has a radial flux submarine motors and Jeumont uses axial flux generator in wind turbines. The impression is that at the time, the large machine manufacturers in Europe have radial flux machines in their assortment and are developing the axial flux technology. While the smaller and more specialised companies have already developed axial flux machines for their applications.

	High Power Linear Electric Machine - made possible by gas springs By E. Hoff; J.E. Brennvall; R. Nilssen; L. Norum	[View] [Download]
Abstract: In some applications, such as compressors, free piston linear machines have several advantages compared to rotating machines. The power level of linear machines has been limited, mainly due to difficulties with the spring. A solution for this has now been found and will be described in this paper. It can open up new areas of applications, where the power level exceeds the present power limit of about 2kW. This machine needs special regulators in order to work efficiently. Two regulator algorithms for piston phase and one for position amplitude are therefore implemented for this prototype.

	Saliency Modeling in Radial Flux Permanent Magnet Synchronous Machines By S. Ovrebo; R. Nilsen; R. Nilssen	[View] [Download]
Abstract: Sensorless control of Permanent Magnet Synchronous Machines is popular for several reasons: cost saving and system reliability. The basis for most low and zero speed sensorless control is that there exist a difference in the direct and quaderature inductance of the machines. This difference is also reefed to as saliency. In this paper the different contributors to the resulting saliency is modeled. This type of modeling is useful for several reasons: increased understanding of the fundamentals of sensorless control, incorporating the combined effects of leakage and main inductance variations, incorporating the effects of loading of the machine and finally it gives valuable insight when the saliency ratio is attempted increased by machine design.

	High frequency flux distribution in Permanent Magnet Synchronous Machines By S. Ovrebo; R. Nilssen; R. Nilsen	[View] [Download]
Abstract: High frequency flux distribution is of great interest when working with low and zero speed Sensorless Control. The flux distribution determines what part of the machine structure that gives position dependent variations in the inductance. In induction machines the leakage inductance has been the source of the position dependent variation while for the IPMSM the rotor structure has been assumed as the source for the position dependent variations. In this paper the IPMSM flux distribution is discussed and inductance measurements are performed in order to verify the high frequency flux distribution.