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Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise

Martinez, David LU (2005)
Abstract (Swedish)
Popular Abstract in Swedish

Avhandlingen består av två delar, den första som behandlar konstruktionen av järn-pulver maskiner, och den andra med analys av ljud från el-maskiner.



I Del I, en elektrisk magnetiserad klo-pol synkron maskin på 1.6 kW har byggts. Maskinen är byggt från mjuk magnetisk material (SMC), också kallad järn-pulver. Detta materialet har isotropiska magnetiska egenskaper, som gör möjligt att bygga tre-dimensionella maskiner. Detta är den största fördelen jämfort med plåt, där flödet är begränsad till två dimensioner. Det som är ny med prototypen är att släp-ringarna i rotorn behövs inte längre, eftersom fältlindningen har flyttats från rotorn till gavlarna i stator sidan, som är... (More)
Popular Abstract in Swedish

Avhandlingen består av två delar, den första som behandlar konstruktionen av järn-pulver maskiner, och den andra med analys av ljud från el-maskiner.



I Del I, en elektrisk magnetiserad klo-pol synkron maskin på 1.6 kW har byggts. Maskinen är byggt från mjuk magnetisk material (SMC), också kallad järn-pulver. Detta materialet har isotropiska magnetiska egenskaper, som gör möjligt att bygga tre-dimensionella maskiner. Detta är den största fördelen jämfort med plåt, där flödet är begränsad till två dimensioner. Det som är ny med prototypen är att släp-ringarna i rotorn behövs inte längre, eftersom fältlindningen har flyttats från rotorn till gavlarna i stator sidan, som är magnetisk ledande. Detta förbättrar också möjligheterna till att kyla kopparförlusterna, som i sin tur gör möjligt att öka strömen. Flödet går från statorn till roton genom gavlarna. Maskinen har optimerats med en så kallad "magnetisk equivalent krets" (MEC), som inkluderar modelering av icke-linjär material. Detta har åstadkommits genom att använda en rutin baserad på en lineariserad BH kurva. De traditionella leakage vägar som är vanliga i klo-pol maskinerna ser nu annorlunda ut på grund av de magnetiska gavlarna. Rotorn har fyllts med permanent magneter av olika styrka med syftet att minimera leakage. Maskinen har också jämförts med två andra topologier av elektrisk magnetiserade maskiner och en permanent magnet maskin.



Del II handlar om mätningar och beräkning av ljudet från asynkronmotorer med hjälp av vektor reglering. Man har också undersökt ändringar i statorhuset med syftet att minimera ljuded. Ett drivsystem har utvecklats för en 2.2 kW asynkronmotor, som fungerar inom ett stort frekvensområde. Detta har använts för att utvärdera ljud strålningen när man modellerar flödet och/eller moment med högfrekventa ljud signaler. Resultaterna visade att man fick mer ljud när man modulerade flödet än moment, fast skillnaden var mycket mindre när maskinen belastades. Mätningar av ljudtryck och ljudeffekt genomfördes med maskinen stillastående och roterande vid låg varvtal. Det visade sig att det bästa sättet att utvärdera ljudet från elmaskiner är att mäta ljudeffekt. En metod för att beräkna ljudet från elmaskiner har undersökts. Metoden kombinerar olika kommersiella programvara för mekaniska, magnetiska och akustiska beräkningar baserade på FEM (finita element metoden) och BEM (randvillkor element metoden). Slutligen, en studie genomfördes för att undersöka hur effektiv man kan minska ljudet genom att införa ett luftgap lager nära den yttre statorkanten. (Less)
Abstract
This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines.



In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. The machine is built from soft magnetic composite material (SMC), also known as iron-powder. The magnetic isotropy of SMC gives enormous flexibility in electrical machine design, enabling new topologies exploiting three dimensional flux paths. This is the main advantage compared to conventional machines using laminations, where the flux is constrained into two dimensions. The novelty... (More)
This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines.



In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. The machine is built from soft magnetic composite material (SMC), also known as iron-powder. The magnetic isotropy of SMC gives enormous flexibility in electrical machine design, enabling new topologies exploiting three dimensional flux paths. This is the main advantage compared to conventional machines using laminations, where the flux is constrained into two dimensions. The novelty of the machine presented lies in that the slip-rings in the rotor are no longer needed, since the field coils are removed from the rotor and placed in magnetically conducting end-plates attached to both sides of the stator. This also improves the cooling capability of the copper losses from the field winding, allowing an increased electric loading. The rotor is of the claw-pole type, and the end-plates close the magnetic circuit between the stator and the rotor. The machine has been optimized using a magnetic equivalent circuit model allowing rotation, where non-linearities have been included using an iterative approach based on the linearisation of the BH curve. The traditional leakage paths in claw-pole machines are modified because of the magnetically conducting end-plates, and alternatives are proposed to reduce them. The machine has also been compared to two alternative topologies with electrical magnetization and another with permanent magnets.



In Part II, the measurement and prediction of the noise emissions from induction motors using the vector control technique is analyzed together with some structural changes to reduce these emissions. A drive system has been developed for a 2.2 kW induction motor, and its dynamic capabilities demonstrated for a wide range of the frequency spectrum. This tool has been used for the experimental evaluation of the noise emissions when the flux and/or the torque are modulated with high frequency noise signals. The results showed that the noise emissions were higher when the flux was modulated compared to the torque, although the differences were considerably reduced when the machine was loaded. It was also observed that the noise emissions were decreased importantly at load. Sound pressure and sound intensity measurements have been conducted with the rotor stationary and rotating at low speed, showing that the most proper way to quantify the noise emissions from electric machinery is to measure the sound power. A method for the prediction of the noise emissions has been proposed, based on the interactive use of commercial packages for mechanical, electromagnetic and acoustic analyses based in the finite and boundary element methods. Finally, a study has been conducted to assess the effectiveness of introducing peripheral air gap layers around the stator core to reduce the noise emissions. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Jahns, Thomas M., University of Wisconsin - Madison
organization
publishing date
type
Thesis
publication status
published
subject
keywords
BEM, induction machine, noise prediction, vector control, acoustic noise, HEV, series magnetization, leakage reduction, thermal model, FEM, MEC, claw-poles, SMC, slip-ring-less machine, sound intensity measurements, vibration, Electrical engineering, Elektroteknik
pages
338 pages
publisher
Department of Industrial Electrical Engineering and Automation, Lund Institute of Technology
defense location
Lecture hall M:B, M-Building, Ole Römers väg 1, Lund.
defense date
2005-01-14 10:15
ISBN
91-88934-35-7
language
English
LU publication?
yes
id
a104e6b1-e530-41bc-9de4-10bcdb0079e7 (old id 24280)
date added to LUP
2007-05-31 15:39:39
date last changed
2016-09-19 08:45:06
@phdthesis{a104e6b1-e530-41bc-9de4-10bcdb0079e7,
  abstract     = {This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines.<br/><br>
<br/><br>
In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. The machine is built from soft magnetic composite material (SMC), also known as iron-powder. The magnetic isotropy of SMC gives enormous flexibility in electrical machine design, enabling new topologies exploiting three dimensional flux paths. This is the main advantage compared to conventional machines using laminations, where the flux is constrained into two dimensions. The novelty of the machine presented lies in that the slip-rings in the rotor are no longer needed, since the field coils are removed from the rotor and placed in magnetically conducting end-plates attached to both sides of the stator. This also improves the cooling capability of the copper losses from the field winding, allowing an increased electric loading. The rotor is of the claw-pole type, and the end-plates close the magnetic circuit between the stator and the rotor. The machine has been optimized using a magnetic equivalent circuit model allowing rotation, where non-linearities have been included using an iterative approach based on the linearisation of the BH curve. The traditional leakage paths in claw-pole machines are modified because of the magnetically conducting end-plates, and alternatives are proposed to reduce them. The machine has also been compared to two alternative topologies with electrical magnetization and another with permanent magnets.<br/><br>
<br/><br>
In Part II, the measurement and prediction of the noise emissions from induction motors using the vector control technique is analyzed together with some structural changes to reduce these emissions. A drive system has been developed for a 2.2 kW induction motor, and its dynamic capabilities demonstrated for a wide range of the frequency spectrum. This tool has been used for the experimental evaluation of the noise emissions when the flux and/or the torque are modulated with high frequency noise signals. The results showed that the noise emissions were higher when the flux was modulated compared to the torque, although the differences were considerably reduced when the machine was loaded. It was also observed that the noise emissions were decreased importantly at load. Sound pressure and sound intensity measurements have been conducted with the rotor stationary and rotating at low speed, showing that the most proper way to quantify the noise emissions from electric machinery is to measure the sound power. A method for the prediction of the noise emissions has been proposed, based on the interactive use of commercial packages for mechanical, electromagnetic and acoustic analyses based in the finite and boundary element methods. Finally, a study has been conducted to assess the effectiveness of introducing peripheral air gap layers around the stator core to reduce the noise emissions.},
  author       = {Martinez, David},
  isbn         = {91-88934-35-7},
  keyword      = {BEM,induction machine,noise prediction,vector control,acoustic noise,HEV,series magnetization,leakage reduction,thermal model,FEM,MEC,claw-poles,SMC,slip-ring-less machine,sound intensity measurements,vibration,Electrical engineering,Elektroteknik},
  language     = {eng},
  pages        = {338},
  publisher    = {Department of Industrial Electrical Engineering and Automation, Lund Institute of Technology},
  school       = {Lund University},
  title        = {Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise},
  year         = {2005},
}