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Comparison of Different Electrical Machines for Belt-driven Alternator and Starter

Hagstedt, Dan LU (2013)
Abstract (Swedish)
Popular Abstract in Swedish

I takt med att fossila bränslen, så som olja och bensin, minskar av jordens resurser så ökar tyvärr samtidigt förbrukningen och därmed efterfrågan på mer bränsle. Detta beror delvis på ökningen av antalet fordon samt på den ökande transportsektorn i världen. De enorma koldioxidutsläppen fortsätter att förstöra vår miljö. I ett kraftfullt försök att minska utsläppen och möta bristen på fossila bränslen har en satsning på hybridfordon skett runt om i världen, såväl inom själva fordonsindustrin samt genom samhällsfinansierade projekt på universiteten.



De elektriska hybridfordonen kan delas upp i en mängd olika hybridklasser, allt från den lättaste, microhybriden, till den... (More)
Popular Abstract in Swedish

I takt med att fossila bränslen, så som olja och bensin, minskar av jordens resurser så ökar tyvärr samtidigt förbrukningen och därmed efterfrågan på mer bränsle. Detta beror delvis på ökningen av antalet fordon samt på den ökande transportsektorn i världen. De enorma koldioxidutsläppen fortsätter att förstöra vår miljö. I ett kraftfullt försök att minska utsläppen och möta bristen på fossila bränslen har en satsning på hybridfordon skett runt om i världen, såväl inom själva fordonsindustrin samt genom samhällsfinansierade projekt på universiteten.



De elektriska hybridfordonen kan delas upp i en mängd olika hybridklasser, allt från den lättaste, microhybriden, till den kraftigaste, så kallade plug-in hybriden. Microhybriden är ett fordon som automatiskt stänger av förbränningsmotorn när det står stilla och med hjälp av en något kraftigare startmotor rullar iväg och startar fordonet när föraren trampar på gaspedalen. Den reducerar bränsleförbrukningen med ca 20 % i stadstrafik. En så kallad plug-in hybrid är ett fordon som har en kraftig elmotor och ett batteri som är stort nog att möjliggöra en normal framdrift av fordonet på endast eldrift upp till några mil.



Denna avhandlig undersöker några olika typer av lämpliga elmaskiner för en microhybrid, med kombinerad startmotor och generator i en personbil. Den presenterar också en ny typ av elmaskin som kombinerar permanentmagneterna med de elektriska magneterna i rotorn (den roterande delen) av en elmaskin. På så sätt kan man få en ökad prestanda och bättre möta kraven på elmaskinen i en microhybrid. Elmaskinen måste kunna starta förbränningsmotorn även i ett klimat av -40oC då oljan i motorn är extremt trögflytande. Den måste även kunna växla över och kunna fungera som generator i väldigt höga varvtal. (Less)
Abstract
This thesis focuses on the electromagnetic design of a synchronous machine suited for a belt-driven alternator and starter (BAS) in a micro hybridisation of a mid-size passenger car. The BAS needs to provide a high cranking torque to start the combustion engine, especially in a cool condition where the requirements are highest. Besides the high cranking torque it is desirable to have high power performance over a wide speed range.

This thesis compares four potential excitations of a synchronous machine: the permanently magnetised (PMSM), the electrically magnetised (EMSM), the EMSM with series magnetisation (SMSM), and the hybrid magnetised (HMSM). These are treated both theoretically and with numerical analyses, where the... (More)
This thesis focuses on the electromagnetic design of a synchronous machine suited for a belt-driven alternator and starter (BAS) in a micro hybridisation of a mid-size passenger car. The BAS needs to provide a high cranking torque to start the combustion engine, especially in a cool condition where the requirements are highest. Besides the high cranking torque it is desirable to have high power performance over a wide speed range.

This thesis compares four potential excitations of a synchronous machine: the permanently magnetised (PMSM), the electrically magnetised (EMSM), the EMSM with series magnetisation (SMSM), and the hybrid magnetised (HMSM). These are treated both theoretically and with numerical analyses, where the numerical calculations use finite element analyses (FEA). The fundamental boundary conditions, as current density set by thermal limitations, are based on a deep analysis of an existing Lundell alternator. This is presented with computational fluid dynamic (CFD) and finite volume analysis (FVA) in order to explain the heat dissipation of the alternator. A complete loss separation of the alternator is discussed and presented, both by calculations and experimental work.

The SMSM is a new configuration of an electrically excited synchronous machine with the field winding in series with the phase windings via a rectifier. This thesis shows the relationship between the magnetical and the electrical connection to the stator and the rotor. The power and torque characteristics are highlighted.

This thesis presents an electromagnetic design and experimental evaluation of a compact HMSM. A relatively simple and compact slip ringless rotor with EM and PM excitation is proposed, analysed and tested. A series of 3D FE dynamic computations are made in order to estimate efficiency at different operation points and with different types of rotor core materials: solid iron and powder composite core. A rotor with the solid iron core is built and tested, including different aspects of torque and power loss production. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Liu, Yujing, Chalmers University of Technology, Sweden
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Belt-driven Alternator and Starter, Permanently Magnetised Synchronous Machine, Electrically Magnetised Synchronous Machine, Series Magnetisation Synchronous Machine, Hybrid Magnetised Synchronous Machine
pages
166 pages
publisher
Tryckeriet i E-huset, Lunds universitet
defense location
Lecture hall M:B, M building, Ole Römers väg 1, Lund University Faculty of Engineering
defense date
2013-05-30 10:15
ISBN
978-91-88934-59-8
language
English
LU publication?
yes
id
fa79bee9-2db3-44ab-82e4-9ed13296cc13 (old id 3735393)
date added to LUP
2013-05-07 07:39:55
date last changed
2016-09-19 08:45:02
@misc{fa79bee9-2db3-44ab-82e4-9ed13296cc13,
  abstract     = {This thesis focuses on the electromagnetic design of a synchronous machine suited for a belt-driven alternator and starter (BAS) in a micro hybridisation of a mid-size passenger car. The BAS needs to provide a high cranking torque to start the combustion engine, especially in a cool condition where the requirements are highest. Besides the high cranking torque it is desirable to have high power performance over a wide speed range.<br/><br>
This thesis compares four potential excitations of a synchronous machine: the permanently magnetised (PMSM), the electrically magnetised (EMSM), the EMSM with series magnetisation (SMSM), and the hybrid magnetised (HMSM). These are treated both theoretically and with numerical analyses, where the numerical calculations use finite element analyses (FEA). The fundamental boundary conditions, as current density set by thermal limitations, are based on a deep analysis of an existing Lundell alternator. This is presented with computational fluid dynamic (CFD) and finite volume analysis (FVA) in order to explain the heat dissipation of the alternator. A complete loss separation of the alternator is discussed and presented, both by calculations and experimental work. <br/><br>
The SMSM is a new configuration of an electrically excited synchronous machine with the field winding in series with the phase windings via a rectifier. This thesis shows the relationship between the magnetical and the electrical connection to the stator and the rotor. The power and torque characteristics are highlighted.<br/><br>
This thesis presents an electromagnetic design and experimental evaluation of a compact HMSM. A relatively simple and compact slip ringless rotor with EM and PM excitation is proposed, analysed and tested. A series of 3D FE dynamic computations are made in order to estimate efficiency at different operation points and with different types of rotor core materials: solid iron and powder composite core. A rotor with the solid iron core is built and tested, including different aspects of torque and power loss production.},
  author       = {Hagstedt, Dan},
  isbn         = {978-91-88934-59-8},
  keyword      = {Belt-driven Alternator and Starter,Permanently Magnetised Synchronous Machine,Electrically Magnetised Synchronous Machine,Series Magnetisation Synchronous Machine,Hybrid Magnetised Synchronous Machine},
  language     = {eng},
  pages        = {166},
  publisher    = {ARRAY(0x88b4620)},
  title        = {Comparison of Different Electrical Machines for Belt-driven Alternator and Starter},
  year         = {2013},
}