Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The position sensorless controllability of the reluctance synchronous machine (RSM) is investigated in
this thesis with the focus on industry applications where variable and dynamic torque is required from
startup up to rated speed. Two low speed as well as one medium to high speed position sensorless control
(PSC) method for RSMs are investigated. These methods are extended to operate in the entire rated
speed region with a hybrid PSC structure that makes use of phase locked-loop synchronisation and a
hysteresis changeover method.
It is shown in this thesis that PSC of the lateral rib rotor RSM is not possible from zero up to ± 0.2 p.u
current. It is shown through finite element (FE) simulations that PSC of the ideal rotor RSM however,
is possible at zero reference current. A novel construction method is used to build two ideal rotor RSMs.
Measured flux linkage curve results of the ideal rotor RSMs correlate well with simulation results and it
is shown that the electrical angle of the machine can be tracked successfully at zero reference current.
The FE simulation package is used to compare the saliency of the RSM on a per-unit scale to three
types of field intensified permanent magnet (FI-PM) synchronous machines and a field weakening interior
permanent magnet synchronous machine. It is shown that the saliency of the RSM is larger than that of
the investigated PM machines from zero up to rated load. It is thus concluded that the RSM is well suited
to saliency-based PSC (SB-PSC) methods, which are used to control synchronous machines at startup
and low speeds.
The hybrid PSC methods developed in this thesis, are tested and evaluated on three proposed industry
applications. The first is a reluctance synchronous wind generator with an inverter output LC filter. The
LC filter allows long cables to be used and reduces the voltage stress on the stator windings of the machine.
The combination of the LC filter and hybrid PSC method allows the power electronics and controller to
be stationed in the base of the turbine tower. A new stator quantity estimation method is derived to omit
the need of current and voltage sensors on the machine side of the LC filter. Good maximum power point
tracking laboratory results are shown with the high frequency injection-assisted hybrid PSC method.
The second application investigated is a position sensorless controlled variable gear electric vehicle
(EV) RSM drive. Simulation and measured results show good torque capabilities of the position sensorless
controlled EV RSM. It is shown through simulation results that the fundamental current harmonic is
dominant in the demodulation scheme of the high frequency injection position sensorless control (HFIPSC)
method due to the high current rating of the proposed RSM. The HFI-PSC method is extended to
reduce the effect of the fundamental current harmonic in the demodulation scheme without adding any
additional filters.
The final investigated application is a novel mine scraper winch, which uses two position sensorless
controlled RSMs to retrieve ore from the blast site underground. The new design improves on the safety,
efficiency and durability of the current scraper winch design. Measured results show that the position
sensorless controlled winch RSM is able to deliver rated startup torque with both investigated SB-PSC
methods. Finally an automation method is implemented and tested to limited the applied force on the
scraper and automatically free itself when stuck. / AFRIKAANSE OPSOMMING: Die posisie sensorlose beheer eienskappe van die reluktansie sinchroonmasjien (RSM) word in hierdie tesis
ondersoek met die fokus op industriële toepassings waar varierende dinamiese draaimoment vereis word
vanaf stilstand tot by ken spoed. Twee lae spoed- en een ho¨e spoed posisie sensorlose beheer (PSB)
metodes vir RSMe is ondersoek. Hierdie metodes is uitgebrei om twee hibriede PSB metodes to skep wat
die RSM van stilstand tot by kenspoed posisie sensorloos kan beheer. Die ontwikkelde hibriede metodes
maak gebruik van ’n histerese oorskakelings skema en fase geslote lus sinchronisasie
Daar word in hierdie tesis bevestig dat die laterale rib RSM nie beheer kan word met die geondersoekte
PSB metodes by nul stroom nie. Eindige element simulasie resultate wys egter daarop dat die ideale rotor
RSM wel beheer kan word met die geondersoekte metodes by nul stroom. ’n Nuwe konstruksie metode is
voorgestel om twee ideale rotor RSMe to bou. Gemete vloed omsluiting kurwes resultate korreleer baie
goed met dié van die eindige element simulasies. Gemete resultate wys ook daarop dat PSB van die nuwe
masjiene moontlik is by nul stroom.
’n Eindige element pakket is gebruik om die speek-koëffissiënt van die RSM te vergelyk met drie tipes
veld-versterkte permanent magneet masjiene, asook een veld verswakte permanent magneet versinkte
masjien. Die simulasie resultate wys dat die RSM se speek-koëffissiënt hoër is as die van die geondersoekte
permanent magneet masjiene. Die RSM is dus geskik vir speek-koëffissiënt georienteerde PSB metodes,
wat hoofsaaklik by stilstand en lae spoed gebruik word.
Die ontwikkelde hibried PSB metodes is getoets en geëvalueer met drie voorgestelde industriële toepassings.
Die eerste is ’n reluktansie sinchroon wind generator met ’n omsetter uittree laagdeurlaat filter. Die
laagdeurlaat filter laat toe dat langer kabels vanaf die omsetter na die generator gebruik kan word. Die
kombinasie van die laagdeurlaat filter en die PSB metodes laat toe dat die drywingselektronika en die
beheerders in die toring basis geplaas kan word. Dit kan die gewig van die nasel verminder. Goeie maksimum
drywingspunt volging laboratorium resultate word getoon met die hoë frekwensie ondersteunde
hibried PSB metode.
Die tweede geondersoekte toepassing is ’n posisie sensorlose beheerde, varierende ratkas elektriese
voertuig RSM. Goeie simulasie en gemete draaimoment resultate van die RSM word getoon. Simulasie
resultate toon dat die fundamentele q-as stroom harmoniek dominant is in die demodulasie skema van
die hoë frekwensie PSB metode, as gevolg van die hoë ken stroom van die motor. Die hoë frekwensie
PSB metode is uitgebrei om die fundamentele stroom harmoniek te onderdruk in die demodulasie skema
sonder om enige filters by te voeg.
Die finale toepassing is ’n nuwe myn windas wat van twee posisie sensorlose beheerde RSMe gebruik
maak om klippe ondergronds te verplaas vanaf die ontploffings area. Die voorgestelde ontwerp verbeter die
huidige ontwerp ten opsigte van die veiligheid, energie effektiwiteit en robuustheid. Gemete resultate wys
dat ken draaimoment moontlik is met altwee speek-koëffissiënt metodes. ’n Automasie metode, wat die
maksimum draaimoment op die windas beperk en automaties homself bevry indien hy vasval, is voorgestel
en geëvalueer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/86527 |
| Date | 04 1900 |
| Creators | Villet, Wikus Theo |
| Contributors | Kamper, M. J., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xxii, 151 p. : ill. |
| Rights | Stellenbosch University |
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