Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The use of power electronic converters provides a more efficient, accurate and
dynamic solution to reactive compensation. In this thesis the application of power
electronic converters to shunt reactive compensation will be discussed. In particular
voltage dips and voltage unbalance are considered as both can be mitigated by
means of shunt reactive compensation.
A pre-existing uninterruptible power supply is adapted to operate as a shunt reactive
compensator. The uninterruptible power supply consists of a 250 kVA three phase
voltage source inverter. The modifications are limited to software and control
algorithms that do not alter the normal operation of the uninterruptible power supply.
Control algorithms are designed and discussed in detail. A typical double loop
control strategy is implemented on the power electronic converter. The inner loop
consists of a dead-beat current controller. The outer loop consists of three
proportional and integral controllers controlling the DC-bus voltage, AC voltage and
voltage unbalance respectively.
Voltage dips and unbalance are compensated for using only reactive power. Focus
is placed on producing a result can be used easily in practice. / AFRIKAANSE OPSOMMING: Drywings elektroniese omsetters wat gebruik word vir newe reaktiewe kompensasie
lewer meer effektiewe, akkurate en dinamiese resultate. In hierdie tesis word die
toepassing van drywings elektroniese omsetters vir newe reaktiewe kompensasie
bespreek. Daar word meer spesifiek na spannings duike en spannings wanbalans
gekyk aangesien albei met newe reaktiewe kompensasie verminder kan word.
’n Bestaande nood kragbron is aangepas om as n newe reaktiewe kompenseerder te
funksioneer. Die nood kragbron bestaan hoofsaaklik uit ’n 250 kVA drie fase
omsetter spanningsbron. Die aanpassings is beperk tot sagteware en beheer
algoritmes wat nie die oorspronklike funksionaliteit van die nood krag bron beinvloed
nie. Beheer algoritmes word ontwerp en deeglik bespreek. ’n Tipiese dubbel lus
beheer strategie word op die drywings elektroniese omsetter toegepas. Die binnelus
bestaan uit ’n voorspellende stroom beheerder. Die buite-lus bestaan uit drie
proportioneel en integraal beheerders wat onderskeidelik die GS-bus spanning, WS
spanning en spanning wanbalans reguleer.
Spannings duike en wanbalans is verminder deur slegs reaktiewe drywing te gebruik.
Die doel was ook om ’n prakties bruikbare resultaat te lewer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/5315 |
| Date | 12 1900 |
| Creators | Welgemoed, Frans Marx |
| Contributors | Beukes, H. J., University of Stellenbosch. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 130 p. : ill. |
| Rights | University of Stellenbosch |
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