System control and intelligent protection in a DC traction substation

Date
1997
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: A prototype dc traction substation has been developed that consists of several subsystems. The system models the operation of a traction substation and simulates a traction load. Two additions are proposed to the substation, the one being an anti-parallel path for active power filtering and regeneration. The other is a high voltage IGBT dc switch developed by the author to dump excessive regenerated energy into resistor banks. PI and fuzzy logic control algorithms have been implemented to control the dc dump. The operation of the controllers were practically evaluated and a comparison drawn. The protection of the system was then expanded from the localised dc dump protection to system wide protection control. The concept of "intellegent" control was investigated and implemented in two system protection controllers. A shutdown protection strategy was put in juxtaposition to a fuzzy logic controller in the protection of the system. Both system controllers were practically evaluated and a comparison is drawn between the two. Some conclusions are made concerning the protection issues addressed in the thesis.
AFRIKAANSE OPSOMMING: 'n Prototipe gelykstroom (gs) traksie stelsel is ontwikkel wat uit die verskeie sub-stelsels bestaan. Die stelsel modelleer die werking van 'n traksie substasie en simuleer 'n traksie las. Daar word twee byvoegings tot die huidige stelsel voorgestel. Die een is 'n anti-parallel pad vir aktiwew drywingsfiltering en regeneratiewe energie. Die ander is 'n hoogspanning IGBT gs skakelaar wat deur die outeur ontwikkel is om oormatige regeneratiewe energie in resistor banke te verkwis. Beide PI en "Fazzy Logic" beheerders is geïmplimenteer om die gs skakelaar te beheer. Die werking van beide beheerdes is prakties ondersoek en 'n vergelyking word getref. Die beveiling van die stelsel word dan uitgebrei van die gelokaliseerde beveiling van die gs skakelaar tot stelselwye beveilingsbeheer. Die konsep van "intelligente" beheer is ondersoek en op twee wyses geïmplimenteer. 'n Aan/af beveiligings strategie is afgespeel teen 'n "Fuzzy Logic" beheerder in die beveiliging van die stelsel. Beide stelsel beheerders is prakties geëvalueer en die twee is met mekaar vergelyk. Sekere afleidings word gemaak na aanleiding van die beveiligingskwessies wat in die tesis aangeraak word.
Description
Thesis (MEng)--University of Stellenbosch, 1997.
Keywords
Electric substations, Electric power systems -- Control, Electric power systems -- Protection
Citation