The development of a IGBT-based tap changer

Fourie, Reinhart (2010-03)

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.

Thesis

ENGLISH ABSTRACT: Voltage regulation on distribution networks has so far been done by means of mechanical tap changers. However, these tap changers are plagued by high maintenance costs due to the arcing caused while switching, which degrades both the contacts and transformer oil. The major advances made during the last decade with regard to semiconductor technology have led to the development of high power IGBTs. These high power IGBTs are capable of conducting currents up to 1 000 A, while the voltage over the IGBT reaches well over 3 000 V. Using these high power IGBTs to design and build a solid-state tap changer allows the tap changer to regulate the output voltage with higher accuracy and speed. The supporting hardware is also discussed, while the design is verified by the use of simulations and practical measurements conducted on a scale-model of the IGBT-based solid-state tap changer.

AFRIKAANSE OPSOMMING: Spannings regulasie op distribusie netwerke word hedendaags verrig deur meganiese tap geskalde spanning reguleerders. Maar hierdie tap skakelaars word konstant beïnvloed deur oorvonking wat plaasvind tussen die kontakte wat hierdie kontakte beskadig en die transformator olie degradeer. Die laaste dekade het groot vordering getoon in halfgeleier navorsing wat gelei het tot die ontwikkeling van hoë drywing halfgeleiers. Die halfgeleiers of IGBTs kan strome so groot soos 1 000 A gelei terwyl die spanning oor die halfgeleier 3 000 V kan oorskry. Die gebruik van die hoë drywing halfgeleiers maak die pad oop vir die ontwerp en bou van ’n tap geskakelde reguleerder wat die uitree spanning akurater en vinniger kan reguleer. Die aanvullende hardeware is ook bespreek en die ontwerp is geverifieër deur middel van simulasies en deur praktiese metings wat geneem is op ’n skaal model van die hoogspanning spannings reguleerder.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/4272
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