Supervisory control and sliding mode control of a medium voltage direct AC-AC electronic voltage regulator

Abrie, Dewald Johan (2013-03)

Thesis (MScEng)--Stellenbosch University, 2013.

Thesis

ENGLISH ABSTRACT: As control problems become more and more complex, techniques are required that surpass the capabilities of simple controllers that are linearized about certain parametric set points. Controllers that can operate over a large range of model parameter variations and even controllers that are largely model-independent are becoming more valuable and necessary. In this control application, voltage regulation is done on a direct AC-AC medium voltage regulator, making use of a type of regulated autotransformer configuration. The fifth order system is shown to be prone to oscillations on the input bus. This, together with the control requirement of robustness to load variations, provides a challenging control problem that is rarely addressed in literature. This thesis solves the control problem by means of applying sliding mode control on voltage regulator module level, and supervisory control on system level.

AFRIKAANSE OPSOMMING: Soos die soeke na oplossings vir hedendaagse beheer probleme al hoe meer uitdagend raak, word die behoefte vir model onafhanklike en robuuste beheerders dienooreenkomstig groter. Eenvoudige beheerders wat gelineariseer is om ’n parametriese werkpunt raak ondoeltreffend vir vandag se vereistes vir doeltreffende beheer ongeag van parametriese veranderinge. In hierdie tesis word spanning regulasie toegepas deur ’n direkte WS-na-WS medium spanning reguleerder in te span. Hierdie toestel maak gebruik van ’n tipe van outotransformator opstelling waar die sekondêre wikkelings gereguleer word deur die skakelaksie van die drywingselektroniese regulasie modules. Die vyfde-orde stelsel se intree bus is geneigd om onstabiel te raak, en moet dus aktief gedemp word terwyl die uitreespanning reguleer word. Die vereiste dat die beheer boonop robuus ten opsigte van las veranderings moet wees maak hierdie probleem ’n monster van ’n uitdaging wat skaars in die literatuur aangeraak is. Hierdie tesis los die probleem van robuuste beheer op deur glymodus beheer toe te pas op reguleerder module vlak, en ook deur toesighoudende beheer op stelsel vlak toe te pas.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/80166
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