ENGLISH ABSTRACT: Energy-efficient (EE) lighting projects form a substantial percentage of Demand Side Management (DSM) initiatives. These largely entail the exchange of one lighting technology for another more energy-efficient lighting technology. The DSM process typically involves a proposal from an Energy Services Company (ESCO) to retrofit an existing lighting technology with another on the property of a third party, the client. For scoping purposes, ESCOs perform energy savings calculations based on information obtained from the datasheets of the relevant lighting technologies. Such datasheet specifications rarely incorporate the effects of supply voltage fluctuations on energy consumption, which can impact on the accuracy of the savings calculations. Furthermore, modern EE lighting technologies such as Compact Fluorescent lamps (CFLs) employ power electronic circuitry that can in principle give rise to Quality of Supply (QoS) problems such as harmonic distortion. The usage profiles of artificial light fittings targeted in DSM interventions represent another important factor in determining the savings impacts of such projects. There is currently limited information on methodologies for obtaining such usage profiles. In practice, the scoping and impact verification of EE lighting projects are conducted using project-specific applications and spreadsheets that are time-consuming and error-prone.
In view of the above-mentioned considerations, this investigation aims to address the lack of voltage-dependent energy consumption data and QoS impacts by conducting a laboratory investigation for all relevant lighting technologies, namely incandescent lamps, CFLs, tubular fluorescent lamps and high intensity discharge lamps. Appropriate mathematical models for the voltage-dependent energy consumption characteristics of these light technologies are derived from the measurements. The supply current harmonic distortion associated with the various lamp types are investigated, particularly with regard to neutral current loading caused by zero-sequence harmonics. Methodologies for obtaining accurate and reliable light usage data using commercially available data loggers are reviewed. A database structure is subsequently designed and implemented to store the information relevant for impact assessment, including the mathematical models of energy consumption, supply voltage profiles and light usage profiles.
Finally, an Integrated Software Program (ISP) is developed to implement a methodology for assessing the savings impacts of practical EE lighting projects, using the database as the main input source. The ISP is tested by implementing a real case study. It is shown that the ISP yields accurate results for the case study considered in the evaluation.
AFRIKAANSE OPSOMMING: Energiedoeltreffende (ED) beligtingsprojekte vorm ‟n wesenlike persentasie van vraagkantbestuur (VKB) inisiatiewe. Dit het grootliks te doen met die vervanging van een beligtingstegnologie met ‟n ander meer energiedoeltreffende beligtingstegnologie. Die VKB proses behels normaalweg ‟n voorstel van Energie Dienste Maatskappy (EDM) om ‟n bestaande beligtingstegnologie te vervang met ‟n ander op die perseel van ‟n derde party, die kliënt. EDMs doen energiebesparingsberekeninge op grond van tegniese inligting wat vanaf die datablaaie van die betrokke beligtingstegnologieë verkry word. Hierdie datablad spesifikasies maak selde voorsiening vir die uitwerking van toevoerspanningfluktuasies op energieverbruik, wat die akkuraatheid van die besparingsberekeninge kan beïnvloed. Moderne ED beligtingstegnologieë soos kompakte fluoresseerlampe maak verder gebruik van drywingselektronika stroombane wat in beginsel kan lei tot kwaliteit van toevoer (KVT) probleme soos harmoniese distorsie. Die gebruiksprofiele van kunsmatige lig verteenwoordig nog ‟n belangrike faktor wat die besparingsimpakte van VKB projekte bepaal. Daar is tans beperkte informasie oor die metodologie om sulke gebruiksprofiele te verkry. In die praktyk word die verifiëring van die impak van ED beligtingsprojekte gedoen deur gebruik te maak van projekspesifieke programme en sigblaaie wat tydrowend is en geneig is om te lei tot foute.
In die lig van die bogenoemde oorwegings, streef hierdie ondersoek om die tekort aan spanningsafhanklike energieverbruiksdata en KVT impakte te aan te spreek deur „n laboratorium ondersoek uit te voer vir al die relevante beligtingstegnologieë, naamlik filament lampe, kompakte fluoresseerlampe, buisvormige fluoresseerlampe en hoë-intensiteit ontladingslampe. Gepaste wiskundige modelle vir die spanningsafhanklikeenergieverbruik eienskappe van hierdie beligtingstegnologieë word vanuit die metings afgelei. Die harmoniese vervorming van die toevoerstroom van die verskillende beligtingstegnologieë word ondersoek, veral met verwysing tot neutraalstroombelasting wat veroorsaak word deur zero volgorde harmoniese ordes. Metodologieë vir die verkryging van akkurate en betroubare ligverbruikprofiele deur die gebruik van komersieel beskikbare dataversamelaars is nagegaan. ͗n Databasis struktuur is vervolgens ontwerp en geïmplementeer om die toepaslike inligting vir bepaling van die impakte te stoor, insluitend die wiskundige modelle vir energieverbruik, toevoerspanning-en ligverbruikprofiele.
‟n Geïntegreerdesagtewareprogram (GSP) is ontwerp om die metodologie vir die bepaling van besparingsimpakte van praktiese ED beligtingsprojekte te implimenteer, deur gebruik te maak die databasis as die hoofbron van insette. Die GSP is getoets deur ‟n werklike gevallestudie te implimenteer. Daar is bewys dat die GSP akkurate resultate lewer vir die gevallestudie wat in die evaluering gebruik is.
