Contributions to the understanding of harmonics, flicker and voltage unbalance management in future electricity distribution networks

摘要: The connection of electromagnetically disturbing installations, including new forms generating systems, to power distribution networks continue increase. As a result, managing the network electromagnetic compatibility (EMC) within stipulated limits has become major challenge service providers (DNSPs). Therefore, availability set guidelines and recommendations based on well researched engineering practices would facilitate DNSPs in provision adequate supply quality customers connected networks. Accordingly, International Electrotechnical Committee (IEC) released series standards technical reports address management EMC Despite these reports, there remain inadequacies documents as gaps existing knowledge relation EMC, where further refinements contributions are required. These must be addressed order for properly manage low frequency concerns this Thesis include harmonics, voltage fluctuations flicker, unbalance (VU). focus is investigate key issues future recently published IEC Technical Report 61000-3-14, provides (PQ) emission large installations (LV) Noting that harmonic voltages arise due both smaller (whose current levels governed by equipment standards), 61000-3-14 proposes an additional factor, which referred ‘reduction factor’. This factor represents fraction contribution global allowance from emissions installations. recommends iii determine reduction factors considering prevailing system conditions their analyses presented show establishment universal value (network independent) not advisable, it depends number variables unique under consideration. difficulty undermines applicability approach practical LV Furthermore, methodologies exist literature assessment public closely examined, emphasising strengths weaknesses each approach. A comparative study using test conducted. shows that, though underlying philosophies data requirements investigated vary significantly, they provide individual installation too dissimilar. In VU, application may or lead conservative allocation, especially complex radial An alternative VU allocation methodology constrained bus (CBV) method proposed Thesis. theoretical bases formulation CBV together with several examples. shown superior comparison Reports, former enables absorption capacity fully utilised. Compared methodologies, novel procedure concept droop (VD), simplistic, less computationally intensive technique. addition harmonics flicker expected concern integration intermittent fluctuating renewable energy generators (REGs) little