Abstract
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etermining sources of voltage unbalance (VU) and
quantifying their individual contributions in an interconnected
network is a complex task due to multiple interactions that take
place between them. Post-connection VU emission assessment
techniques in relation to customer installations are important
not only in compliance assessment according to IEC/TR 61000-3-
13:2008 Limits - Assessment of emission limits for the connection
of unbalanced installations to MV, HV and EHV power systems,
but also in determining the various emission contributors in
the power system being considered. This paper presents a case
study on the application of a recently developed post-connection
VU emission assessment methodology to a 66 kV interconnected
sub-transmission network owned and operated by an Australian
network service provider. The study incorporates the evaluation
of constituent components of the resultant VU factors at bus bar
levels, identification of the dominant emission contributors and a
methodology for ranking of the emission contributions made by
the asymmetrical transmission lines in the network. Outcomes
obtained through the VU emission assessment methodology are
validated using three-phase, unbalanced load flow analysis.