Characterization of power quality performance at network buses using unified power quality index

Power Quality performance is a critical issue for both contemporary and future distribution networks operation and planning. DSOs started to pay significant attention to the levels of the PQ provided in their networks for many reasons, such as, the current deregulated electricity markets, increased DG penetration, regulatory frameworks and the increased numbers of sensitive loads to voltage variations. Although main PQ phenomena are well defined in international standards, there is no standard way to evaluate the PQ as a whole for a site or a network. This paper presents a methodology to comprehensively evaluate the PQ for a network considering both the suggested planned levels set by the utility and the expected different customers’ PQ requirements. The suggested index is calculated using numerical consolidation of several separate indices. The considered phenomena in this paper, to demonstrate the methodology, are voltage harmonics, unbalance and flicker. The results are presented in a 295-bus Generic Distribution Network.