Power quality monitoring at the supply side

/sup T/his paper summarizes a power quality (PQ) monitoring investigation conducted at the utility distribution substation level. The main goal was to determine the real-time PQ monitoring issues from the user's perspective: what type of data needs to be captured; and how it should be presented to the user. These issues have been investigated from a supply (utility) point of view, rather than the demand (customer) side view. The investigation involved installing three relays with PQ monitoring capability (ABB DPU2000R) to monitor the voltage quality at three distribution substations of Carolina Power and Light - A Progress Energy Company in North Carolina, USA. The PQ field data captured by these devices is then analyzed and presented to the user (CP&L PQ engineers) to see if the data provides the appropriate information to the user. The paper summarizes the typical voltage quality events monitored and also their presentation to the user. The paper shows that the PQ devices used facilitate the PQ monitoring effectively, in that they provide the user the PQ data in a form that minimizes the data manipulation. In particular, the paper illustrates how the user can use the PQ data directly to construct the voltage sag and outage profiles for a distribution substation.