Implementation of an innovative advanced loop scheme to provide distribution reliability improvement

With the ever-increasing importance of electricity, excellent service reliability is no longer a luxury in the eyes of consumers but an expectation. In response to this expectation, Public Service Electric and Gas Company (PSE&G) is making a significant investment in a new technology to help improve reliability. This new technology has resulted in an automated feeder reconfiguration scheme that not only minimizes the duration of an outage due to a fault and the number of customers impacted by it but also reduces the number of customers experiencing a blink and subsequent switching. PSE&G has implemented an innovative solution designed to improve their reliability indices. The advanced loop scheme (ALS) builds on the PSE&G standard distribution scheme that used a normally open tie to separate two feeders. The original scheme offered automatic reconfiguration but was inherently slow and subjected customers to unnecessary blinks during reconfiguration. The new scheme uses a close-before-open methodology in which the tie is closed before sectionalizing is done. Because of this manner of operation, customers on unfaulted line sections are not exposed to an outage for the fault or the switching performed to isolate the faulted line section. Additionally, with communication comes the ability to simplify coordination and apply transmission protection principles to improve protection and increase the density of protective devices along the feeders, thus reducing the number of customers per section. This paper examines the design and implementation of the ALS. It gives specific settings and operational details of the scheme. Additionally, a review of the operational history highlights the impact that the scheme has had on the reliability of the utility distribution network.