Improving open-loop medium-voltage feeder self-healing

Abstract

This paper outlines the application of new technologies that enhance the benefits of the conventional looped distribution scheme by testing for feeder segment faults without using conventional reclosing. Pulseclosing technology, unlike conventional reclosing, reduces thermal and mechanical stress on substation transformers and other interim-feeder equipment by eliminating the repeated occurrence of high fault currents, thus also extending the life of legacy system assets. This revolutionary new technology also overcomes coordination constraints, allowing the expansion of a distribution loop or radial feeder to an unlimited number of series overcurrent protection devices. Maximum system restoration can be achieved within a few seconds after initial fault detection, and without the need for communication between devices.

New technology yields three ways to overcome coordination constraints on the distribution system

“…These advanced protection features are especially helpful on looped distribution systems. [1] Even in a worst case scenario where several devices in series have the exact same overcurrent protection setup, pulseclosing helps recover the unfaulted sections within seconds. In this scenario, all the pulseclosers will trip in response to the initial fault.…”