Staged-fault testing for high impedance fault data collection

Faulted lines must be repaired and returned to service in the shortest possible time to provide reliable service to the customers. Fault detection is an important aspect of system protection, as it involves personnel as well as equipment safety. The research on high impedance fault (HTF) detection techniques is mainly based on conventional methods, familiar to the power system engineers. TXU Electric Delivery (TXUED) and ABB have initiated a project to collect HIF data from staged-fault testing, to assist ABB in the research and development of suitable techniques for detecting high impedance faults. Since most protective relay engineers have spent their careers avoiding faults on the electric system, they are not usually comfortable with the process of staging faults on a system in service. The purpose of this paper is to describe one method of staging faults that is both safe for utility personnel performing the tests and results in no interruption or break in service to the utility consumers connected to the distribution feeder. Also, the analysis of the resulting HIF test data is discussed. These staged fault tests occurred on January 27-29, 2004 and also on September 27-28, 2004 on a distribution feeder at the TXU Huntington Substation near Lufkin, Texas.