Study of End Point Voltage Measurements on Distribution Systems for Avoiding Open or Falling Conductors from Evolving to Ground Faults and Wildfire Ignitions

Abstract

Detection of open conductor conditions and de-energization of overhead distribution electric systems before a conductor hits the ground would reduce safety hazards from electrical shocks and fire ignitions. This paper presents methods for detecting and isolating the open conductor without the advanced communication system for PMUs and identifies methods to minimize reliability trade-offs that may be realized with such a detection system. The approach focuses on the use of voltage measurements at circuit end-point locations. The combination of sequence and phase voltages are used to detect the open phase condition. Details are provided for circuit measurements and PSCAD simulations used to refine the pickup voltages to help discriminate against conditions where the open phase detection (OPD) should avoid initiating an operation, such as adjacent feeder faults. The logic developed was implemented to existing devices which have been monitoring for open phase conditions for a year. During this time more than ten open phase conditions have been captured.