Abstract: The present invention features a method and apparatus for detecting and enabling the clearance of high impedance faults (HIFs) in an electrical transmission or distribution system. Current in at least one phase in a distribution system is monitored in real time by sensors. Analog current signature information is then digitized for processing by a digital computer. Zero crossings are identified and current maxima and minima located. The first derivatives of the maxima and minima are computed and a modified Fast Fourier Transform (FFT) is then performed to convert time domain to frequency domain information. The transformed data is formatted and normalized and then applied to a trained neural network, which provides an output trigger signal when an HIF condition is probable. The trigger signal is made available to either a network administrator for manual intervention, or directly to switchgear to deactivate an affected portion of the network.

Abstract: The present invention features a retrofit, stop replacement device for the repair of damaged, rusted or corroded stop limits or abutments of distribution valves. The repair device is made up of a guide plate that fits over the facial portion of the distribution valve. Included in this guide plate is a replacement stop for the damaged, rusted or corroded stop abutment. This device is designed to be a one-piece unit. The guide plate is also made up of two inverted, U-shaped guide members that are positioned over the surface ribs of the distribution valve. The inverted, U-shaped guide members are held in place by their respective surface ribs. The ribs, via the inverted, U-shaped guide members, prevent the guide plate from being twisted when the rotatable valve abutment comes into contact with the stop abutment. The guide plate also includes at least one flange mounting bracket that is an integral part of the guide plate.