A Comparison of Measured High Impedance Fault Data to Digital Computer Modeling Results

Staged fault tests were conducted by Pennsylvania Power and Light Company to verify the performance of the Ratio Ground Relay concept. Previous development and testing efforts regarding this relay have been reported (1, 2). This paper presents the field measured fault current data in entirety and compares the field data with SCADA collected data and digital computer data. The paper documents that a 12-kV four-wire multi-grounded neutral distribution feeder can be accurately modeled on a digital computer, and that the computer results are field verifiable. The favorable results of this comparison provide confidence in the modeling method for use in development, testing, and application of new relay methods.