Transmission Line Fault Resistance Values Based on Field Data

Systematic deployment of digital fault recorders has made considerable amounts of field data available and raised the interest to compute fault resistance values from large sets of power system faults and analyze the results statistically. Published results are valuable, however scarce. The present paper gives further contributions by showing results obtained from 89 fault records, for the 400 kV, 220 kV, and 150 kV voltage levels, comparing these with recently published data. Furthermore, the present paper addresses the fundamental question on the existence of a theoretical distribution capable to describe the fault resistance value. For such purpose, an exploratory data analysis is applied to the new results, and a comparison between the exponential and the Weibull distribution is carried out. Results show that both distributions can describe the field data based distributions, the Weibull being more adequate for low resistance values.