AC Analysis and Testing of Realistically Contaminated Fas-Insulated Systems

A methodology for the analysis of 60hz data on gas-insulated systems is presented. Results of testing for the EPRI-ERDA Research Project on Optimization of Gas-Insulated Transmission Systems are used as a basis for the analysis. A single-cycle is assumed to be the statistically-independent unit of applied voltage. The conclusions of the study are as follows: 1. A Gaussian distribution of this one-cycle statistic is shown to provide an excellent fit to the data. A standard deviation of 3.2% of the one-cycle mean was found. 2. Particle conditioning in the (realistically contaminated, full-scale) system tested is shown to have a time constant of order days. 3. The large spread of data often found in such testing is accounted for, and maximum likelihood methods used to fit the data and determine the (surprisingly naffow) confidence limits.