Bayesian estimates of transmission line outage rates that consider line dependencies

Transmission line outage rates are fundamental to
power system reliability analysis. Line outages are infrequent,
occurring only about once a year, so outage data are limited.
We propose a Bayesian hierarchical model that leverages line
dependencies to better estimate outage rates of individual
transmission lines from limited outage data. The Bayesian
estimates have a lower standard deviation than estimating the
outage rates simply by dividing the number of outages by the
number of years of data, especially when the number of outages
is small. The Bayesian model produces more accurate individual
line outage rates, as well as estimates of the uncertainty of these
rates. Better estimates of line outage rates can improve system
risk assessment, outage prediction, and maintenance scheduling.