Analyzing the value of equipment testing in a power distribution system

This paper explores the concepts of understanding the economic value gained from applying nondestructive testing techniques to common power distribution equipment. The concept is illustrated using a case study example of testing underground getaway cables at distribution voltage substations. Using a Markov chain model, the authors quantitatively evaluate the impacts of cable failure (both direct cost and outage impacts), the likelihood of cable failure, the results of cable testing (including both false negatives and false positives) and the costs of testing. Using this information, the paper shows how the accuracy of the test can influence when testing is a worthwhile investment and, conversely, when the costs of testing outweigh the actual benefits that are gained