A Practical Method for Cable Failure Rate Modeling

As underground cables continue to increase in age, most utilities are experiencing an increase in underground cable failures. Since cable replacement programs are expensive, it is important to understand the impact that age and other cable characteristics have on cable failure rates. This paper presents a practical method to model cable failure rates categorized by cable features. It addresses the issue of limited data and makes it possible to predict cable failure trends using the available information in power delivery companies. This paper starts with a discussion of historical data and cable features that affect cable failure rate trends, followed by the description on failure rate modeling process. This method is then applied to a test case based on the data from a large U.S. utility. It is shown cable failure rates tend to increase exponentially with chronological age