A review and discussion of failure rate heterogeneity in power system reliability assessment

The failure rate is a reliability measure which is used for planning and operation of the power system. Thus far, average or experience based failure rates were applied to power system equipment due to their straightforward implementation. However, this approach limits the accuracy of the gained results and neglects the important differentiation between population and individual failure rates. Hence, this paper discusses and demonstrates the necessity to distinguish between population and individual failure rates and reviews the existing literature of failure rate estimation within the power system domain. The literature is categorized into statistical data driven approaches and failure rate modelling with focus on different criteria which can be used to describe the heterogeneity within populations. The review reveals that the environmental impact was modelled predominantly.