APPLICATION OF AGING FAILURE MODELS IN POWER SYSTEM RELIABILITY EVALUATION

摘要

This article describes an application of aging failure model in power system reliability evaluation. The defined unavailability of aging failures has a consistent form as that for repairable failures and therefore it is simple and straightforward to include it in the existing reliability evaluation techniques and tools. The unavailability due to aging failures can be modeled using either normal or Weibull distribution. Generally, the normal model provides a lower estimation of unavailability at a young or mid age and a higher estimation at an age around the mean life compared to the Weibull model. Which model should be used in an actual application depends on the match between the parameters of the model and failure data statistics. The results applied to a BC Hydro regional system reliability assessment indicate that aging failures have significant impacts on the system reliability, particularly for an "aged" system. Ignoring aging failures in reliability evaluation of an aged power system will result inconsiderable underestimation of system risk and most likely a misleading conclusion in system planning.