Towards Systematic Approximate Reasoning Methods in Power System Equipment Condition Monitoring and Reliability Analysis

Under the pressure of electric power industry deregulation, the approaches to many traditional power system problems are being reconsidered. Important concerns have arisen with regards to equipment condition monitoring, preventive maintenance and system reliability calculations. Approaches to condition monitoring and maintenance have historically been ad hoc tending to follow broad company guidelines or the experience of company personnel rather than systematic analysis. Recently, there has been increased interest in realizing cost savings by extending equipment lifetimes with focus on a comprehensive view of system reliability. There is not, however, a clear understanding of breakdown mechanisms and equipment stresses that will allow precise probabilistic analysis. This paper formulates an approximate reasoning approach that can incorporate expert judgement into reliability calculations. A novel method for including system constraints to improve the clarity of analysis is proposed. A numerical example illustrates the techniques.