Evidence-based approach to power transmission risk assessment with component failure risk analysis

This study presents a new framework for power transmission risk assessment, which considers not only historical failure statistics of transmission systems but also operation failure risks of system components. The component failure risks are integrated into the new framework based on operation condition assessment of components using the Evidential Reasoning (ER) theory. In this study, the traditional outage probability model of transmission line has been modified to build a new framework for power transmission system risk assessment. The proposed ER-based approach can provide a suitable mechanism to map component assessment grades to failure risks based on the probabilistic behaviours of power system failures. Under the new framework, both up-to-date component failure risks and traditional system risk indices can be processed with the proposed outage model. As a result, failure probabilities are related not only to historical statistic data but also to operation data of components and derived risk indices can reflect current operation conditions of components. In simulation studies, the ER approach is used to evaluate component conditions and link such conditions to failure rates using up-to-date component operation data, including both online and offline data of components. The IEEE 24-bus RTS-1979 system is used to demonstrate that component operation conditions greatly affect the overall transmission system failure risk.