Multi-mode hidden-fault risk analysis method of relaying protection system

The invention belongs to the field of relaying protection and risk analysis of power systems, and discloses a multi-mode hidden-failure risk analysis method of a relaying protection system. The method comprises the steps of building a multi-mode hidden-failure model of the relaying protection system; according to the multi-mode hidden-failure model, performing risk analysis on power grid N-k failures caused by relaying protection hidden failures, and obtaining risk index values of hidden failures of the relaying protection system. According to the method, simplified modeling analysis is performed on the hidden failures of the protection system; the multi-mode hidden-failure model is built by analyzing the characteristics of protection hidden failures with various typical modes; a power N-k grid failure analysis method is provided by aiming at the risk analysis problem of the hidden failures. An N-k failure probability solving method based on an improved functional group decomposition method and an event tree analysis method is adopted during the analysis, and corresponding cascading failure risk indexes are set up; the calculation accuracy of the power grid N-k failure probability is improved, and risk assessment and analysis can be performed on the hidden failures of the relaying protection system.