Relay protection and automation equipment operability evaluation on the basis of the graph probabilistic model

The relay protection and automation (RPA) is the essential part of the power system, which ensures the system failure-free operation. However, the inadequate attention is paid to the RPA operability problem during the electrical network reliability assessment. The study is focused on the determination of the RPA states probabilities with consideration of many factors characterizing the RPA ability to perform the specified functions. On the basis of the developed model calculations and evaluation results the dependences between the terminals self-control rate and the maintenance intervals in terms of the RPA equipment operability improvement were identified. The possibility justification of the further transition to the RPA operation according to its technical state was obtained as the paper result.