Development of the mathematical model for operation of digital substations relay protection complexes

The issues of introduction of electrical digital substations in the Russian Federation are considered. An existing criteria analysis for assessing the modern relay protection devices efficiency is carried out and an assessment of their sufficiency is made. A mathematical model development of the digital substations relay protection complexes operation has been developed using the queuing theory, the graphs theory and Markov chains. The failure-free operation probability calculated value of the relay protection complexes corresponds to the long-term analysis data. This indicates that the mathematical model is correct. The proposed mathematical model makes it possible to take into account the impact of the maintenance quality on the digital substation relay protection complexes efficiency.