Increasing the Reliability of the Centralized Protection of the Digital Substation

Double entry is a system of recording business accounting transactions, used for errors detection. The usage of this approach in differential relay protection (DRP) allows to increase the reliability of the protection system. Current signals measured on the ends of protected units are formed in special matrices. The surplus current signal processing ensures reliable DRP functioning and eliminates needless protection actions in cases of current transformer or communication lines faults. The calculated relations of Markov chains are used for reliability indexes estimation. The obtained results allow us to conclude that the implementation of DRP with the usage of the doubly-entry method is promising for the digital substation.