Reliability assessment of relay protection system considering different protection configuration schemes

The hardware reliability of the microcomputer protection device has been greatly improved, and the different protection principles and configuration schemes have become the main factors affecting the reliability. First, this paper summaries the configuration of primary equipment and its relay protection systems. Second, the Markov state space method is used to establish the integrated model of the primary device and its protection systems according to the common configurations of the power system and on the basis of the system state division. Finally, this paper evaluates the reliability of different protection configurations. The method proposed in this paper can calculate the reliability of the protection system composed of different principles or different manufacturers' protection devices. It has great significance for configuring the protection system with different type and different number of protective devices according to the importance of the power system, improve the reliability level of the relay protection system and ensuring the safe and stable operation of the power system.