CPS based relay protection system for underground coalmine distribution networks

The rapid development of computer and network communication technology makes it possible that the protection devices in the underground coalmine distribution networks solve the complicated faults in independent or/and cooperative way. In China, though the mining protective relaying devices have been developed greatly, power faults such as over-zone tripping, failure and false operation and various of cable faults is common in coalmine. In order to solve these problems, the concept of Cyber-Physical System is introduced into underground relay protection system. In this paper, a novel Cyber-Physical System based relay protection system for underground coalmine distribution networks is proposed. And the structure and features are presented. The greatest superiority of the new proposed system is the global sharing and exchange of data and information of coalmine distribution network, based on which theories of three steps over current protection and selective electrical leakage protection and their executing modes are improved sharply, therefore, the speed and precision of protection functions based on these theories could be increased.