Examination on the applicability of IP-related communications to teleprotection systems

This paper preliminarily examines the applicability of Internet protocol (IP)-related communication technologies such as IP and MPLS (multi-protocol label switching) routers and L2 (layer-two or Ethernet) switches to existing teleprotection systems. The teleprotection systems concerned include microprocessor-based current differential teleprotection with data communications of instantaneous current values or phasors, directional comparison teleprotection, and special or system-wide protection. Taking account of the performance limitations of IP-related telecommunication networks, fully redundant L2 switch networks are indispensable, as is an external timing synchronization scheme for current differential teleprotection. Based on the analyses, a new concept for modernizing teleprotection system associated with L2 switch networks, time synchronization and modular devices is proposed.