Speed and security considerations for protection channels

Communications play a vital role in the fast and reliable operation of protection systems. Advances in communications technologies have enabled utilities to improve the speed, security, and dependability of these systems. Communications-based protection schemes have employed power line carrier (PLC), microwave, fiber-optic communications, time-division multiplexing, Ethernet, and spread-spectrum radio systems. Each communications transport system must provide low latency and be deterministic, secure, and dependable. Pilot protection schemes are not one size fits all. The clearing time requirements for a protected line or a breaker failure transfer tripping scheme can vary based on loading and system stability requirements. This paper describes the communications requirements for various protection and control applications, including channel time, channel asymmetry requirements, and jitter. We discuss the advantages and disadvantages of communications technologies, including PLC, microwave, fiber optics, synchronous optical networks, and spread-spectrum radios. We describe how network topologies can improve security and dependability. We also discuss cybersecurity practices that are suitable for securing protection communications links.