High-speed distribution protection made easy: Communications-assisted protection schemes for distribution applications

With more emphasis being placed on distribution system reliability, there is a need to establish protection methods for the varying communications in use on these systems. This paper examines different communication paths for protection signals, such as spread-spectrum radio, fiber-optic cable, phone lines, and copper pilot wire. Data transmission statistics with performance measures are given for each type of communication. Based on the communication characteristics and their performance during faults, different protection schemes are studied with total clearing times given for each scheme. The consequences of communications failure on each type of scheme are examined, including the possibility of misoperation, as well as backup clearing times.