A Communication-Assisted Overcurrent Protection Scheme for Radial Distribution Systems With Distributed Generation

Abstract

Conventional overcurrent protection schemes for radial distribution systems usually attempt to coordinate a recloser at the beginning of the feeder with the fuses on the laterals. The integration of distributed generation in distribution systems leads to problems related to protection coordination that are difficult to be solved by applying conventional protection techniques. This paper proposes an efficient communication-based protection scheme that implements common directional overcurrent relays instead of reclosers at the line, assisted by intertripping and blocking transfer functions. The proposed protection strategy guarantees selectivity regardless of whether the generating units are connected to the network or not, and can be designed retaining either the fuse-blowing or fuse-saving philosophy. Meaningful conclusions are derived from the application of the scheme on a test distribution system.