Synchrophasor-Based Islanding Detection for Distributed Generation Applications

A Rural Electric Cooperative (CO-OP) is a medium sized utility based in Colorado with a 69 kV subtransmission used primarily to feed their industrial members. The CO-OP is adding 180 MW of natural gas combustion turbine generation onto this sub-transmission network. The network is wholly owned by the CO-OP and is fed from multiple sources of which they own. Multiple sources, switching configurations, and ring buses feeding these sources make breaker status impractical for islanding detection. There exist scenarios outside the sub-transmission system that can lead to an islanded system. If the load and generation are closely matched, then local-islanding detection is not viable to detect an island. The CO-OP will use synchrophasor-based islanding detection in conjunction with over and under-frequency to detect an island.