Windfarm System Protection Using Peer-to-Peer Communications

Windfarm electrical systems present some unique challenges for protection. The grid tie and wind turbine generators provide multiple sources of fault currents to be considered. Collector feeders become isolated ungrounded systems during faults due to separation from the centralized collector bus reference ground. Ground faults on feeders will result in unfaulted phase voltages rising to line levels. In addition, severe transient overvoltages can be produced, which can degrade insulation, resulting in eventual equipment failure. This paper reviews the overall requirements for comprehensive windfarm protection. It also focuses on the particular problem of feeder ground faults. A novel, yet simple solution is presented that makes use of peer-to-peer (GOOSE) messaging via the IEC 61850 protocol. The characteristics of the GOOSE message are discussed with respect to speed and reliability and communications architecture is presented. The performance of the resulting protection scheme is quantified