Evaluation of a new type of protection relay for wind farms

A new type of relay suitable for the protection of wind farms has been described. The relay, installed at the utility end of a power collection circuit, is designed to protect the collection circuit and the LV and MV windings of each wind turbine generator transformer. The relay has been tested on-site at the Cemmaes wind farm and in a laboratory using the EMTDC simulator and an OMICRON relay test set. Numerous tests have shown that the relay remains stable during out-of-zone faults or nonfault disturbances and is sufficiently sensitive to operate on all realistic in-zone faults