The　wind　turbine　with　low-voltage　ride-through　capability　is　required　not　to　disconnect　from　grid　under　certain　fault　conditions,　for　which　the　relevant　relay　protections　should　cooperate　with　it.　The　cooperation　between　the　relay　protection　of　transmission　system　beyond　the　wind　farm　outgoing　line　and　the　relay　protection　of　wind　farm　is　analyzed　for　different　faults　of　transmission　system　components,　wind　farm　outgoing　line,　wind　farm　internal　grid　and　wind　turbine.　The　current　configuration　of　relay　protection　for　the　wind　farm　centrally　connected　to　power　grid　is　analyzed　and　it　is　pointed　out　that,　the　selectivity　of　wind　turbine　protection　and　converter　protection　is　not　enough,　which　leads　to　the　disconnection　of　wind　farm　from　grid　before　the　fault　is　removed　by　wind　farm　internal　relay　protection　or　system　relay　protection,　and　the　current　configuration　regards　the　wind　power　as　a　distribution　network　with　single　source,　which　neglects　the　contribution　of　wind　turbine　to　short-circuit　fault.　Improvements　are　proposed　for　the　relay　protections　of　wind　turbine,　main　transformer　and　outgoing　line　to　ensure　the　successful　low-voltage　ride-through,　and　their　problems　are　pointed　out.