This　paper　analyzes　the　fundamental　frequency　impedance　characteristic　of　a　thyristor　controlled　series　capacitor　(TCSC)　and　presents　a　novel　transmission　line　pilot　protection　scheme　based　on　fault　component　integrated　impedance　(FCII)　calculated　for　a　transmission　line　with　TCSC　and　controllable　shunt　reactor　(CSR).　The　FCII　is　defined　as　the　ratio　of　the　sum　of　the　fault　component　voltage　phasors　of　a　transmission　line　with　TCSC　and　CSR　to　the　sum　of　the　fault　component　current　phasors　where　all　the　phasors　are　determined　at　both　line＇s　terminals.　It　can　be　used　to　distinguish　internal　faults　occurring　on　the　line　from　external　ones.　If　the　fault　is　an　external　one　the　FCII　reflects　the　line＇s　capacitive　impedance　and　has　large　value.　If　the　fault　is　an　internal　one　on　the　line　the　FCII　reflects　the　impedance　of　the　equivalent　system　and　the　line　and　is　relatively　small.　The　new　pilot　protection　scheme　can　be　easily　set　and　has　the　fault　phase　selection　ability　and　also　it　is　not　affected　by　the　capacitive　current　and　the　fault　transition　resistance.　It　is　not　sensitive　to　compensation　level　and　dynamics　of　TCSC　and　CSR.　The　effectiveness　of　the　new　scheme　is　validated　against　data　obtained　in　ATP　simulations　and　Northwest　China　750　kV　Project.