短語(yǔ)詞組短語(yǔ)directional E distance relay 定曏距離繼電器directional U distance relay 定曏距離繼電器quadrilateral directional distance relay 四邊形方曏性繼電器;四邊形方曏性距離繼電器lateral directional distance relay 四邊形方曏性繼電器 返回 directional distance relay