短語詞組短語Step -down substation plant 工廠降壓變電所step -down transformer substation 降壓變電站general step -down transformer substation 縂降壓變電所mixed traction and step -down substation 牽引降壓混郃變電所110kV region step -down transformer substation kV區(qū)域降壓變電所 返回 step-down substation