high-voltage power line
Refers to electric power lines that carry high voltage, typically seen on transmission towers.
Don't fly kites near high-voltage power lines.
There are many high-voltage power lines running through this area.
送電線 is a broader term for transmission lines, while 高圧電線 specifically emphasizes the high voltage.
配電線 refers to distribution lines that carry lower voltage to end users, in contrast to high-voltage transmission lines.
Compound of 高圧 (high voltage) + 電線 (electric wire).