Common aluminum clad steel strand is used as conductor; The steel core is mainly used to increase the strength, and the aluminum strand is mainly used to transmit electric energy. The cross-sectional area of the conductor varies depending on the voltage. For example, the conductors of 500 kV transmission lines are generally LGJ-400/35 conductors. L is the abbreviation of aluminum wire, G is the abbreviation of steel core, J is the abbreviation of strand, 400 is aluminum 400 mm2, 35 is steel 35 mm2.