Product description of electric substations:load-bearing structureelectric power system voltagecable line conductor / wire insulatorbracing wire fittingcross-section steel-reinforced aluminum conductorhigh voltage low voltageextra-high voltageultra-high voltagethree phase three wire systemcross armgenerator step-up transformer substationdistribution systemshield wirealternating currentlinear reactancecorona optical fiber grounding conductor