Field tests on the ¿grid¿ transmission lines

Part 1 of the paper deals briefly with the electrical constants of transmission lines, with special reference to steelcored aluminium lines. Where possible, simple formulÿ are given for the calculation of the various quantities associated with transmission lines, and the limitations of these formulÿ are indicated. In Part 2 an account is given of the methods which have been adopted for the determination of the constants of the ¿grid¿ lines. Three typical lines of diverse characteristics, viz. a 132-kV single-circuit line, a 132-kV double-circuit line, both transposed, and a 33-kV untransposed single-circuit line, are considered and results are given of measurements of 3-phase impedance, loop impedance, single-phase impedance, resistance, charging current, and induced electro-magnetic and electrostatic voltages.