Overvoltage attenuation in power cable lines—A simplified estimation method

Cable lines impart attenuation and distortion to overvoltages coming from overhead lines. In particular the attenuation is an important factor for the insulation coordination of a cable line and consequently for its reliability. The evaluation of such attenuation needs the utilization of numerical programs and their utilization, although it becomes an obliged step, is not an easy task without a specific skill. In this paper a simplified method is proposed which is based on the results of a specific numerical program, in order to evaluate the overvoltage attenuation introduced from cable lines for both the conductor screen (insulation stress) and screen to ground (jacket stress) modes of propagation. Although such method introduces some approximation, it is a useful tool in order to have both a first and conservative evaluation of the overvoltage stressing the cable line insulation when the impinging overvoltage to the cable line is known.