Induced Voltage in Cable Shielding by Harmonics and Deficiencies in Installation Procedures

Abstract

Insulated cables are widely used for the transportation, distribution, and end-use installations of electrical power. They are also essential for the grid interconnection of new generation systems based on renewable sources. These types of conductors mitigate electrical risks and increase the reliability of the networks. However, induced voltages in the cable shield are a determining factor in their performance, as a very high value can lead to insulation deterioration, breakdowns, risks to individuals, and malfunctioning of electrical installations. This article presents the behavior of induced voltage and current on the cable shield based on installation conditions and the effect of harmonics in the system. Simulation results show that induced voltage in the cable shield increases due to factors such as the presence of harmonics in the system and cable length. To control these induced voltages, the cable installation procedure must be improved, incorporating good practices for transposition and grounding. Thus, for example, it was found that in the presence of harmonics and supraharmonics the voltage induced in the cable shield increases up to nine (9) times compared to the base case of not having harmonics in the system, but if there is an adequate transposition and grounding, that voltage induced in the cable shield only increases three (3) times with respect to the base case.