During the INMR World Congress recently held in Tucson (US), Lukasz Chmura, Product Development Engineer at Lovink Enertech, presented a paper on the future challenges of cable accessories in medium-voltage networks.
The three-day conference, which is organised in a different country every two years, focuses on overhead and underground power cables and substations. This year, the programme focused on critical components, including cable splices and terminations. Making the correct selection of these important components is a key determinant of reliability, maintenance and safety. The programme featured more than 100 papers presented by speakers from utilities, universities, manufacturers and testing laboratories from all over the world.
Future cable accessory challenges
The increasing application of sustainable input is leading to an increase in harmonics. Transmission controllers are utilised to facilitate the flow of energy from sustainable sources. These controllers are equipped with high-frequency switches and cause harmonics in the electricity grid. These phenomena influence the quality of the cable accessories and are a concern to the utility managers.
In his paper, Lukasz Chmura discussed the influence of harmonics on the reliability of cables, terminations and transformers. One of his conclusions is that geometric stress control at elevated field strengths does not lead to increase in temperature and is, therefore, better suited to networks that are polluted with harmonics.
For years now, Lovink Enertech has utilised geometric stress control in its LoviSil® cable splices. In addition to this, electrical insulation is also achieved by liquid silicones. This liquid insulation fills all of the splice spaces, significantly reducing the chance of partial discharges.