Understanding partial discharges in low-power relay and silicone cable modified to suit high-voltage requirement of deep sea electrical system

Abstract

Modern trend in the ocean engineering sector focuses on improvising the existing technology and enhancing the cost-cutting measures to meet the economic constraints. In addition, the safety and reliability of the applied technique must be increased. A possible way to achieve this is by suitably modifying the existing low-cost devices to meet the requirements of underwater application. At any cost, the reliability of such modified devices has to be ensured well before their underwater deployment. Currently, the most attention is provided to the high-power apparatus such as submarine power cables, structural components, etc., while the reliability of the other supporting components, ie, high-voltage relay switches and connecting cables, is provided with scanty attention or at least, the sensitive data are not made available in the public domain. Considering this, an experimental investigation on understanding the reliability of a standard high-voltage relay switch and its high-voltage connecting cable, modified to suit the requirement of 20 kV deep-sea switching application, is initiated. The reliability of the chosen components is assessed through partial discharge measurements. First, a high-voltage relay and connecting cable are selected and suitably modified to meet the underwater condition. Later, the chosen samples are emulated at underwater conditions and subjected to conventional and non-conventional partial discharge test methods. Depending on the level of discharge, the modification made on the standard relay and connecting cable, is validated and subsequently deployed in an underwater application.