Analysis of Protective Solutions for Underground Cable System - Application for Danang Distribution Grid

In the context of the digitalization of electric power systems, a series of other measures are adopted that aim at the easier integration of electrical installations both from the point of view of operation and monitoring, as well as from the aesthetic point of view. For example, underground cable system (UCS) is encouraged for wide applications in electrical system development and urbanization. The trend of laying cables in the ground for the electrical circuits of overhead transmission lines can contribute to improve the aesthetics of large urban areas, avoiding incidents caused by storms and overlap of the grid. Given that these systems are arranged deep underground, in their case a series of solutions must be considered for protecting and minimizing loss and to increase stability and reliability during operations. However, for the current installation and operation of UCS no attention was paid to the grounding of the metal protective layer. This study will analyze, compare, and evaluate these metal protective layer grounding methods to propose the most reasonable grounding protection according to IEEE standards based on an actual distribution grid. The results clearly reflect the advantages and disadvantages of the protection methods that contribute to improving the performance of UCS.