Transient Processes and Voltage Overloads in Single-Phase High Voltage Cable Lines

Abstract

High-voltage lines with overhead and cable sections are getting high popularity in nowadays energetics. These transmission lines are normally constructed using a single-phase cables with XLPE insulation. On the other hand an application of this type of cables leads to certain unsolved problems, for instance- a numerous amount of breakdowns at the cable joints. This paper takes as an example the power line of 330kV in the city of Saint-Petersburg, which connects substations Severnaya and Vasileostrovskaya. There were considered three accidents, which led to a number of breakdowns of cable joints along the entire line. Basing on the simulation results it was proposed, that the accidents were caused by a significant overvoltage at the joints during the short-circuits. Firstly, it concerns high-frequency overvoltage, which cannot be bounded by a surge arrestor. Secondly, excessive current flows going through the arrestors.