Analysis techniques of diagnosis high voltage underground cables

Thesis (M.A.) from the year 2015 in the subject Electrotechnology, grade: -, Warsaw University of Technology (Electrical Engineering), language: English, abstract: This study is focused on installations and faults diagnosis of high voltage underground cables and examined on the various ways through which they can be identified and corrected. It has been found that wear and tear is one of the major issues leading to electric faults like power loss. There has been seen that several causes of failure which could be identified with them and analyze better ways of detecting them. So, it has been looked at how to detect degradation of insulation of the underground cable. After a thorough analysis of fault detection techniques have been explained, the pre-location fault techniques is described; I illustrated many methods which aid to discover the fault location. I also developed a method which contributes in pre-location of the fault based on Matlab simulation and mathematical slope equation. This method was invented after the observation that the voltages measured at the local and remote substations, after filtering and after Fourier analysis, showed a linear behavior that was proportional to the respective distances between the fault location and the mentioned substations or generators. Thus, the developed method exploits such a linearity to estimate the fault location by interpolation, assuming that the parameters of the line are previously known and that dedicated devices are located on site in both substations to provide post-fault measurements of the faulted line. Finally, I clarify many pin-pointing methods to precisely determine the fault location.