Analysis of the electrical behavior of polyester insulators under high voltage and high frequency conditions

Ensuring the safe and efficient transmission of electricity, particularly in high-voltage systems, relies heavily on the proper selection and application of insulating materials. Electrical insulation materials prevent the uncontrolled flow of current to undesired areas, thereby enhancing electrical safety and improving system performance. Therefore, understanding the behavior of insulation materials under high-frequency and high-voltage conditions is of great importance for reliable and efficient power transmission. Insulating materials exist in three different phases: solid, liquid, and gas. However, this thesis focuses exclusively on the investigation of solid insulating materials. Solid insulating materials play a critical role, especially in high-voltage systems. During sudden and unexpected events such as lightning strikes, high-frequency and high-voltage signals may occur on these materials. Such occurrences can affect the performance of the insulators and may even jeopardize system safety. The aim of this study is to examine the effects of high-frequency, high-voltage signals on solid insulating materials. In this context, a series of experimental tests were conducted, and the high-frequency high-voltage signals required for these tests were first generated. These signals were then applied to additive and non-additive polyester materials using the inclined plane test system. During the experiments, leakage current signals were transmitted to a computer system via a voltage divider and recorded using the sound card interface. The acquired signals were then imported into MATLAB, where CEEMDAN (Complete Ensemble Empirical Mode Decomposition with Adaptive Noise) was applied to perform advanced signal analysis. This process yielded IMF (Intrinsic Mode Function) graphs, IMF energy distributions, and partial discharge patterns. The outcomes of the analyses were used to understand the impact of high-voltage signals on solid insulators and to assess the performance of insulating materials under high-frequency electrical stress.