Influence of Dielectric Coatings on AE Signals Generated in High Voltage Gas Insulated Systems

Modern insulation systems work in hard conditions and it is important to constantly monitor their condition to ensure the highest reliability of energy supply. One way to assess the state of gas insulation is to measure the intensity of PD. One of the non-invasive methods for measuring these discharges is the AE method. This work concerns the analysis of the influence of the presence of additional dielectric coatings placed on the surface of electrodes in the high-voltage insulation system of the plate-plate type for parameters of acoustic emission signals accompanying the PD. The research was carried out in a test setup constructed for this purpose. In order to compare the effect of coatings on the parameters of EA signals, a series of measurements were erformed for electrode pairs: covered with additional coatings, and without coatings. In each case, the voltage in the test system was raised gradually until a jump occurred. As a result of the conducted analyzes, which were carried out using the procedures developed for this purpose in the MATLAB environment, the comparison of the time parameters of the signals (sum and rate of emissions and events) and the energy parameter (RMS) were provided. The analyzes carried out showed the impact of additional coatings on the recorded signals AE, and thus indirectly on the PD. Results of these studies suggest that the use of additional dielectric layers can increase the performance characteristics of the insulation system.