Evaluation of the Insulation Condition of High-Voltage Transformers by Detecting Partial Discharges Using the Electromagnetic Wave Radiation Method

Abstract

High-voltage transformers are among the most important elements in an electric-power system. Each one of them is affected by various external factors: overvoltage, partial discharge (PD), overheating, vibrations, etc., which are created by a strong electric field, thermal effect, humidity, impurities, factory defects, dissolved water and gas in oil-type-transformer insulation. These and other factors, caused by the environment, reduce the life of a device. Thus, the evaluation of the device condition is one of the most important factors for a system-safety evaluation, which ensures a reliable and economical electrical-network operation. This work reviews different contact and non-contact methods, used to evaluate the conditions of transformers by measuring the level of PD. The selected method, i.e., the non-contact measurement of electromagnetic-wave radiation was used to evaluate the voltage-transformer status. The experiment was performed at a 110 kV substation. The authors discuss the efficiency of the selected method to evaluate the voltage-transformer insulation condition.

Design and implementation of a novel high-frequency current transformer for partial discharge measurements

“…High-voltage cables are widely used in city power supply, large-scale industrial and mining enterprises, railroad departments, and so on. Manufacturing process, workers' construction technology, aging, and other factors will lead to partial discharge phenomenon in cables, and when accumulated to a certain extent, insulation defects deteriorate, and even breakdown or burn phenomenon [1][2][3][4][5][6][7]. Partial discharge detection is an important method to determine the performance of cable insulation [8][9][10][11][12].…”