부산대학교 도서관

Power transformers are critical components of the electrical power systems that are used for high voltage energy transmission and distribution. Insulating oil is required for their electrical insulation and cooling. Electrical discharges have the potential to degrade the insulation and alter the properties of the oil. This can lead to reduced transformer performance and a shorter lifespan. The present work will look at the effect of electrical discharges on the impedance of mineral oil in the frequency range of 20 Hz to 10 MHz. In this research investigation, we used a high-precision LCR meter to measure the impedance of Borak 22 new mineral oil, the commonly used insulating oil in Algerian power transformers. The measurements are made before and after a 50 series of electrical discharges in the frequency range of 20 Hz to 10 MHz with a point-plane electrode system and an electrode gap of 2.5 mm. Then, well correlations are found between the oil impedance and the discharges occurrence, especially in the 20 – 100 Hz bandwidth.