Temperature Effect on Space Charge Behavior in Oil-impregnated Paper Insulation

Oil-paper is widely used as a good-performance insulating material in power transformers. The dielectric properties of oil-paper insulation play an important role in the reliable operation of power transformers. And the formation, distribution and mobility of space charge will affect its dielectric performance. The space charge behavior in dielectrics is known to be influenced by many factors, such as electric field, temperature, etc. In this paper, a series of measurements are performed on the oil-impregnated paper insulation at different temperatures (15, 30, 40 and 50 degrees C), and the Pulsed Electro-Acoustic (PEA) method is used for space charge measurement in this work. The dynamics of space charge in oil-paper sample at different temperatures is observed, such as charge density and mobility. The effect of temperature on the space charge behavior in oil-impregnated paper is investigated.