温度梯度下双层油纸绝缘系统的空间电荷分布特性

emperature gradient existing in the oil impregnated paper insulation such as coverting transformer or DC bushing will impace on the space charge distribution. In this paper, the space charge profiles and field distributions in double layers of oil impregnated paper within 20 minutes were measured by the pulse electro-acoustic (PEA) method under different temperature differences(ΔT=0℃, 20℃, 40℃), and DC voltage of -3.4, -10.2, -20.4kV (DC stresses of 10, 30, 60 kV/mm), respectively. The test results show that homocharge will exist in both electrodes when the field stress is low; the heterocharge appears in the low temperature side due to the temperature difference. Moreover, the higher the temperature difference and filed stress the more the heterocharges at the low temperature side which results in a greater field distoration there; the homocharge of the up-electrode starts to accumulate in the space between two layers of oil impregnated paper samples. The higher of the temperature and electric field stress the more the space charge while the density of the charge is saturated. It suggests that the oil paper interface plays the defending role to prevent the charge from passing the charges by and the temperature is the main factor which affects the spacecharge distribution and the conduction of the electricity in the sample.