Polarization and depolarization characteristics of different structure oiled paper composite insulation under high applied voltage

Transformers are an important part of the power transmission and distribution process of power systems. Designing and manufacturing a stable transformer is essential for the stable operation of the entire power system. Accordingly it is critical for the stable operation of the entire power system to design and manufacture a stable transformer. In order to improve the composite insulation performance of the oil-paper in power transformer, studying the polarization characteristics of oil-paper composite insulation is essential. In this paper, the polarization characteristics of high external applied voltage and different oil-paper composite insulation structures are studied. In the three-electrode system, the cardboard has obvious polarization characteristics at the two poles, and the polarization characteristics are most obvious when the cardboard is at the high pressure pole. The initial value and the attenuation function of the polarization and depolarization current do not match the laws determined by the RC circuit. When the voltage is at a higher level, the difference between the initial values of the polarization and depolarization currents at different positions of the cardboard at the same voltage level is greater, and the polarity effects are more obvious. the above rules still exist when the distance between the electrodes is changed.