考虑绝缘老化或受潮的变压器绕组变形判据优化

Frequency response analysis is an important measure detecting transformer winding deformation. However, the frequency response results will be affected by transformer insulation state, such as insulation aging or dampness, thereby giving a wrong diagnosis result of transformer winding deformation. But there is no better solution to this problem at present. This paper focuses on the optimization method of winding deformation diagnosis criterion due to insulation aging or dampness. Firstly, the frequency response with different dampness or aging degrees was obtained with the damp or aging test of oil-immersed paper and frequency response simulation. Secondly, the correlation coefficient of frequency response curves with insulation aging or dampness was calculated. Finally, two criterion optimization methods were proposed. Research results indicated that the insulation aging or dampness will cause misjudgment of winding deformation diagnosis with the criterion of correlation coefficient R. By adjusting the frequency range of the correlation coefficient criterion, the misjudgment in specific wiring modes will be avoided. By introducing the auxiliary criterion based on capacitance change rate, the misjudgment possibility in both wiring modes will decrease.