关键词: 绝缘子污秽等级, 特征量, 偏最小二乘（PLS）, 模型方程, 变量投影重要性指标

Abstract: In view of the characteristics of multi-correlation of infrared thermography of polluted insulators, a method based on partial least squares regression analysis is proposed to determine the pollution class of high voltage insulators. On the premise of preserving the original data to the maximum extent, the partial least squares regression equation between the characteristic parameters of high-voltage insulator contamination and contamination grades is built, and through analyzing the importance of  indicators of variable projection of the regression model equation, the effect degree of various characteristic parameters on contamination grades is obtained. The method solves the multi-correlation problem of the independent variables effectively, and quantifies the relationship between the characteristic parameters and contamination grades. The test result shows that, judging the high-voltage insulator contamination grades by applying partial least squares regression analysis is scientific and reliable, with high accuracy and strong practicability.

Key words: insulators pollution class, characteristic parameters, Partial Least Squares（PLS） regression, model equation, variable importance in projection