Aiming at the problem of inaccurate aging assessment of single characteristic quantity in the oil-paper insulation dielectric response method

the grade cloud model is proposed to assess the aging state of oil-paper insulation with multiple characteristic quantities. First

the matrix pencil method is used to identify the parameters of the equivalent circuit

and two new time-domain characteristic quantities that can characterize the aging state of the geometric branch and the polarization branch are proposed respectively. Then

the comprehensive weight calculation is performed in combination with the subjective and objective weighting methods. Finally

the grade cloud model is used to construct the assessment model of the aging state of the equipment. According to the theory and the actually measured data of the cloud model

the digital characteristics of each standard grade cloud model are obtained. The correlation calculation of the various indexes of the equipment to be assessed and the standard grade cloud model is performed to obtain the insulation aging grade of the equipment. It is proved by a number of examples that the assessment results obtained by this method can correctly reflect the real condition of the equipment and have high application feasibility.