Condition Assessment of Cable Intermediate Joint Based on Variable Weight and Interval Number-set Pair Analysis Theory

For the randomness and dynamics problem of condition information and evaluation level boundary in the cable joint, an insulation state evaluation method of cable intermediate joint based on variable weight and interval number-set pair analysis theory is proposed. The partial discharge characteristic parameters of cable joint are extracted as the state evaluation index, and the index data are expressed in intervals. The variance and standard deviation are introduced to measure the volatility of the interval data of each index, and then the objective weight of the index is given. For the problem of unbalanced deterioration of partial discharge indicators, the corresponding state variable weight function is constructed to obtain the variable weight by comprehensively considering the deterioration degree and trend parameters of the indicators. Finally, the coupling method of interval number and set pair analysis is applied to obtain the state level of cable joint according to the expectation of comprehensive connection. By analyzing the online monitoring data of a 10 kV cable intermediate joint, the validity and feasibility of the state evaluation method are verified.