Application of Improved Gray Target Theory Based Assessment on Insulation State of Solid-Insulated Ring Main Unit

In allusion to the assessment on insulation state of solid-insulated ring main unit, a novel method for assessment and classification of its insulation state under the condition of not existing standard fault model is proposed. Through improving calculation method in traditional gray target theory, a method to calculate the approaching degree of the improved weighted gray target is achieved. For the weights of various indicators a weighting method combining analytic hierarchy process with entropy weight method is adopted to calculate the impacting weight of various indicators to solve the problem that various insulation parameter indicators differently impact the assessment result of insulation state. According to the features of solid-insulated ring main unit of its own, a strategy to classify the insulation state of solid-insulated ring main unit is given. Finally, the validity of the proposed assessment method is verified by experiments, and the results of the verification show that the proposed method can assess the insulation state of solid-insulated ring main unit objectively and reasonable, and the assessment results are available for reference to condition based maintenance of solid-insulated ring main units.