变压器状态评估方法的分析-高电压与绝缘技术专业论文.docx

华中科技 大学硕士 学 华 中 科 技 大 学 硕 士 学 位 论 文 II II Abstract Transformer is the most important equipment in a power system. The reliability of the operating transformers has great influence on the safety and stability of the power system. With the increase of the capability and scale of the power system in china, the consequence of the fault of running transformer will be more and more serious. It is significant for the improvement of the reliability of the power system to realize condition based maintenance of the transformers. Firstly, some typical faults and their mechanism are analyzed in this thesis. Combined with the analysis of transformer faults in ? the Guide for Condition Evaluation of Oil-immersed Power Transformers (Reactors) (Q/GDW 169－2008)?, nine synthetic status parameters are chosen, including moistened insulation, core fault, current circuit fault, winding fault, partial discharge, oil-flow discharge, arc discharge, insulation aging and oil deterioration. Independent status parameters related to each synthetic status parameter are determined. Secondly, association rules and variable weight coefficients theory are used to determine the weight coefficient. By comparing calculation of the support degree and confidence degree of the association rules, the constant weight coefficients of independent status parameters are got. The problem that the accuracy of weight coefficient is influenced by expert opinion or subjective experience can be solved. The synthetic status parameters are variable according to their scores. It can avoid the problem that the true state of the transformer may not be accurately reflected under the condition of constant weight coefficients. At last, a transformer condition assessment system is established based on the above theories. Furthermore, fuzzy theory, which include membership, relative impairment grade and membership function of semi-ladder and triangular, is used to dispose the assessment result. This method makes th