An Approach to Comprehensive Health Status Evaluation of Oil-Immersed Transformers

An Approach to Comprehensive Health Status Evaluation  of Oil-Immersed Transformers

Feng-bo Tao1,Chao Wei1,Cheng-bo Hu1, Bi-junChen2,You-yuanWang2


1JiangSu Electric Power Company Research Institutes, Jiangsu, Nanjing, 211103, China

2State Key Laboratory of Power Transmission Equipment&System Security and New Technology, School of Electrical Engineering, Chongqing University, Chongqing, 400044, China

The oil-immersed transformers take upon important position in transmission and distribution engineering. The operation life cycle of oil-Immersed transformers is far and away lower than its designed life for the most part in Jiangsu province of China. One of its major reasons is the insufficientof running status evaluation. As everyone knows, the health condition ofpower transformer has a high degree of availability, and provides the foundation forcondition based maintenance (CBM) and decommission. The article puts forward a comprehensive health condition assessment model based on non-repairable model (aging failure model) and repairable model (status evaluation model).Therein, the first mentioned of two contains parameters which have irreversibledamage to insulation, such as long-term loading and operating environment, and the other one includes parameters which would be able to recover from the damage trough maintenance, such as oil quality test and partial discharge test.The health status value is quantized into scores between 0-100 by means of mathematical toolslike conditionclassification and fuzzy inference and so on. The model represents health condition intuitively, and modified by defectivework condition information, which has anirreversibledamage on insulating materials, and enhances theaccuracy rating. The article provides a visualized and reliable basis of CBM.