Summary of Reliability and State Evaluation Methods for Transformer

There are a variety of reliability evaluation methods for the key equipment of power system-transformer. Reliability evaluation is divided into long-term reliability analysis and short-term state evaluation. This paper summarizes the common reliability evaluation methods, describes their principles and applications, and compares their advantages and disadvantages in order to provide guidance for selection of appropriate reliability evaluation method of transformer. There is no special reliability evaluation method for ultra-high-voltage transformer at present, however all kinds of transformers have almost same structure and working principle, so the existing evaluation methods can be referred to.