Study on the fault diagnosis of transformer based on the grey relational analysis

Transformer incipient faults are often diagnosed with dissolved gas analysis (DGA) of transformer oil. Various methods have been developed to interpret DGA results such as IEC ratio code and the Rogers method. But, they sometimes fail to determine these faults. In this paper, the grey relational analysis method is applied to diagnose the fault pattern of power transformer. Based on the principles of grey relational analysis, a group of reference sequences are selected from fault data. Practical data are analyzed through the method and compared with other methods. The results of diagnosis have proved that grey relational analysis is a useful tool for evaluating the faults of power transformers. With the method introduced, the diagnosis will be more effective.