Application of Comprehensive Correlation Degree Analysis in Power Transformer Fault Diagnosis

Based on the dissolved gases analysis and grey correlation theory, the power transformer faults were diagnosed according to the comprehensive correlation degree composed by the grey correlation degree and the similar coefficient. First, the power transformer fault diagnosis model of comprehensive correlation degree analysis was analyzed, and six sets of typical fault sequences were chosen to structure the power transformer fault reference types. Secondly, according to the given calculation methods of grey correlation degree, similar coefficient and comprehensive correlation degree, the traditional grey correlation degree and the comprehensive correlation degree of power transformer fault compared sequences were calculated. Finally, according to the correlation sequence of traditional grey correlation degree and comprehensive correlation degree, the fault classifications were identified for power transformers. The results indicate that the proposed method is available for the power transformer fault diagnosis and has good fault classified diagnosis ability than three-ratio method and traditional grey correlation degree method.