Insulation fault diagnosis based on group grey relational grade analysis method for power transformers

摘要

Utilising dissolved gases analysis, a new insulation fault diagnosis method for power transformers is proposed. This method is based on the group grey relational grade analysis method. First, according to the fault type and grey reference sequence structure, some typical fault samples are divided into several sets of grey reference sequences. These sets are structured as one grey reference sequence group. Secondly, according to a new calculation method of the grey relational coefficient, the individual relational coefficient and grade are computed. Then according to the given calculation method for the group grey relation grade, the group grey relational grade is computed and the group grey relational grade matrix is structured. Finally, according to the relational sequence, the insulation fault is identified for power transformers. The results of a large quantity of instant analyses show that the proposed method has higher diagnosis accuracy and reliability than the three-ratio method and the traditional grey relational method. It has good classified diagnosis ability and reliability.