Frequency response analysis is an important method of detecting transformer winding deformation. Experienced professionals are able to judge winding deformation accurately by qualitative analysis of the frequency response data atlas. Firstly
the qualitative analysis methods for frequency response data are summarized. Secondly
according to the characteristics of the qualitative analysis
the mathematical morphology is introduced and the quantitative analysis for the amplitude difference is researched. The frequency domain is defined to divide the extreme points of the frequency response data into matched extreme point
shifted extreme point
lost extreme point
excess extreme point and the quantitative analysis for the extreme points is researched. Finally
the block frequency point method is proposed. The main points of the qualitative analysis for frequency response data atlas are mathematically presented with the block frequency point method
and the quantitative analysis for frequency response data is realized. The effectiveness of the method is proved by verification of an example.