Relationship between engineering correlation coefficient and deformation degree of transformer winding

Winding deformation degree

Correlation coefficient R

Severe deformation

RLF＜0.6

Obvious deformation

1.0＞RLF≥0.6 Or RMF＜0.6

Mild deformation

2.0＞RLF≥1.0 Or 0.6≤RMF＜1.0

Normal winding

RLF≥2.0 and RMF≥1.0and RHF≥0.6

Note: RLF is the correlation coefficient of the curve in the low frequency band (1kHz~100kHz);

RMF is the correlation coefficient of the curve in the middle frequency band (100kHz~600kHz);

RHF is the correlation coefficient of the curve in the high frequency range (600kHz~1000kHz).