Currently available prediction models for dissolved gases in transformer oil are GM(1
1) and its improved forms
which have the drawback of considering only one gas separately. To make up for this disadvantage
the multivariable grey model MGM(1
n) is introduced to allow for the change in several indices described simultaneously. Thus
the prediction with the multivariable grey model has proved more scientific and effective. The relationship between seven dissolved characteristic gases
viz. hydrogen (H2)
methane (CH4)
ethane (C2H6)
ethylene (C2H4)
acetylene (C2H2)
carbon monoxide (CO)
and carbon dioxide (CO2)
based on the grey relational analysis theory is discussed. The MGM(1
7) model is then developed. Finally
the effectiveness and superiority of the proposed method has been verified with the result of an actual case.