Interaction of Transformer Oil Parameters on Each Other and on Transformer Health Index Using Curve Estimation Regression Method

Table 7

Comparison of two regression methods to predict the relationship between HI and CO₂ components of transformer.

Equation	Model summary					Parameter estimates
	R-Square	F	df1	df2	Sig	Constant	b1	b2	b3
Cubic	0.470	34.334	3	116	0	0.983	−3.790E − 5	1.033E − 10	2.319E − 13
S	0.148	20.524	1	118	0	-0.143	37.202	—	—

Dependent variable: HI, independent variable: CO₂.