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

Table 5

Comparison of two regression methods to predict the relationship between acidity and water components of the transformer.

Equation	Model summary					Parameter estimates
	R-Square	F	df1	df2	Sig	Constant	b1	b2	b3
Linear	0.052	6.495	1	118	0.012	0.076	−0.001	—	—
Cubic	0.134	5.978	3	116	0.001	0.044	0.009	0	7.674E − 6

Dependent variable: acidity; independent variable: water.