To guarantee power transformer in good woking condition

regular inspection and maintenance

such as preventive test

on-line monitoring and live detection

are necessary after the equipment is put into service.Condition evaluation and fault diagnosis of power transformer must be conducted according to corresponding standards

regulations and experiences.In this paper

a method for predicting insulation condition of power transformer is proposed on the basis of operating load

in which two typical load growth trends are established via outlier extraction and data reduction

and a time series model is built to analyze the load characteristics and load growth modes.Example shows that the proposed load time series model could be applied to the trend analysis of equipment operating status. This approach may be applied to condition pre-warning of power transformer insulation based on load monitoring.