Abstract：The oil temperature of a transformer reflects its load capacity and influences its working life. From the current and the historical temperature data for forecasting the top oil temperature of a transformer, a mathematical model for the temperature changes of the top layer oil of a transformer has constructed, based on the grey theory GM ( 1, 1) model through the analysis of the transformer heating and cooling principle, and a software and hardware system for the predictive control of oil temperature in a transformer is designed by a Microcontroller. Simulation results showed that this designed system could control the fan opening and closing through determination conditions, and the control purpose to keep the top oil temperature of a transformer under limits could be thusly achieved.

Keyword：transforme;oil temperature;grey model;microcontroller;predicting;