Strength of magnetic leakage field of transformer increases with increasing of capacity transformer

greater the leakage magnetic field strength increases

the leakage loss caused by the transformer in the structure

resulting in low operating efficiency of the transformer

there by affecting the normal operation of 35 k V transformer are tested

magnetic flux leakage generating produced at the top end of the temperatures are compared with the maximum temperature and the fuel tank. The results show that when the fan on the premises and the fuel tank at the top of the highest temperature difference is 8. 7 ℃; when the load is reduced to 1 times the power

temperature difference is 2. 9 ℃

their real-time temperature curve is coincidence with operation of transformer

results in phenomenon of local temperature rise. Situation of magnetic leakage reflected by temperature changes detected by fiber Bragg grating（ FBG）

real time on-line monitoring on magnetic leakage of transformer is realized.