During process of electric power tower cross arm long-term operation

the stress of insulation cross arm change complex. Real-time monitoring on cross arm stress is an important factor that ensure long-term security and stability of tower cross arm. Put forward a kind of fiber Bragg grating（ FBG） strain sensor which can transform stress variation beared by cross arm into wavelength shift of FBG

and applied in substation of power tower. According to the climatic feature of Yan Jin transformer substation

install four strain sensors in the center of the tower truss material up and down surface. Aiming at the climatic conditions on February

2011

stra

in monitoring range is- 58. 05 × 10- 6

-

242. 52 × 10- 6; snow

rain weather occur at 10 o’clock

on January 12

2011

the strain monitoring range is- 93. 71 × 10- 6

-

3. 46 × 10- 6and four strain sensors simultaneously fluctuations at the same time. The experiment indicates that in normal circumstances

cable dance

snow

rain and other weather conditions are the important factors which cause cross arm deformation of tower.