In order to study the propagation characteristics of partial discharge optical signals in T-type GIS cavities

the optical signals on each detection plane are observed and analyzed under the conditions of different discharge positions

detection distances and angles by modeling and simulation. The results show that: 1) In the case of different discharge positions

the occlusion of the GIS component enables the light spot on the detection plane to generate a dark area

reducing the optical signal strength of the detection plane and the detection point. 2) After T-shaped cornering

the farther the power source is away from

the weaker the optical signal will be. The x50

namely

the discharge source is set at x=50 cm

is taken as an example

it is revealed that the average relative irradiance decreases to 44.31% when the distance from the discharge source is 75 cm is compared to when the distance is 50 cm. 3) When the detection angle is different

the relative irradiance value of the detection point of direct ray is relatively large

and the value of the detection point which is obscured by the component is relatively small. The C1 detection surface and x50 coordinates on the T-type angle are taken as examples

it is revealed that the relative irradiance is largest when the detection angle is 270 degrees

and the relative irradiance is smallest when the detection angle is 225 degrees

which is only 39.02% of the former.