Simulation analysis on the propagation of the optical partial discharge signal in I-shaped and L-shaped GILs

Abstract

When partial discharge (PD) occurs in the gas-insulated transmission line (GIL), accompanied by the occurrence of sound, light, electricity and thermal phenomena, the propagation characteristics of the optical PD signal are the basis for the arrangement of the optical sensors and PD source location. To study the propagation characteristics, simulation models of GIL are established. The total irradiance map (TIM) and the average value of the relative irradiance (AVRI) for the optical PD signal on each detection plane are observed under different PD source positions, detection distances and L-shaped angles. The simulation results indicate that 1) when the PD occurs near the inner conductor or the tank inner surface, it is more difficult to detect than other places. Taking the distance between the detection plane and the PD source (DDP), which is 60 cm, as an example, when the position of the PD source (PPS) is Up-50 mm, the AVRI is 79.56% of that when the PPS is Up-140 mm. 2) In the process of the L-shaped angles increasing, the value of relative irradiance has a certain increase. Taking the PPS below-95 mm as an example, when the L-shaped angle is 165°, the relative irradiance is 29.92% larger than that when the L-shaped angle is 90°. These findings can provide some reference for the optical PD detection in GIL.