Simulation on Propagation Characteristics of Optical Signals of Partial Discharge in Single-core and Three-cores GIL

Due to the high transmission capacity and low loss, Gas-insulated metal-enclosed transmission line (GIL) is gradually replacing conventional overhead lines and highvoltage cables. As the basis of the research on the optical detection of partial discharge (PD), the propagation characteristics of the PD signal in GIL must be paid attention. In this paper, the single-core and three-cores GIL simulation models were established. And parameters of the optical signals generated by PD were observed and compared at the detection point and different detection surfaces. The results show that: In the cavity with different structures, there are different shades of faculae on detection surfaces, and the symmetry properties are also different. The horizontal location of the PD source affects the faculae and relative irradiance values. The optical signals on the detection surface of single-core and three-cores GIL have similar variations. The relative irradiance value obtained at the fixed detection point is related to the internal structure of the cavity, the position and surface of the PD source.