Theoretical and experimental investigation on electrical design of a fully composite pylon

The major challenges in the electrical design process of a fully composite pylon are addressed in this paper.

One of the challenges is that the electrical dimensioning of the fully composite pylon, i.e. the phase-to-phase and phase-to-ground air clearances on the pylon, should be determined. The minimum required air clearances on the pylon are calculated based on an extensive insulation coordination study. Another challenge is the proper design of insulation for the unibody crossarm and the evaluation of electric field performance. In this regard, numerous finite element analyses (FEM) of the pylon are carried out to evaluate electric field magnitudes in the different regions of interest on the fully composite pylon. What’s more, a water induced corona discharge test was performed on an equivalent full-scale phase-to-phase composite cross-arm segment in wet conditions to verify the theoretical analysis based on FEM simulation. The next challenge
is the lightning shielding performance of fully composite pylon, which has been addressed by electro-goemetric model (EGM) method and by long-gap electrical discharge tests with impulse voltage. Environmental effects, including audible noise, radio noise and electromagnetic emissions from OHLs in the pylon are investigated. Additionally, material selection for the fully composite cross-arm core is evaluated by experimental methods.

On the basis of theoretical analysis and experimental results obtained in the present research work, the initial electrical design of the fully composite pylon is evaluated and feasible improving measures are put forward. This is a combined paper which contains all theoretical and experimental analyses’ results in such a way as to enhance and emphasize the completeness of each other. This paper provides an important basis on the design of fully composite pylon.