The Noise Performance of Overhead Line Conductors with Superhydrophobic Coatings

  • Xu Zhang

Student thesis: Phd

Abstract

The continued growth of ultra-high voltage (UHV) and extra-high voltage (EHV) transmission line applications presents a challenge to optimise overhead line systems to ensure they deliver the required electrical/mechanical performance while minimising their footprint and meanwhile meet many environmental constraints, including audible noise, corona loss, and radio interference. Overhead line conductors can generate audible noise across a broad frequency spectrum due to the elevated electric fields at the conductor surface, which negatively influences people’s health and results in power loss. The main objective of the research is to examine the role of superhydrophobic surfaces in reducing audible noise. NeverWet®, a commercial coating, was applied to overhead line conductors to achieve a repeatable superhydrophobic surface. Noise measurements and partial discharge (PD) tests were conducted in a semi-anechoic chamber under AC and DC electric fields with continuous water spraying. High speed images of the movement of single water droplets on the uncoated/superhydrophobic conductors were captured. The distribution of droplets on standard and superhydrophobic conductors was also analysed to correlate the distributions against the measured audible noise and PD behaviour. Ageing behaviour under the AC electric field was also assessed for superhydrophobic surfaces through long-term HV testing. The achievements of this research include the following: The superhydrophobic surface was proven to reduce the sound power by up to 44.02% under AC electric fields but increase A-weighted sound pressure level by up to 5 dBA under positive DC electric fields. The influence of the droplets on the partial discharge behaviour and the further correlation of this discharge behaviour with audible noise was established by analysing the noise and PD data along with images from standard and high speed cameras. The longevity of two superhydrophobic surfaces, laser patterned samples and NevetWet® coated conductor, was assessed under an AC electric field. The results showed that laser patterned samples are more robust than NeverWet® coated conductors. It is concluded that superhydrophobic surfaces can deliver noise reduction in AC overhead line systems.
Date of Award1 Aug 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorIan Cotton (Supervisor) & Simon Rowland (Supervisor)

Keywords

  • superhydrophobic coating
  • audible noise
  • overhead line conductors

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