Space And Surface Charge

500fps surface discharge

Techniques available for the measurement of space charge within the laboratory include Pulsed Electroacoustic (PEA) measurements and Laser Induced Pressure Pulse (LIPP) measurements.  The majority of our research is concerned with polymeric insulating materials used for power transmission cables, in both planar and cable geometries, under either DC or AC electric stress.Typical applications of space charge measurements include:

  • The effect by space charge on electric stress modification.
  • Material evaluation of dielectrics such as epoxy resins, low density polyethylene and crosslinked polyethylene.
  • The study of electrical ageing.

Apart from insulating materials, trapped charge within piezoelectric materials and glass can now be measured with our improved PEA system that has a spatial resolution of 5 μm.

Dynamic surface charge is measured using a Pockels cell. This approach ensures that surface charge is not influenced by the measurement itself, it allows not only different materials to be studied but also the effect of local environment on surface charge behaviour.  The technique uses a fast CCD camera with microscope lens and this ensures both good spatial and temporal resolution (typically one pixel represents a surface area of 10x10μm monitored at 1000fps) Current research on surface charge is funded by National Grid and is concerned with investigating the phenomena of surface charging of GIS spacers.

Projects

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  • Computational modelling of the process of electrical breakdown in a dielectric fluid
  • Electric Field Determination in DC Polymeric Power Cable in the Presence of Space Charge and Temperature Gradient
  • Insulation for high voltage dc power transformer
  • Polymeric Insulation for high voltage DC application
  • Potential decay of corona charged LDPE film
  • Space charge measurement and analysis in polyethylene film

    • Featured ProjectDC conductivity measurement of transformer oils and its application in diagnosis of oil status

    Transformer oil, or insulating oil, is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. Its functions are to insulate,... [more]

    Most Recently Added Publications

    Alghamdi, H A, Chen, G and Vaughan, A S (2013) A New Electro-Thermal Aging Model Based on Trapping and De-trapping Process in Polymeric Materials. In, Dielectrics 2013, Reading, GB, 10 - 12 Apr 2013. , 15-16.

    Lau, K Y, Vaughan, A S, Chen, G, Hosier, I L and Holt, A F (2013) Absorption Current Behaviour of Polyethylene/Silica Nanocomposites. In, Dielectrics 2013, 10 - 12 Apr 2013. , 24-25.