Jan 2012
Electricity Transmission
Potentials and profiles around earth electrodes and opposite-side injection for large-area earthing
Jan 2012
Apr 2014
National Grid Electricity Transmission
Dongsheng Guo
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Network Innovation Allowance
To determine accurately the extension of hot-zones is crucial in terms of earthing system design and need of mitigation measures. With the wide use of simulation software packages, the credibility of the outcomes has yet to be verified experimentally.

In addition, current testing methods/instruments operate in the range of 10mA to 5A hence the scalability of the measurement (to high fault current) is yet to be established.

Cardiff University had carried out research projects covering the above issues with promising preliminary results. Furthermore, they have acquired necessary site facilities and experience. It is more likely that the above issues will be addressed more efficiently and successfully.

The objectives for this project are as follows;

  • To evaluate the current simulation approaches against site experimental results (at both Dinorwig power station and Cardiff University test sites) in determining the extension of substation hot-zones

  • To investigate the scalability of low-current injection testing

  • To investigate the non-linear effects, including current and frequency dependency, of earth impedance. 

This project will be successful if we can understand in greater detail the issues faced around earth electrodes.