Large-scale earthing test facilities at Dinorwig power station

In this paper, experimental set and initial test results are described of low voltage DC, AC and impulse tests on a rod electrode immersed in a water reservoir of a large hydro power station. A detailed water resistivity survey indicates largely uniform temperature and resistivity throughout the reservoir. Calculations and simulations of the rod electrode under DC and power frequency AC show reasonable agreement with experimental results. Further investigations are required to understand better the behaviour of the test system under high frequency and impulse conditions.