Partial discharge testing of power cables at 400 kV in an open test environment

The paper summarizes the various factors considered in establishing a partial discharge test facility for testing at voltages up to 400 kV in an open, unscreened test area in close proximity to manufacturing machinery. The installation was prefaced by an initial assessment of the actual interference noise problems present at the site which allowed an equipment definition to be established and an expected performance, in terms of pC sensitivity, to be defined. The main body of the paper contains detail of the steps that have been carried out on site in order to achieve the required results. The partial discharge detection system used in the installation was the pulse discrimination system which includes various features for the suppression of different types of interference noise. The installation required the use of a non-inductive link for the minimization of induced interference and the construction of this is described. Particular attention was given to other factors such as the test area earth, high voltage connections and the control of particular sources of interference, broadcast RF and conducted low frequency noise