Pulse height analysis of partial discharges in air

Study of electric discharge and space charge formation phenomena in the air gaps of an ice-covered insulator using an icicle/ice-covered plate electrode system =

“…The space charge does not reach completely to the electrode plane. This calculation result means that when the influence of space charge is eliminated, the space charge ions have not arrived to plate or been absorbed as mentioned in [20] [85]. In addition, the calculation result is in fair agreement with the experimental result simulated by R. Morrow et al [147], in which the streamer in the conditions of 20 kV and 50 mm gap is predicted to cease propagation after it has traversed 3.5 cm.…”

“…To date, there have been no related investigations on the influence of the gap distance on the mean discharge magnitude. However, a similar relationship between the discharge pulse amplitude and the radius of the electrode was found [85]. The increase of the electrode radius will increase the amplitude of the discharge pulse.…”

“…Some electrode materials such as nickel are found to be more resistant to reaction with corona-generated SFÔ decomposition products than other materials like aluminum or stainless steel. [85] investigated that the mean amplitude of discharge pulses at voltage range between inception voltage Vin C and 1.05 times of Vin C increases with an increase in electrode tip radius. The discharge frequency N increases with applied voltage to a critical voltage, V cr , above which the discharge frequency decreases to a few pulse.…”

“…The electric field at the vicinity of the electrode was calculated based on the experimental results of Vi nc using the following equation (4-2) [85]:…”

Electric Field Modelling in Gas-Insulated Substation for Analysis of Conditions for Partial Discharge Phenomena

“…A model of micro-needle defect has been adopted as hyperboloidal electrode in above-mentioned case [20]. Here the electric eld stress at a distance x from the needle tip equals to…”