0000000000108422
AUTHOR
R. Candela
Sulla sincronizzazione delle misure wireless di scariche parziali con il segnale di tensione a 50 Hz
L’articolo descrive i vari aspetti dei sistemi di misura wireless delle scariche parziali (PD). In particolare, sul problema della sincronizzazione dell’angolo di fase della tensione per il rilevamento e la classificazione delle PD.
Partial discharges characteristics during load transients in an HVDC model cable
The occurrence of Partial Discharges (PD) in HVAC cables is widespread considered as one of the most important concerns for the stability of the insulation. To date, the role of PD in the ageing and definitive fault of HVDC cables has been poorly investigated. This is mainly due to some practical difficulties in the performing of the measurements. Compared to the PDs occurring under AC stress, the higher inception voltages and the lower repetition rates, obtainable under DC voltage, make the exclusion of the measurement noise more difficult. This paper is focused on the study of the characteristics of the PDs occurring in an artificial defect located in proximity of the outer dielectric' su…
PD recognition by means of statistical and fractal parameters and a neural network
A novel partial discharge (PD) defect identification method is described. Starting with PD data on different families of specimens, a suitable set of parameters are determined and then used as input variables to a neural network for the purpose of identifying the defects within the insulation. In this procedure the statistical Weibull analysis is performed on PD pulse amplitude histograms to obtain the scale parameter /spl alpha/ and the shape parameter /spl beta/. Thereafter, the two statistical operators (skewness and kurtosis) and two fractal parameters (fractal dimension and lacunarity) are evaluated from the PD phase on the discharge epoch histogram and from the 3 dimensional (pulse am…