AN ACTIVE MEASURING IMPEDANCE FOR SENSITIVITY IMPROVEMENT AT PARTIAL DISCHARGE MEASUREMENT IN POWER CABLES

Autor/autori: Assit.Eng. Mircea-Emilian ARDELEANU, PhD, Prof. Eng. Andrei MARINESCU PhD, Prof. Eng. Lucian MANDACHE PhD

Rezumat: In lucrare se analizeaza rolul pe care il are impedanta de cuplaj asupra sensibilitatii schemei de masurare a descarcarilor partiale (DP) in cablurile electrice, prin compararea diferitelor solutii de realizare a acestora. Se descriu caracteristicile de frecventa ale unor impedante de cuplaj clasice ca filtre trece-sus pasive constatindu-se o rejectie redusa a tensiunii de incercare de joasa frecventa cat si utilizarea unei impedante de cuplaj active bazata pe un filtru trece-sus de tip Butterworth de ordinul IV care permite extragerea impulsurilor de descarcare partiala chiar la nivele reduse ale intensitatii acestora .

Cuvinte cheie: cabluri electrice de putere, descarcari partiale, filtru trece-sus, impedanta de cuplaj

Abstract: The paper analyses the role of the coupling impedance on the sensitivity of the measuring diagram of partial discharge (PD) in power cables by comparing different solutions for achieving them. The frequency characteristics of some classical coupling impedances as high-pass filters are described finding out a low rejection of the low frequency test voltage the use of some active coupling impedances based on high-pass filter type Butterworth a 4-th order allowing partial discharge impulse extraction even for low intensity ones.

Keywords: power cables, partial discharges, high-pass filters, coupling impedances

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