G.Murtaza Hashmi

On-line PD detection for condition monitoring of covered-conductor overhead distribution networks-A literature survey

Partial discharge (PD) measurements are universally accepted as an effective and reliable tool for on-line condition monitoring of high voltage (HV) equipment. A relatively new application is the monitoring of falling/leaning trees on the covered-conductor (CC) overhead distribution lines. Rogowski coil is used as a sensor for the detection of PDs produced due to falling trees on the CC overhead lines. This sensor is non-intrusive and superior to the conventional PD detector methods. In the next stage, this wired sensor will be converted into a wireless one. This paper gives the brief introduction to the concept and methodology of PD detection and sensor characteristics for localization of falling trees on the CC lines.

Determining wave propagation characteristics of MV XLPE power cable using time domain reflectometry technique

In this paper, the wave propagation characteristics of single-phase medium voltage (MV) cross-linked polyethylene (XLPE) power cable are determined using Time Domain Reflectometry (TDR) measurement technique. TDR delivers the complex propagation constant (attenuation and phase constant) of lossy cable transmission line as a function of frequency. The frequency-dependent propagation velocity is also determined from the TDR measurements through the parameters extraction procedure. The measurement results can be used to localize the discontinuities as well as the design of communication through distribution power cables.