Effect of Temperature on Partial Discharge Feature in a Void in Polypropylene Blends as Cable Insulation

Power cable is an essential component of power system, its reliability is critical for grid stability. Polypropylene (PP)/elastomer blends have great potential to be used as AC cable insulation. However, voids tend to appear in the blends due to long-term operation with thermal cycle, which would trigger partial discharge (PD) that degrades the insulation. In this paper, the temperature-dependent <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$P D$</tex> features in an artificial void within PP and PP/propylene-based elastomer (PBE) blend have been investigated. The PD signals are measured by a high frequency current transformer (HFCT) at temperatures of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2 5 - 8 5}{ }^{\boldsymbol{\circ}} \mathrm{C}$</tex>, the phase resolved partial discharge (PRPD) pattern are employed to estimate the influence of temperature on the PD activity. The test results indicated that the iPP/PBE blend exhibited higher discharge peaks at elevated temperatures, while pure iPP showed more stable discharge rate with temperature.