Study of an initial transient relaxation in XLPE cable insulation by TSDC and PEA

Practical Notes on the Measurement and Interpretation of Thermally Stimulated Discharge Currents in Biaxially Oriented Polypropylene

“…As proposed by Neagu et al, a complex TSDC peak can be decomposed step-by-step by first fitting the most prominent peak, subtracting it from the data and then continuing this procedure for the remaining side peaks until a satisfactory fit is achieved [16]. For the BOPP films studied here, the polarity reversal phenomenon in the high temperature region poses a further challenge for curve fitting [20]. Multi-peak fitting is exemplified in Figure 3 where the complex TSDC curve of a BOPP-1 specimen was decomposed into five elementary peaks using the above procedure and taking into account the presence of both homo-and heteropolar components in the space charge region [20].…”

“…For the BOPP films studied here, the polarity reversal phenomenon in the high temperature region poses a further challenge for curve fitting [20]. Multi-peak fitting is exemplified in Figure 3 where the complex TSDC curve of a BOPP-1 specimen was decomposed into five elementary peaks using the above procedure and taking into account the presence of both homo-and heteropolar components in the space charge region [20]. Although a good fit does not necessarily mean correct deconvolution, the trap parameters given in Table 3 are nevertheless within physically acceptable range for a thermally stimulated process.…”

Thermally stimulated depolarization current spectra of cross‐linked polyethylene and the influence of cross‐linking byproducts

“…[15] It is clear that these studies demonstrating what factors contribute to space charge buildup in XLPE have revealed much of use for improving its performance in HVDC cables, and also that there is room for studies using complimentary techniques to further understand the storage and movement of trapped charges within XLPE. [16] One such complimentary technique is the thermally stimulated depolarization current (TSDC) technique, which measures the temperature-dependent relaxation of dipoles and space charge. That information can be used to extract the energy of the states that trap them and help uncover their origin, which is directly relevant for power cable applications.…”

“…They include: DCP byproducts, [17] charge injection, [17,18] and trapped charge in crystals and at interfaces [17] as influenced by recrystallization during measurement [19] or changes in the concentrations of byproducts over time. [16] While charge injection from the electrodes would not be unique to XLPE, the charges introduced by the DCP byproducts should be. However, direct comparisons between LDPE and XLPE appear to be absent in the literature.…”

Recovery Algorithm for Space Charge Waveform in Coaxial Cable under Temperature Gradient

“…PEA technoogy has been widely adopted for the nondestructive measurement of space charge worldwide, (4,5) but many studies are mainly focused on flat samples because the PEA device used for flat samples is not only well established but also easily operated. (6)(7)(8)(9) Some researchers have begun to measure the space charge profiles in coaxial cables and achieved preliminary results. (10)(11)(12)(13)(14)(15)(16) For example, Fukunaga et al applied the high-frequency pulse to a cable conductor through a coupling capacitor.…”