Comparative study of AC breakdown voltage for various polymers: Influence of electrodes shape, thermal and hydrothermal ageing

Abstract

International audienceThis work deals with a comparative study of AC breakdown voltage (BDV) of various polymeric samples. The investigated materials cover thermoplastics (namely polyamide 6 (PA6/50), fireproofed polyamide 66 (PA66/50), polyarylamide (PARA/50), polycarbonate (PC/40), polyethylene (HDPE) and polyphenylene sulfide (PPS/65)); and two EPDM based elastomers (namely unfilled EPDM (EPDM) and fireproofed EPDM (EPDM V0)). We mainly analyze: (i) the effect of electrodes shape (namely cylindrical and spherical); (ii) thermal ageing at high temperatures (100, 130 and 150°C); and (iii) hydrothermal ageing in salt fog conditions. It is shown that obtained BDV with spherical electrodes exhibits the highest values because of small surface contact of electrodes with polymeric surfaces; materials such as PEHD and EPDM show the highest BDV. It is found that thermal ageing affects seriously BDV of EPDM based materials. PPS/65 depicts the lowest BDV but is less affected by thermal ageing because of its high thermal stability. Hydrothermal ageing reveals that the moisture absorption is the main reason of the significant decrease of BDV for polyamides

Analysis of breakdown mechanism based on contact area and field enhancement factor of different electrode‐material combinations

“…In this context, although slightly higher electric fields were generated by point-cylinder and spherical-cylinder electrode system compared to the cylinder-cylinder electrode configuration, the contact area became the dominant factor and characteristic breakdown voltages were ordered inversely proportional to the contact areas for PET and presspaper. These results are consistent with studies [24][25][26][27][28][29][30] mentioned in the literature overview and they can be supported by the explanation of higher electrode areas causes an increase in the chance to coincide with defects or impurities underneath the electrode which lead to a failure. 24 On the other hand, FEF of cylinder-cylinder and sphere-cylinder were nearly the same for SBR/NR similar to other materials.…”

“…Lastly, Douar et al measured the breakdown voltages of various polymers with cylinder‐cylinder and spherical‐spherical electrode systems. Like other studies, they attributed the low breakdown voltages seen with the cylinder‐cylinder electrodes to the larger electrode contact area 30 …”

“…Like other studies, they attributed the low breakdown voltages seen with the cylinder-cylinder electrodes to the larger electrode contact area. 30…”

Insulation Properties of PMMA:TiO2 Nanodielectric Film for High Voltage Applications

“…In conclusion, sharp tip electrode gives greater BDV than spherical electrode for about twice the lowest BDV value. This is because breakdown of polymeric materials decreases as the electrode area increase because of the electric field enhancement [3]. The treeing process in the voids may excitedly initiate as the area under the electrode is increases.…”

“…Each polymer has different characteristics in terms of their physical and chemical structure and also in terms of electrical and mechanical behavior [2]. Thermoplastics, poly amide, polyacrylamide, polycarbonate, and polyethylene are examples of polymer material that is being used as insulation in HV applications [3]. Despite its advantages,  ISSN: 2502-4752 Indonesian J Elec Eng & Comp Sci, Vol.…”