Polarity-Dependent DC Dielectric Behavior of Virgin XLPO, XLPE, and PVC Cable Insulations
| dc.contributor.author | Ruangwong, Khomsan | |
| dc.contributor.author | Pattanadech, Norasage | |
| dc.contributor.author | Pannil, Pittaya | |
| dc.date.accessioned | 2026-08-06T10:52:17Z | |
| dc.date.available | 2026-08-06T10:52:17Z | |
| dc.date.issued | 2025-10-01 | |
| dc.description.abstract | Reliable DC cable insulation is crucial for photovoltaic (PV) systems and high-voltage DC (HVDC) networks. However, conventional materials such as cross-linked polyethylene (XLPE) and polyvinyl chloride (PVC) face challenges under prolonged DC stress—notably space charge buildup, dielectric losses, and thermal aging. Cross-linked polyolefin (XLPO) has emerged as a halogen-free, thermally stable alternative, but its comparative DC performance remains underreported. Methods: We evaluated the insulations of virgin XLPO, XLPE, and PVC PV cables under ±1 kV DC using time-domain indices (IR, DAR, PI, Loss Index), supported by MATLAB and FTIR. Multi-layer cable geometries were modeled in MATLAB to simulate radial electric field distribution, and Fourier-transform infrared (FTIR) spectroscopy was employed to reveal polymer chemistry and functional groups. Results: XLPO exhibited an IR on the order of 10<sup>8</sup>–10<sup>9</sup> Ω, and XLPE (IR ~ 10<sup>8</sup> Ω) and PVC (IR ~ 10<sup>7</sup> Ω, LI ≥ 1) at 60 s, with favorable polarization indices under both polarities. Notably, they showed high insulation resistance and low-to-moderate loss indices (≈1.3–1.5) under both polarities, indicating controlled relaxation with limited conduction contribution. XLPE showed good initial insulation resistance but revealed polarity-dependent relaxation and higher loss (especially under positive bias) due to trap-forming cross-linking byproducts. PVC had the lowest resistance (GΩ-range) and near-unit DAR/PI, dominated by leakage conduction and dielectric losses. Simulations confirmed a uniform electric field in XLPO insulation with no polarity asymmetry, while FTIR spectra linked XLPO’s low polarity and PVC’s chlorine content to their electrical behavior. Conclusions: XLPO outperforms XLPE and PVC in resisting DC leakage, charge trapping, and thermal stress, underscoring its suitability for long-term PV and HVDC applications. This study provides a comprehensive structure–property understanding to guide the selection of advanced, polarity-resilient cable insulation materials. | |
| dc.identifier.citation | Energies, 18(20), 2025 | |
| dc.identifier.doi | 10.3390/en18205404 | |
| dc.identifier.issn | 19961073 | |
| dc.identifier.other | 2-s2.0-105020240041 | |
| dc.identifier.uri | https://dspace.kmitl.ac.th/handle/123456789/17264 | |
| dc.source | Energies | |
| dc.subject | dielectric properties | |
| dc.subject | FTIR spectroscopy | |
| dc.subject | PVC | |
| dc.subject | space charge | |
| dc.subject | XLPE | |
| dc.subject | XLPO | |
| dc.title | Polarity-Dependent DC Dielectric Behavior of Virgin XLPO, XLPE, and PVC Cable Insulations | |
| dc.type | Article |