Aiming at the electrical tree degradation and discharge breakdown of cross-linked polyethylene (XLPE) insulation for high-voltage cables, we prepared XLPE composite materials using photon-trapping voltage stabilizers, including two trifunctional triazine compounds (1,3,5-triallyl cyanurate (TAC) and triallyl isocyanurate (TAIC)) and two hydrogen-capturing phenyl ketones (4-methyl diphenyl ketone (MBP) and 4,4′-di-chlorobenzophenone (DCBP)). The influence rule of photon-trapping voltage stabilizers on the electrical tree degradation of XLPE composite materials was studied, and the photon trapping and excitation properties of the aromatic photon-trapping compounds, and their chemical reaction pathways were analyzed. The inhibition mechanism of the additive types on the electrical tree degradation was explored by using quantum chemical calculations. The results show that the addition of DCBP and TAC with the mass fraction of 1% can increase the initial voltage and initiation time of electrical tree in XLPE insulation. Compared with the pure XLPE insulation under the same voltage, the electrical tree length of DCBP/TAC/XLPE composite insulation decreases by 16.3%, the cumulative damage area decreases by 72.8%, and the maximum amplitude of partial discharge decreases by 29.7%, which shows the best partial discharge suppression and resistance to electrical trees. According to the quantum chemical calculations, MBP and DCBP have strong photon absorption properties, and DCBP can absorb photons with a wavelength of 334 nm, demonstrates a higher reactivity than MBP, and is more capable of capturing photons generated by partial discharge to hinder the damage of photons on the XLPE molecular chain. According to the reaction pathway analysis, DCBP molecure enters excited state after capturing photons, which triggers the proton transfer within the XLPE molecular chains, and promotes the free radical cross-linking reaction between TAC and PE molecular chain, thereby enhancing the local stability of the molecular chain and inhibiting the electrical tree deterioration of XLPE insulation.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |