In order to ensure the safe operation of submarine cables, it is of great significance to analyse the insulation state of submarine cables from the perspectives of microstructure, carrier transport characteristics and macroscopic dielectric properties. In this study, based on the high-voltage frequency domain spectroscopy (HV-FDS) measurement system, HV-FDS experiments of fresh and thermally aged submarine cables were carried out under continuous (0.5, 2, 4 and 10 kV) and cyclic (2-10-2 kV) applied alternating voltages. Then, combining the changes of the microstructure structure of cross-linked polyethylene (XLPE) insulation, the aggregate structure deterioration model of XLPE was proposed to discuss the physical mechanism of HV-FDS characteristics of submarine cables under different voltages and insulation states. Results show that the HV-FDS characteristics of submarine cables have significant voltage dependence under continuous voltage excitation. The HV-FDS of submarine cables show memory characteristics under cyclic voltage excitation. Compared with the fresh submarine cable, the thermally aged submarine cable shows more significant voltage dependence and memory characteristics of HV-FDS. The memory characteristics of HV-FDS are mainly determined by the carriers transport and the interfacial polarisation caused by the accumulation of polar particles at the electrode/dielectric interface. This study covers the correlation mechanism among the microstructure, carrier transport and macroscopic HV-FDS properties of submarine cable insulation, which lays a foundation for further research and condition evaluation of submarine cables.

中文翻译：

---

基于载流子传输和极化特性的连续和循环电压下热老化 XLPE 海缆的高压频域光谱分析

为保障海缆的安全运行，从微观结构、载流子传输特性和宏观介电性能等角度分析海缆绝缘状态具有重要意义。本研究基于高压频域光谱（HV-FDS）测量系统，在连续（0.5、2、4和10 kV）和循环（ 2-10-2 kV) 施加的交流电压。然后，结合交联聚乙烯（XLPE）绝缘材料微观结构的变化，提出了交联聚乙烯的聚集结构劣化模型，探讨了不同电压和绝缘状态下海底电缆HV-FDS特性的物理机制。结果表明，在连续电压激励下，海底电缆的HV-FDS特性具有显着的电压依赖性。海缆HV-FDS在循环电压激励下表现出记忆特性。与新鲜海缆相比，热老化海缆表现出更显着的HV-FDS电压依赖性和记忆特性。HV-FDS的存储特性主要由载流子传输和极性粒子在电极/介质界面的积累引起的界面极化决定。本研究涵盖了海缆绝缘的微观结构、载流子输运和宏观HV-FDS性能之间的相关机制，为进一步研究和评估海缆的状况奠定了基础。