Electrical Characterisation of Solid-Liquid Composite Insulation Systems used in Subsea Connectors

海底电力输送不仅对石油和天然气的回收至关重要，而且对开发近海可再生技术也是至关重要的。在海底环境中，通常需要配对/断开高压电缆连接器。海底电缆连接器采用矿物油作为绝缘液。然而，在意外泄漏的情况下，它会带来污染海水的风险。因此，人们迫切需要使用对环境影响小的替代介电液体。合成酯因其优越的生物降解性而成为一种替代候选材料。此外，合成酯的燃烧/闪点高，约为矿物油的两倍，可提供更好的防火安全保障。该PHD项目旨在研究电缆连接器绝缘材料(包括有机硅聚醚醚酯)的电学特性，包括体绝缘的击穿强度和沿固-液界面的爬电放电/表面跟踪现象。该项目将从深入的文献回顾开始，然后设计合适的实验装置。固体绝缘材料的击穿强度将在不同温度下进行测试。蠕变放电和沿固-液界面的表面跟踪将从起始、传播和直至击穿阶段进行研究。短期和长期的压力都将被考虑。这项研究将促进更环保、更安全的海底高压电缆连接器的应用。

Subsea power delivery is essential for not only oil and gas recovery but also for developing off-shore renewable technologies. High voltage cable connectors are often required to mate/demate at the subsea environment. Mineral oil has been used as the dielectric liquid in the subsea cable connectors. It, however, poses a risk to contaminate the sea water in case of unexpected leakage. Therefore, it is motivated to use alternative dielectric liquids with low environmental impact. Synthetic ester is such an alternative candidate due to its much superior biodegradability. In addition, the synthetic ester can provide better fire safety guarantee due to its high fire/flash point, which is about double of that of mineral oils. This PhD programme aims to investigate the electrical characteristics of the cable connector insulation materials including Silicone-PEEK-Ester in terms of breakdown strength of the bulk insulation and creepage discharge/surface tracking phenomena along the solid-liquid interface. The project will start from an in-depth literature review and then followed by designing the suitable experimental setup. Breakdown strength of the solid insulation materials will be tested at different temperatures. Creepage discharge and surface tracking along the solid-liquid interface will be studied from initiation, propagation and till breakdown stages. Both short-term and long-term stresses will be considered. The study will promote applications of greener and safer subsea high voltage cable connector.