Towards Enhanced HVDC Cable Systems

为了让英国在2020年及以后实现具有法律约束力的可再生能源目标，一系列风力发电场正在建设中，更多的新项目正在开发中。海上电网及其与现有输电系统的连接只能通过高压直流输电线路实现。使用高压将使电力传输更有效率，唯一可行的解决方案是对现有工厂进行极端升级。作为高压直流输电环节的关键部分，电缆将被迫远远超过现有的限制(目前约为+/-500千伏和1000兆瓦)。这意味着电缆绝缘和运行条件都必须远远超出目前认为可以接受的极限。因此，迫切需要对绝缘性能有一个基本的了解，并开发新的操作方法来应对挑战。该项目将研究固有缺陷、空间电荷动态、局部放电、电气树枝和电能质量对高应力搭接电缆绝缘电气性能的影响，并开发考虑上述因素影响的新操作方法，以实现高压直流输电环节的可靠和安全运行。

For the UK to meet legally binding renewable targets by year 2020 and beyond, a series of wind farms are under construction, and more new projects are being developed. The offshore grids and their connection to the existing transmission systems can only be realised using the HVDC links. Using high voltage will make power transmission more efficient and the only feasible solution is to use extreme upgrades to existing plant. Cables, the key part of the HVDC links, will be forced to operate well beyond their existing limits (currently about +/-500 kV and 1000 MW). This means that both cable insulation and operating conditions have to be pushed far beyond the limits currently considered acceptable. Therefore, a fundamental understanding of the performance of the insulation and the development of novel operating methodologies are urgently required to meet the challenges. This project will investigate the impact of inherent defects, space charge dynamics, partial discharges, electrical tree and power quality on electrical performance of highly stressed lapped cable insulation and develop novel operating methodologies that take account of the influence of the above factors to achieve reliable and safe operation for the HVDC links.