Composite dielectric structures with enhanced lifetimes

多年来，我们的电力传输和配电网络背后的工程一直没有改变。其中一个原因是，电气绝缘系统的可靠性已被证明非常高，这种系统也存在于我们的铁路基础设施中。然而，现有的许多基础设施现在都非常陈旧，远远超过了其设计寿命。此外，电力系统现在正在进行根本性的改革。这在很大程度上是由促进可再生(低碳)能源供应的愿望推动的。此外，随着电力取代天然气用于家庭供暖，电动汽车取代汽油和柴油动力汽车，将消耗更多电力，需要更高密度的电力传输，特别是进入我们的城市。这些要求需要更高的绝缘电应力和更高的额定温度，同时保持可靠性。因此，提高对绝缘失效机理的认识和设计改进的绝缘对我国电力系统的进一步发展至关重要。绝缘系统的可靠性在发电、铁路网和制造业中也是至关重要的。这个项目将提高我们对绝缘可靠性的理解，并开发性能更好的结构材料。特别是，将详细研究聚合物绝缘中的一种基本老化机制，即电树化。电树生长是聚合物绝缘系统在高电应力下长期失效的一种机制，是导致类似植物树的人工制品发展的过程。它由直径达数十微米的管状中空树枝组成。树的存在最终会导致绝缘故障。该项目将考虑如何使用分层介质来提高绝缘寿命，特别是在有电气树的情况下。罗兰教授(曼彻斯特大学)和蔡教授(伦敦大学学院)最近的可行性研究表明，薄薄的聚合物层可以将树的传播时间改变一个数量级。此外，曼彻斯特的新技术现在已经能够生成树木过程的三维成像。它使用了伦敦大学学院独特的实验设备和技术来制备样品，并使用了曼彻斯特大学的成像能力，包括钻石光源X射线设备。虽然这项工作是以基础科学为基础的，但该项目的一个关键组成部分将是吸收这些发现，并开发一个改进的层状介质结构的框架。将开发一条用于电网、公共交通和电力电子行业的工艺和产品的未来发展路线。已获得外部合作伙伴对制定这一框架的承诺，以确保在项目期间进行技术转让。最终，这项工作将有助于实现更好的性能、更低的成本和更强劲的电力供应。

For many years the engineering behind our power transmission and distribution networks has remained unchanged. One reason for this is that the reliability of electrical insulation systems, also found on our rail infrastructure, has proved extremely high. However much of the existing infrastructure is now very old, well beyond its design life. In addition, radical changes are now being implemented in power systems. These are largely driven by the desire to facilitate renewable (low carbon) energy supplies. Moreover as electricity replaces gas for heating homes, and electric vehicles replace petrol and diesel powered cars, more electricity will be consumed requiring greater densities of power transmission, particularly into our cities. These requirements necessitate higher electrical stresses on insulation and higher temperature ratings, whilst maintaining reliability. For these reasons improving our understanding of the failure mechanisms of insulation and designing improved insulation are both critical to the further development of our power systems. Reliability of insulation systems is also critical in power generation, rail networks and manufacturing industries.This project will improve our understanding of insulation reliability and develop structured materials with improved performance. In particular a fundamental ageing mechanism in polymeric insulation known as electrical treeing will be studied in detail. Electrical tree growth is a mechanism of long-term failure in polymer insulation systems under high electrical stress and is a process leading to the development of an artefact which resembles a botanical tree. It consists of tubular hollow branches of up to tens of microns in diameter. The presence of a tree eventually leads to insulation failure. The project will consider how the use of layered dielectrics can enhance insulation life, particularly in the presence of electrical trees. Recent feasibility work between Prof Rowland (University of Manchester) and Prof Choy (UCL) has shown that thin layers of polymers can change tree propagation times by an order of magnitude. Also novel techniques in Manchester have now enabled three-dimensional imaging of the treeing process to be generated. This has used unique experimental facilities and skills for sample preparation at UCL and the imaging capability at the University of Manchester including the Diamond Light Source X-ray facility. Although this work is based on fundamental science, a key component of the project will be take the findings and develop a framework for improved layered dielectric structures. A route for future development of processes and products for the power networks, mass transit and power electronics industries will be developed. The commitment of external partners to generating this framework has been obtained to ensure technology transfer during the project life. Ultimately this work will contribute to better performing, lower cost and more robust electricity supplies.