Investigation of Technologies for Fault Level Management in Future Distribution Networks

对于英国来说，热量的脱碳是一个越来越重要的问题，需要扩大区域供热和分布式热电联产（CHP）的使用。然而，故障水平限制正在成为城市地区连接新分布式发电的障碍，随着本地发电（特别是热电联产）计划的增加，变电站已经有限的剩余空间将很快耗尽。传统的加固技术被用来整合新的分布式发电，这使得它在经济上对开发者没有吸引力。不同的技术和研究正在进行中，以找到适合配电网运营商的解决方案。在配电层面，故障层面对电网的整体安全运行起着重要的作用，包括保护协调。UKPN的项目名为powerfu - cb，旨在在伦敦11千伏电网上试用两种新型故障限制断路器装置，其中一种由ABB开发，用于变电站部署，另一种由应用材料公司（AMAT）开发，用于分布式发电厂。博士项目的主要目标包括：1。有助于理解配电网的故障水平（或故障电流）要求，并与低碳技术（如CHP， Power park模块和ev）相结合。2 .研究中压（11kV）配电网中产生故障电流的不同技术（如使用晶闸管作为附加电流通路）和限制技术（如IS限流器、有源故障解耦器、FLCB等）。调查保护系统的发展，通过在配电网中摆脱通常使用的过电流检测，更好地与电力电子设备一起工作，并进一步了解电路的电压和阻抗。随着配电网向更网状的方向发展，探索电力系统保护的改进机会

The decarbonisation of heat is an increasingly important issue for the UK, requiring expanded use of district heating and distributed Combined Heat and Power (CHP). However, fault level constraints are becoming a barrier to connecting new distributed generation in urban areas, and with plans for increased local generation, especially CHP, the already limited headroom in substations will be quickly exhausted. Traditional reinforcement techniques are used to incorporate new distributed generation, making this financially unattractive to developers.Different technologies and research is ongoing, to find a solution suitable to distribution network operators. At the distribution level, the fault level plays an important role in the overall safe operation of the network, including protection co-ordination. UKPN's project, called PowerFuL-CB, aims to trial two novel fault limiting circuit breaker devices on the London 11 kV network, one being developed by ABB, for deployment in substations, the other from Applied Materials (AMAT), designed for use at distributed generation plant sites. Main objectives of the PhD project include the following:1. Contribution towards understanding of fault level (or fault current) requirements for distribution networks, integrating with low carbon technologies such as CHP, Power park modules and EVs.2. Investigation of different technologies for fault current generation (e.g. use of thyristors as additional current paths) and limitation techniques (e.g. IS limiter, Active Fault De-coupler, FLCB etc) in medium voltage (11kV) distribution network.3. Investigate the evolution of protection systems, to work better with power electronic devices by moving away from normally used over-current detection in distribution networks and gaining further understanding of voltage and impedance of the circuit.4. Explore improvement opportunities in power system protection, as we move towards a more meshed distribution network