ZEFAL The Zero Fault Level Generator for Active Urban Networks

目前由伦敦市长发布的《伦敦计划》要求通过现场可再生能源发电满足10%的能源需求。2007年2月公布的《伦敦计划进一步修改草案》更进一步，具体要求新开发项目在可行的情况下由冷热电联供系统提供能源，并通过现场可再生能源发电将二氧化碳排放量再减少20%。预计英国、欧洲和国际上的其他主要城市将遵循这种方法的变化，并且所需的百分比将随着时间的推移而增加。高负载密度区域（例如主要城市）内本地发电的快速扩张正在迅速侵蚀现有配电网络上剩余的可用故障水平净空。2003年的一项调查表明，大约200个变电站的剩余故障水平净空不足5%，72%的英国变电站（900个）的剩余故障水平净空不足25%。已经在伦敦的滨海港区，城市和伦敦西区的净空接近或为零，约。由于故障水平限制，每年1.5至3.5 MVA的6个方案没有进行。使用传统工程解决方案克服故障水平限制所需的总计5- 10百万帕的额外连接费用使这些方案对开发商来说不经济。预计2007/2008年度这一数字将翻一番。拟议的开发将通过允许将大量旋转机器发电机连接到城市和城市网络而不会导致故障水平来解决这个问题。这将允许快速和低成本连接许多其他故障水平的设备，如传统的电动机和发电机以及光伏电源和感应风力机。这一问题的严重性意味着国际上已经在研究和开发各种故障水平管理解决方案，包括超导和电力系统电子方法。这些发展旨在为现有网络提供更大的故障水平净空。这被认为是必要的和补充的潜在消除故障水平的贡献，从一个新的品种的旋转发电机，特别是适合于CCHP和生物质发电的废物。缺乏故障水平净空是英国城市国家和区域规划政策所要求的分布式发电快速和经济连接的主要制约因素，以减少英国的二氧化碳排放。在这一基础研究阶段，我们的目标是建立一个零故障水平发电机的可行性，为主动城市网络，并产生一个示范发电机在25- 50千瓦范围内的完整故障穿越能力和规定，使电压，无功功率和频率的支持，在正常运行和故障后恢复作出积极的贡献。

The current London Plan issued by the Mayor of London, requires that 10 per cent of energy demand should be met through on-site renewable generation. Draft Further Alterations to the London Plan published in February 2007 go one step further by specifically requiring new developments to have energy supplied by Combined Cooling Heating and Power (CCHP) systems wherever feasible and to reduce their CO2 emissions by a further 20 per cent through the production of onsite renewable energy generation. It is expected that other major cities both in the UK, Europe and internationally will follow variations of this approach and that the required percentages will escalate over time The rapid expansion of local generation within high load density areas - such as major cities - is rapidly eroding the remaining available fault level headroom on existing distribution networks. A survey in 2003 indicated that some 200 substations had less than 5% fault level headroom remaining and that 72% of UK substations (900) had less than 25% headroom. Already in London's Docklands, City and West End where headroom is near or at zero, approx. 6 schemes each of 1.5 to 3.5 MVA a year are not proceeding due to fault level constraints. Additional connection charges totalling 5-10m pa, necessary to overcome fault level constraints using conventional engineering solutions, render these schemes uneconomic to the developers. The number is expected to double during 2007/8. The proposed development will tackle this issue at source by permitting the connection of large numbers of rotating machine generators to city and urban networks without contributing to fault levels. This will allow the rapid and low cost connection of many other fault level contributing devices such as conventional motors and generators as well as PV sources and induction wind machines. The criticality of this problem means that a variety of fault level management solutions are already being internationally researched and developed including superconducting and power system electronic approaches. These developments are aimed at providing greater fault level headroom on existing networks. This is seen as being both essential and complimentary to the potential elimination of fault level contributions from a new breed of rotating generators particularly suitable for CCHP and biomass generation from waste. Lack of fault level headroom is a major constraint to the rapid and economic connection of distributed generation required by national and regional planning policies in UK cities to reduce the UK's CO2 emissions. In this basic research stage we aim to establish the feasibility of developing a Zero Fault Level Generator for Active Urban Networks, and to produce a demonstration generator in the 25-50kW range with full fault-ride through capability and provision to make active contributions to voltage, reactive power and frequency support in nromal operation and in post-fault recovery.