Integration of Wind Power Generation with Compressed Air Energy Storage 1=Energy 2=Wind Power

在英国，随着化石燃料发电厂的退役，2017-2018年冬季发电能力与高峰负荷需求之间的差距不到5%。因此，任何不可预测的重大发电量波动都可能导致电力短缺。与此同时，间歇性风力发电的渗透率在过去五年里迅速增加。因此，维持发电和负荷平衡变得极具挑战性，对电网的稳定性和可靠性产生了很大影响。相反，风力涡轮机的运营和维护成本可能很高，特别是海上风力涡轮机。与其他涡轮分系统相比，风力发电机组齿轮箱的故障率相对较高。变速箱故障的严重性(每台涡轮机每年发生0.154次重大故障--是所有子系统中最高的)、维修时间长(大修/更换估计为300小时)和高昂的维修费用(大修或更换平均估计为230,000欧元)加剧了这一问题。变速箱磨损和故障的一个重要原因是在运行过程中经历的高扭矩尖峰，这在风力涡轮机变速箱中很常见，这是由于突如其来的阵风。开发可储存的二次能量载体来解耦波动供应被广泛接受为解决已确定的挑战的可行方案。在各种储能技术中，本项目考虑的是压缩空气储能(CAES)。CAES具有清洁、安全、廉价、可持续、维护量小、寿命长、规模大(大容量、大功率)等优点。选择这项技术有两个主要原因：-丰富的存储容量，最近有报道称，英国至少有6TWh的合适地下存储容量用于压缩空气能量，同时，合适的存储地点靠近现有的风力发电场或计划中的未来风力发电场。-变速箱寿命，一名博士生在2017年前学习的一种与风力发电机轴直接机械连接的混合风力涡轮机。初步分析表明，与CAES的直接连接可能会产生一种吸收高扭矩尖峰的机制，从而延长风力涡轮机变速箱的使用寿命。该项目旨在研究CAES在支持风力发电方面的潜力。研究将解决混合风力涡轮机的技术挑战，并进行技术经济分析。项目任务安排如下：1.调查利用CAES最大限度地利用风力发电的潜力；2.分析英国风电与CAES并网的机会；3.进行风电与CAES并网的混合连接系统结构研究以及目前在提高系统往返效率方面的技术差距；4.从个别部件设计、微观几何形状、材料和优化等方面优化变速箱设计，以提高系统承载能力(例如从1兆瓦增加到8兆瓦)；5.通过风力机轴和CAES的混合机械连接来提高冲击负荷能力，以延长变速箱寿命。

In the UK, with the retirement of fossil fuel power plants, the margin between power generation capacity and peak load demand was less than 5% for the winter of 2017-2018. Therefore any major unpredicted generation fluctuation may cause power shortfall. Simultaneously, the penetration of intermittent wind power has rapidly increased in the past five years. As a result it, has become extremely challenging to maintain generation and load balance, impacting greatly on grid stability and reliability. Conversely, operational and maintenance costs of wind turbines, especially offshore, can be high. Wind turbine gearboxes possess relatively high failure rates when compared to other turbine subsystems. This is compounded by the severity of gearbox failure (0.154/yr major failures per turbine - the highest of any subsystem), the long repair time (estimated at 300 hours for a major repair/replacement) and high repair cost (estimated at 230,000 Euros on average for a major repair or replacement). A significant cause of gearbox wear and failure is the high torque spikes experienced during operation, which are common in wind turbine gearboxes owing to sudden wind gusts.Development of storable secondary energy carriers for decoupling fluctuating supply is widely accepted as a feasible solution to the identified challenges. Among various energy storage technologies, this project considers Compressed Air Energy Storage (CAES). CAES has the advantages of being clean, safe, cheap, sustainable, low maintenance, long lasting and large scale (large capacity and power). There are two principle reasons to choose this technology:-Rich storage capacity, It is recently reported that the UK has a minimum of 6TWh suitable underground storage capacity for compressed air energy, where also, the suitable storage sites are close to the existing wind farms or planned future wind farms. -Gearbox lifetime, A hybrid wind turbine with a direct mechanical connection to a wind turbine shaft studied by a PhD student prior to 2017. Initial analysis indicated that a direct connection with CAES may produce a mechanism to absorb high torque spikes, prolonging wind turbine gearbox lifetime. The project aims to study the potential of CAES in supporting wind power generation. Research will address technical challenges in hybrid wind turbines and conduct techno-economic analysis. The project tasks are organised as follows:1. Investigate the potential for using CAES to maximise wind power generation; 2. Analyse the UK opportunities of integration of wind power with CAES;3. Conduct the research on hybrid connection system structure for wind turbine integration with CAES and the current technology gap for improving system round trip efficiency;4. Optimise the gearbox design for system loading capacity increase (e.g. from 1MW to 8MW) from individual part design, micro-geometry, materials, and optimisation;5. Improve shock load capacity via hybrid mechanical connection of wind turbine shaft to CAES for prolonging gearbox lifetime.