UNIfying Grid-FOllowing And Grid-foRMing Control In Inverter-based Resources (UNIFORM)

英国和全球雄心勃勃的脱碳能源目标将导致前所未有的逆变器资源（IBR）（例如风能，太阳能，电动汽车）进入电力系统。该项目的合作伙伴国家电网ESO预测，到2028年，IBR将从2020年的约10 GW增加到约30 GW。电力系统的快速转型带来了新的机遇，也带来了新的运营和稳定性挑战。与传统发电厂的机器相比，IBR的电力电子设备（逆变器）允许更快和更可编程的操作，但它们在干扰（例如线路故障，发电机跳闸）期间的表现也非常不同。这种不同的动态响应导致网络中出现大量逆变器驱动的不稳定性，国家电网ESO在2030年之前因电网薄弱而在苏格兰北部的远程风电场以及整个GB网络的系统惯性快速降低而对此类复杂性发出了警告。不解决这些问题就等于限制了IBR对我们网络的渗透，无法实现我们的净零目标。这些挑战主要涉及逆变器的动态行为。传统上，IBR一直在“电网跟随”模式（GFL）下运行，即表现得像网络中的电流源。最近，“网格形成”（GFM）已成为一种替代，模仿电压源特性。然而，最近的研究结果表明，虽然GFL在弱电网中失败，但GFM在强电网中也失败，因此这两种技术都不是所有电网和条件的银弹。作为一种折衷方案，系统运营商目前正在考虑在整个网络中以“正确的组合”分配GFL和GFM逆变器，这实际上是一种临时措施，无法完全解决这个问题。我们将联合收割机在逆变器本身内结合这两种行为，而不是在网络内混合单独的电流和电压源。通过将GFL和GFM模式统一为通用的“复合V-I源”，每个逆变器都可以根据电网条件以可编程比率模拟混合电压/电流响应。这基本上意味着一个通用控制器，（i）对任何电网都具有鲁棒性，（ii）模拟逆变器输出，确保最佳的稳定性结果。这将是释放IBR真正潜力的垫脚石，并增加任何IBR驱动网络的稳定裕度，从而为设想的100% IBR电力系统铺平道路。南安普顿大学将领导该项目，利用PI在逆变器控制方面的专业知识，并与世界领先的电网稳定性专家NTUA（Nikos Hatziargyriou教授）密切合作。国家电网ESO将分享来自GB网络的案例研究和实际经验，而智能电网将指导工业开发的实验验证阶段。一个精心设计的知识交流和研究访问计划将建立一个强大的伙伴关系，具有独特和互补的技能，将在“逆变器驱动的电力系统”的新兴领域进行创新。这些工具和知识不仅有助于实现我们的能源目标，而且还有助于提升我们在全球具有巨大工业和商业潜力的领域中的全球领导者地位。

The ambitious decarbonisation energy targets of the UK and worldwide will lead to unprecedented levels of inverter-based resources (IBRs) (e.g. wind, solar, electric vehicles) into the power system. National Grid ESO, partner of the project, forecasts a threefold IBR increase from about 10GW in 2020 to approximately 30GW by 2028. This rapid transformation of our power system comes with new opportunities, as well as new operational and stability challenges. The power electronics (inverters) of IBRs allow for faster and much more programmable operation compared to the machines of conventional power plants, but they also behave very differently during disturbances (e.g. line faults, generator trip). This different dynamic response gives rise to a multitude of inverter-driven instabilities in the network, with National Grid ESO raising a red flag for such complications in distant wind farms in North Scotland by 2030 due to weak grid, and for the entire GB network with the rapid reduction of its system inertia. Not resolving these issues equals to limiting the IBR penetration into our network and failing our net-zero targets.These challenges relate primarily to the dynamic behavior of the inverters. Conventionally, IBRs have been operating in 'grid-following' mode (GFL), that is behaving like a current source in the network. Lately, 'grid-forming' (GFM) has emerged as an alternative that emulates voltage-source characteristics. However, recent findings show that while GFL fails at weak grid, GFM also fails at strong grid, hence neither technology is a silver bullet for all grids and conditions. As a compromise to this, system operators are currently looking into distributing GFL and GFM inverters across the network in the "right mix", which is really a makeshift measure and cannot address the issue fully.UNIFORM approaches this problem from an entirely new perspective. Instead of mixing individual current and voltage sources within the network, we will combine these two behaviors within the inverter itself. By unifying the GFL and GFM modes into a universal 'Composite V-I source', every single inverter can emulate a hybrid voltage/current response at a programmable ratio depending on the grid conditions. That essentially means a universal controller that (i) synchronizes robustly to any grid, and (ii) emulates an inverter output that ensures the best possible stability outcome. This will be the steppingstone in unlocking the true potential of IBRs and increase the stability margin of any IBR-driven network, thus paving the way for the envisioned 100%-IBR power system.A rare academia-industry partnership is formed to implement this idea. The University of Southampton will be leading the project, leveraging on the PI's specialization on inverter control, and closely working with the international partner NTUA (Prof Nikos Hatziargyriou), world-leading expert in grid stability. National Grid ESO will be sharing case studies and real-life experience from the GB network, while Smart Power Networks will be guiding the experimental validation phases towards industrial exploitation. An elaborate knowledge exchange and research visits plan will establish a strong partnership with unique and complementary skillsets that will innovate in the emerging area of 'inverter-driven power systems'. These tools and knowledge have the potential to not only facilitate meeting our energy targets, but also boost our position as a global leader in a field with tremendous industrial and commercial potential worldwide.