Control and operation of MVDC systems with grid forming capability for the future GB power system

未来英国电力系统具有并网能力的 MVDC 系统的控制和运行

• 批准号: 2437667
• 金额: --
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2437667
• 关键词: Control; operation; MVDC; systems; grid

The aim of this PhD is to explore the control and operation of new MVDC system enhanced with grid forming controllers for the GB power system beyond 2025 showing the advantages that the combination of these two technologies might bring. In particular, this thesis will explore the idea to replace an existing AC medium voltage line in a congested area, like the Scottish central belt or London, for a MVDC line. This will increase the power transmission capacity but, at the same time, the flexibility of the electrical network. Using standard converter controls, the AC voltage at the point of connection of the MVDC line can be controlled improving the network capacity compared to AC lines. But if this converter controlled is enhanced with grid forming capabilities, the controllability and stability of the medium voltage network can be increased further. Thanks to the MVDC converters with grid forming capabilities, the electrical system can be better supported providing inertia in case of a frequency event, more supportive voltage control, increasing the penetration of renewable power and even providing black start capabilities. Taking into consideration the previous points, these PhD goals are designed to study the control challenges and solutions of MVDC systems with grid forming converters:- Study the operation and control of hybrid medium voltage AC and DC networks in meshed areas with high penetration of renewable power. Medium voltage networks are known for being more meshed than high voltage networks. In terms of voltage and power flow control, this might suppose a challenge. As more flexibility is added into the grid thanks to the MVDC line, a novel strategy should be developed to achieve optimal power flow control and voltage profiles. At the same time, as new renewable generation is connected to the medium-voltage network control coordination between the MVDC link and the renewable power should be studied.- Study the provision of ancillary services such as inertia and frequency support and black start from a medium-voltage hybrid AC and DC. Historically, MVDC networks had a passive behaviour but with the addition of distributed renewable power, electric vehicles and MVDC systems, the medium voltage network might have a new role ensuring the power system stability, control and operation. The provision of stability ancillary services from the medium voltage network is new and require some study such as the control coordination between the MVDC link and the renewable energy sources for inertia support provision. At the same time, new services like black start can be provided, helping the system to recover quicker from a blackout rs. This thesis would study the black start precedent considering the MVDC link and the renewable power sources. - Study the control interactions in hybrid AC and DC medium voltage networks. As the medium voltage networks become more active with the proliferation of power converters is more likely that control interactions between the renewable electrical sources, MVDC lines and any other converter interfaced system (e.g. electrical vehicle charging station) might appear. This thesis will study the potential control interaction and will suggest mitigation techniques to avoid this problem.

该博士学位的目的是探索新的MVDC系统的控制和操作，该系统通过2025年之后的GB电力系统的电网形成控制器进行增强，显示这两种技术的结合可能带来的优势。特别是，本论文将探讨的想法，以取代现有的交流中压线在拥挤的地区，如苏格兰中央带或伦敦，为MVDC线。这将增加电力传输能力，但同时也增加了电网的灵活性。使用标准转换器控制，可以控制MVDC线路的连接点处的AC电压，从而与AC线路相比提高网络容量。但是，如果该转换器控制的电网形成能力增强，中压网络的可控性和稳定性可以进一步增加。由于具有电网形成能力的MVDC转换器，可以更好地支持电气系统，在频率事件的情况下提供惯性，更支持的电压控制，增加可再生能源的渗透，甚至提供黑启动能力。考虑到前面的几点，这些博士目标旨在研究具有电网形成转换器的MVDC系统的控制挑战和解决方案：-研究可再生能源高度渗透的网状区域中混合中压AC和DC网络的操作和控制。已知中压网络比高压网络更网状。在电压和功率流控制方面，这可能是一个挑战。由于MVDC线路增加了电网的灵活性，因此应开发一种新的策略来实现最佳潮流控制和电压曲线。同时，由于新的可再生能源发电连接到中压网络，因此应研究MVDC链路与可再生能源之间的控制协调。研究辅助服务的提供，例如惯性和频率支持以及中压混合AC和DC的黑启动。从历史上看，MVDC网络具有被动行为，但随着分布式可再生能源，电动汽车和MVDC系统的增加，中压网络可能具有确保电力系统稳定性，控制和运行的新角色。从中压网络提供稳定辅助服务是新的，需要一些研究，如MVDC链路和可再生能源之间的控制协调，以提供惯性支持。与此同时，可以提供像黑启动这样的新服务，帮助系统从停电中更快地恢复。本文将研究考虑MVDC链路和可再生能源的黑启动先例。- 研究交直流混合中压电网中的控制交互作用。随着中压网络随着功率转换器的激增而变得更加活跃，更有可能出现可再生电源、MVDC线路和任何其他转换器接口系统（例如，电动车辆充电站）之间的控制交互。本论文将研究潜在的控制相互作用，并提出缓解技术，以避免这一问题。