Enabling Next Generation Direct Current (DC) Power Networks

在实现更可持续和更有效率的电力系统的努力中，大型集中式不可再生发电厂正在被许多较小的、分散的、以可再生能源为基础的发电厂所取代。为了促进风能和太阳能等可再生能源的大规模集成，直流(DC)电力网络的前景因其提供的优于交流(AC)网络的技术优势而越来越受欢迎。特别是，高压直流输电被广泛认为是未来直流网络的关键骨干技术。*由于其设计和运行与传统交流电力系统有很大的不同，直流网络的发展面临着巨大的挑战。拟议的研究计划侧重于解决阻碍未来直流电网广泛部署的核心挑战，未来直流电网将包括网状高压直流电网和混合(即混合)AC/DC系统。根据这一研究计划，该建议的短期目标是：*1.开发新的模块化电力电子换流系统，使其能够灵活地控制DC和AC/DC混合电网。*2.提出并验证网状高压直流电网的潮流控制和故障保护策略。*3.开发一个统一的建模框架，能够对基于模块化多电平换流器的拓扑结构进行系统的稳定性和故障分析。*模块化和可扩展的换流系统对于实现具有成本效益的DC和AC/DC混合网络至关重要。在我博士工作的基础上，将开发新的模块化换流器结构，以消除多余的能量转换阶段，产生对实际直流电力系统至关重要的产出效率和成本改善。*直流线路潮流控制和直流故障电流的快速中断是阻碍网状高压直流电网建设的两个长期障碍。通过利用提供这些关键功能的新的模块化换流器技术，将设计和验证用于网状高压直流电网的潮流管理和故障处理的可行策略。*基于模块化多电平换流器的拓扑分析构成了一个主要的建模挑战。将部署状态空间广义平均技术来解决这一挑战，提供统一的数学建模框架，从而能够系统地分析直流网络中的变流器稳定性问题和故障行为。*将使用行业标准的数字时域模拟包和数值软件工具对上述工作进行验证。该研究计划将培养高素质的人才，以解决未来电力电子化直流电网的根本挑战。这项工作使加拿大能够帮助塑造下一代直流电力系统的演变，鉴于高压直流项目目前正在多个省份进行，这是一个重要而及时的好处。**

Large centralized non-renewable power-generating plants are being displaced by many smaller dispersed renewable-based power-generating sources in the drive towards realizing a more sustainable and efficient electric power system. To facilitate the large-scale integration of these renewable energy resources, e.g. wind and solar, the prospect of direct current (DC) power networks is gaining traction due to the superior technical benefits they offer over alternating current (AC) networks. In particular, high-voltage dc (HVDC) transmission is widely considered a key backbone technology for future DC networks.***The development of DC networks faces significant challenges as their design and operation differ greatly from conventional AC power systems. The proposed research program focuses on addressing the core challenges hindering the widespread deployment of future DC power networks, which will comprise meshed HVDC grids and mixed (i.e. hybrid) AC/DC systems. Under this research plan, the short-term objectives of this proposal are to:***1. Develop new modular power electronic converter systems that enable flexible control of DC and mixed AC/DC power networks.***2. Propose and validate power flow control and fault protection strategies for meshed HVDC grids.***3. Develop a unified modeling framework that enables systematic stability and fault analyses of modular multilevel converter based topologies.***Modular and scalable converter systems are essential to realizing cost-effective DC and mixed AC/DC networks. Building on my doctoral work, new modular converter structures will be developed that eliminate redundant energy conversion stages, yielding efficiency and cost improvements vital for practical DC power systems.***Control of DC line power flows and rapid interruption of DC fault currents are two long-standing obstacles inhibiting construction of meshed HVDC grids. By leveraging new modular converter technologies that provide these critical functions, viable strategies for power flow management and fault handling of meshed HVDC grids will be devised and validated.***The analysis of modular multilevel converter based topologies poses a major modeling challenge. State space generalized averaging techniques will be deployed to resolve this challenge, providing a unified mathematical modeling framework that enables systematic analysis of converter stability issues and fault behaviour within DC networks.***Validation of the above work will be performed using industry standard digital time-domain simulation packages and numerical software tools. The research program will train highly qualified personnel to solve fundamental challenges of future power electronic enabled DC power networks. This work allows Canada to help shape the evolution of next generation DC power systems, an important and timely benefit given that HVDC projects are currently underway in multiple provinces. **