Collaborative Research: Large-Signal Stability Analysis and Enhancement of Converter-Dominated DC Microgrid

合作研究：变流器主导的直流微电网的大信号稳定性分析与增强

• 批准号: 2034812
• 负责人: Alex Huang
• 金额: $ 20万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034812&HistoricalAwards=false
• 关键词: Collaborative; Research; Large; Signal; Stability

Title: Collaborative Research: Large-Signal Stability Analysis and Enhancement of Converter-Dominated DC MicrogridAbstract: While DC microgrids have many well-understood advantages (e.g., simpler, more efficient and compact power conversion system as well as less copper consumption in the cables), the unique DC electric characteristics, such as direct P-V coupling (i.e., even a small load/generation change can lead to voltage flickers and equipment malfunctions) and low system inertia (i.e., very little overload capacity), pose great challenges to grid stability. Small-signal stability can only ensure the stability of the system at the equilibrium point, but the true boundary of the stability domain cannot be determined; hence there are major limitations in securing stability when the system has large disturbances. Existing large-signal analysis tools in the literature have either limited applicable ranges or non-rigorous theoretical foundations. Therefore, there is an urgent need to develop a fundamental knowledge base of large-signal stability analysis in converter-dominated DC microgrids and a comprehensive design guideline for DC grid stability. The research findings of this project directly contribute to the overall goal in our country to maintain high reliability and resilience electricity with more and more microgrids and distributed energy sources. The proposed education and outreach research plan will (i) incorporate theoretical frameworks, curated data sets, and testbed from this project into the existing curriculum at both the University of Michigan-Dearborn and the University of Texas at Austin; (ii) promote K-12 students’ interest in STEM; (iii) disseminate all project materials, processes, designs and results in the public domain via public-access websites, top-ranking conference and journal publications and in diverse media; and (iv) provide rich research opportunities to under-represented undergraduates by creating societally meaningful projects on microgrids.The goal of this project is to (a) take a rigorous step toward deriving the sufficient criteria for large-signal global stability in DC microgrids with multiple distributed energy sources and constant power loads, which is still an unsolved puzzle because traditional small-signal stability analysis does not apply to converter-dominated power systems when a large disturbance occurs, such as a fault, a pulse power load, or load switching; and (b) investigate a systematic methodology to improve the global asymptotic stability of a converter-dominated DC microgrid in a theoretically sound yet easy-to-implement manner, ultimately bridging the technology gap between three traditionally disjointed areas: control theory, power systems, and power electronics. The proposed project aims to fulfill this goal by leveraging the range and depth of the PIs’ expertise (e.g., power systems, power electronics, optimization, control theory, and machine learning). The proposed research will have intellectual merits in the following areas: (1) a fundamental knowledge base to understand the large-signal stability criteria of inertia-less DC microgrids with 100% penetration of constant power loads and converter-based distributed energy sources; (2) a stability-aware converter to collectively improve the global asymptotic stability of converter-dominated DC microgrids in a theoretically sound yet easy-to-implement manner; (3) rigorous mathematical methods and safe learning algorithms for estimating the region of attraction of a general dynamic system (i.e., a DC microgrid) with multiple equilibria; and (4) a power-hardware-in-the-loop testbed allowing for dynamic interactions of the proof-of-concept prototypes of innovative stability-aware converters.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

标题：协作研究：以转换器为主导的直流微电网的大信号稳定性分析和增强摘要：虽然直流微电网具有许多众所周知的优点（例如，更简单、更高效和紧凑的电力转换系统以及电缆中铜消耗更少） 、独特的直流电气特性，例如直接 P-V 耦合（即，即使很小的负载/发电变化也会导致电压闪变和设备故障）和低系统惯性（即过载能力很小），对电网稳定性提出了很大的挑战，小信号稳定性只能保证系统在平衡点的稳定性，但无法确定稳定域的真实边界；文献中现有的大信号分析工具在保证系统稳定性方面存在很大的局限性，要么适用范围有限，要么理论基础不严谨，因此迫切需要开发大信号的基础知识库。稳定性分析该项目的研究成果直接有助于我国通过越来越多的微电网和分布式能源维持高可靠性和弹性电力的总体目标。教育和推广研究计划将 (i) 将该项目的理论框架、数据集和测试平台纳入密歇根大学迪尔伯恩分校和德克萨斯大学奥斯汀分校的现有课程中；(ii) 促进 K-12 学生的“感兴趣STEM；(iii) 通过公共网站、顶级会议和期刊出版物以及多种媒体在公共领域传播所有项目材料、流程、设计和结果；以及 (iv) 为代表性不足的本科生提供丰富的研究机会；通过在微电网上创建具有社会意义的项目。该项目的目标是 (a) 采取严格的步骤，推导出具有多个分布式能源和恒定功率负载的直流微电网中大信号足够的全局稳定性的标准，这仍然是一个未解决的难题，因为当发生大扰动（例如故障、脉冲功率负载或负载切换）时，传统的小信号稳定性分析不适用于以转换器为主的电力系统；以及（b）研究一种系统方法来改进全局稳定性；以理论上合理且易于实施的方式实现以转换器为主导的直流微电网的渐近稳定性，最终弥合三个传统上脱节的领域：控制理论、电力系统和电力电子之间的技术差距。通过利用 PI 专业知识的广度和深度（例如电力系统、电力电子、优化、控制理论和机器学习）来实现这一目标。拟议的研究将在以下领域具有智力优势：(1) 基础知识。知识库，了解恒功率负载 100% 渗透的无惯量直流微电网和基于转换器的分布式能源的大信号稳定性标准；(2) 稳定性感知转换器，以共同提高全球的稳定性。以理论上合理且易于实现的方式实现变流器主导的直流微电网的渐近稳定性；（3）用于估计具有多个的一般动态系统（即直流微电网）的吸引区域的严格数学方法和安全学习算法； (4) 电源硬件在环测试台，允许创新稳定性感知转换器的概念验证原型进行动态交互。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。

项目成果

Shared Redundancy Strategy to Improve the Reliability and Fault-Tolerant Capability of Modular Multilevel Converter

提高模块化多电平变换器可靠性和容错能力的共享冗余策略

• DOI: 10.1109/tie.2022.3181416
• 发表时间: 2023-04-01
• 期刊: IEEE Transactions on Industrial Electronics
• 影响因子: 7.7
• 作者: Saleh Farzamkia;Houshang Salimian Rizi;A. Huang;H. Iman‐Eini
• 通讯作者: H. Iman‐Eini