Collaborative Research: Hierarchical Intelligent and Adaptive Techniques to Enable Resilient DC Power Systems

随着采用固有直流电压的能源和负载的不断增加，基于直流电源的电力系统可以提供比交流电源更高的效率、更少的功率转换阶段、更小的占地面积和更高的可靠性。由于这些原因，直流电力系统和微电网现在被用于电动汽车、船舶、飞机和农村地区。然而，直流电网中的电气故障可能导致极其危险的情况，比交流电网更难中断，特别是由于缺乏零电压交叉点。此外，由于故障电流很小，因此很难检测到电弧形式的高阻抗故障，例如由松动的连接或磨损的导线引起的故障。带有先进控制器的电子负载的高渗透率使得故障检测和定位变得更加困难。为了提高基于直流的系统的安全性和弹性，拟议的项目将通过开发建立在全面和系统的故障建模和表征研究基础上的智能和自适应故障检测、定位和隔离技术来解决直流电力系统中检测高阻抗故障的这些技术挑战。这些技术可以显著提高现有和未来直流系统的性能，使其能够在更大范围内广泛采用，可以为许多可再生资源、储能单元和现代电子负载提供高效可靠的接口，并与国家在使用清洁和绿色能源方面的倡议保持一致。这个项目本质上是多学科的，将先进和令人兴奋的现代控制理论、人工智能和信号处理技术引入电力工程。该项目的任务涉及从软件仿真和控制算法到硬件测试；从电路级研究到系统级实施的广泛专业知识和经验，这为未来的工程师提供了一个独特的高质量的培训机会。拟议的教育活动还将扩大妇女和其他代表性不足的学生的参与。拟议研究的目标是通过具有智能和自适应功能的分层方法，为现代直流电力系统开发故障检测、定位和隔离技术。它以系统和变革性的努力解决了直流电力系统保护中最具挑战性的问题。拟议项目的故障建模和表征研究将通过全面的实验和分析方法，在现代应用环境中产生高阻抗故障的基础和关键知识。所提出的高阻抗故障检测和定位技术将通过动态参数估计来考虑先进控制器的影响。将采用现代非线性控制理论和人工智能工具，开发的自适应集成故障检测和定位方案将极大地改进现有保护系统设计和在线稳定性评估方法。该研究有望对直流电力系统领域产生重要的理论和实用价值。成功完成后，该项目有可能彻底改变直流电力系统的控制和保护方面，最大限度地减少高阻抗故障和恒定功率负载的不利影响。建议的技术可应用于不同规模的直流系统，从孤立的直流配电网络到互联的直流微电网，以提高故障保护的有效性，从而提高其弹性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

As the adoption of energy sources and loads with inherent dc voltage continues to increase, an electric system based on dc power can offer tremendous advantages over ac, with higher efficiency, less power conversion stages, smaller footprint, and higher reliability. For these reasons, dc power systems and microgrids are now used in electric vehicles, ships, aircraft, and in rural areas. However, electrical faults in dc power networks can lead to extremely dangerous situations which are more difficult to interrupt than their ac counterparts, particularly due to the lack of zero voltage crossings. Moreover, high impedance faults in the form of electrical arcs, such as those caused by loose connections or chafed wires, are very difficult to detect because of the low fault current. The high penetration of electronics loads with advanced controllers make the fault detection and localization even more challenging. To increase the safety and resiliency of dc based systems, the proposed project will address these technical challenges in detecting high impedance faults in dc power systems by developing intelligent and adaptive fault detection, localization, and isolation techniques that are built upon a comprehensive and systematic fault modeling and characterization study. These techniques can significantly improve the performance of existing and future dc systems to enable their wide adoption at larger scales, which can provide efficient and reliable interfaces to many renewable resources, energy storage units, and modern electronic loads and align with the nation's initiatives in using clean and green energy. This project is intrinsically multidisciplinary by bringing advanced and exciting modern control theories, artificial intelligence, and signal processing techniques into electric power engineering. The tasks in this project involve a wide range of expertise and experience from software simulation and control algorithms to hardware testing; from circuit level study to system level implementation, which provides a unique and high quality training opportunity for future engineers. The proposed educational activities will also broaden participation of women and other under-represented students.The goal of the proposed research is to develop fault detection, localization, and isolation techniques for modern dc power systems through a hierarchical approach with intelligent and adaptive functionalities. It addresses the most challenging issues in the protection of dc power systems with a systematic and transformative effort. The fault modeling and characterization study of the proposed project will generate fundamental and critical knowledge of high impedance faults in modern application settings through comprehensive experimental and analytical approaches. The proposed high impedance fault detection and localization techniques will take into account the effect of advanced controllers through dynamic parameter estimation. The adaptive and integrated fault detection and localization schemes to be developed will significantly enhance the existing protection system design and online stability assessment methodologies by adopting modern nonlinear control theory and artificial intelligence tools. The proposed research is expected to produce significant results of both theoretical and practical values to the field of dc power systems. When successfully completed, the project has the potential to revolutionize the control and protection aspects of dc power systems, minimizing the adverse impact of high impedance faults and constant power loads. The proposed techniques can be applied to dc systems in different scales ranging from isolated dc distribution networks to interconnected dc microgrids, to improve the fault protection effectiveness and therefore their resiliency.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.