ERI: Efficient and Power-Dense Modular Power Electronic Architecture for Utility-Scale DC-AC Conversion

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。作为一个致力于清洁能源未来的社会，可再生能源的整合被认为越来越重要。美国能源情报署预计，可再生能源在美国发电中的份额将从2019年的19%增加到2050年的38%。大部分增长来自风能和太阳能，到2050年，这两种能源将占可再生能源总量的近80%。由于它们的间歇性，能量储存变得至关重要。电池储能系统具有高能量密度、高能效、低自放电等优点，是目前发展最快的储能技术之一。为了使直流电池与交流电网互连，电力电子转换器是必要的。这样的转换器要求其构建模块（半导体开关、电感器和电容器）符合公用事业规模规格。目前的商业实现具有二/三电平变换器和电压升压功能的变压器。变压器体积大、损耗大、价格昂贵。与这些解决方案相比，模块化电子转换器具有更好的可扩展性、容错性和可靠性。本项目专注于基础构建模块的变革性设计，以构建适合电池储能系统的创新，高效和功率密集的DC-AC模块拓扑。该模块的创新之处在于三相集成设计，可实现高密度、高效的功率转换。该项目还通过部署学习工具和夏季电力转换项目促进本科生和高中生的参与，以吸引来自代表性不足社区的学生。现有的模块化拓扑结构由于其固有的转换器设计而存在功率密度低和效率低的问题。它们需要额外的组件，如滤波器和/或DC-DC转换器，以克服由转换器作用施加的低质量波形。文献研究表明，这些元件可占变流器体积的40%-80%，并造成50%-75%的变流器损耗。使用滤波器需要体积庞大的电容器，这被认为是最薄弱的环节，对系统的使用寿命是有害的。这个项目的重点是通过专注于基础构建模块的创新设计来消除这些组件。该项目的第一个重点将是建立建议设计的基本和分析理论，包括动态和稳态模型。这些模型将为开发电池储能系统的鲁棒调制和控制方法奠定基础。利用第一次推力的结果，该项目将提供一个实验室规模的工作原型，展示高度可扩展和模块化的设计特征。此外，结果将提供详细的比较研究，以量化效率和功率密度方面的预期定性效益。工作的目的是为未来超密集和高效的模块化电力电子变换器奠定基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).As a society striving towards a clean energy future, integration of renewable energy sources is considered increasingly essential. The U.S. Energy Information Administration projects the share of renewables in the U.S. electricity generation to increase from 19% in 2019 to 38% in 2050. Most of the growth is attributed to wind and solar, which will account for nearly 80% of the renewables total in 2050. Due to their intermittency, energy storage is becoming critical. Battery energy storage systems are one of the fastest growing energy storage technologies due to their high energy densities, efficiency, and low self-discharge. To interconnect the DC batteries with the AC utility grid, power electronic converters are necessary. Such converters require that their building blocks (semiconductor switches, inductors, and capacitors) be rated for utility-scale specifications. Current commercial implementations feature a two/three-level converter with a transformer for voltage step-up function. Transformers are bulky, lossy, and costly. In contrast to these solutions, modular electronic converters have improved scalability, fault-tolerance, and reliability. This project focuses on a transformative design of a fundamental building block module to build an innovative, efficient, and power-dense DC-AC modular topology suitable for a battery energy storage system. The innovative feature of the proposed module is the three-phase integrated design, which enables high-density and efficient power conversion. The project also facilitates the involvement of undergraduate and high-school students through the deployment of learning tools and summer programs in power conversion to engage students from underrepresented communities.Existing modular topologies suffer from poor power density and low efficiencies which stem from their inherent converter design. They require additional components such as filters and/or DC-DC converters to overcome the low-quality waveforms imposed by the converter action. Literature studies indicate that these components can occupy 40%-80% of the converter volume and contribute to 50%-75% of the converter losses. The use of filters requires bulky capacitors, which are considered the weakest link and are detrimental to the system’s lifetime. The focal point of this project is the elimination of these components by focusing on an innovative design of the fundamental building block module. The first thrust of the project will aim to establish the fundamental and analytical theory of the proposed design including dynamic and steady-state models. These models will lay the groundwork to develop robust modulation and control methods for battery energy storage systems. Using the results from the first thrust, the project will deliver a laboratory-scale working prototype that demonstrates the highly scalable and modular design features. Further, the results will deliver detailed comparative studies to quantify the expected qualitative benefits in terms of efficiency and power density. The aim of the work is to lay the foundation of future ultra-dense and efficient class of modular power electronic 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.