CAREER: Adjustable-Voltage-Ratio Magnetoelectric Transformer: A New Voltage Conversion and Control Device for Smart Grids

电压转换（即将电压从一个电平转换到另一个电平）和控制（即将电压调节在标称值附近的一定范围内）是现代电网安全、经济运行的一个重要问题，特别是可再生能源大量渗透的未来智能电网。在目前的电网中，有载分接变换（OLTC）电磁变压器和步进稳压器已被广泛用于电压转换和控制。然而，用于OLTC变压器和步进稳压器的分接转换机构通常是机械机构或机电机构，响应缓慢，只能以离散的步骤调整变压器或稳压器的电压比。因此，OLTC变压器和步进稳压器不能满足未来智能电网对灵活、连续、快速的电压转换或控制的要求。目前的替代方案是固态变压器（SST）。然而，SSTs目前仍然受到固态器件的电压和功率额定值以及可用电路拓扑结构的限制。此外，与传统的电磁变压器相比，SSTs需要更复杂和昂贵的热管理，并且可能具有更短的预期寿命。这个学院早期职业发展计划（Career）项目将探索和证明一个新颖的概念，即具有连续和快速可调电压比的磁电变压器，用于灵活，快速的电压转换和控制，以帮助确保电力供应，适应更多的可再生能源整合，并降低电力输送成本。此外，项目团队将通过整合研究生和本科生的研究和教学以及K-12外展，建立一个蓬勃发展的多元化电力和能源项目。该项目将为培训新一代年轻专业人员提供一个独特的平台，以适应不断变化的环境，满足美国电力和能源行业新兴的劳动力和教育需求。本计划的研究目标是开发一个完整的框架，用于设计，原型，建模，控制，操作和演示一种新型可调电压比（AVR）磁电变压器，用于灵活，连续和快速作用的电压转换和控制电网。提出的概念的新能力将通过开发：(1)具有可调磁导率的新型电压控制磁电装置来控制变压器中的磁通，(2)集成磁通控制装置的新型变压器结构，以及(3)利用新型磁通控制装置通过调节磁通来控制变压器电压比的新模型和方法来实现。该项目将为克服电网中使用的现有电压转换和控制设备的现有限制提供创新和变革性的解决方案。为新型AVR变压器建立的物理原理和工作原理以及模型和设计框架将为提出的概念在电网中的未来发展和应用奠定坚实的理论基础。一旦提出的概念通过该项目得到证实，进一步发展和部署该概念将需要不同学科的新进展，如电气工程、材料科学与工程、系统与控制工程以及机械工程，从而刺激新的跨学科研究的创造。该项目的研究结果将影响未来电网的控制和运行，并将有助于创建智能电网，以提供更好的电力能源安全性、效率和可持续性。

Voltage conversion (i.e., converting voltage from one level to another) and control (i.e., regulating voltage within a certain range around the nominal value) is an important issue for the secure, economic operation of modern power grids, particularly future smart power grids with significant penetration of renewable energy resources. In current power grids, on-load tap-changing (OLTC) electromagnetic transformers, and step-voltage regulators have been commonly used for voltage conversion and control. However, the tap-changing mechanisms used in OLTC transformers and step-voltage regulators are typically a mechanical mechanism or an electromechanical mechanism with a slow response and can only adjust the voltage ratio of the transformer or regulator in discrete steps. Therefore, OLTC transformers and step-voltage regulators cannot meet the requirement for flexible, continuous, and fast-acting voltage conversion or control for future smart power grids. The current alternative is the solid-state transformer (SST). However, SSTs are currently still limited by voltage and power ratings of the solid-state devices and available circuit topologies. Moreover, when compared to traditional electromagnetic transformers, SSTs would require more complicated and expensive thermal management and may have a shorter life expectancy. This Faculty Early Career Development Program (CAREER) project will explore and prove a novel concept for a magnetoelectric transformer with a continuous and quickly adjustable voltage ratio for flexible, fast-acting voltage conversion and control to help secure the electricity supply, accommodate more renewable energy integration, and reduce the cost of electricity delivery. In addition, the project team will build a thriving, diversified electric power and energy program through the integration of graduate and undergraduate research and teaching with K-12 outreach. The program will provide a unique platform for training a new generation of young professionals to accommodate the changing environment and meet the emerging workforce and educational needs of the U.S. power and energy industry.The research goal of this project is to develop a complete framework for designing, prototyping, modeling, controlling, operating, and demonstrating a novel adjustable-voltage-ratio (AVR) magnetoelectric transformer for flexible, continuous, and fast-acting voltage conversion and control of power grids. The new capabilities of the proposed concept will be achieved through the development of: (1) a new voltage-controlled magnetoelectric device with an adjustable permeability to control the magnetic flux in the transformer, (2) a new transformer configuration for the integration of the flux control devices, and (3) new models and methods for controlling the voltage ratio of the transformer by regulating the magnetic flux using the new flux control devices in the transformer. This project will provide an innovative and transformative solution for overcoming the existing limitations of existing voltage conversion and control devices used in power grids. The physical and operating principles to be established and the models and design framework to be created for the new AVR transformer will build a solid theoretical foundation for future development and application of the proposed concept in power grids. Once the proposed concept is proven by this project, further development and deployment of the concept will require new advancements in different disciplines, such as electrical engineering, material science and engineering, system and control engineering, and mechanical engineering, thus stimulating the creation of new interdisciplinary research. The findings of this project will impact the control and operation of the future power grids, and will contribute to the creation of a smart power grid to provide better electric energy security, efficiency, and sustainability.