Power Electronic Converter and Control System Technologies for AC-DC Distribution Systems

在环境、经济和技术问题的推动下，电网面临着前所未有的现代化压力。配电系统越来越多地集成了由可再生能源提供动力的分布式发电单元和分布式储能单元。这些资源中的大多数产生直流电，并通过电力电子转换器连接到主机电网。以交流方式输送的大量能源现在以直流方式消耗(例如，电动汽车及其充电站、电机驱动器、数据中心和消费电子产品)。为了有效地整合这些资源和负荷，配电系统正在发展成为由多个交流和直流子电网通过电力电子换流器互联组成的交直流混合系统。电力电子和控制系统是交直流配电系统的关键驱动因素。现有的电力电子变流器和控制系统技术在几个关键的新兴领域存在不足。首先，中压交直流配电系统需要高效率、高功率密度、容错和可扩展的多端口电力电子转换器，以实现交流和直流终端的可靠和经济有效的集成。模块化多端口变流器拓扑最近被提出用于中高压交直流电网，但其优化设计、系统分析和控制设计、故障下运行以及与可再生能源和储能资源集成的理论和算法尚不存在。其次，交直流配电系统将主要是电力电子换流器为主的电网，比传统电网具有更快的动态响应速度和复杂的控制系统交互作用。这种相互作用既不被理解，也不被量化，因此，实际上没有系统的工具来协调控制系统和减轻不稳定性。最后，下一代交直流配电系统的几种系统级实时控制算法还不存在。用于稳健能源管理、通过电力电子换流器协调控制的电网故障管理以及与传输网络控制器的协调控制的实时算法还有待开发。拟议研究计划的主要目标是开发改进的和新的电力电子转换器和控制系统技术，使开发可靠、高效和优化管理的交-直流配电系统成为可能。涉及电力转换、建模、控制和系统优化理论的基础研究有望提高知识，为高素质的人才提供培训，并为加拿大行业提供及时的知识和解决方案。

Driven by environmental, economic, and technical concerns, power grids are facing unprecedented pressure to modernize. Power distribution systems are increasingly integrating distributed generation units empowered by renewable energy resources and distributed energy storage units. Most of these resources produce dc power and interfaced to host grids via power electronic converters. Large amounts of energy delivered as ac are now consumed as dc (e.g., electric vehicles and their charging stations, motor drives, data centers, and consumer electronics). To integrate these resources and loads efficiently, distribution systems are evolving to become hybrid ac-dc systems composed of several ac and dc subgrids interconnected via power electronic converters. Power electronics and control systems are the key enablers for ac-dc distribution systems. Existing power electronic converter and control system technologies fall short in several key emerging areas. First, medium-voltage ac-dc distribution systems demand highly efficient, power-dense, fault-tolerant, and scalable power electronic converters with multiple ports for reliable and cost-effective integration of ac and dc terminals. Modular multiport converter topologies have been recently proposed for medium- and high-voltage ac-dc grid applications; however, theory and algorithms for their optimal design, systematic analysis and control design, operation under faults, and integration with renewable and energy storage resources do not exist. Secondly, ac-dc distribution systems will mostly be power electronic converter-dominated grids with faster dynamics and complicated control systems interactions than classical grids. Such interactions are neither understood nor quantified, and, as a result, there are virtually no systematic tools for control systems coordination and instability mitigation. Finally, several system-level real-time control algorithms of next-generation ac-dc distribution systems do not exist. Real-time algorithms for robust energy management, grid fault management via coordinated control of power electronic converters, and cooperative control with transmission network controllers are yet to be developed. The main objective of the proposed research program is to develop improved and new power electronic converter and control system technologies enabling the development of reliable, efficient, and optimally managed ac-dc distribution systems. The fundamental research involving theories in power conversion, modeling, control, and system optimization is expected to advance knowledge, provide training to highly qualified personnel, and provide timely knowledge and solutions to the Canadian industry.