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

由于环境、经济和技术方面的考虑，电网面临着前所未有的现代化压力。配电系统越来越多地将可再生能源驱动的分布式发电单元和分布式储能单元集成在一起。这些资源大多产生直流电，并通过电力电子转换器与主机电网接口。大量以交流电形式传输的能量现在被以直流电形式消耗（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载，配电系统正在发展成为由几个交流和直流子电网组成的混合交流-直流系统，这些子电网通过电力电子变流器相互连接。电力电子和控制系统是交直流配电系统的关键推动者。现有的电力电子变换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、功率密集、容错和可扩展的多端口电力电子转换器，以实现可靠和经济高效的交流和直流终端集成。模块化多端口转换器拓扑最近被提出用于中高压交直流电网应用；然而，其优化设计、系统分析与控制设计、故障运行、与可再生能源和储能资源的整合等方面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变流器主导的电网，具有比传统电网更快的动态和复杂的控制系统相互作用。这种相互作用既不被理解也不被量化，因此，实际上没有用于控制系统协调和减轻不稳定性的系统工具。最后，下一代交直流配电系统的几种系统级实时控制算法尚不存在。鲁棒能量管理的实时算法、通过电力电子变流器协调控制的电网故障管理算法以及与输电网控制器的协同控制算法还有待开发。提出的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，从而开发可靠，高效和优化管理的交流-直流配电系统。基础研究涉及功率转换、建模、控制和系统优化等理论，旨在提高知识水平，为高素质人才提供培训，并为加拿大工业界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.