考虑限流型能量路由器的微网群故障穿越协调控制研究

In order to fully take advantage of large-scale distributed generation (DG) units, the introduction of microgrid clusters is a critical approach, which is able to offer more flexibility and robustness than a single microgrid. However, for the fault ride-through (FRT) issue of microgrid clusters, there are very few works on its mechanism, and a valid solution is still absent. Based on Lyapunov function, this project plans to investigate the transient behaviors of the microgrid clusters with multiple sub-microgrids, and it is expected to clarify the relationship between the FRT capability of each sub-microgrid and the transient stability of the microgrid clusters. Then, the sensitivity and tolerability of each sub-microgrid towards the short-circuit faults will be considered, and the time-domain simulation on the microgrid clusters will be conducted, so as to study the FRT mechanism and FRT indexes of the microgrid clusters. Furthermore, this project plans to propose a novel energy router with great current-limiting capability for the microgrid clusters, and it is to suppress the potential short-circuit current and to achieve the prerequisite of the FRT operation. To strengthen the safety and stability of the microgrid clusters under the process of the FRT operation and after the fault is removed, a hierarchical coordination control based on multi-agent system (MAS) will be proposed for the microgrid clusters, and it is to achieve an efficient cooperation among all of the sub-microgrids. The detailed research contents of this project will cover the following aspects: 1) Investigating the typical structure, operation mode and basic control of the microgrid clusters considering energy routers. 2) Studying the transient stability, FRT mechanism and FRT indexes of the microgrid clusters. 3) Researching the topology structure, work principle and parameter configuration of the energy router with duplicated current-limiting functions. 4) Exploring the hierarchical coordination control based on MAS to handle the FRT issue of the microgrid clusters. According to the achievements of this project, the FRT mechanism of the microgrid clusters will be revealed, and a feasible method to improve the FRT capability of the microgrid clusters will be put forward. This project enables to provide a solid theoretical foundation for that the microgrid clusters can flexibly and effectively deal with the short-circuit faults.

微网群是促进规模化分布式能源消纳的重要途径，比单微网具备更强的灵活性和鲁棒性。但是，针对微网群的故障穿越问题，目前仍缺乏系统性研究与有效解决手段。本项目拟采取李雅普诺夫法探讨各子微网的故障穿越能力与微网群暂态稳定性之间的关系，考虑各子微网对短路故障的敏感性和耐受性并结合时域仿真，研究微网群故障穿越机理及其关键指标。本项目拟应用限流型能量路由器抑制短路电流冲击实现故障穿越之前提条件，引入多代理协调控制以确保微网群在故障穿越期间及故障清除后的安全稳定运行。研究内容有：1）考虑能量路由器的微网群典型架构、运行方式和基本控制；2）微网群暂态稳定性分析与故障穿越机理及其关键指标；3）计及双重化故障抑制的限流型能量路由器拓扑结构、工作原理和参数配置；4）基于多代理系统的微网群故障穿越层次化协调控制。本项目旨在揭示微网群故障穿越机理，提出故障穿越的解决手段，为微网群灵活应对短路故障奠定坚实的理论基础。

微网群对规模化分布式电源的消纳和利用有极强的技术优势，但在带来诸多机遇的同时也引发了新的难题，妥善处理微网群的故障穿越问题，保障微网群及相连配网的安全稳定具有重要意义。本项目以考虑能量路由器的微网群故障穿越为研究对象，计及限流型能量路由器的结构原理、控制策略及微网群的故障暂态特性，采取理论分析与仿真验证等手段，系统地研究了微网群暂态稳定分析模型、分析方法与故障穿越协调控制方法，有效增强了微网群应对短路故障的鲁棒性。.按照项目任务书研究计划，掌握了考虑能量路由器的微网群典型架构、运行方式和基本控制策略，建立了详细电磁暂态仿真模型并验证了其正确性；提出了基于能量函数的微网群暂态稳定性分析模型和分析方法，揭示了子微网的故障穿越能力与微网群暂态稳定性之间的关系，明确了各子微网对短路故障的敏感性和耐受性；提出了计及虚实融合双重化故障抑制的限流型能量路由器拓扑结构、工作原理和参数配置方法，实现了微网群在不同故障工况下的短路电流充分抑制；提出了基于深度强化学习的微网群故障穿越协调控制方法，实现了微网群在故障穿越期间及故障清除后的安全稳定运行。.本项目研究成果理清了微网群暂态稳定性的主次因素，建立了考虑能量路由器的微网群故障穿越关键指标，提出了切实可行的穿越辅助措施，为微网群灵活应对短路故障奠定了坚实的技术基础。