适用于配电网柔性互联的新型电能路由器关键技术

With the development of renewable energy, the permeability of renewable energy is increasing in the distribution network. However, the traditional distribution network in the form of one-direction radiation topology is lack of real-time control ability, so that it is difficult to meet the demand of flexible operation. The development of DC distribution network is promoted by distributed power, energy storage and DC load. The flexible interconnection technology and DC distribution network technology are proposed to solve the problem. The combination of flexible interconnection and DC power distribution technology, which constructs the AC/DC hybrid distribution network, can achieve efficient and rapid power flow control with high reliability and flexibility. Thus the flexible interconnection technology of distribution network can improve greatly the power system’s reliability , renewable energy consumptive capability and voltage regulation capability. And the power router is the key device. This project proposes a novel power router that is suitable for flexible interconnection of distribution network. The power router's topology is constructed in detail to analyze its operation mode, and its control strategies are systematically researched for power balance and decoupling coordination. This paper also analyzes the interaction mechanism between power routers and ports, to research the steady-state control technology, transient fault ride-through technology and fault isolation technology. At last, energy management mechanism between the power router and the distribution network is analyzed to verify its feasibility.

随着可再生能源发展，其在配电网中渗透率逐渐上升。然而，传统配电网中单向辐射供电，调控能力欠缺，难以满足灵活实时运行需求。基于电力功率变换的柔性互联技术可实现多配网间灵活、快速的潮流控制。而分布式电源、储能以及直流负荷的发展，推动了直流配电网的发展。将柔性互联和直流配电技术结合，构建网状的交直流混合配电系统，可实现高效、可靠、灵活、快速的潮流控制，极大提高其可靠供电、可再生能源消纳及电压调节能力，优化系统运行水平，而其中电能路由器为其核心电力变换装置。.本课题将研究适用于配电网柔性互联的新型电能路由器，构建新型电能路由器拓扑族，分析其工作机理与运行方式；深入研究电能路由器内部功率平衡控制与端口间的解耦协调控制；分析电能路由器和端口互联网络交互机理，研究其运行控制技术及暂态故障穿越技术、端口间故障传递隔离技术；进而探索电能路由器和各配电网络间的协调控制和能量管理机制，验证其优化系统运行的可行性

未来配电系统具有高比例的分布式电源及柔性负荷（电动汽车、分布式储能）接入、用户高电能质量及多种电能形式的定制需求等特点。因此，以具备电能多路径可控能力，附加电能质量治理功能的电能路由器为核心的互联化柔性交直流混合配电系统是配电网发展的趋势之一。本项目针对适用于互联化柔性交直流混合配电网的新型电能路由器关键技术进行深入研究。研究了电能路由器多级联变换环节能量平衡方法；在此基础上，揭示了多阶变换器的模块间传输功率均衡机理，提出了电能路由器模块间功率均衡控制策略。分析了电能路由器内部波动功率形成机制，提出了基于波动功率传递的模块电容电压波动平抑方法，并给出装置主电路关键参数的优化方案，实现装置紧凑化设计。研究了电能路由器在柔性互联配电网中的多端口之间协调控制策略，实现多网有功功率互备互用；提出了具有中压直流故障耐受能力的电能路由器拓扑及故障穿越控制策略，解决了中压直流短路故障引起的配电网失电问题，可实现短路电流快速清除，以及非故障端口间的不间断供电。进一步的，研究基于主动环流注入的电能路由器低压直流母线真双极运行控制策略，针对装置的多直流端口扩展能力进行了初步探索。搭建了2MVA电能路由器仿真模型与4.8kVA小功率实验样机，对以上控制策略进行了仿真及实验验证。. 本项目完成论文22篇(IEEE Trans on PE 2篇，IEEE Trans on IE 3篇，中国电机工程学报期刊论文6篇、国际会议论文8篇)，授权中国发明专利8项、美国专利2项。