大规模电力外送通道重合闸所致重大风险分析与规避控制策略研究

在当前不断涌现的大规模电力外送通道上，因重合闸失败或不合理动作所致后果将可能波及区域电网，甚至危及系统全局。本项目拟从系统级安全层面出发，分析重合闸盲目重合加剧系统失稳及发电机群纵序脱机、自适应单相重合闸诱发发电机负序保护动作切机、短路电流超标ARSIP技术危及系统失稳等现有重合闸技术对电力系统非正常运行期间所造成的重大风险。并以此为着眼点，寻求规避上述风险的控制策略：提出建立系统层面的能量再平衡协调优化模型，研究重合于永久性故障下的基于直流功率快速调制的大规模送端系统首摆稳定性附加控制理论；探索非全相运行期间全网负序电流分布规律，并在发电机极限耐受时间约束下，提出基于负序电流有效弱化的保护核心判据；依托大数据和人工智能辅助决策基本理论，研究应对短路电流超标N-x主动故障隔离的智能型广义重合闸。本项目研究成果将为有效规避重合闸相关问题所致电网重大安全隐患的基本理论和关键技术奠定坚实基础。

Followed by the rapidly emerging large-scale channels for power delivery, the consequences of reclosing failure or its unreasonable operation may threaten the regional power grid or even the overall system. This project intends to analyze the major risks caused by the existing reclosing technology during the abnormal operation of power system from the system-level security. Major risks are mainly characterized by: blind operation of reclosing increases instability of system and vertical sequence off-line of generator group; long exposure to large negative-sequence currents during adaptive single-phase reclosing causing synchronous generators off grid; ARSIP technology causes system instability under short-circuit-current exceeds standard. Focus on this and seek control strategies to avoid the above risks: 1) establish a system-level energy rebalance coordination and optimization model, and study the additional control theory of the stability of the first swing of the large-scale transmission system based on rapid modulation of DC power under permanent faults. 2) explores the distribution law of negative-sequence current in the whole network during the open-phase operation, and puts forward the core criterion of protection based on the effective weakening of negative-sequence current, under the constraints of the limit of generator tolerance time. 3) study the intelligent generalized reclosing to deal with the N-x active fault isolation in short-circuit-current excessive scenarios, based on big data and artificial intelligence-assisted decision-making theory. The research of this project will lay a foundation for constructing the basic theory and key technology of effectively mitigating the major potential safety risks of reclosing.