含柔性多状态开关的多端互联配电系统可靠性评估与量化分析

Reliability Evaluation and Quantitative Analysis of Multi-terminal Interconnect Power Distribution System with Flexible Multi-state Switch

为满足多端互联配电系统中柔性多状态开关接入策略规划的需求,提出了含柔性多状态开关的多端柔性互联配电系统可靠性评估方法。首先,基于柔性多状态开关的物理结构及其控制运行策略,建立了柔性多状态开关的可靠性评估模型;其次,依据柔性多状态开关接入系统后带来的系统运行方式及网络结构的改变,设计了失联侧负荷恢复方法并提炼了影响系统可靠性的因素;最后,为兼顾可靠性评估的速度和精度,提出了基于序贯抽样与故障分析解耦的可靠性评估方法,同时量化分析了柔性多状态开关不同的接入策略对系统可靠性的影响。仿真结果表明,柔性多状态开关接入后,可靠性指标系统平均停电频率(system average interruption frequency index,SAIFI)提升了约38.2%,系统平均停电时间(system average interruption duration index, SAIDI)提升约49.6%,系统供电可靠率(average service availability index, ASAI)提升了约1.1%,配网系统可靠性提升显著;同时,对比分析不同柔性多状态开关接入策略下系统可靠性水平,结果表明柔性多状态开关接于系统末端、靠近重要负荷以及接入容量较大时对系统可靠性的提升最优。研究成果可为柔性多状态开关接入策略研究提供理论支撑,同时也可为今后柔性互联配电网的规划设计提供参考。

In order to meet the requirements of flexible multi-state switch access strategy planning in multi-terminal interconnected power distribution systems, a reliability evaluation method for multi-terminal flexible interconnected power distribution systems with flexible multi-state switches is proposed in this paper. Firstly, based on the physical structure of the flexible multi-state switch and its control operation strategy, the reliability evaluation model of the flexible multi-state switch is established. Secondly, based on the system operation mode and network structure change brought by the flexible multi-state switch access system, the load recovery strategy for disconnected side is designed and the factors affecting the system reliability are refined. Finally, a reliability evaluation method based on sequential sampling and fault analysis decoupling is proposed,and the influence of different access strategies of flexible multi-state switches on system reliability is quantitatively analyzed. The simulation results show that after the flexible multi-state switch is connected, the SAIFI is increased by about 38.2%, the SAIDI is increased by about 49.6%, the ASAI is increased by about 1.1%, and the reliability of the distribution network system is improved significantly. The research results can provide theoretical supports for the research of flexible multi-state switch access strategy, and provide references for the planning and design of flexible interconnected power distribution network in the future.