大容量直流输电系统的受端接入模式比较

Comparison and Analysis of Receiving-End Connection Modes for Large-Capacity HVDC

首先分析了大容量直流输电(large-capacity high voltage direct current,large-capacity HVDC)系统常规接入模式(general connection mode,GCM)、分极接入模式(separate poles mode,SPM)和分层接入模式(hierarchical connection mode,HCM)的结构特点,对比了3种接入模式对系统中其他直流系统多馈入短路比(multi-feed short-circuit ratio,M ISCR)的影响,并得到落点选择的约束条件,使受端交流系统对直流系统的电压支撑能力整体提升,较好地平衡了限制短路电流与增加多馈入短路比间的矛盾。之后,提出了基于最大功率曲线法的静态稳定接纳系数指标用于判断受端电网接纳直流功率的能力。最后,结合南方电网2020年的规划数据,从多个方面对比分析了3种接入模式的优缺点,为直流系统接入模式的规划提供决策参考和技术支撑。

This paper firstly analyzes the structural characteristics of three connection modes for large-capacity high voltage direct current （ large-capacity HVDC） systems ~ general connection mode （ GCM）, separate poles mode （SPM） and hierarchical connection mode （ HCM）, compares the impacts of these three connection mode on the multi-feed short-circuit ratio （MISCR） of other DC systems and obtains the constraint conditions of placement selection, which can improve the voltage supporting ability of receiving-end AC system for DC system, and better balance the contradiction between the short circuit current limiting and multi-feed short-circuit ratio （ MISCR）. And then this paper puts forward a margin receiving indicator of steady-state stability to evaluate the DC power absorbing ability of receiving system based on the maximum power curve method. Finally, combing with the 2020 planning data from the China Southern Power Grid, this paper compares and analyzes the advantages and disadvantages of the 3 access modes from several aspects, which can provide decision reference and technical support for the planning of DC system access mode.