一种与直流暂态稳定强相关的交流断面识别方法

随着投运直流的不断增加，电力系统中交直流系统间的耦合程度越加紧密，相互影响更加密切。量化评估直流与交流多断面间的暂态稳定耦合程度，进而实现自动搜索识别与直流暂态稳定强相关的交流断面对于提高电力系统安全稳定协调优化控制和在线辅助决策水平都具有重要意义。基于EEAC理论，分析了直流与交流输电断面暂态稳定耦合的机理，通过计算直流不同功率扰动下的系统不同分群下各映象的暂态稳定裕度，并拟合直流扰动功率下交流断面的暂态稳定裕度曲线，从而量化评估直流与交流断面间的暂态稳定耦合程度。该方法可同时识别多个交流输电断面与多条直流暂态稳定耦合相关性。通过实际电网的算例验证方法的有效性。

A quantitative assessment method for degree of transient stability coupling of DC and AC transmission sections

Along with increasing operation of DC, the coupling degree between DC and AC power systems is more tightly and the influence with each other is more closely. It has great significance on improving the level of coordinated optimization control of power system security and stability and online auxiliary decision-making for evaluating the degree of transient stability coupling between DC and AC transmission sections quantitatively, and then searching automatically and identifying the more closely related AC transmission sections with the transient stability coupling between DC and AC transmission sections. The transient stability coupling mechanism between DC and AC transmission sections is revealed by the theory of Extended Equal Area Criterion. On this basis, the matrix of transient stability margin of the dominant generators image of AC transmission sections is established through different DC power disturbances, and then the curves can be fitted with least square method. The curve slopes reflect quantitatively the transient stability coupling between DC and AC transmission sections. Finally, the example demonstrates the effectiveness of the method.