联络线有功潮流对互联电网低频振荡阻尼的影响研究

Influence of Tie-line Power on Low-frequency Oscillations Damping of Interconnected Power System

近年来,大区互联电网中的低频振荡现象时有发生,严重危害电网的正常运行。通过推导两机互联系统的阻尼转矩表达式,从理论上分析了电网低频振荡阻尼的影响因素,重点研究了联络线有功潮流变化对系统阻尼的影响。对四机两区域系统模型和某大区互联电网进行仿真分析,结果表明影响该电网内联络线低频振荡的主要因素是联络线有功潮流的大小,与故障线路的有功潮流大小没有直接关系,同时得到该联络线上的有功潮流极限。

The frequent occurrence of low-frequency oscillations in power system brings in a great harm on normal operation of the grid. The damping torque expression has been firstly derived applied in the two-machine interconnection system, which analyzes the impact of the change of tie-line power on the system damp theoretically. By simulating the operation of the four-machine two-region with some grid, the impact on the system damp is verified, yielding a valuable conclusion that power on the tie line is the main factor of influence on low-frequency oscillations.