负荷分布对互联电网低频振荡的影响

负荷是电力系统的重要组成部分,其对互联电网的低频振荡特性具有重要影响。通过Phillips-Heffron模型的推导,研究负荷接入位置及大小对互联电网低频振荡影响的机理。首先,以单机无穷大系统为例,推导含有负荷的阻尼转矩系数表达式,分析负荷分布对阻尼转矩系数的影响变化趋势;然后,将电磁转矩分析方法推广到两机系统,分析区间振荡模式下发电机自身阻尼和系统阻尼受负荷接入位置和负荷大小的影响规律;并通过算例验证理论分析的正确性。

The influence of load distribution on low frequency oscillation in power system

Power load is an important part of power system,which has a significant impact on the low-frequency oscillation characteristics of interconnected power grid.In this paper,the influence mechanism of the load location and load size on the low-frequency oscillation in power system was analyzed based on Phillips-Heffron Model.Firstly,in the single machine infinite bus system with the load,the damping torque coefficient expression was derived and the influence of load on damping torque coefficient was analyzed.Then,the electrical torque oscillation analysis method was extended to a two-machine power system.The influence of load location and load size on the single generator damping and system damping in inter-area oscillation mode was analyzed.Finally,an example testing resultsverified the validity and efficiency of theoretical analysis.