双馈风电场并网对汽轮发电机次同步振荡的影响

Impact of DFIG-based wind farms interconnected to power grid on subsynchronous oscillation of turbogenerator

考虑在风火打捆输电方式中大容量风电场并网可能会加剧汽轮发电机轴系扭振的风险,提出双馈风电场并网对汽轮发电机次同步振荡影响的研究。首先建立含风电场系统的小信号稳定分析数学模型,基于模态分析法研究风电场并网前后系统次同步振荡模式的变化,并利用数字仿真平台建立时域仿真,对模态分析结果进行验证。其次,借鉴参数灵敏度概念,研究系统次同步振荡阻尼比对风电场参数的灵敏度。最后,针对风电场在不同风速和不同无功功率的情况下,研究含风电场的电力系统次同步振荡模式的变化规律。结果表明,在保持外部条件一定情况下,双馈风电场并网会降低系统次同步振荡阻尼,且风电场有功功率和无功功率参数对其次同步振荡阻尼影响明显。

Considering the shaft torsional vibration risk of the turbogenerator caused by the integration of large capacity wind farms in wind ＆ thermal power transmission system, the impact of doubly fed induc- tion generator （DFIG）-based wind farms interconnected to power grid on subsynchronous oscillation of turbogenerator was investigated. Firstly, the detailed mathematical models for the small signal stability a- nalysis with DFIG-based wind farms were established. By utilizing modal analysis method, the changes of the system subsynchronous oscillation modes with and without DFIG-based wind farms were investigated, respectively, and the presented models and modal analysis were demonstrated by comparison with the time-domain simulation results. Then, based on the concept of parameter sensitivity, the analytical sensi- tivity expression of subsynehronous oscillation damping ratio on wind farm parameters was deduced. Fi- nally, Regarding for the different conditions of wind speed and reactive power of the wind farms, the vari- ation of subsynchronous oscillation mode was discussed. The results show that the connected DFIG-based wind farm could reduce the subsynchronous oscillation damping in keeping the external condition. Fur- thermore, the parameters of active power and reactive power of the wind farms have an obvious effect on the system subsynchronous oscillation damping.