基于第一标准型含直驱风电场并网引发系统次同步振荡特性的分析

Analysis on Characteristics of Secondary Synchronizing Oscillation Incurred in Wind Power Plant Connection Including Direct Driving to the Grid Based on First Standard Model

在现如今风火打捆的输电方式日益增长的情况下,中国多个地区的火电厂汽轮机组轴系扭振保护由于系统次同步振荡而动作跳闸,大规模风电场并网可能会导致火电厂汽轮机组轴系扭振加剧。为深入研究该问题,针对新疆某直驱风电场并网引发的次同步振荡问题展开研究。文章建立含直驱风电场和火电厂汽轮机组的系统数学模型,再利用特征结构分析法研究风电场并网后对系统次同步振荡造成的影响,并利用PSCAD仿真平台建立时域仿真,对特征结构分析的结果进行验证。结果表明,直驱风电场并网在一定的条件下会使得邻近汽轮机组次同步振荡阻尼下降,但不会改变次同步振荡模式的数量和频率的大小。最后,指出了这种次同步振荡的危害。

With increment of the wind-thermal power integrated transmission, the torsional vibration protection of the turbine system in some thermal power plants in several regions in China trips as the secondary synchronizing oscillation of the system. Inclusion of the wind power plants in a large quantity to the national grid may result in intension of the torsional vibration. To deeply study this subject, the secondary synchronizing oscillation caused by inclusion of one direct-driving wind farm in Xinjiang is analyzed. The mathematical model for the direct-driving wind farm and the thermal power plant system is built. The characteristic structural analysis method is applied to study impacts on the secondary synchronizing oscillation of the system by the inclusion of the wind power plant. Furthermore, the PSCAD simulating platform is applied to build the time-domain simulation so as to verify the results from the characteristic structural analysis method. The study proves that inclusion of the direct-driving wind farm to the grid may, at certain conditions, decrease damping of the secondary synchronizing oscillation of the nearby unit but quantity and frequency of the synchronizing oscillation mode cannot be changed. In the paper, hazards of the synchronizing oscillation are also described.