混合双馈入系统对风电外送能力的提升分析

Analysis on the Mixed Dual Feed-in System in Improving Wind Power Transmission Capacity

由于我国高负荷地区聚集,能源呈逆向分布,风电消纳主要以外送为主,针对风电场大量弃风的现象和高压直流输电网架的大量建设,提出了一种能够提高风电外送能力的混合双馈入直流输电系统。该系统是在传统风火联网直流外送基础上,增加风电孤岛经VSC直流外送系统,提出由短路容量比、直流最大传输功率指标与传统双馈入系统进行对比,在DIg SILENT软件中建模,结果显示了混合双馈入的优越性,最后基于故障扰动法对混合双馈入和传统双馈入的暂态特性进行对比分析,仿真结果表明混合双馈入系统能增加风电场的外送功率,故障期间VSC系统可以有效调节电网侧交流母线电压,增加LCC直流通道的外送功率。

In this paper,a kind of mixed dual feed-in DC transmission system is proposed because of aggregation of high load area in China,reverse distribution of power and main transmission of wind power consumption and as for large number of wind abandon circumstance and large construction HVDC transmission grid. This system is based on wind and thermal interconnection DC transmission,to add wind power island through VSC DC transmission system. The comparison among short circuit capacity ratio,the maximum DC transmission power index and traditional dual feed-in system is proposed and the simulation model is set up in DIg SILENT software and the superiority of the mixed dual feed-in is shown by the result. Finally,the transient characteristics of dual and traditional feed-in based on fault disturbance method is compared and analyzed. The simulation results show that the mixed dual feed-in system can increase transmission power of wind farm,the VSC system can regulate effectively AC busbar voltage at power grid side during the fault and increase transmission power of LCC DC channel.