双馈风电机组故障行为及对电力系统暂态稳定性的影响

由于双馈风电机组具有不同于同步发电机的运行特性,且不同型号双馈风电机组在实现故障穿越时采用不同的控制策略,造成大规模风电并网的电力系统暂态稳定性发生变化。文中通过对双馈风电机组控制特点及故障行为的深入研究,指出双馈风电机组的故障行为由故障穿越运行控制策略决定,并给出其等效外特性。基于等面积定则定性分析了双馈风电机组接入单端送电系统后,其故障行为对系统暂态稳定性影响的机理。在理论分析基础上进行了时域仿真验证,仿真结果表明,故障期间减小双馈风电机组有功给定值、增加无功注入控制比例系数有利于系统的暂态功角稳定性,故障清除后有功恢复控制对系统的暂态功角稳定性影响不大,验证了所提理论分析的正确性。

Performances of DFIG-based Wind Turbines During System Fault and Its Impacts on Transient Stability of Power Systems

Because of the difference in the operating characteristics between doubly-fed induction generator (DFIG) based wind turbines and conventional synchronous generators, and the difference in the fault ride through (FRT) technologies adopted by different wind turbines, the transient stability of a power system will change after being integrated with large-scale wind power. Based on the analysis results of DFIG-based wind turbines and their FRT control characteristics, this paper points out that the performances of DFIG-based wind turbines are determined by their FRT control strategies. The equivalent external characteristics of DFIG-based wind turbines are given. The impact of different behaviors of DFIG-based wind turbines on the transient stability of the single-terminal delivery system is analyzed based on the equal area criterion. The time domain simulation is carried out on the basis of theoretical analysis. The simulation results show that reducing active power setpoint or adding reactive power injection proportion coefficient of DFIG-based wind turbines during the fault will enhance the system transient stability, and the active power recovery control following the fault clearance has little effect on the system transient stability. Therefore the correctness of the theoretical analysis proposed has been verified. This work is supported by National Basic Research Program of China (973 Program) (No. 2012CB215105).