在风电机组出口装设静止无功补偿器(SVC)进行电压调节对于改善风电机组电压特性具有重要作用,但对于增加SVC后系统的暂态特性尚未进行较深入的研究。分析了SVC阻抗特性,并利用RTDS搭建了含SVC的双馈风电机组的实时暂态模型。对电网发生不同故障时含SVC双馈风电机组的暂态输出特性进行了仿真分析。结果表明:在电网侧故障后,SVC将提高双馈风电机组的出口电压,并增大向系统提供的短路电流,从而使DFIG出口处低压保护的动作灵敏度降低、过流保护的动作灵敏度有不同程度的提高。
It plays an important role by installing SVC at the exit of wind turbine generator (WTG) to regulate voltage and to improve voltage characteristic of WTG subsequently. But very few researches have been done till now on transient characteristic of system after installing SVC. Analysis in this paper is done on impedance characteristics of SVC, and by using RTDS a real-time transient model of doubly-fed generator with SVC has been built. Furthermore, the transient output characteristic of doubly-fed generator with SVC has been analyzed in the simulation and several grid faults which occured during this simulation could be monitored. The simulation has manifested that the output voltage of DFIG would be increased and short-circuit current would also be increased by SVC while grid breakdown. Thus, the sensitivity of under-voltage protection at the exit of DFIG should be lowered and sensitivity of over-current protection should also be increased accordingly. This work is supported by National Natural Science Foundation of China (No. 50777068).