Crowbar保护对风电场LVRT的影响分析与仿真

Analysis and Simulation of the Influence of Crowbar Protection on LVRT of Wind Farm

现阶段风机低电压穿越(LVRT)的主要手段为撬棒(Crowbar)保护与变流器的投切配合,且具备了LVRT能力的双馈感应发电机(DFIG)的故障暂态特性发生了改变,其中Crowbar保护的影响尤为重要。针对上述情况,首先研究Crowbar保护投入与否对风机短路暂态特性的影响,其次分别对Crowbar保护投入与变流器工作时的风电场故障情况进行仿真分析,并进一步仿真分析Crowbar阻值和投切时间对风电场短路电流的影响。算例仿真分析表明Crowbar阻值及其投切时间都会影响风电场短路电流。该研究对风电场保护整定设计具有重要意义。

At present,the main means of fan low voltage ride through(LVRT)is the Crowbar protection and the switching of the converter,and the fault transient characteristics of the LVRT-capable doubly-fed induction generator(DFIG)have changed.The impact of Crowbar protection is important.In view of the above situation,firstly,the impact of Crowbar protection input on the short-circuit transient characteristics of the fan was studied.Secondly,the Crowbar protection input and the wind farm fault condition during the working of the converter were simulated and analyzed.Furthermore,the effects of Crowbar resistance and switching time on the short-circuit current of wind farm were analyzed.The simulation analysis of the example shows that the Crowbar resistance and its switching time will affect the short-circuit current of the wind farm.This research is of great significance for the design of wind farm protection and setting.