风电典型机型的闪变严重度分析

Analysis of Short-Term Flicker Severity for Typical Wind Turbines

风力发电机组的并网运行对当地电网的电能质量有不良影响。为此,根据定速机型、变速机型引起电压波动和闪变的原理及并网风电机组电能质量的国际电工标准IEC61400-21,讨论了测量风电机组输出闪变的方法,给出了两种典型机型的短时闪变严重度与风速的关系实验曲线,并对不同风速段的闪变成因进行了分析。结果表明,变速风电机组在高风速区域综合应用桨叶节距角和变流器控制实现输出功率的稳定能够减小短时闪变严重度,在低风速区域追求最佳风能利用系数将使闪变严重度值增高。

Operation of grid connected wind turbines has a negative impact on the power quality of local network. This paper concentrates on the theoretical aspects of voltage fluctuation and flicker caused by constant speed and variable speed wind turbines, and discusses the method of measuring the flicker emission by wind turbines, according with IEC61400- 21.The paper makes the curve of short-term flicker severity as a function of wind speed of two types of wind turbines, analyzes the causation of flicker during each wind speed bins. The result include that variable speed wind turbine could achieve stable output power via adjustment of the pitch angle combined with converter control strategy at high wind speed in order to reduce short term flicker severity Pst, and at low wind speed.