考虑风资源影响的风电场电压波动和闪变评估

摘要

风电并网后引起的电压波动和闪变水平可能超出国家有关标准,造成严重的电能质量问题,因此,在风电并网之前需对这两者进行评估.采用了一种新的评估方法.区别于国际电工标准(IEC61400-21)中电压波动与闪变的评估,此方法考虑了风电场的风资源情况对这2个指标的影响.对风电场在不同出力下由阵风引起系统的电压波动进行计算,并用IEC闪变仪计算短时间闪变值Pst.用所提方法和IEC标准对我国某一新建的风电场进行评估.结果表明,所提方法不仅能有效地进行电压波动与闪变评估,而且能更好地考虑风速变化对风电场带来的潜在影响.%Voltage fluctuation and flicker level induced by grid-connected wind power may exceed the national standard, resulting in serious power quality problems, which makes it necessary to assess these two items before the connection of wind power. This paper adopts a new assessment method. Different from the calculation methods of voltage fluctuation and flicker presented in the international electrotechnical standards (IEC61400 -21), it takes the influence of wind resources on these two indexes into account. The voltage fluctuations induced by gust wind under different wind power outputs is calculated and short -term flicker value Pst is obtained from the IEC flickermeter. A new wind farm in China is assessed by the proposed method and IEC standards respectively. The results show that the proposed method can not only carry out assessment of voltage fluctuation and flicker effectively, and can also better consider the potential impact of wind farm caused by wind speed changes.