基于DFIG频率模型的风电功率爬坡事件预测方法

Prediction Method for Wind Power Ramp Events Based on DFIG Frequency Model

随着风力发电的快速发展,风电出力的随机波动性引起的风电功率爬坡事件将威胁电网的稳定运行,因此需要研究能够有效预测风电功率爬坡事件的方法。首先介绍了传统的爬坡事件定义,提出了一种基于频率变化判断爬坡事件的方法。然后建立了计及频率偏差的双馈异步风机(doubly-fed induction generators,DFIG)模型,采用状态估计技术解决含DFIG的频率估计问题,并根据利用状态估计方法计算出的频率偏差,生成相应指标,对风电功率爬坡事件进行预测。最后对含DFIG的IEEE 14、IEEE 30和IEEE 118改进系统进行仿真分析,结果表明,所提方法可成功预测风电功率爬坡事件的发生,并且提高了预测精度。

With rapid development of wind power technology, wind power ramp events caused by stochastic volatility of wind power output will threaten stability of power grid operation, so to study effective methods for forecasting wind power ramp events is urgently needed. This paper presents traditional definition of wind power ramp events and proposes a definition of judging ramp events based on frequency change. After establishing doubly-fed induction generators（DFIG） model considering frequency deviation, state estimation technology is used to solve problem of frequency estimation containing DFIG. Then frequency deviation is calculated with state estimation method to generate PWPRESSF（post wind power ramp eventssteady state frequency） index for predicting wind power ramp events. Finally, simulations are carried out on IEEE 14, IEEE 30 and IEEE 118 modified systems with DFIG. Results show that the method can successfully predict wind power ramp events and improve prediction accuracy.