高比例风电系统宽频振荡紧急控制策略研究

Study on Emergency Control Strategy of Wideband Oscillation in Power Systems with High-percentage Wind Power

宽频振荡紧急控制是保障风电系统安全运行的“兜底”措施之一。由于风电系统非线性强度大及运行工况多变,难以建立宽频振荡在线风险评估的解析模型。为此,提出了基于数据驱动的宽频振荡风险在线评估方法及紧急控制策略。首先,设计了能够应对宽频振荡多模态和时变特征的宽频相量检测算法,为后续宽频振荡特征评估提供数据支撑;其次,利用最大李雅普诺夫指数作为宽频振荡动态演化趋势的量化指标,并根据风电机组模态阻抗的负电阻效应在线辨识宽频振荡源;然后,融合宽频振荡特征辨识结果,提出宽频振荡风险在线评估策略,进一步将评估结果应用于宽频振荡紧急控制;最后,通过RTDS硬件在环平台验证所提方法的有效性和可靠性。

Wideband oscillation emergency control is one of the “bottom line” measures to ensure the safe operation of wind power systems.It is difficult to establish an accurate mathematical model to assess this risk,due to the complex and variable nature of wind power systems.To address this issue,a new emergency control strategy has been proposed that is based on data analysis.Firstly,a wideband phasor monitoring algorithm has been developed to detect and assess wideband oscillation.Secondly,the largest Lyapunov exponent(LLE) is used to measure the dynamic evolution trend of wideband oscillation and identify its source.The oscillation source is identified by analyzing the negative resistance characteristic of the wind turbine.Based on the identification results,an online risk assessment method for wideband oscillation has been proposed and applied to the emergency control strategy.The effectiveness and reliability of the proposed method have been verified using a real-time digital simulator(RTDS) hardware-in-the-loop platform.