基于功率偏差估计主导区间模式下的参与因子与参与方向

Estimation of Participation Factors and Participation Orientations for Dominant Inter-Area Mode by Power Deviations

提出一种基于功率偏差估计主导区间模式下参与因子与参与方向的方法。该方法首先利用参数化时域辨识方法提取受测振荡功率信号中的各模式分量,并由一个新的指标(模式能量级E)确定主导区间模式。然后,计算该模式对应的右特征向量的归一化幅值和相对相位,继而估算各大区机群和主力电厂的参与因子。最后,借助Δω振型相位引入参与方向信息,形成新的概念——参与度振型。它可以为运行人员提供主导区间模式下区域同调机群和主力电厂的参与程度和参与方向的合成信息,亦可为在线准实时识别或分类强相关区域、电厂甚至机组提供参考。利用一个扩展的IEEE3机9节点算例对文中方法的适用性进行了验证,并讨论了工况与模型详细程度对结果的影响。案例分析在一个华东电网规划系统中展开,结果表明了该方法的有效性。

This paper presents a novel approach to estimate participation factors and participation orientations （called mode shape for participation, MSFP） in the dominant inter-area mode through analyzing power deviation （△P） signals. In the context of WAMS （wide area measurement system）, it firstly extracts each mode component from the measured △P signals in the critical sections using the commonly used parametric methods such as Prony or ESPRIT, and consequently determines the dominant inter-area mode by a new index （i.e. modal energy-level, MEL）, which would be also checked and confirmed by the corresponding relative phases of AP mode shape in the modal form. Then the amplitudes and phases of right eigen-vectors for the objective mode are estimated so that the participation factors of areas or power plants could be calculated. Finally, the new concept named by mode shapes for participation （MSFP） can be established through combining the relative phases among areas or power plants from △ω mode shape and their corresponding participation factors. It is enabled to provide more visual information about the extents and directions of participation for targets, and also may offer a reference to on-line and quasi real-time recognition or classification of strongly correlated areas or groups, power plants and even units. The case study has been carried out on a planning case in East China Power Grid （ECPG）, and the numerical simulation results indicate that the algorithm is effective.