一种综合分析算法在电网低频振荡振型快速估计中的应用

Application of an Integrated Analysis Algorithm in Rapidly Estimating Mode Shape of Low Frequency Oscillation for the Power Grid

为了提高电网振荡动态特性中振型信息的有效获取速度,提出了一种综合分析算法,基于实测数据用于快速估计低频振荡振型、获取节点参与振荡程度的大小。它采用经验模态分解(EMD)对实测信号进行预处理,并基于信号能量分析方法、Teager能量算子和相关分析技术快速估计系统模态参数,通过计算各节点在电网关心模式的频率下有功注入功率占系统中该频率总有功振荡功率的比例,来衡量相应节点所关联的发电机对该模式的低频振荡的参与或贡献程度,从而得到该振荡模式下系统的振型信息。通过人工合成信号和某实际电网仿真算例,验证了该算法的快速性、有效性以及实用性。

In order to improve the effective acquisition speed of low frequency oscillation mode shape information,this paper proposes an integrated analysis algorithm for rapidly estimating the mode shape and obtaining the contribution factors of each node in the power grid. It uses empirical mode decomposition(EMD)to pre-proceed the measured signals and estimates the mode shape parameters based on the signal energy method, Teager energy operator and correlation analysis technique in a fast speed. The ratio of the generator node's active oscillation power and the total active oscillation power under the particular frequency shows how the generator participates in or contributes to the oscillation,so the mode shape of the power system can be obtained. The case studies have been carried out on synthetic signals and an actual power grid,and the results show that the proposed algorithm is fast,effective and practical.