基于Teager能量算子的低频振荡节点同调分群

Teager Energy Operator Based Coherent Node Grouping for Power System Low-Frequency Oscillation

实际互联电网发生低频振荡时,除了需要获取振荡的频率、幅值、阻尼比外,还需获得振荡节点的同调分群关系、振荡中心或分界面的位置信息,以便运行人员及时采取措施抑制振荡。为此基于Teager能量算子提出了节点同调分群方法。首先采用经验模态分解方法对各节点实时注入有功功率或频率信号进行预处理,然后利用Teager能量算子快速求取分解后模态曲线的频率、幅值,在电网关心模式的频率下应用相关分析技术计算各模态曲线相对幅值最大模态曲线的相角差,从而得到低频振荡过程中节点的同调分群关系。仿真算例验证了该方法的有效性。

When low-frequency oscillation occurs in interconnected power grid, for the purpose that the operation personnel can adopt appropriate measures to suppress the oscillation timely, except acquiring the frequency, amplitude and damping ratio of the oscillation, it is necessary .to obtain the coherent grouping relation of the nodes where oscillation occurs and location information of oscillation center or location information of boundary surface of the oscillation. For this reason a method for coherent grouping of nodes based on Teager energy operator is proposed. Firstly, the empirical modedecomposition （EMD） is utilized to preprocess the measured real-time power injection signals or frequency signals of all nodes; then Teager energy operator is utilized to rapidly obtain the frequencies and amplitudes of decomposed mode curves and under the frequency of such a mode that operation personnel specially cares about the correlation analysis is used to calculate the phase differences between the mode curve with the highest amplitude and each mode curves respectively, thus the coherent grouping relation of nodes during low-frequency oscillation can be obtained. The effectiveness of the proposed method is verified by simulation results.