电网低频振荡扰动源线路暂态特征频带选取算法

为了有效利用线路暂态特征频带包含的故障信息,准确选取线路暂态特征频带,使得频率在该频带内的暂态分量可有效体现电网低频振荡扰动源位置,提出电网低频振荡扰动源线路暂态特征选取算法。分析了线路边界频率特性,获取线路暂态特征频带上限约束值。将电网低频振荡扰动源线路的始端和末端当成端口,通过二端口网络方程获取线路等值阻抗,对暂态特征进行分析。在此基础上,通过矩阵束法对不同线路电流频率分量和频率分量相位进行提取,按照升序顺序排序,对不同频率分量相位进行比较。将与90°相角相应的频率当成频带上限,完成对电网低频振荡扰动源线路暂态特征频带的选取。实验结果表明:所提算法可得到线路暂态特征频带选取结果,获取电网低频振荡扰动源位置;和特高压直流输电线路暂态保护特征频带选取算法与基于暂态相电流特征分析的故障选线算法相比,所提算法选取结果和实际结果间的误差最小。可见所提算法暂态特征频带选取结果准确。

Selection of Transient Characteristic Frequency Band of Power Network Low Frequency Oscillating Disturbance Source Line

In order to effectively utilize the fault information contained in the line transient characteristic frequency band and accurately select the line transient characteristic frequency band, so that the transient component of the frequency in the frequency band can effectively reflect the location of the low frequency oscillation disturbance source of the power grid, an algorithm for selecting the line transient characteristics of the low frequency oscillation disturbance source of the power grid is proposed. The frequency characteristics of line boundary are analyzed and the frequency band limit constraints of line transient characteristics are obtained. The beginning and end of the low frequency oscillation disturbance source line are regarded as ports. The equivalent impedance of the line is obtained by two-port network equation, and the transient characteristics are analyzed. On this basis, the phase of frequency component and frequency component of current in different lines is extracted by matrix beam method, sorted in ascending order, and the phase of different frequency component is compared. The frequency corresponding to the 90 degree phase angle will be taken as the frequency band limit to complete the selection of the transient characteristic frequency band of the power network low frequency oscillation disturbance source line. The experimental results show that the proposed algorithm can obtain the selection results of the transient characteristic frequency band and the location of the low-frequency oscillation disturbance source of the power grid. Compared with the characteristic band selection algorithm of UHVDC transmission line transient protection and fault line selection algorithm based on transient phase current characteristic analysis, the error between the selected results and the actual results of the proposed algorithm is the smallest. It can be seen that the frequency band selection results of the proposed algorithm are accurate.