预想事故分析中低频振荡特征值的快速算法  

Fast Algorithm to Calculate Eigenvalues of Low Frequency Oscillations in Contingency Analysis

作　　者：武诚[1] 徐政[1] 韩松[1] 

机构地区：[1]浙江大学电气工程学院,杭州310027

出　　处：《高电压技术》2011年第7期1805-1810,共6页High Voltage Engineering

基　　金：国家"十一五"科技支撑计划重点项目(2006BAA02A17)~~

摘　　要：针对预想事故分析中小信号分析计算速度的难点,提出了一种低频振荡特征值的快速计算方法。首先,指出在使用经典二阶模型下,两机系统的振荡频率平方可以表示为互同步转矩系数的线性组合且系数为常数,而振型基本不变的多机系统也有上述关系;其次,给出了互同步转矩系数的合并方法,以期能够减少估计公式中独立变量的数目;再次,给出了在实际系统中应用该方法的步骤,即通过离线计算获得振荡频率的估计公式,再根据振荡频率的估计值及事故后的系统状态矩阵,使用反幂法求出精确的特征值;最后,在发电机使用详细模型并考虑励磁系统的前提下用两个算例系统对比该法与PSS/E的计算结果,证明了它的有效性。We have proposed a fast algorithm to perform eigenvalue calculation in contingencyanalysis ot power systems. Firstly, a two-machine system is analyzed to theoretically illustrate that the square of oscillatory frequency can be represented by the linear combination of mutual synchronizing torque coefficients if classical model for generator is used. In multi-machine system the relationship mentioned above is still valid as long as the mode shape is essentially unchanged. Then, the procedure to incorporate mutual synchronizing torque coefficients is given in order to reduce the amount of independent variables in the prediction formula. Thirdly, the steps to implement the algorithm in real power systems are presented, i.e. , the prediction formula for oscillatory frequency is obtained in advance, then the inverse power method is used to calculate the precise eigenvalue taking into account the predicted frequency and post- contingency state matrix. Finally, the algorithm is applied to a four-machine-two-area system and the simplified Southeast Australian power systems. When generators are represented by detailed model and equipped with excitation system, the eigenvalues are calculated and compared with those obtained by PSS/E. Results show that the method is feasible.

关 键 词：预想事故分析 振荡频率估计 特征值计算 互同步转矩系数 反幂法 线性组合 最小二乘法 

分 类 号：TM711[电气工程—电力系统及自动化]