单时滞电力系统时滞稳定裕度的简便求解方法

时滞稳定裕度定义为在保证小扰动稳定的前提下系统可承受的最大延时值。确定电力系统的时滞稳定裕度对于合理利用广域测量系统数据、评估广域控制效果具有重要意义。文中介绍了单时滞电力系统的数学模型;提出一种求解单时滞电力系统时滞稳定裕度的简便方法，该方法在虚轴上将特征方程转化为多项式方程求解系统的纯虚特征根，无需任何中间的变量代换，可以有效求解单时滞电力系统的时滞稳定裕度;用该方法对一个单机无穷大系统进行时滞稳定裕度研究，得到了典型运行方式下的时滞稳定裕度，并研究了励磁系统参数变化对时滞稳定裕度的影响;对结果进行了时域仿真验证，验证了该方法的准确性。

A Simple Method to Compute Delay Margin of Power System with Single Delay

The delay margin is defined as the maximum time delay that a power system can sustain without losing its small signal stability. The estimation of delay margin is important in the application of wide area measurement system (WAMS) data and evaluation of wide area controllers. Firstly, the single time-delay model of power system is introduced. Then, a simple and effective method to determine the delay stability margin is proposed. The transcendental characteristic equation is converted into polynomial equations at the imaginary axis without any substitutions. The delay margin of a single-machine infinite-bus system at typical equilibrium point is obtained through this method. The effect of exciter parameters on the system delay margin is also discussed. At last, the validity of this method is verified with the time domain simulation results.