This letter presents a technique to calculate the variance of algebraic variables of power system models represented as a set of stochastic differential-algebraic equations. The technique utilizes the solution of a Lyapunov equation and requires the calculation of the state matrix of the system. The IEEE 14-bus system serves to demonstrate the accuracy of the proposed technique over a wide range of variances of stochastic processes. The accuracy is evaluated by comparing the results with those obtained with Monte Carlo time domain simulations. Finally, a case study based on a 1479-bus dynamic model of the all-island Irish transmission system shows the computational efficiency of the proposed approach compared to the Monte Carlo method.

中文翻译：

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电力系统动态模型中随机过程代数变量方差的计算

这封信介绍了一种计算电力系统模型代数变量方差的技术，该模型表示为一组随机微分代数方程。该技术利用李雅普诺夫方程的解，需要计算系统的状态矩阵。IEEE 14 总线系统用于证明所提出的技术在随机过程的广泛变化范围内的准确性。通过将结果与使用蒙特卡洛时域模拟获得的结果进行比较来评估准确性。最后，基于全岛爱尔兰传输系统的 1479 总线动态模型的案例研究显示了与蒙特卡罗方法相比所提出的方法的计算效率。