The essence of stability analysis is to solve a group of differential - algebraic equations. In this paper, a closed-form solution of the network equations is derived based on the familiar Dommel-Sato iteration. After applying the improved Euler integration, a discrete system model of AC power grid dynamics is obtained. Examples using the proposed discrete system model are provided, and compared with the simulation results using BPA.

Dommel-Sato iteration, Discrete system, Stability analysis