A reliable and efficient method for assessing voltage stability in transmission and distribution networks

Voltage collapse has been the topic of an increasing body of research during the past few years. In this paper a new method is presented for assessing static voltage stability in transmission and distribution networks. The proposed method (PM) is fast, accurate and robust. The expanded Newton–Raphson–Seydel (NRS) and Down-Hill (DH) algorithms are employed in PM. In addition, the elimination of the trigonometric terms in power flow equations and Jacobian matrix, can improve the convergence of PM algorithm. Standard CPF, CPF–GMRES and expanded NRS methods are compared to PM. These algorithms are tested on 420 bus transmission and 4438 bus distribution networks.