Online pre-fault FACTS tuning in smart grid for transient stability enhancement based on CCT

Abstract

Changing the steady state parameters of power system before fault occurrence is a new approach for increasing the transient stability of the system. With the presence of PMUs in smart grid and the possession of system information at any given time, FACTS devices can be set up online so that total critical clearing time (CCT) of the network is maximized as the most accurate transient stability criterion, by changing the system's steady state variables before the fault occurrence. Calculation of CCT requires iterative fault analysis and time-domain simulation of the network. In this paper, a novel prefault online optimal FACTS tuning is presented for transient stability enhancement of smart grid by CCT maximizing. Also the optimal type, number and location of FACTS devices are determined for long term planning. FACTS devices modeling and New England 39-bus system simulation are done by DIgSILENT software. DPL is used for CCT calculation and proposed approach implementation based on PSO algorithm. Also investment cost of these devices are considered for determining the optimal number of them.