Indexing

Abstract:The objective of this paper is to investigate and understand the behavior of transient stability of the power system. The intention is to check the transient stability of IEEE 6-bus system under a symmetrical three-phase fault. For this purpose, IEEE 6-bus power system is/was  modeled in Power World Simulator using the given data set .When the fault is created on one of the generator bus (bus number 3 in this paper), oscillations in various electrical quantities may result. For damping out of these oscillations and regaining the system-stability ,the fault clearing time must be very short .
Initial load flow solutions are obtained by using Polar Newton - Raphson iteration method in order to know to the pre-fault values for the symmetrical three phase fault .This is followed by the transient stability analysis.
This paper proposes the transient stability analysis by applying a symmetrical fault of 0.3 sec duration . Under fault condition, variations in rotor angles(power angles) and bus frequency are plotted against time to understand the stability status of the system. After restoration of transient stability , it is observed that the system frequency is too high which may cause some serious problems. In order to re-establish the normalcy of system frequency (drop the power system operational frequency to 50 Hz), load shedding option is provided in this paper. For solving various differential equations of the system dynamics, Runge-Kutta method is proposed in the paper.  
Keywords:Fault clearing time, polar Newton Raphson method, Runge Kutta method, Power World Simulator, load shedding,, pre-fault values.