Transient Stability Analysis Based on the Post-Disturbance Two-Machine Equivalent.

Document Type : Research Studies

Author

Assistant Professor of Department of Electrical Power & Machines, Faculty of Engineering, El-Mansoura University, Mansoura, Egypt.

Abstract

This paper presents a method of power system transient stability analysis, based on two-machine equivalent. The method first computes the actual system trajectory using time domain simulation of fault-on system, then at clearing time, evaluates the kinetic energy and acceleration of each machine in order to identify the severely disturbed machine (or machines). Each of the severely disturbed machines and all remaining machines are grouped together in one equivalent machine, forming the two-machine equivalent.
Based on the relative kinetic energy of the two-machine equivalent, a method for detecting the system stability or instability and computing the critical clearing time is developed.
The proposed method is applied successfully to a 3-machine 9-bus power system and a 4-machine 19-bus power system which represents the 220 KV Mid-Delta region network of Egypt. The simulation results show that the method can provide reliable and quick information about the transient stability analysis of a power system and it may become effective for on-line applications.

Main Subjects