A MATLAB-BASED SIMULATION TOOL FOR THE ANALYSIS OF UNSYMMETRICAL POWER SYSTEM TRANSIENTS IN LARGE NETWORKS

This paper presents an extendable Matlab-based phasor-time domain toolbox for modeling, simulation and analysis of unsymmetrical power system transients in large networks. Unlike most of the existing transient stability simulators which represent the transmission network on a per phase positive sequence basis, the new simulation function introduced in this paper is based on the symmetrical component technique which employs the three sequence networks. This representation allows consideration of network imbalances in order to include a wide range of disturbances during transient stability studies. The main aim of this paper is to describe the model details of the power system components required for unsymmetrical transients analysis and the solution methodology in the introduced simulation function. The performance of the simulation function is tested using standard IEEE test network models and the promising results are positively compared to respective results in DIgSILENT PowerFactory in terms of accuracy.