Date of Award

Spring 5-13-2017

Level of Access Assigned by Author

Campus-Only Dissertation



Degree Name

Doctor of Philosophy (PhD)


Electrical and Computer Engineering


Mohamad Musavi

Second Committee Member

Paul Lerley

Third Committee Member

Paul Villeneuve

Additional Committee Members

Yifeng Zhu

Richard Eason


The power systems transient stability has posed significant research challenges that involve many factors including system topology changes, upgrades, and integration of new energy sources. Due to these factors, a significant number of stability studies must be conducted to ensure a secure and stable system without any adverse impacts on the system itself and the consumers. To support and enhance these studies, the existing study methodologies may need to be updated and new, effective, and objective methodologies must be added.

In this dissertation, some security and stability aspects of power systems are analyzed. These analyses led to the development of new methodologies and procedures which are proposed as effective and objective study enhancements. First, a flexible generic mathematical model for out-of-step relay coordination with recommended settings is developed by using apparent impedance trajectories. Second, an alternative transient stability limit, based on the changes of apparent impedance trajectories rather than the conventional limit based on the generator rotor angles, is developed. These two

developments constitute a valuable contribution to the secure design and operation of the power system. Finally, a global transient stability performance quantification (TSPQ) method, for power system dynamic performance assessment studies, is proposed. This numerical method applies commonly-used stability criteria and achieves a more efficient and objective stability analysis assessment. This comprehensive data mining tool method can quantify the effect of different system configurations, dispatches, and contingencies on the system transient stability and identify potential mitigation solutions to specific locations and operating conditions. Using the TSPQ method, electric power system planners and operators can reliably design and operate their power systems. The methodologies developed in this dissertation have been successfully tested in the IEEE 39-bus system and the ISO New England power system.