Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Electrical and Computer Engineering

First Advisor

Vijay Vittal


When a power system is in the alert state, a severe contingency may bring the system into the emergency state, resulting in overloads, voltage violations, cascading failures, or even loss of stability, and force system operators to take appropriate corrective control actions. It is widely known that transmission system reconfiguration (TSR), including transmission line switching, bus-bar switching, shunt element switching, transformer tap changing, and FACTS control, may change the states of the power systems, and consequently, affect the distribution of power flows, transmission losses, short circuit currents, voltage profiles as well as the transient stability of power systems. Under the restructured environment of the power industry, TSR has a great advantage in economy compared with other corrective control methods, such as load shedding and system islanding, since it almost has no effect on generation and load, and thereby, becomes a very attractive research topic for on-line corrective control;Focusing on line and bus-bar switching, shunt element switching, and corrective FACTS control, this dissertation has proposed a general framework for employing TSR actions to relieve overloads and voltage violations caused by system contingencies. In this dissertation, a new line and bus-bar switching algorithm for relieving overloads and voltage violations is proposed based on fast decoupled power flow with limited iteration count. A novel shunt switching algorithm is also presented for corrective voltage control based on the newly derived voltage distribution factor. These two algorithms are then integrated into one corrective switching algorithm. Furthermore, an LP-based OPF algorithm is developed for corrective FACTS control based on the newly derived parameter sensitivities of FACTS devices such that the operational constraints of FACTS devices can be considered during optimization. In order to improve computation speed, a general power compensation model is proposed for line and bus-bar switching, and a BIP-based OPF algorithm is developed for line and bus-bar switching on the basis of the proposed model. All the developed algorithms are implemented with MATLAB and tested on the New England 39-bus system and the WECC 179-bus system. The simulation results obtained indicate that the developed approaches could effectively solve the problems of overloads and voltage violations and significantly reduce the computational time.



Digital Repository @ Iowa State University,

Copyright Owner

Wei Shao



Proquest ID


File Format


File Size

123 pages