The paper demonstrates that distributed generators, namely a fuel cell and a microturbine, could cause instability of electric power distribution systems following fault conditions. A control algorithm is then proposed to enhance transient stability in case of large disturbances. The control algorithm consists of (1) disconnecting the fuel cell during the fault, and (2) implementing fixed structure decentralized Solid Oxide Fuel Cell reconnection controllers and fixed structure decentralized Power System Stabilizer for the microturbine generator. The stabilizer parameters are tuned using a Swarm Optimization technique.
This paper introduces the application of intelligent agents to the control and operation of distribution systems that contain distributed generators (DGs). The proposed control architecture is hierarchical with one supervisor that optimizes the overall process and a distributed number of local control agents associated with each DG. Control and protection actions need a fast reaction time and are taken by the control agents. They consist of fixed sets of parameters. Coordination, modifications of the criteria and parameters for the control and protection equipment, are performed at the control center. The proposed intelligent control agent based architecture is illustrated using a test system with two microturbines as DGs.
A steady state analysis is applied to study the voltage collapse problem. The modal analysis method is used to investigate the stability of the power system. Q-V curves are used to confirm the obtained results by modal analysis method and to predict the stability margin or distance to voltage collapse based on reactive power load demand. The load characteristics are considered in this research. Different voltage dependent loads are proposed in order to be used instead of the constant load model. The effect of induction machine load is considered in this study. The load is connected to several selected buses. The analysis is performed for three well-known system; Western System Coordinating Council (WSCC) 3-Machines 9-Bus system, IEEE 14 Bus system and IEEE 30 Bus system. The modal analysis technique is performed for all systems using the constant load model, the voltage dependent load models and induction machine load model. Then, the most critical mode is identified for each system. After that, the weakest buses, which contribute the most to the critical mode, are identified using the participation factor. The Q-V curves are generated at specific buses in order to check the results obtained by the modal analysis technique and to estimate the stability margin or distance to voltage collapse at those buses. iii ACKNOWLEDGEMENTS First I would like to express my sincere appreciation to my research advisor Prof. Muhammad Choudhary for his support and guidance of this research. I would like also to thank Prof. Ali Feliachi for his advice and direction. My thanks are extended to Prof. Ronald Kline for his suggestion and advice. My special thanks are expressed to Dr. Khaled Elithiy (Sultan Qaboos University) for helpful advice, encouragements and discussions. Thanks are also to Sultan Qaboos University for giving me full financial support throughout my education. Special thanks to my wife for her support, help and patience while we are away from our home country, Oman. Finally, I would like to thank my mother, my brothers, and my sister for their help and encouragements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.