Hybrid Power System Intelligent Operation and Protection Involving Distributed Architectures and Pulsed Loads Ahmed A
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Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 3-21-2013 Hybrid Power System Intelligent Operation and Protection Involving Distributed Architectures and Pulsed Loads Ahmed A. Mohamed Florida International University, [email protected] DOI: 10.25148/etd.FI13042301 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Part of the Power and Energy Commons Recommended Citation Mohamed, Ahmed A., "Hybrid Power System Intelligent Operation and Protection Involving Distributed Architectures and Pulsed Loads" (2013). FIU Electronic Theses and Dissertations. 866. https://digitalcommons.fiu.edu/etd/866 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida HYBRID POWER SYSTEM INTELLIGENT OPERATION AND PROTECTION INVOLVING DISTRIBUTED ARCHITECTURES AND PULSED LOADS A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in ELECTRICAL ENGINEERING by Ahmed Mohamed 2013 To: Dean Amir Mirmiran College of Engineering and Computing This dissertation, written by Ahmed Mohamed, and entitled Hybrid Power System Intelligent Operation and Protection Involving Distributed Architectures and Pulsed Loads, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. _______________________________________ Mark Roberts _______________________________________ Arif Islam _______________________________________ W. Kinzy Jones _______________________________________ Armando Barreto _______________________________________ Osama A. Mohammed, Major Professor Date of Defense: March 21, 2013 The dissertation of Ahmed Mohamed is approved. _______________________________________ Dean Amir Mirmiran College of Engineering and Computing _______________________________________ Dean Lakshmi N. Reddi University Graduate School Florida International University, 2013 ii © Copyright 2013 by Ahmed Mohamed All rights reserved. iii DEDICATION I dedicate this dissertation to my lovely wife, Yassmin Ali, my mother and my father, Prof. Ali El-Tallawy. Without their patience, understanding, support, encouragement, and most of all love, the completion of this work would not have been possible. iv ACKNOWLEDGMENTS This dissertation would not have been possible without the help, support, resolute dedication and patience of my principal supervisor, Prof. Osama Mohammed, whose passion for success has inspired me to take my own passions seriously, not to mention his advice and unsurpassed knowledge of the various fields of Electrical Power Systems. Prof. Mohammed has always been an endless supply of ideas, guidance, suggestions and useful discussions for me. I am indebted for his enthusiasm, advice, moral as well as financial support and friendship. I am also grateful for the chance he gave to me to work at the Energy Systems Research Laboratory, where I found all the first-class equipment I needed to experimentally verify my results and, where I was developed professionally in an environment where work and engineering ethics are highly respected. I am thankful to Dr. Mark Roberts, Dr. Arif Islam, Professor W. Kenzy Jones and Dr. Armando Barreto for serving on my committee and for their discussions and support. Thanks are also due to all my colleagues at the Energy Systems Research Laboratory whose discussions, contributions and assistance helped me achieve my research goals. I also owe sincere thankfulness to my family for their love, support and encouragement. I offer my deepest gratitude to my mother for her endless love, tenderness and care and for my father, Prof. Ali Hassan El-Tallawy, for his confidence in me and for his advice, which always brings previously unrecognized aspects of each situation to my attention. I also extend my gratitude to my wife, Yassmin, and my sisters, Rasha and Dina, for their love and support. v ABSTRACT OF THE DISSERTATION HYBRID POWER SYSTEM INTELLIGENT OPERATION AND PROTECTION INVOLVING DISTRIBUTED ARCHITECTURES AND PULSED LOADS by Ahmed Mohamed Florida International University, 2013 Miami, Florida Professor Osama A. Mohammed, Major Professor Efficient and reliable techniques for power delivery and utilization are needed to account for the increased penetration of renewable energy sources in electric power systems. Such methods are also required for current and future demands of plug-in electric vehicles and high-power electronic loads. Distributed control and optimal power network architectures will lead to viable solutions to the energy management issue with high level of reliability and security. This dissertation is aimed at developing and verifying new techniques for distributed control by deploying DC microgrids, involving distributed renewable generation and energy storage, through the operating AC power system. To achieve the findings of this dissertation, an energy system architecture was developed involving AC and DC networks, both with distributed generations and demands. The various components of the DC microgrid were designed and built including DC-DC converters, voltage source inverters (VSI) and AC-DC rectifiers featuring novel designs developed by the candidate. New control techniques were developed and implemented to maximize the operating range of the power vi conditioning units used for integrating renewable energy into the DC bus. The control and operation of the DC microgrids in the hybrid AC/DC system involve intelligent energy management. Real-time energy management algorithms were developed and experimentally verified. These algorithms are based on intelligent decision-making elements along with an optimization process. This was aimed at enhancing the overall performance of the power system and mitigating the effect of heavy non-linear loads with variable intensity and duration. The developed algorithms were also used for managing the charging/discharging process of plug-in electric vehicle emulators. The protection of the proposed hybrid AC/DC power system was studied. Fault analysis and protection scheme and coordination, in addition to ideas on how to retrofit currently available protection concepts and devices for AC systems in a DC network, were presented. A study was also conducted on the effect of changing the distribution architecture and distributing the storage assets on the various zones of the network on the system’s dynamic security and stability. A practical shipboard power system was studied as an example of a hybrid AC/DC power system involving pulsed loads. Generally, the proposed hybrid AC/DC power system, besides most of the ideas, controls and algorithms presented in this dissertation, were experimentally verified at the Smart Grid Testbed, Energy Systems Research Laboratory. All the developments in this dissertation were experimentally verified at the Smart Grid Testbed. vii TABLE OF CONTENTS CHAPTER PAGE 1. Introduction... .......................................................................................................... 1 Types of DC Distributed Power System Architectures ....................................... 3 Centralized power systems .............................................................................. 4 Modular power systems ................................................................................... 4 Distributed power systems .............................................................................. 5 DC Microgrids in Smart Grid Applications ......................................................... 6 Benefits of DC Microgrid Deployment ............................................................... 8 Influence of High Penetration of DC Microgrids in Modern Smart Grids ........ 10 Energy savings (MWH) ................................................................................. 10 Additional benefits for on-site power generation from DC Sources ............. 12 Obstacles against DC Microgrid Deployment ................................................... 12 Information and education program for construction industry and code officials .......................................................................................................... 13 Codes and standards ...................................................................................... 13 Federal tax law .............................................................................................. 14 Business Model and Energy Pricing ............................................................. 14 Renewable Electricity Standard .................................................................... 18 Factors Influencing the AC- versus DC-Distribution Debate ............................ 19 Reliability and Un-interruptible Power Supplies (UPS) ............................... 19 Alternative Energy Sources ........................................................................... 19 Loads…. ........................................................................................................ 33 Protection ....................................................................................................... 34 Cables… .......................................................................................................