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Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study

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Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2015 Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study Marcus Aaron Young II University of Tennessee - Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Electromagnetics and Photonics Commons, and the Power and Energy Commons Recommended Citation Young, Marcus Aaron II, "Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study. " PhD diss., University of Tennessee, 2015. https://trace.tennessee.edu/utk_graddiss/3377 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Marcus Aaron Young II entitled "Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Electrical Engineering. Yilu Liu, Major Professor We have read this dissertation and recommend its acceptance: Kevin Tomsovic, Lee Riedinger, Aleksander Dimitrovski Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Saturable Reactor for Power Flow Control in Electric Transmission Systems: Modeling and System Impact Study A Dissertation Presented for the Doctor of Philosophy Degree The University of Tennessee, Knoxville Marcus Aaron Young II May 2015 DEDICATION This dissertation is dedicated to my wife, Deanne Young, and to my entire family for their continued support throughout my educational endeavors. ii ACKNOWLEDGEMENTS I would like to express my sincere gratitude to Dr. Yilu Liu for her continuous guidance and support as my advisor during my PhD studies at the University of Tennessee. I am thankful to the Oak Ridge National Laboratory (ORNL) for providing the opportunity to participate in innovative research and for its financial support throughout my PhD study. My sincere thanks to Mr. Tom King of ORNL for being supportive of my educational mission and to Dr. Aleksandar Dimitrovski of ORNL for his mentorship throughout the project. My thanks also go out to the ORNL Power and Energy Systems group for their encouragement and support. My heartfelt thanks go to Dr. Kevin Tomsovic, Dr. Lee Riediner and Dr. Aleksander Dimitrovski for their time and effort in serving as members of my dissertation committee. I would also like to thank all the professors and friends of CURENT for their encouragement throughout my research. I would like to acknowledge the U.S. Department of Energy (DOE) Advanced Research Projects Agency – Energy (ARPA-E) for providing financial support. iii ABSTRACT A Saturable Reactor for Power Flow Control (SRPFC) is a novel application of a concept well known to electronics and power electronics engineers that provides continuous modulation of line reactance by controlling the magnetization in a ferromagnetic core. The novelty of the SRPFC is the target application, which is power flow control in meshed electric power networks. Modulation of the line impedance occurs by altering the current in a DC winding to control the magnetization of the ferromagnetic core, thereby varying the reactance of the AC winding. The deployment of power system equipment, like SRPFC, requires careful planning and study to determine if the equipment will meet design objectives and how the equipment, and associated power system, respond to power system transients. This dissertation focuses on the development of SRPFC models for simulation at time resolutions compatible with many power system transient studies. The SRPFC models developed within the course of this effort are simulated within simple power system models under nominal and line to ground fault conditions to observe effectiveness. The simulations also provide a basis for comparison between the methods and the hardware test results of a prototype device. The simulation results demonstrate the effectiveness of all but one of the modelling methods to represent the SRPFC from the perspective of the AC power system. Fault conditions can drive the SRPFC outside of the control point in sub-cycle time and could affect distance protection along the controlled line. This dissertation includes a system impact study that quantifies these effects through transient simulations of a SRPFC model, scaled to transmission levels based on full-scale design parameters, under fault conditions in an industry accepted power system model. Impacts on protection are observed through playback of the resulting waveforms to a distance relay via a relay test set. The results demonstrate that the interaction of the SRPFC has minimal effect on distance protection reach, even when measurements are acquired by coupling capacitor voltage transformers (CCVTs). iv TABLE OF CONTENTS CHAPTER I: Introduction and General Information ........................................................................ 1 Background .................................................................................................................................. 1 Technology Overview .................................................................................................................. 4 SRPFC Development .................................................................................................................. 12 Motivation for Modeling ........................................................................................................... 16 Dissertation Outline .................................................................................................................. 23 CHAPTER II: TWO-CORE MODEL ................................................................................................... 24 Theory of Approach ................................................................................................................... 24 Equivalent Parameters .............................................................................................................. 35 Simulation in MATLAB® ............................................................................................................. 44 Summary of Results ................................................................................................................... 47 CHAPTER III: MODEL DERIVED BY FINITE ELEMENT ANALYSIS ..................................................... 57 Finite Element Analysis ............................................................................................................. 58 Application in Transient Simulation .......................................................................................... 61 Co-Simulation of FEM and Transient Circuit ............................................................................. 66 Simulation Results ..................................................................................................................... 68 Adapting the Model for Transmission Studies .......................................................................... 69 Summary of Results ................................................................................................................... 75 CHAPTER IV: GYRATOR-CAPACITOR MODEL................................................................................. 77 Theory of Approach ................................................................................................................... 77 Nonlinear Permeance ................................................................................................................ 86 Application to SRPFC ................................................................................................................. 87 Summary of Results ................................................................................................................... 95 v CHAPTER V: IMPACT STUDY ON DISTANCE PROTECTION .......................................................... 108 Distance Relaying .................................................................................................................... 108 Impacts of Dynamic Impedance Devices ................................................................................ 111 Potential Impacts of the SRPFC ............................................................................................... 116 Power System Study ................................................................................................................ 117 Relay Configuration and Testing ............................................................................................. 125 Summary and Recommendations ........................................................................................... 135 CHAPTER VI: OVERALL CONCLUSIONS AND FUTURE WORK ...................................................... 137 Conclusions and Contributions ..............................................................................................
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