ELECTRICAL CHARACTERIZATION OF ARCING FAULT BEHAVIOR ON 120/208V SECONDARY NETWORKS A Dissertation by JEFFREY ALAN WISCHKAEMPER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2011 Major Subject: Electrical Engineering Electrical Characterization of Arcing Fault Behavior On 120/208V Secondary Networks Copyright 2011 Jeffrey Alan Wischkaemper ELECTRICAL CHARACTERIZATION OF ARCING FAULT BEHAVIOR ON 120/208V SECONDARY NETWORKS A Dissertation by JEFFREY ALAN WISCHKAEMPER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, B. Don Russell Committee Members, Karen L. Butler-Purry Deepa Kundur Warren Heffington Head of Department, Costas Georghiades December 2011 Major Subject: Electrical Engineering iii ABSTRACT Electrical Characterization of Arcing Fault Behavior on 120/208V Secondary Networks. (December 2011) Jeffrey Alan Wischkaemper, B.S., Texas A&M University Chair of Advisory Committee: Dr. B. Don Russell Arcing faults have been a persistent problem on power systems for over one hundred years, damaging equipment and creating safety hazards for both utility personnel and the public. On low-voltage secondary networks, arcing faults are known to cause specific hazards collectively called “manhole events”, which include smoke and fire in underground structures, and in extreme cases explosions. This research provides the first comprehensive attempt to electrically characterize naturally occurring arcing fault behavior on 120/208V secondary networks. Research was performed in conjunction with the Consolidated Edison Company of New York, whereby a single low-voltage network was instrumented with thirty high- speed, high-fidelity data recording devices. For a nominal one year period, these devices collected detailed, high-speed waveform recordings of arcing faults and other system transients, as well as statistical power system data, offering new insights into the behavior of arcing faults on low-voltage networks. Data obtained in this project have shown the intensity, persistence, and frequency of arcing faults on low-voltage networks to be much higher than commonly iv believed. Results indicate that arcing faults may persist on a more-or-less continuous basis for hours without self-extinguishing, may recur over a period of hours, days, or weeks without generating enough physical evidence to be reported by the public or operate conventional protective devices, and may draw enough current to be observed at the primary substation serving the network. Additionally, simultaneous fault current measurements recorded at multiple locations across the network suggest the possibility of using multi-point secondary monitoring to detect and locate arcing faults before they cause a manhole event. v DEDICATION dixitque Deus fiat lux et facta est lux et vidit Deus lucem quod esset bona et lux in tenebris lucet et tenebrae eam non conprehenderunt. vi ACKNOWLEDGEMENTS This research would not have been possible without the hard work and dedication of multiple people, and this dissertation would not be complete without acknowledging their efforts: I express tremendous gratitude to my committee chair, Dr. B. Don Russell, for his outstanding mentorship, and for granting me the opportunity to work alongside him. Thanks also go to my committee members, Dr. Butler-Purry, Dr. Kundur, and Dr. Heffington, for their service, and for indulging me and my flirtation with multiple deadlines. Special thanks go to Carl Benner, whose knowledge of arcing faults and power system waveforms is unrivaled. Carl’s tremendous insight contributed in no small way to the ideas contained in this dissertation. The data collection platform used in this project would not exist without the work of Karthick Manivannan, my fellow researcher in the Power System Automation Laboratory. His capable management of a team of graduate students ensured the smooth operation of my data monitors. In particular, Jagadish Chandar’s diligent effort in maintaining the DFA platform software had significant impact on the success of this project. Jessica Meadors and Sharon Loe deserve unending thanks for their tireless work behind the scenes in our laboratory. vii I am also tremendously grateful to Tammy Carda, our graduate student advisor, who never rolled her eyes when I asked silly questions. A host of employees of the Consolidated Edison Company of New York contributed to this project. In particular, Serena Lee, Leslie Philp, Neil Weisenfeld, Yingli Wen, Frank Doherty, Stan Lewis and Pete Hoffman contributed their significant expertise and knowledge about the operation of low-voltage networks. Special thanks also go to Gerard Johnson, who installed the data collection devices under the streets of New York City. Additional personal thanks go to Dr. Warren Heffington, and his wife Donna, for their support and encouragement across my collegiate career. I appreciate Dr. Heffington’s work on my committee, but I appreciate more his kind and gentle spirit, and his quiet example of life well lived. Dr. Brian Perkins became a trusted friend during my graduate school experience. His encouragement and example of professionalism did not go unnoticed. Kelly and Sara Davidson were mentors throughout my college years. They opened their home to me, and became a second set of parents. Their wisdom and guidance helped shape who I am. Dr. James Fisher was, and remains, the best of friends. There are no words to describe the respect and admiration I have for his intellect, his humility, and his character. James is not only a wonderful friend, but an incredible human being. To my sister and longtime roommate, Lisa, I extend a special thanks: you’ll always be #1 in my book. viii My parents, Jay and Dianna, challenged me to accomplish great things. Their love, support, and financial assistance made this document possible. Their spirit of generosity to those around them is a testament to the kind of people they are, and the kind of person I hope to become. And finally, I could not have completed this work without the support and love of my wife, Katie. Her encouragement and company make life that much more sweet. ix TABLE OF CONTENTS Page ABSTRACT ..................................................................................................................... iii  DEDICATION ................................................................................................................... v  ACKNOWLEDGEMENTS .............................................................................................. vi  TABLE OF CONTENTS .................................................................................................. ix  LIST OF FIGURES ........................................................................................................... xi  LIST OF TABLES ......................................................................................................... xvii  1. INTRODUCTION TO LOW-VOLTAGE ARCING PROBLEM ................................. 1  1.1 Historical Background ......................................................................................... 1 1.2 Low-voltage Networks ........................................................................................ 5 1.3 Low-voltage Arc Fault Problem .......................................................................... 9 2. DISCUSSION OF RECENT WORK ON 120/208V ARCING .................................. 14  2.1 Prior Work by the Consolidated Edison Company of New York ..................... 14 3. RESEARCH HYPOTHESES, METHODS, AND GOALS ........................................ 31  3.1 Hypotheses ......................................................................................................... 31 3.2 Goals .................................................................................................................. 32 4. EXPERIMENTAL METHODOLOGY ....................................................................... 33  4.1 Overview and Timeline ..................................................................................... 33 4.2 Cooper Square Network .................................................................................... 35 4.3 Measurement Equipment ................................................................................... 42 4.4 Recorded Data ................................................................................................... 52 5. EXPERIMENTAL RESULTS ..................................................................................... 73  6. DATA ANALYSIS ...................................................................................................... 76