(NEPTUNE): Power System Design, Modeling and Analysis

104 Pages·2003·0.61 MB·English

by  Aditya Upadhye

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North east Pacific Time-series Underwater Networked
Experiment (NEPTUNE):
Power System Design, Modeling and Analysis

Aditya Upadhye

A thesis submitted in partial fulfillment of the requirements for the degree of
Master of Science in Electrical Engineering
University of Washington
2003

Program Authorized to Offer Degree: Electrical Engineering
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University of Washington
Graduate School

This is to certify that I have examined this copy of a master’s thesis by
Aditya Upadhye
and found that it is complete and satisfactory in all respects,
and that any and all revisions required by the final
examining committee have been made.

Committee Members:

__________________________
Mohamed A. El-Sharkawi

__________________________
Robert J. Marks II

__________________________
Bruce M. Howe

Date: _______________
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In presenting this thesis in partial fulfillment of the requirements for a Master’s degree at
the University of Washington, I agree that the Library shall make its copies freely
available for inspection. I further agree that extensive copying of this thesis is allowable
only for scholarly purposes, consistent with “fair use” as prescribed in the U.S. Copyright
Law. Any other reproduction for any purposes or by any means shall not be allowed
without my written permission.

Signature: __________________________
Date: ______________________________
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Table of Contents

Page
List of Figures....................................................................................................................iii
List of Tables......................................................................................................................vi
Chapter 1. Introduction..................................................................................................1
1.1 NEPTUNE General Introduction...........................................................................1
1.2 NEPTUNE Power: Basic Concepts.......................................................................2
1.3 Electromagnetic Transients Analyses....................................................................4
1.4 Switching and Sectionalization: Comparison of the Two Design Concepts.........5
Chapter 2. Version 1 Design of the NEPTUNE Power System....................................9
2.1 Introduction............................................................................................................9
2.2 Design of the DC Circuit Breaker.......................................................................12
2.3 Hardware Development of the DC Circuit Breaker Prototype............................18
Chapter 3. Version 2 Design of the NEPTUNE Power System..................................25
3.1 Branching Unit Circuit Description.....................................................................25
3.2 Modes of System Operation................................................................................27
3.3 Algorithms for Branching Unit Controller..........................................................32
Chapter 4. Electromagnetic Transients Analyses........................................................37
4.1 Introduction..........................................................................................................37
4.2 Dynamics of the NEPTUNE Power System........................................................38
4.3 Electromagnetic Transients Program (EMTP)....................................................40
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Chapter 5. Cable Analysis and Modeling....................................................................46
5.1 Introduction..........................................................................................................46
5.2 Theoretical Calculation of Cable Inductance......................................................46
5.3 Calculation of Capacitance..................................................................................53
5.4 Computation of Cable Parameters by ATP .........................................................54
5.5 Computation of Ground Parameters....................................................................56
Chapter 6. EMTP Models for Restrikes and Shore Station Control...........................59
6.1 Introduction..........................................................................................................59
6.2 Initial Switching Arcs..........................................................................................60
6.3 Restrikes..............................................................................................................61
6.4 Modeling of Shore Station Power Supply Controls............................................69
Chapter 7. Network Transient Simulations.................................................................74
7.1 Introduction..........................................................................................................74
7.2 Version 1: Simulation of Non-Fault System Operation......................................74
7.3 Version 1: Simulation of Fault Condition...........................................................81
7.4 Version 2: Fault Transient Studies......................................................................84
Chapter 8. Conclusions and Future Work...................................................................91
Future Work...................................................................................................................92
List of References.............................................................................................................93
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List of Figures

Page
Figure 1.1 NEPTUNE cable system with approximate node locations..............................2
Figure 1.2 Version 1 and Version 2 power system designs................................................6
Figure 2.1 Structure of the NEPTUNE power system........................................................9
Figure 2.2 Block schematic for science node...................................................................11
Figure 2.3 Conceptual schematic of the NEPTUNE node connected to backbone..........13
Figure 2.4 Components of dc circuit breaker....................................................................14
Figure 2.5 CB soft closing................................................................................................15
Figure 2.6 CB when fully closed......................................................................................16
Figure 2.7 CB capacitor charging.....................................................................................17
Figure 2.8 CB capacitor discharging................................................................................17
Figure 2.9 Circuit diagram for driver circuit.....................................................................21
Figure 2.10 Circuit diagram for TTL control logic...........................................................23
Figure 3.1 Branching unit circuit diagram........................................................................25
Figure 3.2 Zener series power supply...............................................................................27
Figure 3.3 Overall system control actions ........................................................................31
Figure 3.4 Typical setup in fault-locating mode...............................................................33
Figure 3.5 Steps in fault-locating mode............................................................................35
Figure 3.6 Steps in restoration mode................................................................................36
Figure 4.1 Switching in RL series circuit.........................................................................37
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Figure 4.2 Node locations and relative distances in km...................................................39
Figure 4.3 Interface between network and TACS solution [3].........................................45
Figure 5.1 Cross-section of tubular conductor..................................................................47
Figure 5.2 Proposed cable for the NEPTUNE observatory..............................................50
Figure 6.1 Restrikes in a circuit breaker...........................................................................62
Figure 6.2 Simulation circuit for restrike model...............................................................64
Figure 6.3 Current through capacitor with restrikes when C= 4m F..................................66
Figure 6.4 Voltage across capacitor for C=4m F................................................................66
Figure 6.5 Capacitor current without restrikes when C=5 m F ..........................................67
Figure 6.6 Voltage across capacitor for C=5 m F...............................................................68
Figure 6.7 Simulation circuit for shore station current limiting model............................71
Figure 6.8 Output current of shore power supply during current limiting........................72
Figure 6.9 Output voltage of shore power supply during current limiting.......................72
Figure 6.10 Output current of shore power supply without current limiting....................73
Figure 7.1 Steady-state simulation circuit ........................................................................75
Figure 7.2 Time sequence of node breaker switching......................................................75
Figure 7.3 Current a the left input of Node 3....................................................................77
Figure 7.4 Voltage at the left input of Node 3..................................................................77
Figure 7.5 Voltage across the left diode on Node N3.......................................................78
Figure 7.6 Current through the left diode of Node N3.....................................................79
Figure 7.7 Voltage across the right diode of Node N3.....................................................79
Figure 7.8 Current through right diode of Node N3.........................................................80
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Figure 7.9 Simulation of fault condition...........................................................................81
Figure 7.10 Current entering Node 2................................................................................82
Figure 7.11 Voltage across Load Z2.................................................................................82
Figure 7.12 Current flowing in fault.................................................................................83
Figure 7.13 Capacitor current for node N2.......................................................................84
Figure 7.14 Simulation circuit for study of pre-insertion resistance placement...............86
Figure 7.15 Plot of fault energy against response time.....................................................88
Figure 7.16 Plot of peak transient current against the fault distance 'X'...........................89
Figure 7.17 Plot of fault energy against the fault distance 'X'..........................................89
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List of Tables

Page
Table 1-1 Comparison of Version 1 and Version 2 power system designs........................8
Table 2-1 Logic for switch operation in circuit breaker...................................................22
Table 5-1 Comparison of cable parameter values.............................................................56
Table 5-2 Comparison of ground parameter values..........................................................58
Table 6-1 Restrike studies.................................................................................................65
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Acknowledgements

This research is sponsored by the National Science Foundation through the grant titled,
“Development of a Power System for Cabled Ocean Observatories.” The author wishes
to express sincere appreciation to the sponsors. The author also wishes to thank the
NEPTUNE Power Group, especially Dr. Harold Kirkham of Jet Propulsion Laboratory,
Dr. Bruce Howe of Applied Physics Laboratory and Professor Chen-Ching Liu for their
insightful inputs. The author thanks the members of Computational Intelligence
Applications Laboratory for their constant encouragement, especially Professor
Mohamed El-Sharkawi for his patience, support and guidance.