OPTIMIZATION OF A STAND-ALONE HYBRID WIND/SOLAR GENERATION SYSTEM FOR ...

83 Pages·2011·1.19 MB·English

OPTIMIZATION OF A STAND-ALONE HYBRID WIND/SOLAR
GENERATION SYSTEM FOR LIFESPAN EXTENSION
by
Daniel A. Mej´ıa
B.S.E.E., University of Colorado Denver, 2007
A thesis submitted to the
University of Colorado Denver
in partial fulfillment
of the requirements for the degree of
Masters of Science Electrical Engineering
Electrical Engineering
2011
This thesis for the Masters of Science Electrical Engineering
degree by
Daniel A. Mej´ıa
has been approved
by
Fernando Mancilla-David
Alexander Engau
Jan Bialasiewicz
Jae - Do Park
Date
Mej´ıa, Daniel A. (M.S., Electrical Engineering)
Optimization of a Stand-Alone Hybrid Wind/Solar Generation System for Lifes-
pan Extension
Thesis directed by Assistant Professor Fernando Mancilla-David and Assistant
Professor Alexander Engau
ABSTRACT
The work presented in this thesis focuses on the optimization of a hybrid
wind/solar system with energy storage for equipment lifespan extension. In
general, electrical equipment is exposed to operational disturbances that result
in temporary or permanent damage to the equipment. This study analyzes
each component of the system, identifies several potential operational distur-
bances, and subsequently proposes a method to minimize the conditions that
create or cause such effects. These conditions are minimized by solving an op-
timization problem that calculates the sources’ supply set points at which the
system’s operational disturbances are minimized. Scenarios with different op-
erating conditions to verify the performance of the proposed formulation along
with illustrative examples in terms of case studies are also presented.
This abstract accurately represents the content of the candidate’s thesis. We
recommend its publication.
Signed
Fernando Mancilla-David
Signed
Alexander Engau
DEDICATION
This Master’s Thesis is dedicated to my Lord and Savior Jesus Christ for His
is all the power, the honor and glory. Amen.
ACKNOWLEDGMENT
I would like to sincerely thank Professor Fernando Mancilla-David for his
support and teaching throughout my entire career. His teaching methodology,
heavily based on conceptual foundation, combined with state-of-the-art technol-
ogy applications has forged my engineering abilities and professional develop-
ment.
I deeply thank Professor Alexander Engau for his continuous support
throughout the entire project. His rich knowledge and talent combined with
his accessibility and delightfulness to teach make him fun and enjoyable to work
with.
I would like to give special thanks to Professor Fernando Valenciaga from La
Plata National University (UNLP) for his valuable support, answering questions
related to his previous research.
I greatly appreciate Professors Jan Bialasiewicz and Jae - Do Park for form-
ing part of my dissertation defense committee.
I would like to also dedicate this work to my brother and best friend Julian
for his support and his unconditional love, support and friendship.
My mother and my father have always been there for me and given me
comfort and support. Their love and support has given me the ability and
courage to accomplish all my goals.
CONTENTS
Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
Symbols and Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Chapter
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Hybrid Systems Review . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Optimization in Power Systems . . . . . . . . . . . . . . . . . . . . 4
2. System Models Review . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Wind Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Wind Subsystem Operation . . . . . . . . . . . . . . . . . . . . . 8
2.2 Solar Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.1 Solar Subsystem Operation . . . . . . . . . . . . . . . . . . . . . 13
3. System Operational Contingencies Analysis . . . . . . . . . . . . . . . 17
3.1 Battery Potential Hazards . . . . . . . . . . . . . . . . . . . . . . . 17
3.1.1 Batteries Discharging Mode . . . . . . . . . . . . . . . . . . . . . 18
3.1.2 Batteries Charging Mode . . . . . . . . . . . . . . . . . . . . . . 18
3.2 Wind Subsystem Potential Hazards . . . . . . . . . . . . . . . . . . 20
3.3 Solar Subsystem Potential Hazards . . . . . . . . . . . . . . . . . . 22
4. System Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . 23
4.1 Operation Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
vii
4.2 Operation Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.3 Operation Mode 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.4 Operation Mode 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.5 Operation Mode 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.6 Operation Mode 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.7 Operation Mode 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.8 Operation Mode 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5. Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.1 Total Harmonic Distortion Index . . . . . . . . . . . . . . . . . . . 29
5.2 Mathematical Optimization Model . . . . . . . . . . . . . . . . . . 31
6. Problem Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.1 Solution Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
6.1.1 Scenario 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.1.2 Scenario 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.1.3 Scenario 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
8. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Appendix
A. Simulation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 54
B. Computational Code . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
B.1 Scenarios Generator . . . . . . . . . . . . . . . . . . . . . . . . . . 56
B.2 Optimization Solving Function . . . . . . . . . . . . . . . . . . . . 57
B.3 Variables Definition Function . . . . . . . . . . . . . . . . . . . . . 58
B.4 Objective Function . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
viii
B.5 Non-linear Constraints Function . . . . . . . . . . . . . . . . . . . . 61
B.6 Weighted Objectives Solver Function . . . . . . . . . . . . . . . . . 62
C. MATLAB’s fmincon Function . . . . . . . . . . . . . . . . . . . . . . 64
D. System Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
ix
FIGURES
Figure
1.1 Wind/solar hybrid generation system . . . . . . . . . . . . . . . . . 2
1.2 Energy technologies hybrid combination matrix [1] . . . . . . . . . 3
2.1 Equivalent circuit of a battery . . . . . . . . . . . . . . . . . . . . . 5
2.2 Wind subsystem block diagram . . . . . . . . . . . . . . . . . . . . 6
2.3 Analytical approximation of C −λ characteristics (blade pitch angle
p
ϑ as parameter [2]) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 Equivalent circuit and vector diagram for a PMSG [2] . . . . . . . . 9
2.5 λ at a blade pitch angle ϑ = 0o . . . . . . . . . . . . . . . . . . . 10
opt
2.6 Solar subsystem block diagram . . . . . . . . . . . . . . . . . . . . 12
2.7 Solar cell equivalent circuit . . . . . . . . . . . . . . . . . . . . . . 12
2.8 I-V characteristic curves . . . . . . . . . . . . . . . . . . . . . . . . 14
2.9 PV Curves maximum values at 25oC . . . . . . . . . . . . . . . . . 16
3.1 Battery charge characteristic curve . . . . . . . . . . . . . . . . . . 19
6.1 Pareto frontiers illustration . . . . . . . . . . . . . . . . . . . . . . 35
6.2 Scenario 1 Pareto set . . . . . . . . . . . . . . . . . . . . . . . . . . 38
6.3 T and i as a function of d for different wind velocities V . . . . 39
e o w w
6.4 f (x) as a function of d . . . . . . . . . . . . . . . . . . . . . . . . 40
1 w
6.5 Scenario 2 Pareto set . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.1 Objective functions variation with respect to i . . . . . . . . . . . 47
L
x