Electrical Energy Conversion System for Pumping Airborne Wind Energy

133 Pages·2013·15 MB·English

Electrical Energy Conversion System for
Pumping Airborne Wind Energy
Jeroen Stuyts
Wouter Vandermeulen
Thesis voorgedragen tot het behalen
van de graad van Master of Science
in de ingenieurswetenschappen:
energie
Promotoren:
Prof.dr. M. Diehl
Prof.dr.ir. J. Driesen
Assessoren:
Prof.dr.ir. W. Dehaene
Prof.dr.ir. J. Meyers
Begeleider:
Dr.ir. A. Wagner
Academiejaar 2012 – 2013
© Copyright KU Leuven
Without written permission of the thesis supervisors and the authors it is forbidden
to reproduce or adapt in any form or by any means any part of this publication.
Requests for obtaining the right to reproduce or utilize parts of this publication
should be addressed to Faculteit Ingenieurswetenschappen, Kasteelpark Arenberg 1
bus 2200, B-3001 Heverlee, [phone].
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products,schematicsandprogramsdescribedinthisworkforindustrialorcommercial
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Preface
Designing, selecting, calculating, buying, implementing, testing and affecting. The
things we learned, we did and were trusted with, have been an incredible experience
for us. A very important reason we were able to do this is due to the people that
helped us on this journey.
First of all we would like to thank our promoters prof. Johan Driesen and prof.
Moritz Diehl. Their input has been greatly appreciated and always helped us to get
a clear view of the greater picture.
NextagreatamountofthanksgoestoAndrewWagnerandKurtGeebelen. Their
daily dose of help, explanations, patience and experience was of extreme importance
to this work. Without them this master’s thesis would not have been the same. The
entire HIGHWIND team needs to be thanked as well for their warm welcome and
introduction to the project. Especially Greg Horn, who helped us a lot with the
optimization, needs to be mentioned.
We would also like to thank Roland Reekmans and the other people from the
ELECTA lab. Their experience and help with implementing the test set-up is deeply
appreciated. Also Harm Leenders needs to be thanked. His help and answers to all
our questions throughout the entire year have been of the utmost importance. We
owe him a lot.
Working on this master’s thesis has taught us a lot of things and it would not
have been possible if it wasn’t for the good teamwork. Doing a master’s thesis with
two isn’t obvious but it worked out really well for us. Therefore we would also like
to thank each other. And finally we would like to thank those who are dearest to
us: our family, friends and girlfriends, who have supported us not only during this
master’s thesis, but during our entire life and education.
Jeroen Stuyts
Wouter Vandermeulen
i
Contents
Preface i
Abstract iv
Samenvatting v
List of Figures vi
List of Tables viii
List of Abbreviations x
1 Introduction 1
1.1 Airborne wind energy . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 HIGHWIND project Leuven . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 From System Requirements to a First Design 5
2.1 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Modeling the power flows . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 First design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3 Selection and System Procurement 19
3.1 ABB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.2 Siemens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.3 WEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.4 Other Suppliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.5 Choice of the drive supplier . . . . . . . . . . . . . . . . . . . . . . . 27
3.6 Risk analysis and safety . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4 Powering the Plane 30
4.1 Design of the plane power electronics . . . . . . . . . . . . . . . . . . 30
4.2 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.3 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.4 Possible improvements . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5 The Final System 50
5.1 The drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
ii
Contents
5.2 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5.3 The switchboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.4 Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.5 Mistakenly tripping of the RCD during testing . . . . . . . . . . . . 60
5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6 Testing the Drives and Implementation of the Results 62
6.1 Testing of the carousel drive . . . . . . . . . . . . . . . . . . . . . . . 62
6.2 Testing of the winch drive . . . . . . . . . . . . . . . . . . . . . . . . 63
6.3 Power loss calculation . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.4 Curve fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
6.5 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7 Conclusions, Leading to the Future 82
7.1 Concluding the design . . . . . . . . . . . . . . . . . . . . . . . . . . 82
7.2 The future of testing . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
7.3 Beyond testing: electricity production . . . . . . . . . . . . . . . . . 85
A The Full Siemens Quote 89
B Datasheets 98
B.1 Carousel motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
B.2 Winch motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
C The Full MAT 102
D Reliability Calculations 109
E Other Information 113
E.1 Contact information . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
E.2 IP rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
E.3 The full Vandecappelle NV quote . . . . . . . . . . . . . . . . . . . . 115
E.4 Used test equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
E.5 Losses in the components . . . . . . . . . . . . . . . . . . . . . . . . 118
Bibliography 119
iii
Abstract
Airborne wind energy offers great opportunity to harvest wind energy, with much
advantages over traditional wind turbines. To fully develop this technology, advanced
test set-ups are required. In this master’s thesis an electrical energy conversion
system is designed to convert the harvested mechanical energy and to power the
test set-up. This means selecting and purchasing the correct converters, motors,
generators, electronic components, safety gear etc. Since this master’s thesis fits
in a bigger research group that tries to optimize the amount of energy that can be
harvested, also the effect of the electrical energy conversion on that optimization is
researched.
To achieve this, system requirements were translated to a real world system. A
Siemens drive system, containing among others converters and motors, was tailored
and combined with all the other electrical components to create an electrical system
design. While doing this, safety was always kept in mind; this means protecting
against all faults, electrical and non-electrical, that could harm people or the set-up
itself. This was then all combined in an initial, non-final, test set-up. The perfor-
mance of this set-up was measured and turned into analytical curves, which could
be implemented in the optimization program.
The results show that the electrical system has a significant influence. Overlook-
ing or simplifying it by means of a single efficiency or simple models, results in a
suboptimal outcome. The difference between the optimized mechanical output and
optimized electrical output is already a couple of percentage points. However it is
shown that by (slightly) overdimensioning, the influence will further increase. It is
also shown that designing an electrical energy conversion system is a complex task
which should not be rushed. The effect on the overall operations of the system and
the impact on safety is substantial.
The effect of the electrical energy conversion on an actual set-up and on an
optimization program is very important, even for a mechanical problem like wind
energy harvesting. It is surely this form of energy that will be used by all the people
and companies enjoying green energy.
iv
Samenvatting
Airborne wind energy biedt interessante mogelijkheden om windenergie te oogsten.
Bovendien zijn er ook vele voordelen ten opzichte van traditionele windturbines. Om
deze technologie te ontwikkelen, zijn geavanceerde testopstellingen nodig. Voor deze
masterproef werd een elektrisch omvormingssysteem ontwikkeld om de geoogste me-
chanische windenergie om te zetten en om de gehele testopstelling van elektriciteit te
voorzien. Hiertoe dienden geschikte convertoren, motoren, generatoren, elektronica,
veiligheden etc. geselecteerd en aangekocht te worden. Omdat deze masterproef
kadert in een groter onderzoeksproject, dat tot doel heeft de hoeveelheid geoogste
energie te optimaliseren, werd ook de invloed van het elektrisch omvormingssysteem
op deze optimalisatie onderzocht.
Om dit te bereiken, werden systeemvereisten vertaald naar een reëel systeem.
Een drive systeem van Siemens, bestaande uit o.a. convertoren en motoren, werd
afgestemd en gecombineerd met alle andere elektrische componenten om zo een
totaal elektrisch ontwerp te bekomen. Hierbij is veiligheid, zowel elektrische als
niet-elektrische, altijd een prioriteit geweest. Dit houdt in dat er bescherming wordt
geboden tegen alles wat personen of de opstelling zou kunnen schaden. Het geheel
werd geïmplementeerd in een eerste testopstelling welke volledig werd gekarakteri-
seerd en in analytische curves gegoten. Deze curves werden nadien geïmplementeerd
in het optimalisatieprogramma.
De resultaten tonen aan dat het elektrische systeem een niet-verwaarloosbare
invloedheeftophetgeheel. Ditoverhethoofdzienofvereenvoudigen,dooreenenkele
efficiëntie of eenvoudige modellen, leidt tot nonoptimale resultaten. Het verschil
tussen de geoptimaliseerde elektrische waarden en de geoptimaliseerde mechanische
waarden bedraagt al enkele procentpunten. Er wordt ook aangetoond dat bij een
(licht) overgedimensioneerd systeem de invloed nog veel groter is. Er wordt ook
aangetoond dat het ontwerpen van een elektrisch omvormingssysteem een complexe
taak is die grondig moet worden uitgevoerd. Het effect op de algemene werking en
de veiligheid is immers substantieel.
Het effect van de elektrische omvorming op de opstelling en de optimalisatie is
dus heel belangrijk, zelfs bij een voornamelijk mechanisch proces zoals het oogsten
van windenergie. Het is immers de elektrische energie die door mensen en bedrijven
gebruikt zal worden als groene stroom.
v
List of Figures
1.1 The ground station of HIGHWIND: the carousel [9] . . . . . . . . . . . 3
2.1 Torque-rotational speed characteristic for the winch motor according to
simulations of one cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Power flow according to simulations of one cycle . . . . . . . . . . . . . 7
2.3 The required torque-rotational speed and power-rotational speed
characteristic of the carousel motor [9] . . . . . . . . . . . . . . . . . . . 8
2.4 Power flow based on Figure 2.2 with an additional 1kW of losses, used
for the model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5 Model results for the power flow for a generator and a braking chopper 13
2.6 Model results for the power flow for a generator, a battery and a braking
chopper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.7 First electrical design based on a DC bus . . . . . . . . . . . . . . . . . 15
2.8 First electrical design based on an AC bus . . . . . . . . . . . . . . . . . 17
3.1 The working principle of the ABB proposal . . . . . . . . . . . . . . . . 20
3.2 The modular Siemens proposal, a schematic overview can be found in
Figure 5.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.3 Possible testing location with a 300m range from a local grid connection,
source: Google Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.1 Transmission power loss for a system which needs 80W and is connected
with a 42Ω cable. The red vertical line indicates the required minimal
voltage for this case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.2 Plane power circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.3 AC/DC converter top 100-112. . . . . . . . . . . . . . . . . . . . . . . . 36
4.4 OPEN UPS board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.5 Configuration of all components . . . . . . . . . . . . . . . . . . . . . . 38
4.6 Resistance measurement cable . . . . . . . . . . . . . . . . . . . . . . . . 39
4.7 Temperature measurement cable on cardboard with 200W load and
230V input. The load is switched off at t = 11,5min. . . . . . . . . . . 40
4.8 Temperature measurement cable on aluminum with 200W load and
230V input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.9 Reliability of the original system . . . . . . . . . . . . . . . . . . . . . . 42
4.10 Separate DC bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
vi
List of Figures
4.11 Reliability of separate DC bus. Two ‘groups’ and thus two OPEN UPS
boards are used to calculate this. . . . . . . . . . . . . . . . . . . . . . . 44
4.12 Secured DC bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.13 Power switch of the secured DC bus . . . . . . . . . . . . . . . . . . . . 46
4.14 Reliability of the secured DC bus - calculated for two OPEN UPS boards 46
4.15 Switched DC bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.16 Switchboard of the switched DC bus . . . . . . . . . . . . . . . . . . . . 48
4.17 Reliability of the full switchboard system . . . . . . . . . . . . . . . . . 48
5.1 Schematic overview of the drives . . . . . . . . . . . . . . . . . . . . . . 51
5.2 Schematic overview of the plane, reworked version of 4.2 . . . . . . . . 56
5.3 Schematic overview of the switchboard . . . . . . . . . . . . . . . . . . 57
5.4 Schematic overview of the final system . . . . . . . . . . . . . . . . . . 58
6.1 Efficiency map of the carousel drive in motor mode . . . . . . . . . . . . 64
6.2 Efficiency map of the winch drive . . . . . . . . . . . . . . . . . . . . . . 66
6.3 Predicted maximal efficiency for a certain mechanical power of the drives,
derived from the data provided by Siemens . . . . . . . . . . . . . . . . 70
6.4 Efficiency curve of the carousel drive . . . . . . . . . . . . . . . . . . . . 75
6.5 Efficiency curve of the winch drive . . . . . . . . . . . . . . . . . . . . . 76
6.6 Mechanical and electrical power during a pumping cycle.. . . . . . . . . 78
6.7 Mechanical optimized orbit (a) and electrical optimized orbit (b) for
4m/s wind speed in a rotational speed - torque map . . . . . . . . . . . 79
6.8 Mechanical optimized orbit (a) and electrical optimized orbit (b) for
10m/s wind speed in a rotational speed - torque map . . . . . . . . . . 80
6.9 Optimized orbits for 10m/s wind speed without winch drive constraints
in a rotational speed - torque map . . . . . . . . . . . . . . . . . . . . . 81
7.1 Implementation of the drives for the test set-up . . . . . . . . . . . . . 83
7.2 The effect on power fluctuations by phase shifting, the cycles are for an
electrical power optimization at 4m/s wind speed . . . . . . . . . . . . . 86
E.1 Losses in the partial load range for Active Line Modules and Smart Line
Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
E.2 Losses in the partial load range for Motor Modules . . . . . . . . . . . . 118
vii
List of Tables
2.1 Maximal winch motor characteristics based on [9] . . . . . . . . . . . . 6
2.2 Maximum winch motor characteristics based on simulations . . . . . . . 7
2.3 Nominal winch motor characteristics based on a group decision . . . . . 7
2.4 Nominal carousel motor characteristics . . . . . . . . . . . . . . . . . . . 9
3.1 The quote made by ABB (price without VAT) . . . . . . . . . . . . . . 20
3.2 The quote made by Siemens, the full quote can be found in Appendix A
(price without VAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.3 The quote made by WEG (price without VAT) . . . . . . . . . . . . . . 24
3.4 The quote made by Vandecappelle NV, the full quote can be found in
Appendix E.3 (price without VAT) . . . . . . . . . . . . . . . . . . . . 26
3.5 Comparison between the drive suppliers via a scoring system on 100 . . 28
4.1 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.2 Battery data for powering the plane . . . . . . . . . . . . . . . . . . . . 32
4.3 Comparison of the different designs . . . . . . . . . . . . . . . . . . . . . 35
4.4 Properties of Top 100-112 [36] . . . . . . . . . . . . . . . . . . . . . . . . 36
4.5 Properties of the OPEN UPS board [22] . . . . . . . . . . . . . . . . . . 37
4.6 Summary table, comparing the effect of faults for the different designs . 47
6.1 Holding torque measurement . . . . . . . . . . . . . . . . . . . . . . . . 67
6.2 Power losses of the set-up . . . . . . . . . . . . . . . . . . . . . . . . . . 68
6.3 The highest measured efficiency of the carousel drive in motor mode for
a certain mechanical power demand is compared with the highest
maximal calculated efficiency. . . . . . . . . . . . . . . . . . . . . . . . . 71
6.4 The efficiency of operating points with the same mechanical power is
compared with the maximal calculated efficiency at that mechanical
power for the carousel drive (in this case 500W). . . . . . . . . . . . . . 71
6.5 The highest measured efficiency of the winch drive in motor mode for a
certain mechanical power demand is compared with the highest maximal
calculated efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.6 The highest measured efficiency of the winch drive in generator mode for
a certain mechanical power demand is compared with the highest
maximal calculated efficiency . . . . . . . . . . . . . . . . . . . . . . . . 72
viii