MAN AND ENERGY
A case for Sustainable Living through
Renewable and Green Energy
Ali Keyhani
Professor of Electrical and Computer Engineering
The Ohio State University
Columbus, OH-43210
keyhani.1@osu.edu
3/12/2016
Keyhani.1@osu.edu
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ABSTRACT
• Energy technologies have a central role in social and
economic developments at all scales.
• Energy is closely linked environmental pollution,
degradation to economic development and quality of living.
• We are dependent on nonrenewable fossil fuels that have
been and will continue to be major cause of pollution and
climatic change.
• Petroleum supplies are dwindling.
• Thus finding sustainable alternatives is an urgent concern.
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….ABSTRACT
Challenges
• To develop technology for integration, control
of renewable energy sources, control of
energy consumption and load management.
• To empower energy user for a sustainable
living.
• Developing Distributed Generation system
where energy user is also an energy producer.
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…ABSTRACT
• In this talk, an overview of humankind energy
use is presented.
• Then the talk, focuses on some of the
challenges and efforts needed to harness
renewable energy.
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In part I, the use of energy by man, environment and
sustainable living were presented.
The use energy in present time was discussed.
Based on British Petroleum (www. bp.com), there is only ten
more years of petroleum reserve remain in US , if the current
rate of utilization continues.
British Petroleum data shows that the Middle East oil would
last only another one hundred years at the current worldwide
rate of consumption.
British Petroleum data shows that the world can continue to
use petroleum at current rate for only another forty years.
Challenge of future is to replace petroleum with renewable
energy sources.
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In part III, the control of Renewable Energy Sources will be
presented.
Uncertain open-loop model of Three-Phase Four-Wire Inverter
Three-Phase Four-Wire Inverter Control
Steady State and Transient response
The robust stability analysis results: System performance
vs. stability robustness under selected gains.
Power Flow Control of A Single DG Unit in Grid Connected Mode
 Single Unit Control- Island Mode of Operation
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Three-Phase Four-Wire Inverter Control
• The current limiter
– Imax is determined by the inverter.
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Three-Phase Four-Wire Inverter Control
• Space vector PWM
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Three-Phase Four-Wire Inverter Control (22)
• Standard space vector PWM – for 3-wire
– Two dimensional modulation
– Equal duration of vectors 7 (000) and 8 (111)
– No 0-sequence control capability
3
V

Vdc
ref , max
– High dc bus voltage utilization 3
• Modified space vector PWM – for 4-wire
– Three dimensional modulation
– Unequal duration of vectors 7 (000) and 8 (111)
1
– With 0-axis control capability
Vref ,max  Vdc
2
– Trade-off: less dc bus voltage utilization – Priority adjustment capability between αβ and 0 axes
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Three-Phase Four-Wire Inverter Control
• Modified SVPWM
Vector 8
(0 0 0)
Vector 2
(1 1 0)
Vector 1
(1 0 0)
Vector 2
(1 1 0)
Vector 7
(1 1 1)
Vector 8
(0 0 0)
Vector 8
(0 0 0)
Vector 2
(1 1 0)
Vector 1
(1 0 0)
Vector 1
(1 0 0)
Vector 2
(1 1 0)
Vector 7
(1 1 1)
Vector 8
(0 0 0)
Vector 1
(1 0 0)
van
0.5vdc
van
0.5vdc
0
t
0
t
-0.5vdc
vbn
0.5vdc
-0.5vdc
vbn
0.5vdc
0
t
0
t
-0.5vdc
vcn
0.5vdc
-0.5vdc
vcn
0.5vdc
0
t
0
t
-0.5vdc
-0.5vdc
T0/2
T1
T2
T8
T0/2
Conventional
T2
T7
Tpwm
Tpwm
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T1
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Modified
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Three-Phase Four-Wire Inverter Control
– Calculation of the vector intervals
Vref  v  v
2

sin    ref
3

T1 

sin
3
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2


T a
z
Vref
a
2
Vdc
3
T2 
 ref  arctan
sin  ref
sin

Tz a
3
keyhani.1@osu.edu
v
v
Tz 
T0  Tz  T1  T2
Tpwm
2
T 
v0
Tz
1
Vdc
2
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Three-Phase Four-Wire Inverter Control
• Frequency domain analysis
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Three-Phase Four-Wire Inverter Control
• Simulation results
– Steady state: Voltage reference 120V(RMS)
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Three-Phase Four-Wire Inverter Control
– Steady state: Voltage reference 120V(RMS)
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100% resistive load
keyhani.1@osu.edu
100% inductive load, pf = 0.8
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Three-Phase Four-Wire Inverter Control
– Steady state: Voltage reference 120V(RMS)
Unbalanced, phase A
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Unbalanced, phase A and B
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Three-Phase Four-Wire Inverter Control
– Steady state: Voltage reference 120V(RMS)
Nonlinear load
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Three-Phase Four-Wire Inverter Control
– Transients:
Load rises: 0 – 100%
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Load drops: 100% - 0
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Three-Phase Four-Wire Inverter Control
• Experiments
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Three-Phase Four-Wire Inverter Control
• Experiments
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Three-Phase Four-Wire Inverter Control
• Reference frame and PWM scheme issues:
– ABC+sine PWM
– Stationary α-β +Modified Space Vector PWM
– Comparison under limited dc bus voltage
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Three-Phase Four-Wire Inverter Control
• The robust stability issue
– Parametric uncertainty
– Load disturbances
– Stability Robustness
• μ-analysis
– Structured singular value
– Robust stability achieved iff
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop
model
– Equivalent circuit model
– Perturbed parameters
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop model
– Linear Fractional Transformation
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop model
– Linear Fractional Transformation
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop model
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop model
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Three-Phase Four-Wire Inverter Control
• Uncertain open-loop model
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Three-Phase Four-Wire Inverter Control
• Uncertain closed-loop model
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Three-Phase Four-Wire Inverter Control
• The robust stability analysis results
– System performance vs. stability robustness under
selected gains.
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Power Flow Control of A Single DG
Unit in Grid Connected Mode
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Grid-Connected Inverter Control
• For distributed generation (DG)
• Control issues
– Island mode: voltage control
– Grid-connected mode: power control
•
•
•
•
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Low steady state error for P and Q
Fast transient response
Low coupling between P and Q
Line current conditioning under nonlinear local load
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Distributed generation
• With or without utility interfacing
– Power supplies for critical loads
– Automotive
• Zero-emission vehicles
• Unlimited business opportunities
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Control of Fuel Cell Generating Source
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FC Energy Conversion System
Development Issues
• System configuration and auxiliary source
DC Bus
Fuel Cell
DC/DC
converter
DC/AC
inverter
Load
Measurement/control
Battery
DC/DC
converter
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Controller
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Low Voltage Distributed Generation
Systems
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FC Energy Conversion System
Development Issues
• DC/AC conversion
– 3-ph or single phase
– Voltage regulation (steady state)
– THD
– Transient response
– Overload protection
– Robustness to various disturbances
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Three-phase IGBT PWM Inverter
éVinv ab ù
êVinv ú
bc ú
ê
êëVinv ca úû
éVpwm ab ù
êVpwm ú
bc ú
ê
êëVpwm ca úû
Delta-Wye Transformer
éVload an ù
êVload ú
bn ú
ê
êëVload cn úû
Linv
x
U
Iinva
Cgrass
Cinv
Vdc
Cinv
n
Iinvb
y
V
Iinvc
Iload a
Iload b
W
L
O
A
D
z
Iload c
gating signals
DSP system
voltages and currents
measurement
• Research focus : Digital Control of the PWM
Inverters for On-Line DG/UPS
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Parallel DG Systems
UPS1
BYPASS STATIC
SWITCH
BYPASS SOURCE
UTILITY INPUT
BATTERY
LOAD
OUTPUT
RECTIFIER
INVERTER
UPS2
BYPASS STATIC
SWITCH
BATTERY
RECTIFIER
INVERTER
• Paralleling for system expansion and
redundancy
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Issues in paralleling DG
• To be avoided
– Unequal loading
– Circulating currents
• Due to the presence of:
– Component mismatches
– Measurement Errors
– Mismatch wiring impedances
• Undesirable:
– Increased system losses
– Decreased total capacity (need to de-rate the units)
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• Single Unit PWM Inverter Control
Propose a novel control using Perfect Robust Servomechanism Problem
(Perfect RSP) Voltage Controller and DiscreteSliding Mode Current
Controller to achieve:
– good voltage regulation
– good THD
– good transient response
– and fast current limiting
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• Parallel PWM Inverters Control
Develop load sharing technique that improves prior works in:
The proposed technique shall attempt to eliminate, if not reduce the
absolute dependency on inter-communication between units to guarantee
proper load sharing.
The technique shall not be sensitive to the following: component
mismatches, measurement error, or unbalanced load or wire impedances.
The proposed technique shall attempt to establish the sharing of harmonic
components of the currents, without significantly degrading the performance
of the outputs voltages.
The proposed technique shall attempt to avoid the existence of a single
point failure in the paralleled units configuration, such as a master/slave
actions and common synchronization signals
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Analysis, design, & development through simulations and experimental works
éVbypab ù
êVbyp ú
bc ú
ê
ëêVbypca ûú
SEMIKRON IGBT POWER CONVERTER SYSTEM
SKM 50 GB 123 D
éVloadan ù
êVload ú
bn ú
ê
ëêVloadcn ûú
éVinvab ù
êVinv ú
bc ú
ê
ëêVinvca ûú
éVpwmab ù
êVpwm ú
bc ú
ê
ëêVpwmca ûú
Linv 2.0mH
x
U
Iinva
THREE
PHASE
RECTIFIER
SYSTEM
240 V
UTILITY
SOURCE
Vdc
Cgrass
Cinv
1100uF
Cinv
Iloada
n
Iinvb
y
V
Iinvc
Iloadb
W
L
O
A
D
z
Iloadc
5 KVA - 60 Hz
240V Delta/ 208 Wye
Transformer
GATE DRIVER
SKHI- 22
PWM control
signals
SEMIKRON IGBT POWER CONVERTER SYSTEM
éVbypab ù
êVbyp ú
bc ú
ê
êëVbypca úû
SKM 50 GB 123 D
Signal
Conditioning
Circuit
INVERTER
F240
DSP system
voltages and currents
measurement
éVloadan ù
êVload ú
bn ú
ê
êëVloadcn úû
éVinvab ù
êVinv ú
bc ú
ê
ëêVinvca ûú
éVpwmab ù
êVpwm ú
bc ú
ê
ëêVpwmca ûú
Linv 2.0mH
x
U
Iinva
THREE
PHASE
RECTIFIER
SYSTEM
Vdc
Cgrass
Cinv
1100uF
Cinv
Iinvb
y
V
Iinvc
Iloada
n
Iloadb
W
z
5 KVA - 60 Hz
240V Delta/ 208 Wye
Transformer
Iloadc
GATE DRIVER
SKHI- 22
PWM control
signals
INVERTER
F240
DSP system
Signal
Conditioning
Circuit
voltages and currents
measurement
RS232
Communication
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2 x 5 kVA Experimental Setup
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Single Unit Control
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Literature Reviews: Control of Single PWM Inverters
Techniques for achieving low THD
• Earlier techniques were PWM generation based
– Carrier modulated PWM techniques
– Preprogrammed optimized PWM
Average
RMS
Voltage Regulation
PWM pulses
generation
Modulation
index
PWM
Inverter
Optimized PWM
patterns
 Slow responses to load transients
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Literature Reviews: Control of Single PWM Inverters
Techniques for achieving low THD
• Real time Pulse-by-pulse digital Control:
– Decoupled PI Control
– Deadbeat control
– Sliding Mode Control
 Good transient response, but high THD on non3/12/2016
linear loads
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Proposed Single Unit Control
• Perfect Robust Servo Mechanism Voltage Controller and Discrete
Sliding Mode Current Controller
r
I cmd qd*
r
Vref qd (k )
r
I cmd qd
r
eVqd
Robust ServoMechanism
Controller
+
-
r
Vpwm qd (k )
Limiter
r
eIqd
+
Discrete Sliding Mode
Controller
-
r
Vload qd (k )
r
I invqd (k )
states
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Line-to-Line
Voltage
Space
Vector
PWM
PWM timing
states
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Development of Single Unit Control
• State space model of the plant in DQ Stationary Reference
Frame
Iinv q
r
dVinv qd
dt
Isnd q
Linv
1

3  Cinv
r
dI inv qd
r
I inv qd 
1
3  Cinv
r
Triqd 0  I snd qd 0
+
+
Vpwm q
-
Vinv q
(
3 2 tr  Isnd q  3 Isnd d
Ltrans
)
+
r
1 r

Vpwm qd 
Vinv qd
Linv
Linv
dt
r
dVload qd 0
dt

1
C load
r
I snd qd 0 
1
Cload
Rtrans
)
Cgrass
Cinv
-
+
Vload q
Iload q
-
Iinv d
1
(
1 2 tr  Vinv q  3Vinv d
Isnd d
Linv
+
+
Vpwm d
Vinv d
-
-
(
3 2 tr  3Isnd q  Isnd d
)
Ltrans
+
(
Rtrans
1 2 tr  3Vinv q  Vinv d
) Cgrass
Cinv
r
I load qd 0
+
Vload d
Iload d
Isnd 0
Ltrans
Rtrans
+
Cgrass
r
dI snd qd 0
dt
Vload 0
r
Rtran
1
1

I snd qd 0 
Trvqd  Vinv qd 
V load qd 0
Ltran
Ltran
Ltran
Iload 0
-
 Zero Components are uncontrollable, not considered for control
design
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Development of Single Unit Control
Design Steps:
• Obtain the discrete plant model
• Design Sliding Mode Current Controller
• Include dynamics of the Sliding Mode Current
controller as the ‘plant’ for the Voltage
Controller
• Design the Perfect RSP Control:
– Include necessary harmonics to be eliminated
– Compute the gains by minimizing PI
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Perfect RSP Voltage Controller
r
*
(k ) > I max
I cmd qd
0
r
Vref qd (k )
+
r
eVqd
Discrete implementation of
1
s  w12
2
r
 I 2´2
r
states h1
r
Vload qd (k )
Discrete implementation of
1
s  w22
2
r
 I 2´2
states
r
h2
r
*
I cmd qd
K1
K2
Stabilizing compensator
gains
1
s2  wn2
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r
 I 2´2
r
I cmd qd
Servo
Compensator
Gains
.
..
Discrete implementation of
Current limit
Equation (4.17)
r
states h n
keyhani.1@osu.edu
r
é Vinvqd (k ) ù
ê r
ú
ê rI invqd (k ) ú
ê Vload (k ) ú
qd
ê r
ú
ê I load qd (k ) ú
êr
ú
êëVpwm qd (k  1)úû
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Steady State Performance
Resistive Balanced Load
0.8 lagging balanced load
0.9 leading balanced load
Resistive single-phase load
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Steady State Performance
Non-linear load
In all cases powers are shared within less than 1%
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Transient Performance
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Balanced resistive  Balanced
0.8 lagging  Unbalanced resistive
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Transient Performance
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Synchronization to bypass and FreeRunning Mode
Phase Error
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DQ Real and Reactive Powers
Frequency
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Currents
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Related Refrences
•
[1] Keyhani. A., M.N. Marwali, L.E. Higuera, G. Athalye, G. Baumgartner, "An integrated virtual learning system for the
development of motor drive systems," IEEE Transactions on Power Systems, Volume 17, No. 1, Feb. 2002, pp. 1-6
•
[2] Keyhani. A., A.B. Proca, "A virtual test bed for instruction and design of permanent magnet machines," IEEE
Transactions on Power Systems, Volume 14, No. 3, Aug. 1999, pp. 795-801
•
•
•
•
•
•
•
•
•
•
•
•
[3].Jung. J. O and A Keyhani, "Control of a Fuel Cell Based Z-Source Converter", IEEE Transaction on Energy Conversion,
volume 22, issue 2, June 2007 Page(s):467 - 476
[4]. Marwali, Mohammad N., Jin-Woo Jung and Ali Keyhani, "Stability Analysis of Load Sharing Control for Distributed
Generation Systems", IEEE Transactions on Energy Conversion, Vol. 22, No.3, September 2007, pp. 737-745]
[5] Marwari. Mohammad N., Min Dai, and Ali Keyhani, "Robust Stability Analysis of Voltage and Current Control for
Distributed Generation Systems," IEEE Transactions on Energy Conversion, Volume 21, No. 2, June 2006, pp. 516-526.]
[6]. Dai. Min, M.N. Marwali, Jin-Woo Jung, A. Keyhani, "Power Flow Control of a Single Distributed Generation Unit", IEEE
Transactions on Power Electronics, Vol. 23, Issue 1,Jan. 2008. pp. 343 - 352
[7] Dai. Min, M.N Marwali, Jin-Woo Jung, A. Keyhani, "A Three-Phase Four-Wire Inverter Control Technique for a Single
Distributed Generation Unit in Island Mode", IEEE Transactions on Power Electronics, Vol. 23, Issue 1, Jan. 2008, pp. 322 331
[8] Dai. Min, Mohammad N. Marwali, Jin-Woo Jung, and Ali Keyhani, "Power Flow Control of a Single Distributed
Generation Unit with Nonlinear Local Load," IEEE Power Engineering Society 2004 Power Systems Conference &
Exposition, October 10-13, 2004, New York city, NY
.
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Related Papers
•
•
•
•
•
•
•
•
•
•
[9] Dai. Min, Ali Keyhani, Jin-Woo Jung, and A.B. Proca, "A Low Cost Fuel Cell Drive System for Electrical
Vehicles," Proceedings of the 2003 Global Powertrain Congress Conference and Exposition, vol. 26, Sept.
2003, USA, pp. 22-26
[10].Dai. Min, Mohammad N. Marwali, Jin-Woo Jung, Ali Keyhani, "A PWM Rectifier Control Technique
for Three-Phase Double Conversion UPS under Unbalanced Load," IEEE Applied Power Electronics
Conference and Exposition, APEC'05, Vol. 1, pp.548-552, March 2005, Austin, TX
[12] Jung. Jin-Woo. Min Dai, and Ali Keyhani, "Modeling and Control of a Fuel Cell Based Z-Source
Converter," IEEE Applied Power Electronics Conference and Exposition, APEC'05, Vol. 2, pp. 1112-1118,
March 6-10, 2005, Austin, TX
[13].Keyhani. A, M. Dai, and J. W. Jung, "Parallel Operation of Power Converters for Applications to
Distributed Energy Systems," 2nd IASTED (The International Association of Science and Technology for
Development) International Conference on Power and Energy Systems, Greece, June 25-28, 2002
[14] Jung. Jin-Woo and Ali Keyhani, "Control of a Fuel Cell Based Z-Source Converter", IEEE Transaction
on Energy
Conversion, volume 22, issue 2, June 2007 Page(s):467 - 476
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Related Papers
•
M. N. Marwali and A. Keyhani, "Control of Distributed Generation Systems Part I: Voltage
and Current Control," IEEE Transactions on Power Electronics, Volume 19, No. 6, November
2004, pp. 1541-1550
[Abstract] [PDF Full-Text (738KB)]
•
M. N. Marwali, J. W. Jung, and A. Keyhani, "Control of Distributed Generation Systems Part
II: Load Sharing," IEEE Transactions on Power Electronics, Volume 19, No. 6, November 2004,
pp. 1551-1561 [Abstract] [PDF Full-Text(873KB)]
• http://www.ece.osu.edu/facultystaff/keyhani.htm
http://eewww.eng.ohio-state.edu/ems
•
3/12/2016
Thank you for coming
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