Sizing and Control of a Flywheel Energy Storage for
Ramea Wind-Hydrogen-Diesel Hybrid Power System
Prepared by : Khademul Islam
Supervisor : Dr. Tariq Iqbal
Faculty of Engineering & Applied Science
Memorial University of Newfoundland, St.John’s, Canada
April 25, 2011
OUTLINE
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Introduction
Ramea Hybrid System Specification
System Sizing & Steady State Simulation
Dynamic Modeling and Simulation
Experimental Set-up
Observations
Design of Control System
Results and Conclusions
INTRODUCTION
LOCATION OF RAMEA
•Ramea is a small island 10
km from the South coast of
Newfoundland.
•Population is about 700.
•A traditional fishery
community
Hybrid Power System
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Hybrid systems by definition contain a number of power generation devices such
as wind turbines, photovoltaic, micro-hydro and/or fossil fuel generators.
The use of renewable power generation systems reduces the use of expensive fuels,
allows for the cleaner generation of electrical power and also improves the standard
of living for many people in remote areas
WIND ENERGY SCENARIO IN CANADA
Canada is blessed with adequate wind resources.
Canada is in a better position to deploy many more number of WECS.
BLOCK DIAGRAM OF RAMEA HYBRID SYSTEM
RAMEA HYBRID SYSTEM SPECIFICATIONS
Load Characteristics
Peak Load – 1,211 kW
 Average Load – 528 kW
 Minimum Load – 202 kW
 Annual Energy – 4,556 MWh
Distribution System
 4.16 kV, 2 Feeders
Energy Production
 Nine wind turbines (6x65 kW and
3x100 kW).
 Three diesel generators (3x925 kW).
 Hydrogen generators (200 kW)
Load profile of Ramea
Wind Resource at Ramea
Weibull shape factor – 2.02.
Correlation factor – 0.947.
Diurnal pattern strength – 0.0584.
WIND TURBINES & HYDROGEN
TANKS IN RAMEA ISLAND
FLYWHEEL ENERGY STORAGE SYSTEM
The amount of energy stored and released E, is
calculated by means of the equation
E= ½ Iω2
Where,
I= Moment of Inertia of the
Flywheel and
ω= Rotational speed of the
Flywheel.
ADVANTAGES OF FLYWHEEL ENERGY
STORAGE SYSTEM
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High power density.
High energy density.
No capacity degradation, the lifetime of the flywheel is
almost independent of the depth of the discharge and
discharge cycle. It can operate equally well on shallow and
on deep discharges. Optimizing e.g. battery design for load
variations is difficult.
No periodic maintenance is required.
Short recharge time.
Scalable technology and universal localization.
Environmental friendly materials, low environmental
impact
Table.1 represents the comparison among the three energy storage system such as Lead –acid battery,
superconducting magnetic storage and flywheel storage system. From the above table we see that the
flywheel is a mechanical battery with life time more than 20 years. It is also superior to other two
with regards to temperature range, environmental impact and relative size
SYSTEM SIZING AND SIMULATION
 Smart Energy (SE25) flywheel from Beacon Power
Corporation is used for the system sizing which has highly
cyclic capability, smart grid attributes, 20-years design life
and sustainable technology.
 Simulation is done in HOMER . For Homer simulation we
used two conditions.
1.
Simulation Without Flywheel
2.
Simulation With Flywheel
Fig: Beacon SE25 Flywheel
HOMER SIMULATION WITHOUT FLYWHEEL
HOMER SIMULATION WITH FLYWHEEL
Comparison of Simulation Results
without and with Flywheel Energy
Storage System
SUMMARY OF OBSERVATIONS FROM HOMER
SIMULATION
Considering Factors
Electrical
Properties
Diesel Generator
(D925)
Hydrogen
Generator
(Gen3)
Without
Flywheel
With
Flywheel
Excess Electricity
3.27%
1.94%
Renewable Fraction
0.238
0.272
Maximum Renewable
Penetration
65.5%
76.6%
Electricity Generation
3540199 kWh/yr
3382941 kWh/yr
Fuel Consumption
965505 L/yr
933848 L/yr
Hours of Operations
752/yr
317/yr
Number of Starts
43848/yr
18727/yr
Hydrogen Consumption
7223 kg/yr
3345 kg/yr
Mean Electrical efficiency
34.6%
34.8%
Operational Life
53.2 yr
126 yr
Carbon Dioxide
2552953 kg/yr
2459094 kg/yr
Carbon Monoxide
6349 kg/yr
6092 kg/yr
Unburned Hydrocarbon
703 kg/yr
675 kg/yr
Sulfur Dioxide
5127 kg/yr
4938 kg/yr
Emission
SIMULATION IN
SIMULINK/MATLAB
65 kW Wind Turbine Simulation
WS=8m/s
WS=8m/s
WS=10m/s
WS=6m/s
WS=6m/s
WS=10m/s
65 kW Wind Turbine Simulation Result
WS=14m/s
WS=12m/s
100 kW Wind Turbine Simulation Result
WS= 6m/s
WS= 6 m/s
WS= 6m/s
WS= 8 m/s
100 kW Wind Turbine Simulation Result
WS=12m/s
WS=14m/s
WS=12m/s
925kW Diesel Generator Simulation
Figure : Simulink Model of Diesel Generator
Figure: Engine and Excitation System of Diesel Generator
Simulation Result of Diesel Generator
SIMULATION OF RAMEA HYBRID POWER SYSTEM
Continuous
Ws
pow ergui
cC
A
B
FREQA
SC
Diesel Generator 925kW
C
C
C
B
bB
Frequency Monotor
390kW
c
B
Wind Field
b
aA
a
A
C
B
A
Bb
Cc
Load
Aa
Scope
A
c
b
a
4.16 kV/ 480 V
150KVA
B
aA
B
bB
cC
Cc
Bb
C
C
B
A
Aa
SL
Load1
Flywheel Energy Storage System
C
B
A
Main Average load 500kW
Open this block
to visualize
recorded power signals
Data Acquisition Station1
Data Acquisition Station 2
c
b
A
B
C
a
3-Phase Breaker
Open this block
to visualize
recorded signals
A
Step Change in Load
Wind-Diesel power system in Ramea, Newfoundland
C
300kW
SIMULATION RESULTS OF RAMEA HYBRID POWER
SYSTEM
Change in
load
Change in
frequency
Charging of
FW
Wind turbines and diesel generator simulation output of
Ramea hybrid power system from Simulink.
Discharging of
FW
Effect of load changing in system frequency and
flywheel charging and discharging characteristics
Experimental Set-up
DC Machine Based FW Storage
Flywheel
Controlable
power
supply
DC Motor/Generator
Main Control
System
Control Signal
Supply
Grid
Components used
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Controllable power supply (two)
Phase control relay, 6V dc (two)
Electromechanical relay (two)
DC machine (3Hp/2kw, 1750RPM, 120V)
Data acquisition card [USB1208LS] from measurement computing.
(one)
Voltage and Current Sensor (one)
Speed Sensor [output 0-10V dc ] (one)
Cast steel Flywheel rotor (one)
Logic Power Supply(+/- 15 Volts, DC)
A personal Computer
DC Motor Based FW Storage
Voltage
Sensor
Flywheel Disk
Data
acquisition card
Relays
DC Machine
(Motor/Generator)
Amplifier
circuit
Current
Sensor
DC Current Transducer (CR5200)
Double Gain Amplifier
Calibration Curves
Calibration Curve for the Rotational Speed of the
Motor
Calibration Curve for the Controllable Power
Supply Unit
Electromechanical Relay and Relay Driving
Circuit
CONTROL SYSTEM OF FLYWHEEL ENERGY
STORAGE
Start
Initialize Motor Starting Parameters
Read Voltage from Tacho Generator
Read Voltage from the Grid
Calculate actual speed of the machine
Convert the grid Voltage to
Frequency, f
Is f <60 Hz
No
Yes
Operate Relay 1
(Generating Mode)
Yes
Is f >60 Hz
Operate Relay 2
Motoring Mode)
Display Results
No
EXPERIMENTAL OBSERVATIONS
Summary of Observations
Load(W)
Charge
Energy
Discharge
Energy
Efficiency
(%)
Chrg
Time
(Sec)
Dcrge Time
(Sec)
100
100
1.85E+01
1.04E+01
56.21621622
235
223
80
100
200
1.84E+01
1.03E+01
55.97826087
264
194
100
100
200
3.06E+01
1.74E+01
56.92810458
340
225
100
80
100
3.33E+01
1.81E+01
54.34913017
341
300
80
100
300
1.88E+01
1.02E+01
54.25531915
235
172
100
100
300
3.24E+01
1.71E+01
52.87037037
353
201
100
80
300
3.34E+01
1.69E+01
50.5988024
325
233
100
70
300
3.54E+01
1.95E+01
55.08474576
295
250
100
70
100
3.57E+01
1.82E+01
50.98039216
356
309
100
60
300
3.12E+01
1.73E+01
55.44871795
353
231
Vamax
(Volts)
Vf
(Volt)
80
Design of Control System
Optimum Control System Design Parameters
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Minimum Charging Parameters
-Vamax=80 Volts, Vf = 100 Volts
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Maximum Discharging Parameters
- Vf= 100, Load= 100 Watts
Armature and Field Control
Circuit
RESULTS AND CONCLUSION
Results clearly shows that an addition of a flywheel system will
Reduce excess electricity,
Increase maximum renewable penetration,
 Reduce fuel consumption, and number of diesel starts per year,
Increase operational life and reduce emissions.
From Ramea system simulation in Simulink , it clearly shows that a step change in
the load of 50kW will lead to a frequency deviation of 0.3Hz. System flywheel will
provide more that 50kW for few seconds to maintain system frequency.
Based on the Experimental observations, a control system is designed for
minimum input energy and maximum output energy.
Visual Basic language is used for the designed control system.
Therefore, we suggest an addition of a 25kWh flywheel system to Ramea hybrid
power system.
Future Work
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Pump Hydro Storage For Long Term Storage
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Advanced Flywheel System. Advanced flywheel
system rotate above 20,000 rpm in vacuum
enclosure made from high strength carbon
composite filament will be very efficient
List of Publications:
1. K.Islam, M.T. Iqbal “Flywheel Energy Storage System for an Isolated WindHydrogen-Diesel Power System” Presented in WESNet Poster Presentation,
CanWEA, 2010, Montreal, Canada
2. K.Islam, M.T. Iqbal and R. Ashshan “Sizing and Simulation of Flywheel Energy
Storage System for Ramea Hybrid Power System” Presented at 19th IEEENECEC Conference 2010, St. John’s, Canada
3. K.Islam, M.T. Iqbal and R. Ahshan “Experimental Observations for Designing &
Controlling of Flywheel Energy Storage System” Presented at 19th IEEE-NECEC
Conference 2010, St.John’s, NL, Canada
4. K.Islam and M.T Iqbal “Sizing and Control of Flywheel Energy Storage for a
Remote Hybrid Power System” Presented at WESNet Workshop, February 24-25,
Ryerson University, Toronto, ON, Canada 2011.
Acknowledgment
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Dr. Tariq Iqbal
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This work is supported by a research grant from the National
Science and Engineering Research Council (NSERC) of
Canada through WESNet. We also thank Newfoundland
Hydro and Memorial University of Newfoundland for
providing data and support
Also thanks to Razzaqul Ahshan, Nahidul Khan and Greg O Lory
Thanks
Questions ?