ABSTRACT
Flywheel Energy Storage has attracted new research attention
recently in applications like power quality, regenerative braking and uninterruptible
power supply (UPS). As a sustainable energy storage method, Flywheel Energy
Storage has become a direct substitute for batteries in UPS applications. Inner
design of the flywheel unit is shown to illustrate the economical way to
construct the system. A comprehensive model of Flywheel energy storage system
(FESS) that bridges the gap caused by power outage for critical loads in
commercial and industrial areas is presented. The basic circuit consists of bidirectional
power converter and flywheel unit coupled with interior permanent magnet
synchronous motor (IPMSM). Maximum
torque per ampere (MTPA) and flux weakening are used in the control scheme on
IPMSM. Detailed block diagrams of the control scheme are given. The FESS for
UPS application is modeled, simulated, and analyzed in MATLAB/SIMULINK environment.
KEYWORDS:
3.
Energy storage
4.
Flywheels
5.
Load flow
control
6.
Pulse width modulated
power converters
7.
Permanent
magnet motors
SOFTWARE: MATLAB/SIMULINK
CIRCUIT
DIAGRAM:
Fig.
1. Basic circuit diagram of the FESS in UPS.
EXPECTED SIMULATION RESULTS:
Fig.
2. Flywheel speed in charging mode.
Fig.
3. Electromagnetic torque of IPMSM.
Fig.
4. Power grid voltage sag and outage
Fig.
5. Power failure detection signal.
Fig.
6. Flywheel speed in discharging mode.
Fig.
7. DC bus voltage
Fig.
8. 3-phase voltage of critical load (phase to ground) without FESS.
Fig.
9. 3-phase voltage of critical load (phase to ground) with FESS
CONCLUSION
This
paper presents a modeling and control method of FESS in UPS system. A cost
effective and reliable flywheel design is brought forward to prove the possible
mass utilization of FESS in industrial applications. The control algorithm of FESS
is described with detailed block diagram, including the torque control of IPMSM
that driving the flywheel, voltage sags and outage detection and DC bus
regulation. Simulation results are presented to validate the control strategy.
Future tasks will include control strategy on mitigating unbalanced voltage
sags, parameter variation of IPMSM and experiment verification of the control
methods.
REFERENCES
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H Jansen. Timothy P Dever, "G2 Flywheel Module Design," University of
Toledo 2801 W. Bancroft St. Toledo, Ohio, US, Tech Rep. NASA/CR-2006-213862,
2006.
[3] Active
Power Corp. (2008), "Quantitative Reliability Assessment of Ball Bearings
versus Active Magnetic Bearings for Flywheel Energy Storage Systems,"
[Online] Available: http://www.activepower.com/fileadmin/documents/white_papers/WP_111_Bearing_Assessment.pdf.
[4] S.
Morimoto, M. Sanada, and Y. Takeda, "Wide-speed operation of interior
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[5] Barbara
H Kenny and Peter E Kascak, "DC Bus Regulation with a Flywheel Energy
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