ABSTRACT
As the power of wind farms (WFs) considerably proliferates
in many areas worldwide, energy storage systems will be required to dynamically
compensate the wind energy intermittency and increase power system stability.
In this paper, a backup power conditioning strategy for wind energy-fed voltage
source converter HVDC transmission systems is presented. An induction machine
based flywheel energy storage systems (FESS) is integrated to the HVDC system
via a solid state transformer (SST). The FESS is connected in parallel with the
dc-link of the grid side converter; therefore, the excess wind energy can be stored
in the flywheel and then restored during the energy shortage periods. The
proposed system aims to compensate the power fluctuations caused by the
intermittent nature of wind energy, levels the power-fed to the grid, and improves
the quality of delivered power. The proposed system including FESS with an interfacing
SST is modeled, simulated, and analyzed in MATLAB/SIMULINK environment. The
results verify the effectiveness of the proposed system.
KEYWORDS:
1. HVDC
2. Wind generation
3. Storage
system
4. Smart grid
5. Flywheel.
SOFTWARE: MATLAB/SIMULINK
BLOCK
DIAGRAM:
Figure 1. The proposed system
EXPECTED SIMULATION RESULTS:
Figure 2. Simulation results of power smoothing operation in pu
(a) grid power, wind power, and flywheel power, (b) flywheel speed, (c) phase
shift between two H-bridges of DAB, (d) HV dc link, (e) LV dc link.
Figure 3. Simulation results of HFT waveforms, in pu, employing
soft switching using phase shift technique (a) positive power flow (from H2 to
H1), (a)negative power flow (from H1 to H2).
Figure 4. Simulation results of power leveling operation in pu.
CONCLUSION
In this paper, a new strategy of improving the integration of large
scale wind farms into HVDC transmission system using SST based FESS has been
proposed to compensate for the wind power oscillations and to enhance the power
profile at grid side. In the proposed technique a low speed induction machine
based flywheel energy storage system is connected in parallel with the DC link
of the grid side converter. Therefore, the excess wind power is stored in FESS
and restored in case of wind power shortage and/or power demand increase
preserving the grid power profile at its required value. The simulation results
have demonstrated that the FESS compensates for power fluctuations caused by
wind nature during different load conditions and exhibits good system performance
with a relatively fast response and high dynamics.
REFERENCES
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