Stability Enhancement of Wind Power System by Using Energy Capacitor System
Stability Enhancement of Wind Power System by Using Energy Capacitor System
Stability Enhancement of Wind Power System by Using Energy Capacitor System
I. INTRODUCTION
The rate of Energy Consumption is increased day by day
because of increasing the living standard of the peoples on
Earth. In fact most of the energy consumed is fossil fuels
based like coal, petroleum, natural gas, diesel etc. The fossil
fuel based energy sources have two major problems. First of
all, they will be extinct within short times like if the present
trend of using fossil fuel continue, according to U.S.
department of energy (2012) Coal will extinct within 109
years, Natural gas within 56 years and Crude Oil within 53
years [1]. Secondly, they increase the formation of CO 2 and
other gases that are responsible for global warming,
greenhouse effect, rising of water level and resulted in
extinction of endangered species. It is a matter of great
concern that- 3.2 billion tons of CO 2 adds to the environment
annually [2]. Therefore it is necessary to introduce clean
energy sources like renewable energy more in place of the
fossil fuel. Wind power is one of the prospective clean
energy resource. However, due to the intermittent and
stochastic nature of the wind, the generated power from the
wind fluctuates randomly thus can cause
frequency
fluctuation in power system and therefore Some methods
have been proposed so far for mitigating the fluctuations.
In many studies, a flywheel energy system is proposed to
smooth the wind power fluctuation [3]. It is possible to smooth
the fluctuations up to a certain range by the pitch angle
controller [4]. Some authors have proposed a superconducting
magnetic energy storage system [5] for the wind power
978-1-4673-7819-2/15/$31.002015 IEEE
PMSG PARAMETERS
Rated Capacity
Rated Voltage
Rated Current
Armature resistance
d-axis Reactance [Xd]
q-axis Reactance [Xq]
Inertia Constant
Armature time constant
Rated frequency
DC link voltage
DC link capacitance
Air gap factor
5 [MVA]
1000 [V]
2.8867 [KA]
0.002 [p.u.]
1 [p.u]
0.7 [p.u.]
1.5
0.332 [p.u.]
50 [Hz]
1.5 [kv]
50,000 [F]
1
1 2
Energy of EDLC is given by EDLC
= cv (ii)
energy 2
Total voltage is given by
Voverall = Vcell * ns (iii)
Capacitance of EDLC bank of our Proposed EDLC system
is 125 F. Where, Cell capacitance = 1200 F Voltage of each
cell=2.7 V No. of series connected cell =546 and parallel
strings =57 EDLC voltage =1.473KV EDLC rated energy=136
MJ. To meet this rating of Energy and voltage of this system
we need to connect 546 cells in series and 57 strings in
parallel.
Fig. 3.
Fig. 1.
Model System.
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Fig. 9.
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
m__opt = 0.0833 V W
(iv)
(v)
(vi)
V. SIMULATION RESULTS
To verify the effectiveness of the proposed system,
simulation analysis have been performed using the two
different patterns of real wind speed data obtained in
Hokkaido Island, Japan (collected by Thesis Supervisor). The
EDLC was charged up to certain level. The simulation have
been done by using PSCAD/EMTDC.
Case-I: In this a moderate wind speed data was chosen
and the time step and simulation time have chosen as 0.00005
sec and 600 sec respectively as shown in Fig.7
Fig. 7.
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VI. CONCLUSION
The simulation results show that the quality of the terminal
voltage and output power penetrated to the grid is not good but
continuously varying without ECS system. Besides, when we
used ECS system, the terminal voltage and grid power is
almost constant and quality of voltage and power is excellent.
So, using ECS system smoothed power can be supplied to the
grid by charging and discharging of EDLC. By using low pass
filter to calculate line power reference instead of SMA, EMA
makes the system very simple, compact and cost effective.
Therefore, it can be concluded that this proposed system can
be applied effectively in power systems to generate high
quality electrical power from the natural fluctuating wind.
References
[2]
[3]
Fig. 17.
[5]
Fig. 18. EDLC active power [case-II]
[6]
[7]
Fig. 19. EDLC energy [case-II]
[8]
[9]
Fig. 20. Grid terminal voltage without & with ECS [case-II].
[10]
Fig. 21. Frequency deviation of SMA, ECS & without ECS [case-I].
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