ABSTRACT:
According
to growth of electricity demand and the increased number of non-linear loads in
power grids, providing a high quality electrical power should be considered. In
this paper, voltage sag and swell of the power quality issues are studied and
distributed power flow controller (DPFC) is used to mitigate the voltage
deviation and improve power quality. The DPFC is a new FACTS device, which its
structure is similar to unified power flow controller (UPFC). In spite of UPFC,
in DPFC the common dc-link between the shunt and series converters is
eliminated and three-phase series converter is divided to several single-phase
series distributed converters through the line. The case study contains a DPFC
sited in a single-machine infinite bus power system including two parallel
transmission lines, which simulated in MATLAB/Simulink environment. The presented
simulation results validate the DPFC ability to improve the power quality.
KEYWORDS:
1. FACTS
2. Power
Quality
3. Sag
and Swell Mitigation
4. Distributed
Power Flow Controller
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1. The DPFC Structure
EXPECTED SIMULATION RESULTS:
Fig.2. Three-phase load
voltage sag waveform.
Fig.3. Mitigation of
three-phase load voltage sag with DPFC.
Fig.4. Three-phase load
current swell waveform without DPFC
Fig.5. Mitigation of
three-phase load current swell with DPFC.
Fig.6. Total harmonic
distortion of load voltage without DPFC.
Fig.7. Total harmonic
distortion of load voltage with DPFC.
CONCLUSION:
To
improve power quality in the power transmission system, there are some
effective methods. In this paper, the voltage sag and swell mitigation, using a
new FACTS device called distributed power flow controller (DPFC) is presented.
The DPFC structure is similar to unified power flow controller (UPFC) and has a
same control capability to balance the line parameters, i.e., line impedance,
transmission angle, and bus voltage magnitude. However, the DPFC offers some
advantages, in comparison with UPFC, such as high control capability, high
reliability, and low cost. The DPFC is modeled and three control loops, i.e.,
central controller, series control, and shunt control are design. The system
under study is a single machine infinite-bus system, with and without DPFC. To
simulate the dynamic performance, a three-phase fault is considered near the
load. It is shown that the DPFC gives an acceptable performance in power
quality mitigation and power flow control.
REFERENCES:
[1]
Ahmad Jamshidi, S. Masoud Barakati, and Mohammad Moradi Ghahderijani, “Power
Quality Improvement and Mitigation Case Study Using Distributed Power Flow
Controller”, IEEE 2012.
[2]
S. Masoud Barakati, Arash Khoshkbar Sadigh and Ehsan Mokhtarpour, “Voltage Sag
and Swell Compensation with DVR Based on Asymmetrical Cascade Multi-cell
Converter”, North American Power Symposium (NAPS), pp.1 – 7, 2011.
[3]
Alexander Eigels Emanuel, John A. McNeill “Electric Power Quality”. Annu. Rev.
Energy Environ 1997, pp. 263- 303.
[4]
I Nita R. Patne, Krishna L. Thakre “Factor Affecting Characteristics of Voltage
Sag Due to Fault in the Power System” Serbian Journal of Electrical
engineering. vol. 5, no.1, May2008, pp. 171-182.
[5]
J. R. Enslin, “Unified approach to power quality mitigation,” in Proc. IEEE
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