ABSTRACT
Recently, within the family of FACTS, the distributed
power flow controller is an additional device. This paper highlights on voltage
sag mitigation which is one of the burgeoning power quality issues. It deals
with the working concept of distributed power flow controller for compensating unbalanced
three phase line currents in the transmission system. The single phase series
converters of DPFC are able to compensate active as well as reactive, negative
and zero sequence unbalanced currents. In this paper the performance of the
DPFC has been studied by considering line to ground fault near the load end.
The MATLAB/SIMULINK results obtained shows an improved performance in voltage
sag mitigation, unbalance compensation, remarkable reduction in load voltage
harmonics and also enhanced power flow control.
KEYWORDS:
1.
DPFC
2.
Power flow
control
3.
Reduction of
load voltage harmonics
4.
Reliability
improvement
5.
Voltage sag
mitigation
6.
Unbalance
fault condition.
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig. 1. Basic DPFC structure.
EXPECTED SIMULATION RESULTS:
Fig. 2. Load voltage sag waveform
during unbalance fault.
Fig.
3. Mitigation of load voltage sag wave form during unbalance fault with DPFC.
Fig.
4. Load voltage. (a) Signal selected for calculating THD without DPFC. (b) THD
without DPFC.
(b)
Fig.
5. Load voltage. (a) Signal selected for calculating THD with DPFC. (b) THD
with DPFC.
.
Fig. 6.
Capacitor dc voltage in dc side of shunt converter within DPFC.
CONCLUSION
This
paper introduces the unbalance compensation and the voltage sag mitigation
during unbalance fault condition by utilizing a recent additional FACTS device
which is distributed power flow controller (DPFC) adopting sequence analysis
technique. The DPFC is designed by employing three control loops. The simulated
system has two machine systems, in presence and absence of the DPFC in the
system. To examine the capability of the DPFC, an unsymmetrical L-G fault is
taken into account near the load end side. In this paper simulation done
verifies that the adopted control is able to give unbalance compensation and
mitigation of voltage sag.
REFERENCES
[1]
N. G. Hingorani and L. Gyugyi, Understanding
FACTS : Concepts And Technology of Flexible AC Transmission Systems. New
York: IEEE Press, 2000.
[2]
L. Gyugyi, C. D. Schauder, S. L.
Williams, T. R. Rietman, D. R. Torgerson, and A. Edris, “The Unified Power Flow
Controller: A New Approach to Power Transmission Control,” IEEE Trans. Power
Del., vol. 10, no. 2, pp. 1085–1097, April 1995.
[3]
Y. H. Song, and A. Johns, “Flexible AC Transmission
Systems (FACTS),” Institution of Electrical Engineers (IEE Power and Energy
Series), London, U.K:, vol. 30, 1999.
[4]
K. Ramya and C. Christober Asir Rajan,
“Analysis And Regulation of System Parameters Using DPFC,” IEEE
International Conference on Advances in Engineering, Science And Management
(ICAESM), March 2012, pp. 505-509.
[5]
M. D. Deepak, E. B. William, S. S.
Robert, K. Bill, W. G. Randal, T. B. Dale, R. I. Michael, and S. G. Ian, “A
Distributed Static Series Compensator System For Realizing Active Power Flow
Control on Existing Power Lines,” IEEE Trans. Power Del., vol. 22, pp.
642-649, Jan. 2007.
