ABSTRACT
Modern industrial equipments are more sensitive to
power quality problems such as voltage sag, voltage swells, interruption,
harmonic, flickers and impulse transient. Failures due to such disturbances
create high impact on production cost. So nowadays high quality power is became
basic needs of highly automated industries This paper deals with modeling and
simulation technique of a Dynamic Voltage Restore (DVR).The DVR is a dynamic
solution for protection of critical loads from voltage sags/swells. The DVR restores
constant load voltage and voltage wave form by injecting an appropriate
voltage. Present novel structure improves power quality by compensating voltage
sag and voltage swells. This control scheme provides superior performance
compared to conventional control methods because it directly measurers the rms
voltage at the load point without involving any transformation process. A new
topology based on Z-source inverter is presented in order to enhance the
voltage restoration property of dynamic voltage restorer. Z-source inverter
would ensure a constant DC voltage across the DC-link during the process of
voltage compensation. The modeling of Z-source based dynamic voltage restorer
is carried out component wise and their performances are analyzed using MATLAB
software.
KEYWORDS
1. Point
Of Common Coupling (PCC)
2. Dynamic
Voltage Restorer (DVR)
3. Active
Power Filter (APF)
SOFTWARE:
MATLAB/SIMULINK
BLOCK
DIAGRAM
Fig.1.
Schematic diagram of DVR.
Fig.2.
Proposed Z source inverter topology.
SIMULATION RESULTS
Fig.3.
Simulation waveform of DVR based system when sag occurred.
Fig.4.
Simulation waveform of DVR based system when swell occurred.
Fig.5.
Simulation waveform of DVR based system when sag/swell occurred.
Fig.6.
Simulation waveform of DVR based system when connected to Z-source inverter.
CONCLUSION
Simulation of
Z-source DVR for Power Quality Improvement is one of the techniques to improve
the power quality by using Z-source DVR. This project has presented a discrete
PWM control scheme for Dynamic Voltage Restorer to improve the system response
and injection capability for the mitigation of voltage sag/swell. As opposed to
fundamental frequency switching schemes already available in the MATLAB/SIMULINK,
this PWM control scheme requires only rms value of the voltage.
REFERENCES
[1] M.H.J Bollen „Understanding
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[2] J.C. smith
J.Lamoree ,P.Vinett,T.Duffy M.Klein “The impact of voltage sag Industrial plant
load” International Conference Power quality end use application and
perspective pp171-178.
[3] Akagi H,”New
trends in active filters for power conditioning” IEEE Transaction
Ind.Application,vol 32 pp 1312-1322 Nov/Dec 1996.
[4] Ghosh A and
Ledwich G (2002) “Power quality Enhancement using Custom Power Devices”.Kluwr
Academics publishers, United States.
[5]
O. Anaya-Lara, E. Acha, “Modeling and Analysis of Custom Power Systems by
PSCAD/EMTDC,” IEEE Trans., Power Delivery, PWDR vol-17 (1), pp. 266-272, 2002.
