ABSTRACT:
Voltage injection methods for DVRs (Dynamic Voltage
Restorers) and operating modes are resolved in this paper. Using fuzzy logic
control DVR with dc link& with BESS systems are operated. Power quality
problems mainly harmonic distortion, voltage swell & sag are decreased with
DVR using Synchronous Reference Theory (SRF theory) with the help of
fuzzificaton waveforms are observed.
KEYWORDS:
1.
Dynamic
Voltage Restorer
2.
Unit Vector
3.
Power quality
4.
Harmonic
distortion
5.
Voltage Sag
6.
Voltage Swell
7.
Fuzzy logic
controller
8.
Matlab/simulink
software
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1.Block
Diagram of DVR
Fig.2
Voltage waveforms at common coupling point (PCC) and load during harmonic
distortion
Fig.3.
the dc voltage injection from BESS connected DVR system at voltage swelling
period
Fig.4.
DVR waveforms during voltage sag at time of voltage in phase injection
Fig.5
Amplitude of load voltages and PCC voltages w.r.t time
Fig
6.DVR waveforms during harmonic distortion at the time of voltage in phase
injection
CONCLUSION:
By
applying different voltage injection schemes the role of DVR has been shown
with a latest control technique. The presentation of DVR has been balanced with
various schemes with a reduced-rating VSC. For getting the control of DVR, the
reference load voltages have been determined with the help of unit vectors, for
which the error of voltage insertion is reduced. By using SRF theory the
reference DVR voltages have been determined. In the end, the result derived are
that the in phase voltage insertion with PCC voltage reduces the DVR rating but
at the same time at its DC bus the energy source is wasted.
REFERENCES:
[1]
Math H.J. Bollen, Understanding Power Quality Problems- Voltage Sags and
Interruptions, IEEE Press, New York, 2000.
[2]
A. Ghosh and G. Ledwich, Power Quality Enhancement using Custom Power
devices, Kluwer Academic Publishers, London, 2002
[3]
Eddy C. Aeloíza, Prasad N. Enjeti, Luis A. Morán, Oscar C. Montero- Hernandez,
and Sangsun Kim, “Analysis and Design of a New Voltage Sag Compensator for
Critical Loads in Electrical Power Distribution Systems”, IEEE Trans. on Ind.
Appl., vol. 39, no. 4, pp 1143-1150, Jul/Aug 2003.
[4]
J. W. Liu, S.S. Choi and S. Chen, “Design of step dynamic voltage regulator for
power quality enhancement”, IEEE Trans. on Power Delivery, vol. 18, no.4, pp.
1403 – 1409, Oct. 2003.
[5]
Arindam Ghosh, Amit Kumar Jindal and Avinash Joshi, “Design of a capacitor
supported dynamic voltage restorer for unbalanced and distorted loads” IEEE
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