ABSTRACT
Power quality problem is t he most sensitive problem in the power
system. The objective of the project is to reduce one of the power quality
issue called “harmonics” using compensation technique. Shunt Active Power
Filter (SAPF) is used to eliminate harmonic current and also it compensates
reactive power. In this project, both PI controller and Fuzzy Logic Controller
based three-phase shunt active filter is employed for a three-phase four wire
systems. The advantage of fuzzy control is that it provides linguistic values
such as low, medium, high that are useful in case where the probability of the
event to occur is needed. It does not require an accurate mathematical model of
the system. A MATLAB/SIMULINK has been used to perform the simulation. Simulink
model is developed for three phase four wire system under balanced source condition
and three phase four wire system for unbalanced source condition. The
performance of both balanced source and unbalanced source is done using Fuzzy
Logic Controller and PI controller and their Simulink results is compared.
Simulation results obtained shows that the performance of fuzzy controller is
found to be better than PI controller.
KEYWORDS
1.
Logic Control
2.
Instantaneous p-q theory
3.
Shunt Active Power Filter.
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM
Fig 1: Block diagram of
proposed system
Fig 2: Structure of three phase four wire APF
SIMULATION
RESULTS
Fig 3: Simulation Waveform using pq with PI
Fig
4: Simulation Waveform using pq with FLC
Fig
5: Harmonic Spectrum of Is using PI for balanced source
Fig
6: Harmonic Spectrum of Is using FLC for balanced source
Fig 7: Harmonic Spectrum of Is using PI for unbalanced source
Fig. 8 Harmonic Spectrum of Is using FLC for unbalanced source
CONCLUSION
The comparative analysis of a three phase four wire system using
SAPF for reducingTHD of source current is done.The analysis uses the control of
compensating current using PI controller and FLC is done for both balanced and
unbalanced source condition. The harmonic spectrum shows the THD of both
balanced and unbalanced source condition using PI and FLC. It is found that the
harmonic reduction using FLC is found to produce better result than PI
controller.
REFERENCES
[1] Akagi. H. 2005. Active Harmonic Filters. Proceedings of the
IEEE, Vol.93, 2128-2141.
[2] Hirofumi Akagi, Yoshihira Kanazawa and Akira Nabae. (1984),
“Instantaneous Reactive Power Compensators Comprising Switching Devices without
Energy Storage Components”, IEEE Transactions on Industrial Electronics,
Vol. 20, pp-625-630.
[3] Fang Zheng Peng and Akagi.H, (1990), “A New Approach to
harmonic Compensation in Power Systems –Acombined System of Shunt Passive and
Series Active Filters”, IEEE Transactions on Industrial Applications,
Vol. 26, pp-6-11.
[4] Karuppanan P and Kamala
kanta Mahapatra (2011), “PI with Fuzzy Logic Controller based Active Power Line
Condtioners” Asian Power Electronics, Vol. 5, pp-464-468.
[5] Kirawanich P and O,Connell R.M.
(2004), “Fuzzy Logic Control of an Active Power Line Condioner”, (2004), IEEE
Transactions on Power Electronics, Vol. 19, pp-1574-1585.
