ABSTRACT:
This
paper presents a new group for multilevel converter that operates as symmetric
and asymmetric state. The proposed multilevel converter generates DC voltage
levels similar to other topologies with less number of semiconductor switches.
It results in the reduction of the number of switches, losses, installation
area, and converter cost. To verify the voltage injection capabilities of the proposed
inverter, the proposed topology is used in dynamic voltage restorer (DVR) to
restore load voltage. The operation and performance of the proposed multilevel
converters are verified by simulation using SIMULINK/MATLAB and experimental
results.
KEYWORDS:
1. Cascaded multilevel converter,
2. New topology
3. Reduction of components
4. DVR
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig. 1. Proposed
cascade topology
Fig. 2. Proposed topology with four DC
voltage sources.
EXPECTED SIMULATION RESULTS:
Fig. 3.
(a)
Supply voltage, (b) DVR injection voltage, and (c) load voltage for the
three-phase balanced voltage sag.
Fig. 4. Output phase voltage in
fault (sag) time
Fig. 5. (a) Supply voltage, (b) DVR injection
voltage, and (c) load voltage for the three-phase balanced voltage swell.
Fig. 6. Output phase voltage in
fault (swell) time.
CONCLUSION:
In this paper, a novel topology was presented
for multilevel converter, which has reduced number of switches. The suggested
topology needs fewer switches for realizing voltages for the same levels of
output voltages. This point reduces the installation area and the number of
gate driver circuits. Therefore, the cost of the suggested topology is less
than the conventional topology. Based on the presented switching algorithm, the
multilevel inverter generates near sinusoidal output voltage, causing very low
harmonic distortion. The suggested inverter used in DVR does not require any
coupling series transformer and has lower cost, smaller size, and higher
performance and efficiency. Simulation results verified the validity of the
presented concept.
REFERENCES:
[1]
Z. Pan, F.Z. Peng, “Harmonics optimization of the voltage balancing control for
multilevel converter/ inverter systems”, IEEE Trans. Power Electronics, pp.
211-218, 2006.
[2]
L.M. Tolbert, F. Z. Peng, T. Cunnyngham, J. N. Chiasson, “Charge Balance
Control Schemes for Cascade Multilevel Converter in Hybrid Electric Vehicles,” IEEE
Trans. Industrial Electronics, Vol. 49, No. 5, pp. 1058-1064, Oct. 2002.
[3]
S. Mariethoz, A. Rufer, “New configurations for the three-phase asymmetrical
multilevel inverter,” in Proceeding of the IEEE 39th Annual Industry
Applications Conference, pp. 828-835, Oct. 2004.
[4]
J.Rodriguez, J.S. Lai, F.Z. Peng, “Multilevel Inverter: A Survey of Topologies,
Controls, and applications”, IEEE Trans. on Industrial Electronics, Vol.
49, No. 4, August. 2002.
[5]
J.S. Lai, F.Z. Peng, “Multilevel Converters-A New Breed of power Converters”, IEEE
Trans. Industry Application, Vol. 32, No. 3, pp. 509-517, MAY/JUNE.1996
