TITLE:
A Novel Asymmetric Three-Phase Cascaded 21 Level Inverter Fed Induction Motor Using Multicarrier PWM with PI and Fuzzy Controller
AUTHORS:
A. Abdul Namith, T. S. Sivakumaran
KEYWORDS:
Multilevel, Multicarrier Level Shifting Pulse Width Modulation MC-LS-PWM, Proportional Integral PI and Fuzzy Logic Controller
JOURNAL NAME:
Circuits and Systems,
Vol.7 No.11,
September
30,
2016
ABSTRACT: Multilevel inverters are
gaining popularity in high power applications. This paper proposes a new ladder
type structure of cascaded three-phase multilevel inverter with reduced number of power semiconductor
devices which is used to drive the induction motor. The ultimate aim of the
paper is to produce multiple output levels with minimum number of semiconductor devices.
This paper uses only 11 switches along with 3 diodes and 4 asymmetrical sources
to produce an output voltage of 21 levels. The modulation technique plays a
major role in commutation of the switches. Here we implement the multicarrier level
shifting pulse width modulation technique to produce the commutation signals
for the inverter. The proposed multilevel inverter is used to drive the three-phase induction motor. The
mathematical modeling of three-phase
induction motor is done using Simulink. Furthermore the PI and fuzzy logic
controllers are also used to produce the reference waveform of the level
shifting technique which in turn produces the commutation signals of the
proposed multilevel converter. The controllers are used to control the speed of
the induction motor. The effectiveness of the proposed system is proved with
the help of simulation. The simulation is performed in MATLAB/Simulink. From
the simulation results, it shows that the proposed multilevel inverter works
properly to generate the multilevel output waveform with minimum number of semiconductor devices.
The PI and fuzzy logic controller performances are evaluated using the results which indicate that
with the help of controllers the harmonics has been reduced and the speed
control of induction motor is achieved under different loading conditions.