27-06-2012, 02:04 PM
Fuzzy Logic Control for a Speed Control of Induction Motor using Space Vector Pulse Width Modulation
Fuzzy Logic Control for a Speed Control.pdf (Size: 660.41 KB / Downloads: 76)
Abstract
This paper presents design and implements a voltage
source inverter type space vector pulse width modulation (SVPWM)
for control a speed of induction motor. This scheme leads to be able
to adjust the speed of the motor by control the frequency and
amplitude of the stator voltage, the ratio of stator voltage to
frequency should be kept constant. The fuzzy logic controller is also
introduced to the system for keeping the motor speed to be constant
when the load varies. The experimental results in testing the 0.22 kW
induction motor from no-load condition to rated condition show the
effectiveness of the proposed control scheme.
INTRODUCTION
HE Space Vector Pulse Width Modulation (SVPWM)
method is an advanced, computation-intensive PWM
method and possibly the best among all the PWM techniques
for variable frequency drive application. Because of its
superior performance characteristics, it has been finding
widespread application in recent year. The PWM methods
discussed so far have only considered implementation on half
bridges operated independently, giving satisfactory PWM
performance. With a machine load, the load neutral is
normally isolated, which causes interaction among the phases.
DESIGN OF A FUZZY LOGIC CONTROLLER
In drive operation, the speed r
ω can be controlled indirectly
by controlling the torque which, for the normal operating
region, is directly proportional to the voltage to frequency.
The speed is controlled by fuzzy logic controller whose output
is the reference current of the inner dc current controller. The
torque is controlled by varying the dc current. The drive
performance of SVPWM is improved by employing 2 sets of
fuzzy logic controllers. From Fig. 4, one set of fuzzy logic
controller is used in the inner loop for controlling the torque of
the motor which is proportional to DC link current Idc, and
another set is used in the outer loop for controlling the actual
motor speed r
ω .
CONCLUSION
The Fuzzy logic controller is applied to speed signal model
of motor and is then downloaded to dSPACE through
Simulink. The experimental results are analyzed in testing the
0.22 kW induction motor from zero load condition to rated
condition, it’s found that the speed of the induction motor can
be controlled. In addition, the motor speed to be constant
when the load varies.