To
overcome these problems, many research works had been carried
out in overcoming the major problem in conventional DTC by
using implementing various techniques and method in order toincrease the performance of the motor. In general, the vector
controlled can be classified into hysteresis based and nonhysteresis
based solution. The variable hysteresis band is
designed to produce a constant switching frequency. By using
this method, the hysteresis band can be modified depending on
the switching frequency[4]. This is a very simple modification of
DTC conventional to reduce the torque and flux ripples and at the
same time can produce the constant switching frequency and
while maintaining the original concept of DTC. Another problem
normally related with DTC drive is the large torque ripple
production. Ideally, the small torque hysteresis band will produce
small torque ripple therefore the possibility selecting of a
reversed voltage vector may occur. Inappropriate selection of
voltage vector will result in a higher torque ripple. By reducing
the sampling time, the high torque ripple has significant by
improved [5, 6]. Furthermore, many solutions were proposed to
overcome the problem of torque ripple such as dithering
technique, Pi-Integrator , SVM [7] and intelligence technique [7-
9]. However, all this approach can generate a complex all
algorithm and delay the computation to execution of the
algorithm.