  Nowadays, asynchronous motors have wide range use in many industrial
applications. Field oriented control (FOC) and direct torque control (DTC) are
commonly used methods in high performance vector control for asynchronous
motors. Therefore, it is very important to identify clearly advantages and
disadvantages of both systems in the selection of appropriate control methods
for many industrial applications. This paper aims to present a new and
different perspective regarding the comparison of the switching behaviours on
the FOC and the DTC drivers. For this purpose, the experimental studies have
been carried out to compare the inverter switching frequencies and torque
responses of the asynchronous motor in the FOC and the DTC systems under
different working conditions. The dSPACE 1103 controller board was programmed
with Matlab/Simulink software. As expected, the experimental studies showed
that the FOC controlled motors has a lessened torque ripple. On the other hand,
the FOC controlled motor switching frequency has about 65-75% more than the DTC
controlled under both loaded and unloaded working conditions.
