DIRECT TORQUE AND FLUX CONTROL OF INDUCTION MACHINE AND FUZZY CONTROLLER
Milan Žalman - Ivica Kuric
In this paper we describe the control of an induction machine (IM) using the
principle of direct torque and flux control (DTFC). This method is designed by
means of fuzzy logic with three inputs and three outputs and contains 180 rules.
For improvement of this method a fuzzy duty ratio controller is added. This
controller prepares an optimum voltage vector (output from fuzzy DTFC control).
In this control the selected inverter switching state is applied for a portion
of the switching period, defined as duty ratio δ, and the zero switching
state is applied for the rest of the period. The duty ratio is chosen to give an
average voltage vector for a change of torque with decreasing ripples. The
control is verified by simulation.
Keywords: induction machine, servo system, direct torque and flux control, fuzzy controller, speed control