Prototype of an induction motor direct stator flux and torque vector control

Based on the instantaneous space vector variables of the induction motor-and-control-vector models, this paper presents the analysis and design of an induction motor direct stator flux and torque vector control. The voltage source inverter commutation strategy is based on the control actions of one stator flux hysteresis controller and one electromagnetic torque hysteresis controller. A switching table is derived from these controllers, that select the optimum inverter output voltage vectors, to obtain a rapid torque response. The instantaneous value of the stator flux space vector, and the region in the αβ domain, to which this instantaneous flux vector belongs, together with the instantaneous value of the electromagnetic torque are directly computed from the output vector voltages and currents of the VSI feeding the induction motor. These stator flux and electromagnetic torque instantaneous values are processed in their respective hysteresis controller to logically determine the switching pulses to the voltage source inverter. Experimental waveforms obtained from a prototype direct stator flux and torque vector control along with simulation waveforms are included to verify the theory presented in this paper