Comparison between sliding model control and vector control for a DSP-based position control applied to squirrel-cage induction motor

The principle of vector control of AC machine enables the dynamic control of AC motors, and induction motors in particular to a level comparable to that of a DC machine. The vector control of currents and voltages results in control of spatial orientation of the electromagnetic fields in the machine and has led to term field orientation. Field oriented control schemes provide significant improvement to the dynamic performance of ac motors. The usual method of induction motor position and torque control, which is becoming an industrial standard, uses the indirect field orientation principle in which the rotor speed is sensed or estimated by rotor position and slip frequency is added to form the stator impressed frequency. Sliding-mode control has gained wide attention because of its simple design and implementation, fast dynamic response, and robustness to parameters variations and load disturbances. This paper proposes a performance comparison between sliding mode-control and field oriented control using synchronous reference applied to a small squirrel-cage induction motor using space vector pulse width modulation(SVPWM) for position and torque control and a digital signal processor and relay feedback method to evaluate the controller parameters.