DSP based implementation of vector controlled induction motor drive using sliding mode speed control strategy

Abstract

This paper deals with the implementation of Vector Controlled Induction Motor Drive (VCIMD) system using a TMS320F240 digital signal processor (DSP). The closed loop control scheme utilizes Sliding Mode Control (SMC) strategy in its outer speed loop while the inner loop is equipped with the Pulse Width Modulated (PWM) current controller. The power circuit of the system consists of a three-phase IGBT based voltage source inverter (VSI), feeding a three-phase squirrel cage induction motor. The control circuits comprise of sensors (for sensing speed and current signals), interfacing circuits and control software (processed in DSP). The sensed speed and sensed winding currents in two of the three phases are used as feedback signals for the closed loop control structure. Test results are presented for starting, speed reversal and load perturbation on the developed VCIMD system.