A comparative experimental analysis of fractional order PI controller based direct torque control scheme for induction motor drive

This article proposes a fractional order (FO) PI controller based direct torque control (DTC) scheme for an induction motor (IM) drive. The induction motor fed with two-level voltage source inverter. The drawbacks associated with the conventional PI controller like addition of DC drift and poor dynamic performance are avoided with the proposed fractional order PI controllers. The DTC scheme provides the required voltage space vector to compensate the torque and flux errors, which are the outputs of the FOPI controller. The obtained voltage space vector is used to generate the modulating wave forms. The necessary gating signals are generated for the voltage source inverter using space vector modulation (SVM) technique. The FOPI controller with DTC-SVM improves the dynamic performance as well as compensates the steady state error produced in both electromagnetic torque and the stator flux. The IM performance is assessed during starting, running, and speed reversal along with the step change in the load torque. The simulation results are presented, to confirm the performance of the IM drive with FOPI controller. The simulation results are validated with the experimental results.