Second‐order SMO‐based sensorless control of IM drive: experimental investigations of observer sensitivity and system reconfiguration in postfault operation mode

Abstract

Abstract In normal operation mode, sensorless speed‐controlled motor drives should be more reliable, less expensive and less bulky than their counterparts with a speed sensor. The sensorless drive structure allows avoiding the electromagnetic and vibratory sensitivity of the mechanical sensor, the additional connecting circuits, additional space for the sensor, its price and maintenance requirements. However, in postfault operation mode, the robustness of speed sensorless control strategies has been poorly addressed in the study. Accordingly, this study deals with an experimental study of the robustness and the availability of speed‐controlled induction motor (IM) drives without speed sensor in the presence of inverter open‐switches faults. For that purpose, a super twisting algorithm‐based observer for motor speed estimation is proposed for experimental investigation. Experimental results are performed upon 3‐kW IM drive by using dSPACE digital signal processing controller board. Experimental investigations evaluate the performances of the method used for the control without speed sensor in prefault, postfault and regeneration operation modes.

Keywords

• angular velocity control
• digital signal processing chips
• fault diagnosis
• induction motor drives
• invertors
• machine control