Real-time DSP-based computation-efficient speed-sensorless drive of induction motors

Induction motors are the workhorse of industries, continuously used in existing and new applications with improved performance utilizing modern power electronics and digital controls. This paper proposes a new computationally efficient real-time control for induction motor drives using state-of-the-art digital signal processing (DSP) technology, but without using a speed sensor. This control is termed the advanced speed-sensorless induction-motor drive (ASID). Its advantages are particularly evident in hostile application environments where maintenance of speed sensors requires costly downtime or installation of sensors is physically difficult or expensive for retrofitting existing electromechanical systems. This paper details the ASID control algorithms, formulations, and implementations utilizing high-speed DSP technology. The features of the ASID are demonstrated and compared with the manufacturer recommended speed-sensorless drive controls. Key comparisons provided in the paper include efficiency of computations, easy of real-time implementations, simplicity of control algorithms, accuracy of speed estimations, convergence and stability of feedback controls, comprehension of control methodology, etc.