Adaptive Nonlinear Direct Torque Control of Sensorless IM Drives With Efficiency Optimization

• Published in: IEEE transactions on industrial electronics (1982) Vol. 57; no. 3; pp. 975 - 985
• Main Authors: Hajian, M., Soltani, J., Markadeh, G.A., Hosseinnia, S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive control; Backstepping; Computational modeling; Computer simulation; Convergence; Direct torque control (DTC); Efficiency; efficiency optimization; induction motor (IM); Induction motors; integrator backstepping; Mathematical analysis; Mathematical models; Microcomputers; Nonlinearity; Optimization; Optimization methods; Programmable control; rotor flux; Rotor speed; Rotor time constant; sliding mode (SM); Sliding mode control; Studies; Torque; Torque control
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2009.2029592

Efficiency optimization of induction motor (IM) drives is a major subject based on these drives' extensive use in the industry. Among the different proposed methods, a model-based approach (MBA) seems to be the fast one. However, this method needs the motor parameters that must be correctly identified. On the other hand, a search-based approach (SBA) is a parameter-independent method but needs a greater convergence time. In this paper, a novel model-based loss-minimization approach is presented, which is combined with a backstepping direct torque control of the IM drive. An improved search-based method for efficiency optimization is also introduced. The proposed controller is realized in the stationary reference frame and has a fast-tracking capability of rotor flux and electromagnetic torque. Moreover, a sliding-mode rotor-flux observer is introduced, which is employed for simultaneous determination of rotor-flux space vector, rotor speed, and rotor time constant. The proposed control idea is experimentally implemented in real time using a field-programmable gate-array board synchronized with a personal computer. Simulation and experimental results are finally presented to verify the effectiveness of the method proposed.