Improved direct torque and flux control of induction motor drive
Purpose - The aim of the paper is to conduct an analytical study of a new method of induction motor torque and flux direct control with nonlinear controllers. Design/methodology/approach - The method is based on the inverter state predictive determination in order to minimize the torque and flux errors. Findings - The proposed method allows one to eliminate known DTC disadvantages, i.e. the hexagonal flux shape and nonsinusoidal current at a low motor speed, and also secures a decrease of torque and flux pulsation. Practical implications - This new method enables a more precise reproduction of the motor torque and flux command signals, working with the same sampling frequency of the control processor as in the case of the standard DTC method. The decreased torque pulsations cause a decrease of the motor speed pulsation. Originality/value - An innovative optimal control method is presented. The correctness of the initial assumptions as well as the expected final results have been verified in practice.
torque control electric motors