PI and fuzzy estimators for tuning the stator resistance in direct torque control of induction machines

Direct torque control (DTC) uses the stator resistance of the machine for the estimation of stator flux. The variation of stator resistance due to temperature changes in the machine, makes the operations difficult at low speeds. A method for the estimation of changes in stator resistance during the operation of the machine is presented. The estimation is implemented with PI control and fuzzy logic control schemes. The estimators observe the stator current vector of the machine to detect the changes in stator resistance. The performance of the two methods is compared using simulation and experimental results.<
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