On Line Stator Resistance Error Compensation for CSI Fed PMSM Drive

This paper presents an online stator resistance estimator to achieve precise torque control of CSI fed PMSMs over a low speed operating region. A quick and precise control several researchers have proposed implementations combining the use of permanent magnet synchronous motor with the direct torque control (DTC) technique. The electromagnetic torque, stator flux and rotor position can be estimated using the measured stator voltage and currents in direct torque control. The estimation does not depend on motor parameter except the stator resistance. The variation of stator resistance due to changes in temperature or low speed operation and degrade the performance of DTC controller by introducing errors in the estimated flux linkage magnitude, position and the electromagnetic torque. So the compensation for the effect of stator resistance variation then becomes necessary. In this paper investigates the effect of variation of stator resistance on DTC) scheme applied in a current source inverter (CSI) fed Permanent magnet synchronous motor drive system.. A method of stator resistance estimation using a proportional-integral (PI) estimator has been proposed in this paper.