A new sliding mode flux observer for a direct torque controlled PMSM drive

An extended sliding mode observer is presented in this study to observe the stator flux linkage in DTFC (direct torque and stator flux control) controlled PMSM (permanent magnet synchronous motor) drives. The test tasks include investigation of stator flux estimation using voltage model observer and sliding mode observer methods. Results show that the sliding mode observer exhibits much less torque ripples and current distortion than the voltage model observer.