Mamo, Mengesha(PhD)Berehanu, Henok2018-07-062023-11-042018-07-062023-11-042011-01http://etd.aau.edu.et/handle/123456789/7061Permanent magnet motors have high efficiency and torque density compared to induction and conventional synchronous motors in general. However, in applications requiring wide speed range, the air-gap field, which is produced by the permanent magnets, can’t be controlled directly to control the back-emf of the motor for field weakening operation. In conventional synchronous machines the excitation current can be controlled to control the field and hence the speed. This thesis presents development of field weakening control for Permanent Magnet Synchronous Motor (PMSM) using demagnetizing component of stator current. The control is implemented using Texas Instruments’ TMS320LF2401A Digital Signal Processor (DSP). The control method presented relies on the field orientated control (FOC) together with a field-weakening operation. The field-weakening operation is required to extend the speed in the constant power range of operation, where there is no more voltage adjustment possible to increase the speed. The field oriented control of the motors has been modeled, simulated using MATLAB and Some of the modules of field oriented control are tested practically and results are given in this thesis. The results demonstrate that the speed of the PMSM can be extended in the constant power range for applications requiring wide speed range like in electric vehicle.enSpeed OperationThesis