SPEED CONTROL OF INTERIOR PERMANENT-MAGNET SYNCHRONOUS MOTOR DRIVE FOR THE FLUX WEAKENING OPERATION

A novel flux-weakening scheme for the interior permanent magnet synchr onous motor (IPMSM) is proposed, This is implemented based on the outp ut of the synchronous PI current regulator-reference voltage to the PW M inverter. The onset of flux weakening and the flux level are adjuste d inherently by the outer voltage regulation loop to prevent saturatio n of the current regulator. Attractive features of this flux weakening scheme include no dependency on the machine parameters, the guarantee of current regulation at any operating condition, and smooth and fast transition into and out of the flux weakening mode. Experimental resu lts at various operating conditions including the case of detuned para meters are presented to verify the feasibility of the proposed control scheme.