Performances for a synchronous machine with optimised efficiency while wide speed domain is attempted

A combined control technique is proposed to improve the efficiency of an in-wheel motor with outer rotor for traction system. The double excited motor has permanent magnets and field winding as excitation sources. The ‘combined control strategy’ employed in the extended speed operation is based on an alternate field-weakening technique by negative d-axis current injection and by adequately feeding the auxiliary field winding, respectively. The alternate technique proposed is detailed and the computed results are obtained using 2D finite-element method analysis, and the MATLAB/Simulink package stand by to validate it. The tests will prove the expected speed gain and the validity of the machine’s topology.