Optimum Vector Control of High Efficiency Interior PM Synchronous Motor

This paper outlines the guidelines for the vector-control of interior permanent magnet synchronous motor drives, allowing to achieve optimum performance and efficiency tailored for the specific motor design. The optimum motor operation is selected in order to give maximum/torque/to/current in the constant-torque region and maximum/torque/to/voltage in the flux-weakening region. In terms of vector control, this reflects in selecting proper “direct” and “quadrature” axes currents as functions of the specific torque/speed operating point over the whole operating region. The characteristics needed to implement the optimum control can be obtained both at design stage by finite elements calculations and through specific tests carried on the vector-controlled drive. Implementation peculiarities and experimental result are presented, in the case of an electrical city-scooter application.