Parameters and volt-ampere ratings of a field-oriented induction motor drive for flux-weakening applications

The purpose of this paper is to individuate the parameters of an induction motor (IM) and the volt-ampere ratings of the drive inverter to meet a desired torque-speed range, including the flux-weakening (FW) region. The study is performed assuming that a field-oriented control strategy is adopted. In such a way, the operating limits of the IM drive are readily carried out by the circle diagram widely used for permanent magnet synchronous motor drives. It is shown that different motor designs have to be developed according to whether the motor is operated only below the base speed or whether a FW region is also requested. Finally, a comparison with synchronous motor drives is included, pointing out the peculiar differences in motor dimensions and inverter size.