A complete characterization of torque maximization for permanent magnet non-salient synchronous motors

This paper considers the problem of maximizing the torque of permanent magnet non-salient synchronous motors in the presence of voltage and current constraints. Formulas are given that enable a drive to extract the maximum torque available from a motor in real-time. Both the motoring and braking modes are considered, and it is shown that the well-known field-weakening formula cannot be used with some motors. An example is discussed to illustrate the contributions of the paper