Field-weakening control schemes for high-speed drives based on induction motors: a comparison

Three sensorless control schemes for the operation of induction motors in the field-weakening region are compared and assessed in terms of performance and complexity. These three control schemes fully utilize the maximum available voltage and current for steady-state torque production at any speed, and thus provide the maximum possible torque in the entire field weakening region. For the comparison, the three control schemes are implemented on the same experimental platform, i.e. the same Digital Signal Processor (DSP) board, power inverter and motor drive. In this way, it is possible to judge not only the performance of each solution, but also its requirements in terms of computational time, tuning complexity, parameter knowledge and stability of operation.