Field oriented control of an asynchronous motor with a very wide region of flux weakening

In the first part of the paper, the torque capability of an inverter-fed saturated induction motor is determined. The maximum torque being available for short-time duty and the corresponding flux are calculated considering the limitations of the current and the voltage only. The flux weakening region consists of two parts which require different control strategies. At partial load the efficiency can be optimized. The results are implemented in a field oriented control which makes use of a flux and a voltage controller. With regard to the coupling of the d-axis and the q-axis existing in the machine, priority is given to the control of the d-components. The improvement of the performance being achieved by the new control strategy is verified by experimental results