Losses minimization of a field oriented controlled induction machine

Different schemes for efficiency optimization of an induction motor drive controlled by the field orientation method are developed for both steady state and dynamic operation. The efficiency optimization is carried out by adjusting the rotor flux level of the induction machine to an optimal value as a function of the operating conditions. In the case of steady state operation, the rotor flux reference is given as a simple analytical expression of motor torque and speed. However, in the case of dynamic operation, the rotor flux reference trajectory is obtained using the dynamic programming method. A new method is also proposed based on the optimal steady state rotor flux reference extended to dynamic operation. These schemes are compared both in simulation and experimentally.