Field oriented control of an induction motor with field weakening under consideration of saturation and rotor heating

Modern signal processors allow computation of the Park transformation for AC machines in real time. Transistor convertors can change machine voltages and currents almost immediately. Together, they perform flux and torque control as fast as it was so far only achieved by DC machines. Besides the synchronous machine with permanent magnet excitation the induction motor with squirrel cage is of special interest because of economical reasons and its field weakening capability. The vector control of an induction motor is described. The possibilities of rotor time constant tuning are discussed and new identification algorithms are presented.