Digital vector control algorithm for induction motor torque drive

High quality precision digital vector control for standard AC drive (induction motor, voltage source inverter, current and speed sensors (or mechanical variable observer)), microprocessor-based controller is described. The synthesis of control algorithm is based on using exact (analytical) discrete model; digital, independent estimation of unmeasured variables; decomposition of vector control on two independent scalar controls of the field current and torque one; using discrete sliding modes control or asymptotic control; using variables predictor on a step of calculations for compensation of delay caused by calculation time of the controller; using optimal vector PWM for reduction of switching losses. The simulation has confirmed essential increase of dynamic accuracy, simplification of algorithm of digital control, reduction of the requirements to computing capacity of the controller.