A simple approach to rotor flux estimation without integration for a DSP based speed sensorless vector control of induction motor

In this paper a simple field orientation control scheme for induction motor is described. The principle is based on the idea of a simplified equivalent circuit of the machine and the orientation of the fluxes, currents and voltage vectors. Here the determination of stator flux avoids integration, which is increasingly difficult when the speed reference becomes lower down to almost zero. In order to estimate the stator flux, a simple algorithm based on the principle of orthogonality of stator flux and stator induced e.m.f. vectors is used. The proposed control technique is validated by some simulation results and also experiments were conducted which showed conformity to the theoretical basis and simulation results.