Induction Machine Sensorless Control Based on Saliency Extraction That Uses One Single SVPWM Active State

Some induction motors present saliencies that periodically modify the air-gap flux following a sinusoidal shape. Consequently, these modulations are reflected in transient leakage inductance. Therefore, inductance can be expressed as constant term or offset, which comes from symmetrical machine, plus all motor saliency sinusoids, modulated by mentioned saliencies. Since linked to rotor position flux, calculation of enables encoderless vector control. A way calculate is excite machine with voltage steps and estimate resulting phase current slopes since they inversely proportional For creating vector, only three single active state sufficient. The sum leads so-called saliency-offset composed an created due contribution several phasors, superposed offset. To access saliencies, it critical accurately identify offset especially much bigger than This article presents advanced signal processing scheme identifies assuming amplitude differsdepending on step applied. Using feedforward scheme, eliminated, leading where slotting extracted from. novel excitation proposed reduce additional distortions coming one-active excitation.