AN INNOVATIVE DIRECT SELF-CONTROL SCHEME FOR INDUCTION-MOTOR DRIVES

The paper presents a new direct self-control (DSC) scheme for inductio n motor drives using the stator voltage third harmonic component in or der to estimate the air-gap flux and the torque as well as to synchron ize the supply voltage vector, Compared to previous DSC schemes the ne w one is independent from any motor parameter variation, specifically on stator resistance thus showing better performances at low speeds, T he paper starts with a quick review on standard DSC main features poin ting out the influence of stator resistance variations on the flux and torque control. The new DSC scheme is then introduced and evaluated b y simulations and experimental tests on a 1.5-kW induction motor drive .