A Study on Fast Maximum Efficiency Control of Stator-Flux-oriented Induction Motor Drives

Abstract

-This paper presents a novel maximum efficiency control scheme for convergence improvement in stator-flux-oriented induction motor drives. Three input powers are calculated at three different flux levels, respectively. A quadratic curve is obtained using the quadratic interpolation method using the three points. The flux level at the lowest point of the interpolated curve is calculated, which is not the real minimum input power of the motor, but an estimated one. Hence, the quadratic interpolations are repeated with three new points chosen using the selection method for new points for refitting until the convergence criteria are satisfied. The proposed method is verified by simulation results.

Numerical Method for Power Losses Minimization of Vector-Controlled Induction Motor

“…The algorithm is fast and effective, however it produces discrete sequence of magnetizing current values, which requires low-pass filtering of algorithm output. Very closely related is method from [9] where losses function locally approximated by quadratic polynomial on every iteration and the next search point selected based on analytically calculated minimum of approximation.…”