Adaptive control for speed-sensorless induction motors with uncertain load torque and rotor resistance

Abstract

The problem of controlling a speed-sensorless induction motor is addressed. Smooth reference signals for rotor speed and flux modulus are required to be tracked for any unknown constant values of load torque and rotor resistance within known bounds. A fourth order non-linear adaptive tracking control is presented which is based on a novel rotor speed observer and on two identifiers for the uncertain parameters; it guarantees asymptotic rotor speed tracking and exponential rotor flux modulus tracking with an explicitly computed domain of attraction. The closed-loop performances are illustrated by simulation

Robust Velocity and Load Observer for a General Noisy Rotating Machine

“…In this plot, it can be seen that w overlaps w after 0.2 s until t * . In t * , the abrupt value change of τ L is introduced, as defined in (16). Consequently, information is lost and w stops overlapping w during 0.25 s. Note that the SDRE observer in ( 12) and ( 14) can recover the estimated angular velocity w in a very short period.…”

“…Nonetheless, these approaches are different from the solution proposed in this paper. Typically, the load torque in certain instances may be unknown, as pointed out in [16]. Estimation of such perturbed variables has been investigated in several research papers; for instance, see [1,[16][17][18][19][20].…”

“…In [20], a novel method for estimating the motor load torque was proposed to reduce the cost associated with torque sensors. In [16], a rotor speed observer was designed for controlling a motor without a speed sensor. In [18], a performance and robustness comparison among three different algorithms for estimating the external load torque for low-power DC motors was presented.…”

A New Flux Observer for Induction Motors with On-Line Identification of Load Torque and Resistances

“…By virtue of a straightforward modification of the Persistency of Excitation Lemma A.1 in [22], we can establish that if there exist two positive reals t p and k p such that the…”

A Nonlinear Tracking Control for Sensorless Induction Motors with Uncertain Load Torque

“…the non-zero elements are a 12 = −b 24 = − k /2 * , a13 = −b 34 = ( /2 * )(T Ln /J + sat(ˆ )/J +˙ * ), a 23 = −a 35 = −b 23 = b 35 = k /2 , a 24 = /2, a 28 = − a 37 = b 37 = /2, a 34 = /2, b 57 = − ( /2 * )(T Ln /J + sat(ˆ )/J +˙ * ), b 58 =− k /2 * , b 67 =−b 37 +( / )b 57 −(M−L r L s /M)b 35 , b 68 =( / )b 58 ), c l = min{ 1 , 2 , 3 } +˙ * / * , c d = (1/2c l )[m p n q + (m p m s / )((2z M + + za ) 2 + (2z M + + zb ) 2 ) 1/2 + m p m q r 2 1 / n q = sup t 0 {|w d (t)|/J * (t)}, m s = sup t 0 { S(t) }, S = [s i j ] 1 i 3,1 j 2(the non-zero elements are s 11 = − * / * 2 , s 12 = / * 2 , s 21 = − (1/ * 2 )(T Ln /J + sat(ˆ )/J +˙ * ), s 22 = ( / * )( * /M +˙ * / M)), m p = P , n p = P −1 , P −1 =[ p i j ] 1 i, j 3 , p 11 = p 12 = p 13 = 1,…”