Abstract: A speed of a motor is estimated by determining a correlation between a current wave sensed at the motor and frequency pairs from a set of weighted frequency pairs representing the current wave. Components of a motor control signal are fit to a corresponding number of first orthogonal pairs in a set of weighted orthogonal pairs. The orthogonal pairs being orthogonal to the frequency pairs. Each of the frequency pairs are fit as the orthogonal pair subsequent to the first orthogonal pairs. The frequency pairs that provide a reduction in the mean squared error between the current wave and the set of weighted orthogonal pairs that satisfies a criteria are identified. Desired frequencies from the identified frequency pairs are then compared with a motor speed harmonic model to determine an estimation of the speed.

Abstract: A speed of a motor is estimated by determining a correlation between a current wave sensed at the motor and frequency pairs from a set of weighted frequency pairs representing the current wave. Components of a motor control signal are fit to a corresponding number of first orthogonal pairs in a set of weighted orthogonal pairs. The orthogonal pairs being orthogonal to the frequency pairs. Each of the frequency pairs are fit as the orthogonal pair subsequent to the first orthogonal pairs. The frequency pairs that provide a reduction in the mean squared error between the current wave and the set of weighted orthogonal pairs that satisfies a criteria are identified. Desired frequencies from the identified frequency pairs are then compared with a motor speed harmonic model to determine an estimation of the speed.

Abstract: A method to estimate motor speed for extended stabilized rotational control of an induction motor at all speeds including slow speeds. The speed estimator supplies real-time time motor control feedback information for a variable speed motor drive controller without a mechanical encoder. The speed estimator is based on an optimized fast orthogonal search algorithm with control of the carrier drive frequency to reduce computation time. The reduced processing time provides for an update rate to the motor controller sufficient to maintain motor stability to near zero the motor rated base speed.

Abstract: A method to estimate motor speed for extended stabilized rotational control of an induction motor at all speeds including slow speeds. The speed estimator supplies real-time motor control feedback information for a variable speed motor drive controller without a mechanical encoder. The speed estimator is based on an optimized fast orthogonal search algorithm with control of the carrier drive frequency to reduce computation time. The reduced processing time provides for an update rate to the motor controller sufficient to maintain motor stability to near zero the motor rated base speed.