Emerson Electric Company

Nidec Motor Corporation

Vinodkumar Sadasivam

Joseph Gerald Marcinkiewicz

Darko Marcetic

Keith I Hoemann

Michael I Henderson

Gregory M Levine

Bret S Clark

Peter Murray

Anandan Velayutham Rajarathnam

Stephen J Thorn

A clothes washing machine system including a method of detecting a load unbalance. The washing machine system includes a cabinet having a drum rotatably mounted therein. A motor is coupled to the drum for rotating the drum within the cabinet. A memory device is accessible by a processor, such as a digital signal processor (DSP). The memory contains program code for implementing a method that includes determining the motor torque ripple, determining the motor speed, and determining the load unbalance mass based on the motor torque and speed.

Method and system for determining a washing machine load unbalance

Cavitation detection systems and methods include generating a signal representing the power factor of a motor driving a pump, analyzing the power factor signal and determining the presence of cavitation based on the analysis of the power factor signal. The power factor may be estimated using various estimation schemes. Analyzing the signal includes filtering the power factor signal.

Cavitation detection device and method

An induction motor drive system and method estimates a motor power factor based on the AC power output to the motor phase windings and estimates the rotor speed based on the estimated power factor. The estimated rotor speed is compared to a rotor speed command signal to generate a speed error, and the voltage and frequency input to the motor are adjusted in response to the speed error. Rotor speed is estimated based on estimated rotor slip, which is estimated based on the applied voltage, frequency, estimated power factor and estimated motor power.

Induction motor control system

An induction motor control system senses the zero-cross angle of a current waveform applied to the motor's phase windings and computes the difference between the sensed current zero-cross angle and a predetermined demand voltage angle to estimate a power factor angle. The estimated power factor angle is compared to a predetermined desired power factor angle, and the voltage applied to the phase windings is adjusted in response to the difference between the estimated power factor angle and the desired power factor angle.

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St. Louis, MO, United States of America

Vinodkumar Sadasivam