Nidec Motor Corporation

Emerson Electric Company

Darko Marcetic

Joseph Gerald Marcinkiewicz

Gregory M Levine

Bret S Clark

J Stephen Thorn

Mile Bozic

Vinod Sadasivam

Thomas J Sheahan

Vinodkumar Sadasivam

Michael I Henderson

Peter Murray

Anandan Velayutham Rajarathnam

An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

Sensorless motor braking system

A motor controller for an electric motor having a stator and a rotor. The motor controller includes a power input for receiving AC power from a power source; a control input for receiving a control signal from a control; and circuitry for switching power from the power source to the electric motor in response to the control signal. The circuitry is operable to: apply a braking waveform to the stator while the rotor is rotating; monitor a reactive power of the stator; detect an increase in the reactive power of the stator to determine the rotor has substantially stopped rotating; and remove the braking waveform from the stator in response to detecting the increase in the reactive power.

Systems and methods for braking an electric motor

An electric motor control system includes a motor control circuit for generating a motor control signal and a braking mechanism for adjusting the motor control signal to augment motor losses when the motor control circuit is in a braking mode. The braking mechanism includes a difference component for receiving a first signal containing motor reference speed information, for receiving a second signal containing actual speed information, and for generating a third signal containing information indicating a difference between the reference speed and the actual speed. An integrating component integrates the third signal and generates a fourth signal representing the integrated third signal. The fourth signal may augment a voltage control signal in a voltage-based control circuit or may augment a flux-producing component of a current control signal in a current-based control circuit. The electric motor control circuit may include multiple braking mechanisms for use in different modes of operation.

Sensorless motor control

A system and method of determining the temperature of a rotating electromagnetic machine, such as an electric motor or generator. A temperature calibration parameter is calculated based on the temperature of an object situated close to the motor, such as a motor drive connected to the motor, and a first resistance value of the winding. In exemplary embodiments, the motor drive and first resistance value are determined only after the motor has been idle for some predetermined time period. Once the calibration parameter is calculated, the processor uses it along with subsequent resistance measurements to calculate the temperature of the motor.

Device and method of sensing temperature of a rotating electromagnetic machine

Device and method for sensing temperature of a rotating electromagnetic machine

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

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.

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Novi Sad, Republic of Serbia

Darko Marcetic