Haier US Appliance Solutions, Inc.

University of Louisville Research Foundation, Inc.

Joseph Wilson Latham

Michael Lee McIntyre

Gregory William Hahn

Srujan Kusumba

Paul Goodjohn

Meher Prasadu Kollipara

A method for operating a linear compressor of an appliance, such as a refrigerator appliance, is provided. In one example implementation, the method can include operating a motor of the linear compressor in order to drive a rotor of the motor. The method can further include obtaining, via a controller of the linear compressor, one or more feedback measurements of one or more electrical characteristics of the motor. The method can further include controlling, based at least in part on the one or more feedback measurements, the motor of the linear compressor using a single-phase vector-like control scheme.

Single phase field oriented control for a linear compressor

A method for operating a salient motor is provided. In one example implementation, the method can include determining, via a controller of the motor, a series of estimated injection angles. The method can further include injecting, via the controller, a high-frequency signal into the motor at each of the series of estimated injection angles to provide a series of high-frequency signal injections. The method can further include, responsive to each of the series of high-frequency signal injections, processing, via the controller, one or more signals associated with each of the series of high-frequency signal injections. The method can further include determining, via the controller, one or more operating parameters based at least in part on the series of estimated injection angles.

Standstill angle detection for salient motors

A method for operating an appliance, such as a stand mixer appliance, is provided. In one example implementation, the method can include operating a motor of the stand mixer appliance in order to rotate a mixer shaft of the stand mixer appliance. The method can further include determining, via a controller of the stand mixer appliance, a difference between an operating parameter and an operating parameter threshold. The method can further include implementing, via the controller of the stand mixer appliance, a field-weakening operation to increase a speed of the motor based at least in part on the difference.

Field weakening for BLDC stand mixer

A method for operating an appliance, such as a stand mixer, is provided. In one example implementation, the method can include operating a motor of the appliance in a first direction. The method can further include detecting, by a feedback system of the appliance, a first trigger condition. The method can further include, responsive to detecting the first trigger condition, operating the motor of the appliance in a second direction that is different than the first direction.

Method for avoiding stalled motor in a stand mixer with sensorless BLDC drive

A method of operating a compressor includes obtaining a mechanical angle and an angular speed of a rotor, determining an amplitude of a fundamental harmonic of a periodic load torque exerted on the rotor based at least in part on the mechanical angle and a harmonic series representation of the periodic load torque, obtaining a speed error by subtracting the angular speed from a reference angular speed, determining a DC component of the periodic load torque based at least in part on a speed error and a closed loop feedback control algorithm, calculating an electromagnetic torque using the DC component of the periodic load torque and the amplitude of the fundamental harmonic of the periodic load torque, and operating the electric motor to generate the calculated electromagnetic torque on the rotor.

Method for operating a compressor

A method of operating a rolling piston compressor includes determining a pressure difference (ΔP) between a discharge pressure (P) within a compression volume and a suction pressure (P) within a suction volume; determining a pressure ratio (r) equal to the discharge pressure (P) over the suction pressure (P); estimating a discharge pressure (P) based at least in part on the pressure difference (ΔP) and the pressure ratio (r); determining that the discharge pressure (P) is greater than a predetermined pressure limit (P); and lowering a target speed (ω) of the rolling piston compressor.

Method for determining a discharge pressure of a rolling piston compressor

A method for operating a voltage source inverter is provided, the method including inducing, via the voltage source inverter, a DC current at a load device to obtain a load voltage value; determining an ideal switching-averaged voltage based on a switching modulation scheme; determining a combined semiconductor voltage drop and deadtime effect; and adjusting the switching modulation scheme such that a resulting ideal switching-averaged voltage is based on the combined semiconductor voltage drop and deadtime effect and the load voltage value.

System and method for voltage calibration

A motor system can include a motor configured to be operated according to at least a portion of an operation cycle specifying at least one target speed for the motor and a controller configured to obtain an estimated winding resistance of the motor, wherein the estimated winding resistance is determined based at least in part on an estimator gain factor, and wherein the estimator gain factor is inversely dependent on a speed of the motor; wherein the at least one target speed comprises at least one low speed such that at least a portion of the operation cycle is a low speed portion of the operation cycle, the at least one low speed having a speed of less than about 10 percent of a maximum speed of the operation cycle.

Low-speed winding resistance estimation of variable speed motor systems

A motor system can include a motor, the motor including at least a rotor, and a controller configured to operate the motor. The controller can be configured to perform operations for operating the motor. The operations can include determining an initial estimated rotor angle, determining one or more estimated currents defined by an estimated rotating reference frame based at least in part on the estimated rotor angle, obtaining one or more current measurements of one or more measured currents respective to the one or more estimated currents, determining one or more current errors based at least in part on a subtractive combination of the one or more estimated currents and the one or more measured currents, determining one or more rotor flux estimates based at least in part on the one or more current errors, the one or more rotor flux estimates comprising at least an estimated &#x3b4;-directed rotor flux vector, and determining an estimated rotor speed based at least in part on an integral of the estimated &#x3b4;-directed rotor flux vector.

Low speed sensorless observation of permanent magnet synchronous motors

A method for operating a variable capacity drive circuit of a compressor includes operating first and second four-quadrant switches in a first state in which the first four-quadrant switch is closed and the second four-quadrant switch is open such that a voltage seen by the motor is equal to an AC line voltage. The method also includes operating the first and second four-quadrant switches in a second state where the first four-quadrant switch is open and the second four-quadrant switch is closed such that the voltage seen by the motor is to zero. Further, the method includes providing a positive firing angle and a negative firing angle for defining when the first and second four-quadrant switches are operated in each of the first and second states. Moreover, the method also includes transitioning between the first and second states using the firing angles at a switching frequency determined by the AC line voltage frequency.

Variable capacity drive circuit for a linear compressor in a refrigeration appliance

A method of operating a motor driving a rotating member includes directing rotation of the rotating member at the motor at an initial speed, determining a first frequency of a first noise component generated by the rotating member at the initial speed, determining a second noise component having a second frequency phase shifted 180&#xb0; with respect to the first frequency, determining a torque modifier of the motor to generate the second noise component from the motor, and directing activation of the motor according to the determined torque modifier.

Noise cancellation of a domestic appliance using a motor control

A linear compressor and methods of operation, for example, to control extension of the linear compressor, are provided herein. A method may include supplying a time varying voltage to a motor of the linear compressor, determining an uneven fatigue condition at the linear compressor, and applying a limiting force at the motor in a negative axial direction in response to the determining step.

Linear compressor and methods of extension control

A method for operating a linear compressor includes establishing a set of predictors, and establishing a model for an estimated head clearance of the linear compressor with the set of predictors. Coefficients of the model for the estimated head clearance of the linear compressor may also be established. The model for the estimated head clearance of the linear compressor may be used to calculate an estimated head clearance during operation of the linear compressor.

Method for operating a linear compressor

A method of operating a rolling piston rotary compressor includes obtaining an angular position and an angular speed of a rolling piston of the compressor, for example, using a tachometer or shaft encoder or observer. The method further includes obtaining an electromagnetic torque applied by an electric motor that is mechanically coupled to the rolling piston. The method further includes calculating a load torque exerted on the rolling piston based on these obtained values by using a load torque observer model that is formulated using known geometries of the compressor and thermodynamic models for the gas compression process. The operation of the electric motor is then adjusted such that the electromagnetic torque applied by the motor is equivalent to the calculated load torque such that noise and vibrations are minimized.

Method for operating a rolling piston compressor

A method for detecting head crashing in a linear compressor includes sampling a rolling average of a peak applied voltage and a desired peak current each time that a current controller adjusts the desired peak current. The method also includes calculating a linear regression for a predicted peak applied voltage as a function of the desired peak current, calculating the predicted peak voltage for the motor of the linear compressor with the linear regression and a current value for the desired peak current from the current controller, and establishing that a piston of the linear compressor is soft crashing when the predicted peak voltage is different than the current value for the rolling average of the peak applied voltage by more than a threshold value.

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Louisville, KY, United States of America

Joseph Wilson Latham