Haier US Appliance Solutions, Inc.

University of Louisville Research Foundation, Inc.

Michael Lee McIntyre

Joseph Wilson Latham

Gregory William Hahn

Srujan Kusumba

Paul Goodjohn

Mohammad Taghi Mohebbi

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.

Method for detecting head crashing in a linear compressor

A method for operating a linear compressor includes substituting a first observed velocity, a bounded integral of the first observed velocity, an estimated clearance, an estimated discharge pressure, and an estimated suction pressure into the mechanical dynamic model for the motor, calculating an observed acceleration for the piston with the mechanical dynamic model for the motor, calculating a second observed velocity for the piston by integrating the observed acceleration for the piston, calculating an observed position of the piston by integrating the second observed velocity for the piston, and updating an estimated clearance, an estimated discharge pressure, and an estimated suction pressure based upon an error between the first and second observed velocities and an error between the bounded integral of the first observed velocity and the observed position.

A linear compressor and methods of operation, for example, to detect polarity for the linear compressor are provided herein. The method may include supplying an initial time varying voltage to the motor of the linear compressor at an assumed polarity; estimating a first acceleration of the motor of the linear compressor when the motor is at a bottom dead center position; estimating a second acceleration of the motor of the linear compressor when the motor is at a top dead center position; comparing the first acceleration to the second acceleration; and determining whether the assumed polarity is correct based on the comparison.

Linear compressor and methods of polarity detection

A method for operating a linear compressor includes providing a dynamic model for a motor of the linear compressor, estimating values for each unknown constant of a plurality of unknown constants of the dynamic model for the motor and repeatedly updating the estimate for each unknown constant of the plurality of unknown constants of the dynamic model for the motor in order to reduce an error between a measured value for the electrical dynamic model and an estimated valve for the electrical dynamic model.

A method of operating a synchronous motor includes using a rotor angle observer model to calculate an observed rotor angle and a speed estimator model to calculate an observed angular speed of the rotor. The observed rotor angle may be used to ensure that the stator magnetic field generated by the stator is oriented 90&#xb0; ahead of the rotor magnetic field. The observed angular speed may be used to regulate the motor operation to achieve the desired speed.

Method for operating a synchronous motor

A method of operating a compressor includes obtaining a harmonic series representation of speed variation as the rotor rotates through each revolution. The method includes regulating an electric motor to compensate for or cancel out the periodic speed variation. Specifically, the method includes calculating an electromagnetic torque using a torque control input model based on the speed error and the harmonic series representation of the speed error. The operation of the electric motor is then adjusted such that the electromagnetic torque applied by the motor cancels out the speed variation such that noise and vibrations are minimized.

Method for operating a compressor

A method for operating a linear compressor is provided. The method includes estimating an acceleration of the motor of the linear compressor using at least a robust integral of the sign of the error feedback. A position of the motor of the linear compressor when the motor of the linear compressor is at the bottom dead center point is also determined based at least in part on a measured current to the motor of the linear compressor and an estimated acceleration of the motor. The position of the motor of the linear compressor when the motor of the linear compressor is at a top dead center point is calculated based at least in part on the position of the motor of the linear compressor when the motor of the linear compressor is at the bottom dead center point and a stroke length of the motor of the linear compressor.

A method for operating a linear compressor includes providing a current controller, a resonance controller and a clearance controller. The current controller, the resonance controller and the clearance controller are configured for regulating operating parameters of a motor of the linear compressor. By managing priority between the current controller, the resonance controller and the clearance controller, the method may assist with efficiently operating the linear compressor while also maintaining stability.

A method for operating a linear compressor includes measuring a current induced in a motor of the linear compressor and calculating an observed current of the motor of the linear compressor using at least an electrical dynamic model for the linear compressor and a robust integral of the sign of the error feedback. The method also includes detecting a head crash within the linear compressor if an error between the observed current of the motor of the linear compressor and the measured current induced in the motor of the linear compressor is greater than a crash threshold.

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Louisville, KY, United States of America

Michael Lee McIntyre