Single phase field oriented control for a linear compressor

A linear compressor defining an axial direction and a vertical direction, the linear compressor for an appliance comprising:

• a cylindrical casing defining a compressor chamber;
• a piston positioned within the compressor chamber and being movable along the axial direction;
• a motor operably coupled to the piston;
• and
• a controller operably coupled to the motor, the controller configured to:
• operate the motor in order to drive a rotor of the motor;
• obtain one or more feedback measurements of one or more electrical characteristics of the motor, the one or more feedback measurements comprising measurement indicative of a phase angle of magnetic flux of the rotor;
• and
• control the motor using a single-phase control scheme based at least in part on the one or more feedback measurements.

An appliance, comprising:

• a cabinet defining an internal chamber;
• a door rotatably mounted to the cabinet to provide selective access to the internal chamber;
• a linear compressor, the linear compressor having a piston movable in a negative axial direction toward a compressor chamber and a positive axial direction away from the compressor chamber;
• a motor operably coupled to the piston;
• an inverter configured to supply a variable frequency waveform to the motor;
• and
• a controller operably coupled to the motor, the controller configured to:
• operate the motor in order to drive a rotor of the motor;
• obtain one or more feedback measurements of one or more electrical characteristics of the motor;
• determine a target current trajectory;
• determine a trajectory difference between the target current trajectory and the one or more feedback measurements;
• and
• adjust a voltage setpoint based at least in part on the one or more feedback measurements.