Method for operating a rolling piston compressor

A rolling piston compressor comprising:

• a casing defining a cylindrical cavity defining a central axis, a suction port, and a discharge port;
• an electric motor comprising a drive shaft, the drive shaft extending along the central axis;
• a rolling piston positioned within the cylindrical cavity, the rolling piston being eccentrically mounted on the drive shaft;
• a sliding vane that extends from the casing toward the rolling piston to maintain contact with the rolling piston as it rotates about the central axis, the sliding vane and the rolling piston dividing the cylindrical cavity into a suction volume in fluid communication with the suction port and a compression volume in fluid communication with the discharge port;
• and
• a controller operably coupled to the electric motor, the controller configured for:
• obtaining an angular position and an angular speed of the rolling piston;
• obtaining an electromagnetic torque applied by the electric motor;
• calculating a load torque exerted on the rolling piston using a load torque observer model based on the angular position of the rolling piston, the angular speed of the rolling piston, and the electromagnetic torque applied by the electric motor;
• and
• operating the electric motor to adjust the electromagnetic torque to be equivalent to the calculated load torque.