Vibration analysis of rolling piston-type compressors driven by single-phase induction motors

Rolling piston-type compressors driven by single-phase induction motors are widely used in low power room air conditioners. Since a rolling piston-type compressor represents an eccentric load to the motor, vibration problems associated with the compressor and motor drive assembly always occur. Furthermore, for ease of starting, a single-phase induction motor is usually designed with unsymmetrical stator windings, which is far more difficult to be analyzed as compared to a typical symmetrical three-phase induction motor. This paper establishes the state-space model for a rolling piston-type compressor driven by a single-phase induction motor. An inverter is proposed for driving the motor-compressor assembly. By varying the line frequency and voltage magnitudes on both primary and secondary windings of the induction motor, this paper seeks to reduce the vibration accompanied with the motor-compressor assembly of a room air conditioner. The paper presents some useful design criteria for reducing vibrations based on computer simulation results