Apparatus and method for controlling stroke of reciprocating compressor

A method for controlling a stroke of the reciprocating compressor comprising:

• detecting a positive half-wave voltage of an AC voltage applied to a motor of the reciprocating compressor and a positive half-wave current of an AC current passing through the motor;
• estimating a negative half-wave voltage of the AC voltage applied to the motor and a negative half-wave current of the AC current passing through the motor based on the detected positive half-wave voltage and the detected positive half-wave current;
• estimating a stroke of the reciprocating compressor based on the detected positive half-wave voltage and the detected positive half-wave current and the estimated negative half-wave voltage and the negative half-wave current;
• comparing the estimated stroke estimate value and a stroke reference value of the reciprocating compressor;
• and
• controlling a stroke of the reciprocating compressor based on the comparison result.

An apparatus for controlling a stroke of a reciprocating compressor comprising:

• a voltage detecting unit for detecting a negative half-wave voltage of an AC voltage applied to a motor of the reciprocating compressor;
• a current detecting unit for detecting a negative half-wave current of the AC current passing through the motor;
• a voltage and current estimating unit for estimating a positive half-wave voltage of the AC voltage applied to the motor and a positive half-wave current of the AC current passing through the motor-based on the detected negative half-wave voltage and the detected negative half-wave current;
• a stroke estimating unit for estimating a stroke of the reciprocating compressor based on the detected negative half-wave voltage and the detected negative half-wave current and the estimated positive half-wave voltage and the positive half-wave current;
• a stroke controller for outputting a stroke control signal of the reciprocating compressor based on a comparison value between the estimate stroke estimate value and a stroke reference value of the reciprocating compressor;
• and
• a power source unit for applying positive DC power to the voltage detecting unit and the current detecting unit.

A method for controlling a stroke of the reciprocating compressor comprising:

• detecting a negative half-wave voltage of an AC voltage applied to a motor of the reciprocating compressor and a negative half-wave current of an AC current passing through the motor;
• estimating a positive half-wave voltage of the AC voltage applied to the motor and a positive half-wave current of the AC current passing through the motor in a symmetrical form of the detected negative half-wave voltage and the detected negative half-wave current;
• estimating a stroke of the reciprocating compressor based on the detected negative half-wave voltage and the detected negative half-wave current and the estimated positive half-wave voltage and the positive half-wave current;
• comparing the estimated stroke estimate value and a stroke reference value of the reciprocating compressor;
• and
• controlling a stroke of the reciprocating compressor based on the comparison result.