Operation control apparatus for compressor and method thereof

Abstract

In an operation control apparatus and a method thereof, the compressor can be protected from overloading through a current control device instead of an OLP (Over Load Protector) and a PTC thermistor (Positive Temperature Coefficient thermistor). The operation control apparatus includes: a stroke estimated unit for estimating a stroke of the compressor on the basis of a current and a voltage applied to an interior motor of the compressor and a motor constant of the interior motor; a control unit for generating a control signal for varying a stroke of the compressor on the basis of the estimated stroke value and a preset stroke reference value; and a current control means being turned on/off so as to vary a stroke voltage applied to the interior motor of the compressor.

1 . An operation control apparatus for a compressor comprising: 
 a stroke estimating unit for estimating a stroke of the compressor on the basis of a current and a voltage applied to an interior motor of the compressor and a motor constant of the interior motor;    a control unit for generating a control signal for varying a stroke of the compressor on the basis of the estimated stroke value and a preset stroke reference value; and    a current control means for varying a stroke voltage applied to the interior motor of the compressor in accordance with the control signal.    
   
   
       2 . The apparatus of  claim 1 , wherein an OLP (Over Load Protector) and/or a PTC thermistor (Positive Temperature Coefficient thermistor) are not used for the operation control apparatus.  
   
   
       3 . The apparatus of  claim 1 , wherein the control unit outputs the control signal for increasing the stroke voltage applied to the compressor when the compressor is initially driven, to the current control means.  
   
   
       4 . The apparatus for  claim 1 , wherein, when the estimated stroke value is smaller than the stroke reference value, the control unit increases a voltage applied to the compressor by lengthening an on/off period of the current control means, and, when the estimated stroke value is greater than the stroke reference value, the control unit decreases a voltage applied to the compressor by shortening the on/off period of the current control means.  
   
   
       5 . An operation control apparatus for a compressor comprising: 
 detecting means for detecting a current and a voltage which are applied to a compressor;    a storing means for presetting a standard current value for preventing an overcurrent generated when the compressor initially starts, and storing the set standard current value;    a comparing means for comparing the detected current value and the standard current value, and outputting a comparing signal corresponding to the comparing result; and    a control means for cutting off a current applied to the compressor by turning off a current control means installed at the compressor by the comparing result, or for controlling a stroke voltage applied to the compressor by turning on/off the current control means at a certain period.    
   
   
       6 . The apparatus of  claim 5 , wherein the current control means is one of a triac, a GTO transistor (gate turn-off transistor), an IGBT (Insulated Gate bipolar Transistor), a bipolar transistor and a relay.  
   
   
       7 . The apparatus of  claim 5 , wherein the compressor is installed at a refrigerator.  
   
   
       8 . The apparatus of  claim 5 , wherein the control means cuts off a current applied to the compressor by turning off the current control means when the detected current value is greater than the standard current value; and compares the stroke value estimated based on the detected voltage value, the detected current value and a motor constant of an interior motor of the compressor with the preset stroke reference value, and then varies a stroke of the compressor on the basis of the comparing result when the detected current value is smaller than the standard current value.  
   
   
       9 . The apparatus of  claim 5 , wherein an OLP (Over Load Protector) and/or a PTC thermistor (Positive Temperature Coefficient thermistor) are not used for the operation control apparatus.  
   
   
       10 . A method for controlling an operation of a compressor comprising the steps of; 
 detecting a current and a voltage applied to the compressor;    estimating a stroke of the compressor on the basis of the detected values of the current and the voltage and a motor constant of an interior motor of the compressor;    when the estimated stroke value is smaller than a preset stroke reference value, increasing a voltage applied to the compressor by lengthening an on/off period of a current control means installed at the compressor, and when the estimated stroke value is greater than a preset stroke reference value, decreasing a voltage applied to the compressor by shortening the on/off period of the current control means.    
   
   
       11 . A method for controlling an operation of a compressor comprising: 
 detecting a current applied to the compressor;    comparing the detected current value and a preset standard current value;    cutting off a current applied to the compressor by turning off a current control means installed at the compressor when the detected current value is greater than the standard current value; and    when the detected current value is the same as or smaller than the standard current value, estimating a stroke of the compressor, and controlling a stroke voltage applied to the compressor by turning on/off the current control means at a certain period on the basis of the estimated value and the preset stroke standard current value.