Refrigerator and control method thereof

Abstract

A refrigerator is provided. The refrigerator includes a main body, a storage compartment formed inside the main body, a cold air supply device including a compressor and being configured to supply cold air to the storage compartment, and a controller configured to operate the compressor in an on-off operation mode, switch the compressor from the on-off operation mode to a continuous operation mode in response to a predefined condition being satisfied while the compressor operates in the on-off operation mode, determine a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode, operate the compressor at the first RPM in the continuous operation mode, change the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being outside a preset temperature range and being lower than a reference temperature in the continuous operation mode, and change the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being outside the preset temperature range and being greater than or equal to the reference temperature in the continuous operation mode.

What is claimed is: 
     
         1 . A refrigerator comprising:
 a main body;   a storage compartment formed inside the main body;   a cold air supply device including a compressor and being configured to supply cold air to the storage compartment; and   a controller configured to:
 operate the compressor in an on-off operation mode, 
 switch the compressor from the on-off operation mode to a continuous operation mode in response to a predefined condition being satisfied while the compressor operates in the on-off operation mode, 
 determine a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode, 
 operate the compressor at the first RPM in the continuous operation mode, 
 change the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being outside a preset temperature range and being lower than a reference temperature in the continuous operation mode, and 
 change the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being outside the preset temperature range and being greater than or equal to the reference temperature in the continuous operation mode. 
   
     
     
         2 . The refrigerator of  claim 1 , wherein the controller is further configured to:
 change the target RPM of the compressor to the second RPM based on the temperature in the storage compartment being outside the preset temperature range, being lower than the reference temperature, and being higher than an off temperature of the compressor in the continuous operation mode.   
     
     
         3 . The refrigerator of  claim 1 , wherein the controller is further configured to:
 change the target RPM of the compressor to the third RPM, based on the temperature in the storage compartment being outside the preset temperature range, being greater than or equal to the reference temperature, and being lower than an on temperature of the compressor in the continuous operation mode.   
     
     
         4 . The refrigerator of  claim 1 , wherein the controller is further configured to:
 switch the compressor from the continuous operation mode to the on-off operation mode based on the temperature in the storage compartment being lower than the reference temperature and being less than or equal to an off temperature of the compressor in the continuous operation mode.   
     
     
         5 . The refrigerator of  claim 4 , wherein the controller is further configured to:
 operate the compressor in the on-off operation mode at an RPM higher than the first RPM.   
     
     
         6 . The refrigerator of  claim 1 , wherein the controller is further configured to:
 switch the compressor from the continuous operation mode to the on-off operation mode based on the temperature in the storage compartment being greater than or equal to the reference temperature and being greater than or equal to an on temperature of the compressor in the continuous operation mode.   
     
     
         7 . The refrigerator of  claim 6 , wherein the controller is further configured to:
 operate the compressor in the on-off operation mode at an RPM higher than the first RPM.   
     
     
         8 . The refrigerator of  claim 1 , wherein the predefined condition includes a condition in which the compressor reaches a target operating rate range in the on-off operation mode. 
     
     
         9 . The refrigerator of  claim 8 ,
 wherein the controller is further configured to:
 operate the compressor at an n th  RPM lower than an (n−1) th  RPM based on an operating rate of the compressor being less than or equal to the target operating rate range by operating the compressor at the (n−1) th  RPM in the on-off operation mode, and 
   wherein n is a natural number greater than or equal to 2.   
     
     
         10 . The refrigerator of  claim 9 , wherein the controller is further configured to:
 operate the compressor in the continuous operation mode at a value obtained by subtracting a predefined value from the (n−1) th  RPM in response to the operating rate of the compressor reaching the target operating rate range at the (n−1) th  RPM.   
     
     
         11 . The refrigerator of  claim 8 ,
 wherein the controller is further configured to:
 operate the compressor at an n th  RPM higher than an (n−1) th  RPM based on an operating rate of the compressor being higher than the target operating rate range by operating the compressor at the (n−1) th  RPM in the on-off operation mode, and 
   wherein n is a natural number greater than or equal to 2.   
     
     
         12 . The refrigerator of  claim 1 ,
 wherein the reference temperature is set by a user, and   wherein the preset temperature range is between a first temperature greater than the reference temperature by a first predefined value and a second temperature less than the reference temperature by a second predefined value.   
     
     
         13 . A method performed by a refrigerator, the method comprising:
 operating a compressor in an on-off operation mode to supply cold air to a storage compartment formed inside a main body of the refrigerator;   determining a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode;   switching the compressor to a continuous operation mode in response to a predefined condition being satisfied while the compressor operates in the on-off operation mode;   operating the compressor at the first RPM in the continuous operation mode; and   changing the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being outside a preset temperature range and being lower than a reference temperature in the continuous operation mode; or   changing the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being outside the preset temperature range and being greater than or equal to the reference temperature in the continuous operation mode.   
     
     
         14 . The method of  claim 13 , further comprising:
 changing the target RPM of the compressor to the second RPM based on the temperature in the storage compartment being outside the preset temperature range, being lower than the reference temperature, and being higher than an off temperature of the compressor in the continuous operation mode.   
     
     
         15 . The method of  claim 13 , further comprising:
 changing the target RPM of the compressor to the third RPM based on the temperature in the storage compartment being outside the preset temperature range, being greater than or equal to the reference temperature, and being lower than an on temperature of the compressor in the continuous operation mode.   
     
     
         16 . The method of  claim 13 , further comprising:
 switching the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode, based on the temperature in the storage compartment being lower than the reference temperature and being less than or equal to an off temperature of the compressor in the continuous operation mode.   
     
     
         17 . The method of  claim 16 , wherein the switching of the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode includes operating the compressor in the on-off operation mode at an RPM higher than the target RPM. 
     
     
         18 . The method of  claim 13  further comprising:
 switching the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode, based on the temperature in the storage compartment being greater than or equal to the reference temperature and being greater than or equal to an on temperature of the compressor in the continuous operation mode. 
 
     
     
         19 . The method of  claim 18 , wherein the switching of the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode includes operating the compressor in the on-off operation mode at an RPM higher than the target RPM.