Refrigerator and controlling method of the same

1. A refrigerator, comprising:

a refrigerating chamber;

a freezing chamber;

one or more refrigerating chamber temperature sensors configured to sense a temperature of the refrigerating chamber;

one or more freezing chamber temperature sensors configured to sense a temperature of the freezing chamber; and

a refrigerating cycle apparatus configured to generate cool air, the refrigerating cycle apparatus comprising;

a first compressor and a second compressor connected to each other, and configured to compress a refrigerant in two stages;

a condenser connected to a discharge side of the second compressor disposed at a downstream side with respect to a flowing direction of the refrigerant;

a first evaporator connected to the condenser, and connected to a suction side of the first compressor disposed at an upstream side with respect to the flowing direction of the refrigerant; and

a second evaporator diverged from the condenser together with the first evaporator, and connected between a discharge side of the first compressor and a suction side of the second compressor; and

a controller configured to control the refrigerating cycle apparatus to generate cool air, and to control driving of the refrigerator based on an amount of change in the refrigerating chamber temperature or an amount of change in the freezing chamber temperature calculated per predetermined time period,

wherein the controller calculates a change in the amount of temperature change by calculating a difference between a first amount of change in the refrigerating chamber temperature in a first time period and a second amount of change in the refrigerating chamber temperature in a second time period, or calculating a difference between a first amount of change in the freezing chamber temperature in a first time period and a second amount of change in the freezing chamber temperature in a second time period, and

wherein, if the change in the amount of temperature change is greater than a first reference value, the controller increases the cooling capacity of the compressors, if the change in the amount of temperature change is smaller than the first reference value but larger than a second reference value, the controller maintains the current cooling capacity of the compressors and if the change in the amount of temperature change is smaller than the second reference value, the controller decreases the cooling capacity of the compressors.

2. The refrigerator of claim 1 , wherein the refrigerating cycle apparatus further comprises:

a refrigerant switching valve installed at an outlet of the condenser on a divergence point of the first evaporator and the second evaporator, and configured to control the flowing direction of the refrigerant,

wherein a discharge side of the first compressor is connected to a suction side of the second compressor so that a refrigerant primarily-compressed at the first compressor can be secondarily-compressed at the second compressor.

3. The refrigerator of claim 2 , wherein the first compressor and the second compressor are driven and a refrigerant passing through the condenser moves toward the first evaporator and the second evaporator when a driving mode of the refrigerator is a simultaneous driving mode.

4. The refrigerator of claim 2 , wherein a refrigerant passing through the condenser moves toward the first evaporator when a driving mode of the refrigerator is a freezing chamber driving mode, and

wherein the refrigerant passed through the first evaporator is compressed twice by the first compressor and the second compressor.

5. The refrigerator of claim 2 , wherein the second compressor is driven and a refrigerant passing through the condenser moves toward the second evaporator when a driving mode of the refrigerator is a refrigerating chamber driving mode.