Control system and control method for saving power by activating power supplies with shortest recorded power supply times

1. A control system for saving power for an electronic device, the control system comprising:

a plurality of power supplies for supplying power to the electronic device;

a controller connected between the plurality of power supplies and the electronic device, the controller comprising:

a processor; and

a memory unit connected to the processor, and storing a plurality of modules each of which contains one or more computerized instructions to be executed by the processor, wherein the modules comprises:

an obtaining module to obtain information of maximum power that can be supplied to the electronic device by each power supply;

a detecting module to detect how much power is demanded by the electronic device, and output the detected power demanded by the electronic device;

a determining module to determine the minimum number of the plurality of power supplies demanded at any given time, based on the detected power demanded by the electronic device, and output the determined minimum number of the plurality of power supplies, and determine if power demanded by the electronic device has changed; if the power demanded by the electronic device has not changed, the detecting module goes on to detect the power demanded by the electronic device; if the power needed by the electronic device has changed, the determining module determines minimum number of the power supplies and output the determined minimum number; and

a control module to turn on the power supplies, of which the number is equal to the determined minimum number, and turn off the other power supplies,

wherein the memory unit further comprises a recording module, the recording module is operable to accumulate and record power supply time for each of the plurality of power supplies, the control module is operable to turn on the power supplies the number of which is equal to the determined minimum number and further to select which of the power supplies should be turned on when less than all of them are demanded according to the recorded power supply times, the power supplies chosen to be turned are those whose recorded power supply times are the shortest among all power supplies, and turn off the other power supplies.

2. The control system of claim 1 , wherein the electronic device is a server.

3. A control method for saving power for an electronic device, the control method comprising:

a: obtaining information of maximum power that can be supplied to the electronic device by each of a plurality of power supplies;

b: detecting how much power is demanded by the electronic device, and output the detected power demanded by the electronic device;

c: determining minimum number of the plurality of power supplies, based on the detected power demanded by the electronic device, and output the determined minimum number of power supplies;

c1: accumulating and recording power supply time for each of the plurality of the power supplies;

d: turning on power supplies, the number of which is equal to the determined minimum number and whose recorded power supply times are the shortest among all power supplies, and turn off the other power supplies;

e: detecting how much power is demanded by the electronic device, and output the detected power demanded by the electronic device; and

f: determining whether the power demanded by the electronic device has changed; if the power demanded by the electronic device has not changed, the control method goes back the step e; if the power needed by the electronic device has changed, the control method goes back the step c.

4. The control method of claim 3 , wherein the electronic device is a server.