Rack and power controlling method thereof

A rack, comprising:

• a plurality of power supplies for supplying work voltages respectively;
• a plurality of nodes for providing power information;
• a rack management controller, coupled with the nodes and the power supplies and configured to receive the power information of each of the nodes to calculate a total power consumption value of the nodes, to calculate a power supply enabling demand according to the total power consumption value and a maximum power supply value of the power supply, and to calculate a first sequence of the power supplies according to state information of each of the power supplies;
• and
• a control unit, coupled with the rack management controller and the power supplies and configured to, according to the power supply enabling demand and the first sequence, generate a plurality of control signals for enabling at least two of the power supplies, setting the enabled power supplies as at least one current master power supply and at least one current secondary power supply, and disabling the rest of the power supplies,
• wherein while the at least one current master power supply provides at least one work voltage to the nodes, the at least one current secondary power supply and the rest of the power supplies do not supply the at least one work voltage to the nodes,
• wherein the rack management controller reads the state information of each of the rest of the power supplies in a preset period to obtain a second sequence of the rest of the power supplies, and transmits the second sequence to the control unit;
• according to the power supply enabling demand and the second sequence, the control unit enables at least two of the rest of the power supplies, sets the enabled power supplies as at least one new master power supply and at least one new secondary power supply, disables the at least one current master power supply and the at least one current secondary power supply, and determines whether the nodes stop operating;
• when the nodes do not stop operating, the rack management controller repeats the reading of the state information of the rest of the power supplies to obtain the second sequence of the rest of the power supplies, and the control unit continues to enable at least one of the rest of the power supplies, set the at least one enabled power supply as the at least one new master power supply, disable the at least one current master power supply and set the at least one disabled master power supply as at least one new secondary power supplies according to the power supply enabling demand and the second sequence until all of the nodes stop operating.