Rack power system and method

1. A rack power system for providing DC power to equipment installed in a rack, comprising:

a first shelf containing a plurality of power supplies, each of the plurality of power supplies configured to receive AC power and to provide DC power to equipment installed in the rack at a nominal voltage;

a second shelf containing a plurality of battery units, each of the plurality of battery units configured to provide DC power; and

a controller coupled to the first shelf and the second shelf and configured to:

control each of the plurality of power supplies and each of the plurality of battery units;

monitor the AC power received by the first shelf;

predict an impending event related to the AC power and, in response, control at least one of the plurality of battery units to operate in an online mode to generate a DC voltage less than the nominal voltage;

detect a loss of AC power and, in response, control the plurality of battery units to operate in an active mode to generate a DC voltage at the nominal voltage.

2. The rack power system of claim 1 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus, and wherein the controller is further configured to control at least one of the plurality of battery units to operate in the online mode to present DC power to the DC power bus at a DC voltage less than the nominal voltage.

3. The rack power system of claim 1 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus, and wherein the controller is further configured to detect an overload condition and control at least one of the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage.

4. The rack power system of claim 1 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus, and wherein the controller is further configured to detect operation of the rack power system at a power level less than a full power level, and in response, control the first shelf to operate in an efficient mode of operation and control at least one of the plurality of power supplies to operate in a mode in which the at least one of the plurality of power supplies does not provide DC power.

5. The rack power system of claim 1 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus, and wherein the controller is configured to detect loss of AC power, and in response, control the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage.

6. The rack power system of claim 2 , wherein:

the first shelf is further configured to accept at least one battery unit;

the first shelf and the second shelf are each configured to be slidingly mounted within the rack; and

the first shelf and the second shelf are each configured to couple to the DC power bus when in a fully inserted position.

7. The rack power system of claim 1 , wherein each of the plurality of power supplies has the same power rating as each of the plurality of battery units.

8. A method for providing power to equipment installed in a rack, the method comprising:

mounting a first shelf into the rack, the first shelf containing a plurality of power supplies, each of the plurality of power supplies configured to receive AC power and to provide DC power to equipment installed in the rack at a nominal voltage;

mounting a second shelf into the rack, the second shelf containing a plurality of battery units, each of the plurality of battery units configured to provide DC power;

independently controlling each of the plurality of power supplies and each of the plurality of battery units;

monitoring the AC power received by the first shelf;

predicting an impending event related to the AC power and, in response, controlling at least one of the plurality of battery units to operate in an online mode to generate a DC voltage less than the nominal voltage; and

detecting a loss of AC power and, in response, controlling the plurality of battery units to operate in an active mode to generate a DC voltage at the nominal voltage.

9. The method of claim 8 , further comprising:

controlling at least one of the plurality of power supplies to provide DC power at the nominal voltage to a DC power bus in the rack; and

controlling at least one of the plurality of battery units to operate in the online mode to present DC power to the DC power bus at a DC voltage less than the nominal voltage.

10. The method of claim 8 , further comprising:

controlling at least one of the plurality of power supplies to provide DC power at the nominal voltage to a DC power bus in the rack;

detecting an overload condition; and

controlling at least one of the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage in response to the overload condition.

11. The method of claim 8 , further comprising:

controlling at least one of the plurality of power supplies to provide DC power at the nominal voltage to a DC power bus in the rack; and

detecting operation of the first shelf at a level less than a full power level, and in response controlling at least one of the plurality of power supplies to operate in a mode in which the at least one of the plurality of power supplies does not provide DC power to the DC power bus.

12. The method of claim 8 , further comprising:

controlling at least one of the plurality of power supplies to provide DC power at the nominal voltage to a DC power bus in the rack; and

detecting a loss of AC power, and in response controlling the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage.

13. The method of claim 8 , further comprising:

mounting a DC power bus in the rack;

wherein the first shelf further contains at least one battery unit;

wherein mounting a first shelf into the rack includes sliding the first shelf into the rack and coupling a connector of the first shelf with the DC power bus; and

wherein mounting a second shelf into the rack includes sliding the second shelf into the rack and coupling a connector of the second shelf with the DC power bus.

14. The method of claim 8 , wherein each of the plurality of power supplies has the same power rating as each of the plurality of battery units.

15. An equipment rack, comprising:

a frame;

a pair of mounting rails coupled to the frame;

a first shelf mounted to the mounting rails and containing a plurality of power supplies, each of the plurality of power supplies configured to receive AC power and to provide DC power to equipment installed in the equipment rack at a nominal voltage;

a second shelf mounted to the mounting rails and containing a plurality of battery units, each of the plurality of battery units configured to provide DC power; and

a controller coupled to the first shelf and the second shelf and configured to:

control each of the plurality of power supplies and each of the plurality of battery units;

monitor the AC power received by the first shelf;

predict an impending event related to the AC power and, in response, control at least one of the plurality of battery units to operate in an online mode to generate a DC voltage less than the nominal voltage; and

detect a loss of AC power and, in response, control the plurality of battery units to operate in an active mode to generate a DC voltage at the nominal voltage.

16. The equipment rack of claim 15 , further comprising a DC power bus mounted in the equipment rack and configured to distribute DC power to equipment mounted to the mounting rails in the equipment rack;

wherein the plurality of power supplies are configured to provide DC power to the DC power bus; and

wherein the controller is further configured to control at least one of the plurality of battery units to operate in the online mode to present DC power to the DC power bus at a DC voltage less than the nominal voltage.

17. The equipment rack of claim 15 , further comprising a DC power bus mounted in the equipment rack and configured to distribute DC power to equipment mounted to the mounting rails in the equipment rack;

wherein the plurality of power supplies are configured to provide DC power to the DC power bus; and

wherein the controller is further configured to detect an overload condition and control at least one of the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage.

18. The equipment rack of claim 15 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus, and wherein the controller is further configured to detect operation at a power level less than a full power level, and in response, control the first shelf to operate in an efficient mode of operation and control at least one of the plurality of power supplies to operate in a mode in which the at least one of the plurality of power supplies does not provide DC power.

19. The equipment rack of claim 15 , wherein the plurality of power supplies are configured to provide DC power to a DC power bus;

wherein each of the plurality of power supplies has the same power rating as each of the plurality of battery units; and

wherein the controller is configured to detect loss of AC power, and in response, control the plurality of battery units to operate in the active mode to provide DC power to the DC power bus at the nominal voltage.

20. The equipment rack of claim 16 , wherein:

the first shelf and the second shelf are each further configured to be slidingly mounted to the mounting rails; and

the first shelf and the second shelf are each further configured to couple to the DC power bus when slid to a fully inserted position.