Power distribution system

1. A power distribution system comprising:

at least one power supply;

a plurality of power distribution modules separate from one another and from the at least one power supply and connected to the at least one power supply and configured to receive power therefrom, each power distribution module of the plurality of power distribution modules including a microcontroller and at least one USB charging port; and

a power distribution bus connected to each power distribution module of the plurality of power distribution modules;

wherein the plurality of power distribution modules is configured to execute a distributed system policy management protocol over the power distribution bus to control a supply of available power from the at least one power supply to loads connected to USB charging ports of the power distribution modules;

wherein each power distribution module additionally comprises memory storing a power system database identifying each power distribution module of the plurality of power distribution modules;

wherein the microcontroller of each of the power distribution modules is configured to perform a discover step by broadcasting a message to discover if other power distribution modules are connected to the power distribution bus; and

wherein each power distribution module is configured to update its respective power system database with the identity of each power distribution module of the plurality of power distribution modules connected to the power distribution bus after the discover step.

2. The power distribution system according to claim 1 , wherein the power distribution bus is a single wire connecting the power distribution modules of the plurality of power distribution modules in parallel.

3. The power distribution system according to claim 1 , wherein each power distribution module additionally comprises a bus interface operatively connecting the microcontroller to the power distribution bus, the bus interface allowing the microcontroller to send and receive signals over the power distribution bus.

4. The power distribution system according to claim 3 , wherein the bus interface comprises an open-collector transmitter for transmitting signals over the power distribution bus.

5. The power distribution system according to claim 3 , wherein the bus interface comprises a voltage sensing comparator configured to receive and monitor voltage on the power distribution bus.

6. The power distribution system according to claim 1 , wherein each power distribution module is configured to store a total power required by each power distribution module of the plurality of power distribution modules in its respective power system database.

7. The power distribution system according to claim 6 , wherein the microcontroller is configured to transmit a signal over the power distribution bus to update the power system database each time a device is connected to or disconnected from the at least one USB charging port.

8. A power distribution module comprising:

a housing;

a power input configured to receive power from a power supply external to the housing;

at least one USB charging port in the housing;

a microcontroller disposed within the housing and configured to control the distribution of power from the power input to the at least one USB charging port;

a bus interface connectable to a power distribution bus, the bus interface allowing the microcontroller to send and receive signals over the power distribution bus to and from other power distribution modules connected to the power distribution bus and external to the housing; and

a memory;

wherein the microcontroller is configured to control the distribution of power from the power input to the at least one USB charging port based on information received from the other power distribution modules over the power distribution bus

wherein the memory stores a power system database identifying a plurality of other power distribution modules connected to the power distribution bus;

wherein the microcontroller is configured to perform a discover step by broadcasting a message to discover if other power distribution modules are connected to the power distribution bus; and

wherein the microcontroller is configured to update the power system database with the identity of each of the plurality of other power distribution modules connected to the power distribution bus after the discover step.

9. The power distribution module according to claim 8 , wherein the bus interface comprises an open-collector transmitter for transmitting signals over the power distribution bus.

10. The power distribution module according to claim 8 , wherein the bus interface comprises a voltage sensing comparator configured to receive and monitor voltage on the power distribution bus.

11. The power distribution module according to claim 8 , wherein the power system database identifies a power available for the at least one USB charging port.

12. The power distribution module according to claim 11 , wherein the power system database identifies a total power required by each other power distribution module.

13. The power distribution module according to claim 12 , wherein the microcontroller is configured to transmit a signal over the power distribution bus to update the power system database each time a device is connected to or disconnected from the at least one USB charging port.

14. A method for distributing power from at least one power supply through a plurality of power distribution modules separate from one another and in communication over a power distribution bus, each power distribution module of the plurality of power distribution modules including at least one USB charging port, the method comprising:

broadcasting, by each power distribution module, a message to discover if other power distribution modules are connected to the power distribution bus;

maintaining, in memory at each power distribution module, a power system database identifying each power distribution module of the plurality of power distribution modules and a total power required by each power distribution module of the plurality of power distribution modules; and

controlling, by a microprocessor of each power distribution module, a supply of power from the at least one power supply to devices connected to the at least one USB charging port of the power distribution module based on information contained in the respective power system database.

15. The method according to claim 14 , additionally comprising:

updating, at each power distribution module, the power system database each time a device is connected to or disconnected from the at least one USB charging port of any of the power distribution modules of the plurality of power distribution modules.

16. The method according to claim 15 , additionally comprising:

transmitting, by a power distribution module of the plurality of power distribution modules, a signal over the power distribution bus each time a device is connected to or disconnected from the at least one USB charging port of the power distribution module of the plurality of power distribution modules.

17. The method according to claim 16 , additionally comprising:

executing, by each power distribution module of the plurality of power distribution modules, an incremental search protocol to identify the other power distribution module of the plurality of power distribution modules and the total power required by each of the other power distribution modules.

18. The method according to claim 14 , additionally comprising:

updating, at each power distribution module, the power system database each time a power distribution module of the plurality of power distribution modules is powered on.

19. The method according to claim 14 , wherein each power distribution module of the plurality of power distribution modules is identified in the power system database by a unique serial number.

20. The method according to claim 14 , wherein the power system database additionally stores a total power available from the at least one power supply.