Power distribution system and power distribution method thereof

Abstract

A power distribution system includes a current-sharing bus, a plurality of power supplies, and a controller. The plurality of power supplies are interconnected via the current-sharing bus. The controller is coupled to a plurality of input terminals of the plurality of power supplies. The controller detects the input voltage of each power supply, determines its power rating based on the input voltage, and provides a corresponding output power control signal to each power supply according to its power rating. Each power supply receives the corresponding output power control signal and the average voltage on the current-sharing bus, adjusts its output current according to the output power control signal, and provides output power to the load according to the output current. The output power of the power supply is determined according to the ratio between the power ratings.

Claims

1. A power distribution system comprising: a current sharing bus; a plurality of power supplies interconnected via the current sharing bus; and a controller coupled to a plurality of input terminals of the power supplies for detecting a plurality of input voltages of the power supplies, determining a plurality of power specifications of the power supplies based on the input voltages, and providing each of the power supplies with a corresponding output power control signal according to the power specifications, wherein the power supplies receive the corresponding output power control signals and an average voltage on the current sharing bus, adjust a plurality of output currents according to the output power control signals and the average voltage, and provide a plurality of output powers to a load according to the output currents, wherein the output powers of the power supplies are determined according to a ratio between the power specifications.

2. The power distribution system as claimed in claim 1, wherein each of the power supplies comprises: a DC-DC converter for converting the input voltage into an operating voltage and generating the output current; an output power control unit coupled to the DC-DC converter for receiving the operating voltage, the output current, and the output power control signal, generating an output voltage, and adjusting the output voltage according to a logic level of the output power control signal; and a current sharing circuit coupled to the output power control unit for receiving the operating voltage from an input terminal of the output power control unit, receiving the output voltage from an output terminal of the output power control unit, and adjusting the output current of one of the power supplies according to a voltage difference between the operating voltage and the output voltage.

3. The power distribution system as claimed in claim 2, wherein the current sharing circuit is coupled to the current sharing bus; and in response to the voltage difference between the operating voltage and the output voltage being less than the average voltage on the current sharing bus, the current sharing circuit outputs a compensation voltage to the DC-DC converter, causing the DC-DC converter to increase the output current.

4. The power distribution system as claimed in claim 2, wherein the output power control unit comprises: a first resistor having a first terminal for receiving the operating voltage and a second terminal having the output voltage; a second resistor selectively coupled in parallel to the first resistor; and a switching circuit coupled to a first terminal of the second resistor and configured to receive the output power control signal, wherein the switching circuit is turned on according to the logic level of the output power control signal, wherein in response to the switching circuit being turned on, the first resistor and the second resistor are coupled in parallel to reduce an equivalent resistance value between the input terminal and the output terminal of the output power control unit, thereby making the voltage difference between the operating voltage and the output voltage less than the average voltage on the current sharing bus.

5. The power distribution system as claimed in claim 1, wherein the power distribution system has a hot-swap function, the hot-swap function being used to enable the power supplies to adjust their output power immediately when the number of power supplies changes.

6. A power distribution method applicable to a power distribution system, wherein the power distribution system includes a current sharing bus, a plurality of power supplies, and a controller, the power distribution method comprising: detecting a plurality of input voltages of the power supplies; determining a plurality of power specifications of the power supplies based on the input voltages; providing a corresponding output power control signal to each of the power supplies according to the power specifications; and receiving the corresponding output power control signals and an average voltage on the current sharing bus through the power supplies, adjusting a plurality of output currents according to the output power control signals, and providing a plurality of output powers to a load according to the output currents, wherein the output powers of the power supplies are determined according to a ratio among the power specifications.

7. The power distribution method as described in claim 6, wherein each of the power supplies includes a DC-DC converter, an output power control unit, and a current sharing circuit, the power distribution method further comprising: converting the input voltage into an operating voltage and generating the output current through the DC-DC converter; generating an output voltage through the output power control unit and adjusting the output voltage according to a logic level of the output power control signal; and receiving the operating voltage from an input terminal of the output power control unit and the output voltage from an output terminal of the output power control unit through the current sharing circuit, and adjusting the output current of one of the power supplies according to a voltage difference between the operating voltage and the output voltage.

8. The power distribution method as claimed in claim 7, further comprising: in response to the voltage difference between the operating voltage and the output voltage being less than the average voltage on the current sharing bus, causing the current sharing circuit to output a compensation voltage to the DC-DC converter, and causing the DC-DC converter to increase the output current.

9. The power distribution method as claimed in claim 7, wherein the output power control unit includes a first resistor, a second resistor, and a switching circuit, the power distribution method further comprising: in response to the switching circuit being turned on, coupling the first resistor and the second resistor in parallel, and reducing an equivalent resistance value between the input terminal and the output terminal of the output power control unit, thereby making the voltage difference between the operating voltage and the output voltage less than the average voltage on the current sharing bus.

10. The power distribution method as described in claim 6, further comprising: performing a hot-swap function, wherein the hot-swap function is used to enable the power supplies to adjust their output power in real time when the number of power supplies changes.

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