POWER SUPPLY SYSTEM WITH DYNAMIC FILTERING

• US 20140126253A1
• Filed: 07/20/2011
• Published: 05/08/2014
• Est. Priority Date: 07/20/2011
• Status: Abandoned Application

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Humphrey, Daniel, Bemat, Mohamed Amin, Trace, Mark
• Application Number:
  US14/127,950
• Publication Number:
  US 20140126253A1
• Time in Patent Office: Days
• US Class Current: 363/44
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power supply system (10) and method (150) are disclosed. The system (10) includes a power converter (16) to provide an output voltage to a load (12) based on an input voltage that is generated from an AC supply voltage. The system (10) also includes a power monitor (16) to monitor the load (12). The system (10) further includes a filter stage (14) to dynamically filter high frequency currents generated by the power converter (16) from the AC supply voltage to substantially maximize a power factor associated with the power supply system (10).

Claims

1. A power supply system (10) comprising:

a power converter (16) to provide an output voltage to a load (12) based on an input voltage that is generated from an AC supply voltage;

a power monitor (18) to monitor a condition of the load (12); and

a filter stage (14) to dynamically filter high frequency currents generated by the power converter (16) from the AC supply voltage based on the condition of the load (12) to substantially maximize a power factor associated with the power supply system (10).

2. The system of claim 1, further comprising a controller (20) to receive a load signal indicative of the load (12) from the power monitor (18) and to control a capacitance of the filter stage (14) based on the load (12) and based on a specification.

3. The system of claim 2, wherein the filter stage (14) comprises an electromagnetic interference filter (EMI) filter stage (14), the EMI filter stage (14) comprising a switch (22) and a capacitor coupled in series, the controller (20) to decouple the EMI filter capacitor via the switch (22) in response to a light-load condition.

4. The system of claim 2, wherein the filter stage (14) comprises a plurality of switches (22) that are coupled in series to a respective plurality of capacitors, the controller (20) being to selectively decouple the plurality of capacitors via the respective plurality of switches (22) based on the load (12).

5. The system of claim 4, wherein each of the plurality of capacitors has a unique capacitance value.

6. The system of claim 4, wherein the input voltage is a DC voltage, and wherein the filter stage (14) comprises a rectifier (52) to convert the AC supply voltage into a DC input voltage.

7. The system of claim 6, wherein a first portion of the plurality of switches (22) and the plurality of capacitors is arranged at an input of the rectifier (52) and a second portion of the plurality of switches (22) and the plurality of capacitors is arranged at an output of the rectifier (52).

8. The system of claim 1, wherein the power converter (16) is configured as a power factor correcting power converter (104).

9. A power supply system (10) comprising:

a power converter (16) to provide an output voltage to a load (2) based on an input voltage that is generated from an AC supply voltage;

a power monitor (18) to monitor a load condition of the load (12);

an EMI filter stage (14) comprising a plurality of switches (22) coupled in series with a respective plurality of capacitors to filter the AC supply voltage; and

a controller (20) to selectively activate and deactivate the plurality of switches (22) to dynamically control a capacitance of the EMI filter stage (14) based on the load condition and based on a specification to substantially maximize a power factor associated with the power supply system (10).

10. The system of claim 9, wherein each of the plurality of capacitors has a different capacitance value.

11. The system of claim 9, wherein the input voltage is a DC voltage, and wherein the EMI filter stage (14) comprises a rectifier (52) to convert the AC supply voltage into the DC voltage.

12. The system of claim 9, wherein the power converter (16) is configured as a power factor correcting power converter (104).

13. A method (150) for dynamically providing EMI filtering in a power supply system (10), the method comprising:

providing an output voltage to a load (12) based on an input voltage that is generated from an AC supply voltage;

quantifying a load condition;

determining if the quantified load condition corresponds to a full-load condition or a light-load condition;

activating a switch (22) to couple a capacitor to an EMI filter stage (14) in the full-load condition, the EMI filter stage (14) arranged to filter high frequency currents to the AC supply voltage; and

deactivating the switch (22) to decouple the capacitor from the EMI filter stage (14) in the light-load condition.

14. The method of claim 13, wherein activating the switch (22) comprises activating a plurality of switches (22) to couple a respective plurality of capacitors to an EMI filter stage (14) in the full-load condition, and wherein deactivating the switch (22) comprises selectively deactivating the plurality of switches (22) to selectively decouple the respective plurality of capacitors from the EMI filter stage (14) in the light-load condition based on the magnitude of the load (12).

15. The method of claim 14, further comprising converting the input voltage to the output voltage by a power converter (16).