Transformer Coupled Current Capping Power Supply Topology

• US 20130257160A1
• Filed: 04/03/2012
• Published: 10/03/2013
• Est. Priority Date: 04/03/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Harris, Shaun L., Peterson, Eric C.
• Granted Patent: US 9,450,452 B2
• Time in Patent Office: Days
• US Class Current: 307/80
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 3/33515 with digital control
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

Described is a technology by which magnetic flux is used to provide backup power. A transformer has a line power source controllably coupled to a first input winding, and secondary power source controllably coupled to a second input winding. A controller monitors the line power and switches to the secondary power source if the line power voltage drops too low, or uses the secondary power source to augment the line power source if the line power current gets too high. Also described is incrementally transitioning from the secondary power source back to the line power source.

Claims

1. A system comprising, a load transfer mechanism for a power supply, the load transfer mechanism including a transformer having a first input winding, a second input winding, and an output winding, and a controller configured to switch load between the first and second sources of power, or both, to achieve a desired output voltage corresponding to the output winding, the controller configured to monitor power supply state to determine switching of the load, including by selectively coupling the first source of power to the first input winding, or the second source of power to the second input winding, or both, based upon the power supply state.

2. The system of claim 1 wherein the controller is further configured to detect an under voltage protection state corresponding to the first source of power, and in response, to switch the load to the second source of power.

3. The system of claim 2 wherein the controller no longer detects the non-under voltage protection state corresponding to the first source of power, and wherein in response, the controller incrementally transitions at least some of the load from the second source of power to the first source of power.

4. The system of claim 3 wherein the controller is configured to incrementally transition the at least some of the load by increasing a first duty cycle corresponding to the coupling of the first source of power to the first source of power and by decreasing a second duty cycle corresponding to the coupling of the second source of power to the second source of power.

5. The system of claim 1 wherein the controller is further configured to detect an over current state corresponding to the first source of power, and in response, to switch at least part of the load to the second source of power.

6. The system of claim 5 wherein the controller no longer detects the over current state corresponding to the first source of power, and wherein in response, the controller incrementally transitions at least some of the load from the second source of power to the first source of power.

7. The system of claim 6 wherein the controller incrementally transitions the at least some of the load by increasing a first duty cycle corresponding to the coupling of the first source of power to the first source of power and by decreasing a second duty cycle corresponding to the coupling of the second source of power to the second source of power.

8. The system of claim 1 wherein the controller is further configured to control charging circuitry to recharge the second source of power.

9. The system of claim 1 wherein the load transfer mechanism is coupled to a computer system.

10. The system of claim 1 further comprising a coupling configured to provide selective coupling and decoupling of the second source of power to the load transfer mechanism.

11. The system of claim 1 wherein the first input winding corresponds to a primary side isolated from a secondary side corresponding to the output winding, and wherein the controller runs on the primary side with respect to voltage and ground.

12. The system of claim 1 wherein the first input winding corresponds to a primary side isolated from a secondary side corresponding to the output winding, and wherein the controller runs on the secondary side with respect to voltage and ground.

13. The system of claim 1 wherein the controller is coupled to a backup power source to allow the controller to operate including when no power is available from the first or second power source.

14. One or more computer-readable media having computer-executable instructions, which when executed perform steps, comprising, monitoring input voltage corresponding to power from a first power source coupled to a first input winding of a transformer, and if the input voltage drops below an under voltage protection threshold, switching to couple power from a second power source to a second input winding of the transformer.

15. The one or more computer-readable media of claim 14 further comprising, detecting that the input voltage is no longer below the under voltage protection threshold, and in response, switching to couple power from the first power source to the first input winding of the transformer

16. The one or more computer-readable media of claim 14 further comprising, monitoring current corresponding to power from the first power source, and if the current exceeds an over current state, switching to couple at least some power from the second power source to the second input winding of the transformer.

17. The one or more computer-readable media of claim 16 further comprising, detecting that the input current no longer exceeds the over current state, and in response, switching to decouple at least some of the power from the second power source to the second input winding of the transformer.

18. A method comprising, controllably coupling a first power source and a second power source through magnetic flux to provide a power supply, including automatically controlling switching mechanisms to input power from the first power source to a first transformer winding, or to input power from the second power source to a second transformer winding, or to both.

19. The method of claim 18 further comprising, monitoring a voltage level corresponding to the first power source, and controllably coupling the second power source to the second transformer winding when the voltage level is below a threshold.

20. The method of claim 18 further comprising, monitoring a current level corresponding to the first power source, and controllably coupling the second power source to the second transformer winding when the current level is above a threshold.