Circuit and method for reducing voltage spikes due to magnetizing current imbalances and power converter employing the same

• US 20060152950A1
• Filed: 01/11/2005
• Published: 07/13/2006
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Acleap Power Incorporated
• Original Assignee: Tyco Electronics Power Systems Incorporated (General Electric Company)
• Inventors: Reddy, Raghothama, Wassef, Karim
• Granted Patent: US 7,372,711 B2
• Time in Patent Office: Days
• US Class Current: 363/39
• CPC Class Codes: H02M 1/15 using active elements
• CPC Class Codes: H02M 3/1555 for the generation of a regulated current to a load whose impedance is substantially inductive

Abstract

For use in a power converter having parallel power trains, a circuit for, and method of, reducing voltage spikes due to magnetizing current imbalances in the power trains and a power converter incorporating the circuit or the method. In one embodiment, the circuit includes: (1) a conductive bypass path coupling nodes between transformer secondary windings and inductors in each of the power trains and configured to provide an alternative path to redirect magnetizing current imbalances from the inductors and (2) a capacitor located in the conductive bypass path.

Claims

1. For use in a power converter having parallel power trains, a circuit for reducing voltage spikes due to magnetizing current imbalances in said power trains, comprising:

a conductive bypass path coupling nodes between transformer secondary windings and inductors in each of said power trains and configured to provide an alternative path to redirect magnetizing current imbalances from said inductors; and

a capacitor located in said conductive bypass path.

2. The circuit as recited in claim 1 wherein said nodes are coupled to center taps of said transformer secondary windings.

3. The circuit as recited in claim 1 wherein said power converter has an inverter coupled to a primary winding of a transformer.

4. The circuit as recited in claim 1 wherein said power converter has only two power trains.

5. The circuit as recited in claim 1 wherein said power converter has a DC filter on an output thereof.

6. For use in a power converter having parallel power trains, a method of reducing voltage spikes due to magnetizing current imbalances caused by transformers in said power trains, comprising:

redirecting magnetizing current imbalances from said inductors with a conductive bypass path coupling nodes between transformer secondary windings and inductors in each of said power trains; and

blocking DC currents with a capacitor located in said conductive bypass path.

7. The method as recited in claim 6 wherein said nodes are coupled to center taps of said transformer secondary windings.

8. The method as recited in claim 6 wherein said power converter has an inverter coupled to a primary winding of a transformer.

9. The method as recited in claim 6 wherein said power converter has only two power trains.

10. The method as recited in claim 6 wherein said power converter has a DC filter on an output thereof.

11. A power converter, comprising:

an inverter;

a transformer having a primary winding coupled to said inverter;

parallel power trains coupled to respective secondary windings of said transformer;

a conductive bypass path coupling nodes between said secondary windings and inductors in each of said power trains and configured to provide an alternative path to redirect magnetizing current imbalances from said inductors; and

a capacitor located in said conductive bypass path.

12. The converter as recited in claim 11 wherein said nodes are coupled to center taps of said secondary windings.

13. The converter as recited in claim 11 wherein said inductors are inductors.

14. The converter as recited in claim 11 wherein said power converter has only two power trains.

15. The converter as recited in claim 11 wherein said power converter has a DC filter on an output thereof.