Coupled inductor output filter

• US 8,427,120 B1
• Filed: 05/05/2011
• Issued: 04/23/2013
• Est. Priority Date: 05/05/2010
• Status: Active Grant

• Current Assignee: Wolfspeed, Inc.
• Original Assignee: Arkansas Power Electronics International, Inc. (Wolfspeed, Inc.)
• Inventors: Cilio, Edgar
• Primary Examiner(s): Han, Jessica
• Application Number:
  US13/068,229
• Time in Patent Office: 719 Days
• Field of Search: 323/222, 323/247, 323/266, 323/267, 323/328
• US Class Current: 323/266
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

The present invention is directed to a coupled inductor output filter to be used with DC/DC switched mode power supply topologies. This new output filter changes the inherent power sharing capability of most DC/DC converter topologies, enabling the overall converter to operate as a truly modular block with no inter-module communication required to accomplish power/current sharing on a multi-module configuration. The coupled-inductor output filter uses a split inductor, Lout1 and Lout2, a main output capacitor, Cout, and a DC blocking capacitor, CDC Block.

Claims

1. A coupled inductor output filter for one or more DC/DC switched mode power supplies with a power output for powering a load with a first load end and a second load end, the filter comprising:

a coupled inductor including a first inductor coupled to a second inductor;

the first inductor connected between the power output and the load;

a first capacitor connected in parallel with the load;

the second inductor connected in series with a second capacitor to form an inductor capacitor series; and

the inductor capacitor series connected in parallel with the load.

2. A method of filtering load power requirements for a load supplied by at least one DC power supply, the method comprising:

providing a coupled inductor including a first inductor and a second inductor;

connecting the first inductor in series with the load;

using the second inductor in series with a capacitor to form a high pass filter; and

connecting the high pass filter in parallel with the load such that the coupling of the inductors causes the first inductor to operate in a discontinuous mode.