Filter for a D. C. converter

• US 6,166,931 A
• Filed: 11/29/1999
• Issued: 12/26/2000
• Est. Priority Date: 11/27/1998
• Status: Expired due to Fees

• Current Assignee: Dornier GmbH (Government of France)
• Original Assignee: Dornier GmbH (Government of France)
• Inventors: Mueller, Wolfgang
• Primary Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US09/449,490
• Time in Patent Office: 393 Days
• Field of Search: 363/39, 363/40, 363/44, 363/45, 363/46, 363/47, 363/48, 363/74, 363/76, 363/77
• US Class Current: 363/46
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output

Abstract

A filter for a direct current voltage converter includes chokes L1, L2 and capacitors C1, C21. The filter is connected between the feeding source and the direct voltage converter, and an auxiliary alternating voltage source U_H connected in series with the capacitor C1 has the same alternating voltage amplitude as the interference voltage U_C1 at 180° phase angle rotation.

Claims

1. Filter for a d.c. voltage converter, the filter being connected between an input d.c. voltage source and the direct voltage converter, and comprising:

series connected chokes;

parallel connected capacitors; and

an auxiliary alternating voltage source connected in series with one of the capacitors, and having an alternating voltage amplitude which is the same as an interference voltage at a 180°

phase angle rotation.

2. The filter according to claim 1, having three L-C stages, wherein:

the auxiliary voltage source is generated by a choke and is coupled via resistors at the one of said capacitors; and

the phase angle rotation achieved by an inductive--capacitive network which, in the case of a frequency to be extinguished, is tuned to 180°

.

3. A method of suppressing an a.c. interference current in a filter for a d.c. voltage converter, having a plurality of series connected inductive elements and a plurality of parallel connected capacitive elements, comprising:

connecting an auxiliary a.c. voltage source in series with one of said capacitors, said a.c. voltage source having a frequency which is the same as a fundamental frequency of said a.c. interference current; and

shifting a phase of the auxiliary voltage source to a phase which is opposite that of the interference current.

4. An a.c. voltage generator comprising:

a d.c. voltage source;

a d.c. to a.c. converter;

a filter connected between the d.c. voltage source and the converter;

wherein the filter comprises

series connected chokes; and

parallel connected capacitors; and

an auxiliary alternating voltage source connected in series with one of the capacitors, and having an alternating voltage amplitude which is the same as an interference voltage at a 180°

phase angle rotation.