AC power line filter

• US 6,985,370 B2
• Filed: 09/22/2003
• Issued: 01/10/2006
• Est. Priority Date: 05/24/2002
• Status: Expired due to Fees

• Current Assignee: David Kerstetter
• Original Assignee: David Kerstetter
• Inventors: Kerstetter, David
• Primary Examiner(s): Vu, Bao Q.
• Application Number:
  US10/667,962
• Publication Number:
  US 20040090803A1
• Time in Patent Office: 841 Days
• Field of Search: 363/44, 363/39, 307/105
• US Class Current: 363/39
• CPC Class Codes: H02M 1/126 using passive filters

Abstract

A parallel resonant circuit for removing noise and harmonic frequencies from the AC power source is connected directly in parallel to a power source with no intervening electrical components. The parallel resonant circuit is comprised of at least one inductor for drawing an inductive current that is substantially equal to but one hundred and eight degrees out of phase with at least one capacitor that draws a capacitive current. The capacitors and the inductors of the parallel resonant circuit are connected in parallel and may be tuned to the fundamental frequency of the power line.

Claims

1. A circuit for correcting perturbations in a power system signal operating at a system line frequency said circuit comprising:

at least one capacitive element for drawing a capacitive current;

at least one inductive element for drawing an inductive current substantially equal in amplitude and substantially one hundred eighty degrees out of phase with said capacitive current;

said at least one inductive element connected in parallel with said at least one capacitive element to form a parallel resonant circuit;

said parallel resonant circuit is tuned to resonate at said system line frequency and is connected in parallel directly across a power source with no intervening electrical components between said power source and said parallel resonant circuit;

said parallel resonant circuit has circulating currents of substantially the same amplitude as a load current, wherein said parallel resonant circuit absorbs voltage perturbations in excess of the amplitude of said power system signal at all frequencies above and below said system line frequency and wherein said parallel resonant circuit provides energy to restore notches in the amplitude of said power system signal at all frequencies above and below said system line frequency.

2. A circuit as claimed in claim 1, where said parallel resonant circuit is a stand-alone device.

3. A circuit as claimed in claim 1, where said parallel resonant circuit is part of a power inlet system.

4. A circuit as claimed in claim 1, where said power system is a single phase unit.

5. A circuit as claimed in claim 1, where said power system is a three-phase unit.

11. A circuit as claimed in claim 1, wherein said parallel resonant circuit is directly coupled with a load with no intervening component.

6. A filtering circuit, comprising:

a plurality of capacitive elements coupled in parallel;

at least one inductor connected in parallel to said plurality of capacitive elements to form a filter circuit;

a reactive impedance of said at least one inductor and a combined reactive impedance of said plurality of capacitive elements set substantially equal in value and one hundred and eighty degrees out of phase and tuned to resonate at a frequency value equal to a fundamental frequency value of a parallel connected power source with no intervening components connected between said power source and said filtering circuit.

7. A circuit as claimed in claim 6, where said filtering circuit is a stand-alone device.

8. A circuit as claimed in claim 6, where said filtering circuit is part of a power inlet system.

9. A circuit as claimed in claim 6, where said power system is a single phase unit.

10. A circuit as claimed in claim 6, where said power system is a three-phase unit.

12. A circuit as claimed in claim 6, wherein said parallel resonant circuit is directly coupled with a load with no intervening component.