Low level ground conditioning (gcl)

• US 5,781,386 A
• Filed: 07/30/1996
• Issued: 07/14/1998
• Est. Priority Date: 06/05/1995
• Status: Expired due to Term

• Current Assignee: Powervar, Inc. (Ametek Incorporated)
• Original Assignee: Powervar, Inc. (Ametek Incorporated)
• Inventors: Muelleman, Norman F.
• Primary Examiner(s): Gaffin, Jeffrey A.
• Assistant Examiner(s): SHERRY, MICHAEL JUDE
• Application Number:
  US08/692,928
• Time in Patent Office: 714 Days
• Field of Search: 361/111, 361/58, 361/42, 361/43, 361/45, 361/46, 361/49, 361/50, 361/56
• US Class Current: 361/43
• CPC Class Codes: H02H 9/005 avoiding undesired transient conditions

Abstract

The present invention relates to suppressing transient impulses in a power distribution system and more particularly to a device and method for suppressing transient impulses at frequencies which exceed the power frequencies while maintaining an acceptable "safety" impedance level at the power frequencies.

Claims

1. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located between an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

a resistor connected in parallel with said inductor means between said input and said output terminals of the ground wire;

whereby said inductor means and said resistor isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line, and

wherein said coupling of said surge current to the ground line is an injection coupling whereby an electronic device is coupled between the power line and the ground line and said device supplies said surge current.

2. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located between an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

a resistor connected in parallel with said inductor means between said input and said output terminals of the ground wire;

whereby said inductor means and said resistor isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line, and

wherein said coupling of said surge current to the ground line is an injection coupling whereby an electronic device is coupled between an external wiring system and the ground line and said device supplies said surge current.

3. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located between an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

a resistor connected in parallel with said inductor means between said input and said output terminals of the ground wire;

whereby said inductor means and said resistor isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line, and

wherein said coupling of said surge current to the ground line is a transmission coupling from a remote source of electromagnetic radiation which remote source induces said surge current in the ground line.

4. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling in the power distribution system with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

whereby said inductor means isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line;

said impedance being low level ground conditioning (GC_L) which operates within the impedance of 0.1 Ω

or less for currents more than 25 A at 2.5 VAC;

said device having a transformer based power supply circuit;

said transformer based power supply circuit having a primary side ground line and a secondary side ground line;

said device being operatively connected to said secondary ground line;

said device having an isolation transformer based power supply circuit;

said isolation transformer based power supply circuit having a primary side ground line and a secondary side ground line;

said ground conditioning device being operatively connected to said primary ground line and a second ground conditioning device being operatively connected to said secondary ground line.

5. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling in the power distribution system with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

whereby said inductor means isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line;

said impedance being low level ground conditioning (GC_L) which operates within the impedance of 0.1 Ω

or less for currents more than 25 A at 2.5 VAC.

6. A device for suppressing transient currents on a ground line of a power distribution system, the power distribution system having a power line and a neutral line, the device comprising:

inductor means for attenuating a surge current propagating on the ground line, said inductor means located an input terminal and an output terminal of the ground line, said surge current being supplied to the ground line by a coupling in the power distribution system with the ground line, said inductor means having a primary winding on a saturable core of a predetermined inductive reactance value; and

whereby said inductor means isolate the ground line from the power line between said input and said output terminals of the ground wire thereby forming a ground impedance for suppressing transient currents on the ground line;

said impedance having low level ground conditioning (GC_L) which operates within the impedance of 0.1 Ω

or less for currents more than 25 A at 2.5 VAC

said device having an earth ground and a neutral-ground bond;

said impedance being connected to said ground line on the output side of said neutral-ground bond.