Three-phase ferroresonant transformer structure embodied in one unitary transformer construction

• US 4,274,071 A
• Filed: 11/16/1979
• Issued: 06/16/1981
• Est. Priority Date: 11/16/1979
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Pfarre, Edgar L.
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US06/095,094
• Time in Patent Office: 578 Days
• Field of Search: 336/155, 336/160, 336/165, 336/212, 336/213, 336/214, 336/215, 336/5, 336/10, 336/12, 323/48, 323/49
• US Class Current: 336/12
• CPC Class Codes: G05F 3/06 using combinations of saturated and unsaturated inductive devices, e.g. combined with resonant circuit

Abstract

A three-phase transformer structure has a double-window magnetic structure with an independent flux path encircling each window and an outer flux path encircling both windows. A shunt path for the outer flux path bridges both windows and two additional shunt paths bridge each window independently. Hence, each flux path has an independent and isolated shunt permitting operation of the three-phase transformer in a ferroresonant mode.

Claims

1. A three-phase ferroresonant transformer structure comprising;

a first and second closed flux path positioned adjacent each other and encircling a first and second window;

a third closed flux path encircling said first and second closed flux paths;

first and second magnetic shunts joining opposite portions of the first and second closed flux paths and bridging the first and second windows;

respectively

a third magnetic shunt joining opposite portions of the third closed flux path and bridging the first and second windows; and

said first, second and third magnetic shunts each being independent and isolated from the other two magnetic shunts and magnetically coupled only to its related magnetic shunt path.

2. A three-phase ferroresonant transformer structure as defined in claim 1 wherein;

said first and second directed flux paths are constructed of tape wound magnetic cores each comprising;

two abutting cut C-type structures of concentrically wound tape of magnetic material and positioned adjacent within the third closed flux path;

said third closed flux path also comprising a tape wound magnetic core constructed of two abutting cut C-type structures of concentrically wound tape of magnetic material so that the first and second flux paths are nested within a clear open area encircled by the third flux path;

whereby the third flux path encircles the first and second flux paths including the first and second windows.

3. A three-phase ferroresonant transformer structure as defined in claim 2 wherein;

said first and second magnetic shunts comprise;

a first and second construction of sheet laminations of magnetic material each arranged to have their edges abutted against the edges of the wound magnetic tape core of the first and second flux paths, respectively and abutting contact thereto constricted to connect only to their respective first and second magnetic flux paths; and

said third magnetic shunt comprising a third construction of sheet laminations and having the edges thereof abutting against edges of the wound magnetic tape of the third magnetic flux path only.

4. A three-phase transformer as defined in claim 3 wherein;

each of the first, second and third magnetic shunts having a similar and oppositely positioned magnetic shunt structure of likewise construction coupled to the opposite side of the magnetic transformer core and bridging the same identical window arrangement.

7. A three-phase ferroresonant transformer structure as defined in claim 1, wherein said first, second and third flux paths are constructed of a main transformer structure including two identical E-type structures each constructed of three C-shape cut tape wound cores as component parts, two smaller C-shape cores being nested within a larger C-shape core to form E-type structures and two E-type structures abutted together to form a three leg magnetic transformer structure enclosing said first and second windows and including the said first, second and third flux paths, the first and second flux paths each encircling a different one of the first and second windows and the third flux path encircling both the first and second windows.

the first, second and third magnetic shunts each comprised of sheet laminations, and edges of the sheet laminations of the first, second and third magnetic shunts abutting tape edges of a related one of the first, second and third magnetic flux path structures.

8. A three-phase ferroresonant transformer structure as defined in claim 7 wherein;

input windings are y-connected and a winding in each phase is coupled to two magnetic paths and output windings are y-connected and a winding in each phase is split and couples two magnetic paths to form a six-phase output arrangement.

5. A three-phase ferroresonant transformer structure comprising;

a main transformer structure including two identical E-type structures each constructed of three C-shape cut tape wound cores as component parts, two smaller C-shape cores being nested within a larger C-shape core and the two E-type structures abutted together to form a three leg magnetic transformer structure having two windows and first, second and third well defined magnetic flux path structures, the first and second flux path structures each encircling a different one of the two windows, and the third flux path structure encircling both the two windows;

first, second and third magnetic shunts each constructed of sheet lamination;

said first, second, and third magnetic shunts each bridging windows encircled by said first, second, and third magnetic flux paths, respectively; and

edges of the sheet laminations of the first, second and third magnetic shunts abutting tape edges of a related one of the first, second, and third magnetic flux path structure.

6. A three-phase ferroresonant transformer structure as defined in claim 5 wherein;

input windings are y-connected and a winding in each phase is coupled to two magnetic paths and output windings are y-connected and a winding in each phase is split and couples two magnetic paths to form a six-phase output arrangement.