Variable impedance transformer with equalizing winding

• US 5,163,173 A
• Filed: 03/29/1991
• Issued: 11/10/1992
• Est. Priority Date: 03/29/1991
• Status: Expired due to Term

• Current Assignee: Top Gulf Coast Corporation
• Original Assignee: Top Gulf Coast Corporation
• Inventors: Casagrande, Serge
• Primary Examiner(s): BEHA JR, WILLIAM
• Application Number:
  US07/677,768
• Time in Patent Office: 592 Days
• Field of Search: 323/251, 323/253, 323/249, 323/329, 323/332, 323/335, 323/338, 336/155, 336/73
• US Class Current: 323/335
• CPC Class Codes: G05F 1/335 on different cores
• CPC Class Codes: H01F 2029/143 with control winding for generating magnetic bias
• CPC Class Codes: H01F 29/146 Constructional details

Abstract

An apparatus and method is disclosed for an improved variable impedance transformer for controlling the power from an alternating input power source to a load in accordance with a direct current control signal. The invention comprises a DC control winding simultaneously wound about a plurality of saturable reactor cores and a plurality of AC power input windings simultaneously wound about a power core and each of the saturable reactor cores. A power output winding is wound about the power core for delivering power to the load. A low impedance equalizing winding is wound about the saturable reactor cores for shunting any resultant alternating voltage as a result of physical variations between the saturable reactor cores.

Claims

1. A variable impedance transformer for controlling the power from an alternating input power source to a load in accordance with a direct current control signal, comprising:

a first and second saturable reactor core;

power core means;

a first and a second power input winding being simultaneously wound about said power core means and said first and second saturable reactor cores, respectively;

means connecting said first and second power input windings in parallel across the alternating input power source for establishing a magnetic flux in said power core means and for establishing a magnetic flux in said first and second saturable reactor cores;

a power output means winding for transferring power to the load;

a control winding being simultaneously wound about said first and second saturable reactor cores for controlling saturation of magnetic flux in said first and second saturable reactor cores in accordance with the direct current control signal;

first and second saturable reactor cores and said first and second power input windings being established to substantially cancel said magnetic flux proximate said control winding leaving only a non-substantial magnetic flux proximate said control winding as a result of non-substantial physical variations between said first and second saturable reactor cores;

a low impedance equalizing winding having a plurality of turns being wound about said first and second saturable reactor cores; and

said low impedance equalizing winding having a number of equalizing winding turns that is greater than approximately six percent of the number of turns of said control winding for producing a magnetic flux proximate said control winding in a direction opposite to said non-substantial magnetic flux for reducing the voltage induced within the control winding by said non-substantial magnetic flux.

2. A variable impedance transformer as set forth in claim 1, wherein said power output winding means is wound about said power core means.

3. A variable impedance transformer as set forth in claim 1, wherein said equalizing winding is connected to a low impedance for shunting any resultant alternating voltage induced by said first and second saturable reactor cores.

4. A variable impedance transformer as set forth in claim 1, wherein said equalizing winding is shorted for shunting any resultant alternating voltage induced by said first and second saturable reactor cores.

5. A variable impedance transformer as set forth in claim 1, wherein each of said first and second saturable reactor cores and said power core means provide a closed loop for said magnetic flux.

6. A variable impedance transformer as set forth in claim 1, wherein said first and second saturable reactor cores and said first and second power input windings are substantially identical to one another for substantially canceling said magnetic flux proximate said control winding.

7. A variable impedance transformer as set forth in claim 1, wherein said power core means comprises a first power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor core;

said second power input winding being simultaneously wound about said first power core and said second saturable reactor core; and

said power output winding means comprising a first power output winding wound about said first power core.

8. A variable impedance transformed as set forth in claim 1, wherein said equalizing winding is simultaneously wound about said first and second saturable reactor cores.

9. A variable impedance transformer as set forth in claim 1, wherein said equalizing winding comprises a first and a second equalizing winding;

and

said first and second equalizing windings being wound about said first and second saturable reactor cores, respectively.

10. A variable impedance transformer for controlling the power from an alternating input power source to a load in accordance with a direct current control signal, comprising:

a first and a second saturable reactor core;

power core means;

a first and a second power input winding being simultaneously wound about said power core means and said first and second saturable reactor cores, respectively;

means connecting said first and second power input windings in parallel across the alternating input power source for establishing a magnetic flux in said power core means and for establishing a magnetic flux in said first and second saturable reactor cores;

a power output means winding for transferring power to the load;

a control winding being simultaneously wound about said first and second saturable reactor cores for controlling saturation of magnetic flux in said first and second saturable reactor cores in accordance with the direct current control signal;

said first and second saturable reactor cores and said first and second power input windings being established to substantially cancel said magnetic flux proximate said control winding;

a low impedance equalizing winding being wound about said first and second saturable reactor cores for shunting any resultant alternating voltage induced by any residual magnetic flux as a result of non-substantial physical variations between said first and second saturable reactor cores;

said power core means comprising a first and second power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor core;

said second power input winding being simultaneously wound about said second power core and said second saturable reactor core;

said means connecting said first and second power input windings across the alternating input power source establishing a magnetic flux in said first and said second power cores propagating in the same direction;

said power output winding means comprising a first power output winding wound about said first power core and a second power output winding about said second power core; and

means connecting said first and second power output windings in parallel.

11. A variable impedance transformer for controlling the power from an alternating input power source to a load in accordance with a direct current control signal, comprising:

a first and a second saturable reactor core;

power core means;

a first and a second power input winding being simultaneously wound about said power core means and said first and second saturable reactor cores, respectively;

means connecting said first and second power input windings in parallel across the alternating input power source for establishing a magnetic flux in said power core means and for establishing a magnetic flux in said first and second saturable reactor cores;

a power output means winding for transferring power to the load;

a control winding being simultaneously wound about said first and second saturable reactor cores for controlling saturation of magnetic flux in said first and second saturable reactor cores in accordance with the direct current control signal;

said first and second saturable reactor cores and said first and second power input windings being established to substantially cancel said magnetic flux proximate said control winding;

a low impedance equalizing winding being wound about said first and second saturable reactor cores for shunting any resultant alternating voltage induced by any residual magnetic flux as a result of non-substantial physical variations between said first and second saturable reactor cores;

said power core means comprising a first and second power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor core;

said second power input winding being simultaneously wound about said second power core and said second saturable reactor core;

said means connecting said first and second power input windings across the alternating input power source establishing a magnetic flux in said first and said second power cores propagating in the opposing directions;

said power output winding means comprising a first power output winding wound about said first power core and a second power output winding wound about said second power core; and

means connecting said first and second power output windings in parallel.

12. A variable impedance transformer for controlling the power from an alternating input power source to a load, in accordance with a direct current control signal, comprising:

a first and a second saturable reactor core each having a first leg and a second leg;

said first and second saturable reactor core being substantially identical to one another;

power core means having a primary leg and a secondary leg;

a first and a second power input winding each having a first end and a second end;

said first and a second power input windings being substantially identical to one another;

a power output winding means having a first end and a second end;

a control winding having a first end and a second end;

said first power input winding being simultaneously wound about said primary leg of said power core means and said first and leg of said first saturable reactor core,

said second power input winding being simultaneously wound about said primary leg of said power core means and said first and leg of said first saturable reactor core,

said power output winding means being wound around said secondary leg of said power core means transferring power to the load;

said control winding being simultaneously wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core,

means connecting said first end of said first power input winding with said first end of said second power input winding and connecting said second end of said first power input winding with said second end of said second power input winding;

means connecting said first and second power input windings to the alternating input power source for establishing a magnetic flux in said power core means and said first and second saturable reactor cores;

means for positioning said first and second saturable reactor cores for enabling said magnetic flux in said second leg of said first saturable reactor core to substantially cancel said magnetic flux in said second leg of said second saturable reactor core leaving only a non-substantial magnetic flux proximate said control winding as a result of non-substantial physical variations between said first and second saturable reactor cores;

means connecting said first and second ends of said control winding to the direct current control signal for controlling said magnetic flux in said first and second saturable reactor cores to control the saturation thereof; and

an equalizing winding having a plurality of turns being wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core; and

said equalizing winding having a number of equalizing winding turns that is greater than approximately six percent of the number of turns of said control winding for producing a magnetic flux proximate said control winding in a direction opposite to said non-substantial magnetic flux for reducing the voltage induced within the control winding by said non-substantial magnetic flux.

13. A variable impedance transformer as set forth in claim 12, wherein said power output winding means is wound about said power core means.

14. A variable impedance transformer as set forth in claim 12, wherein said equalizing winding is connected to a low impedance for shunting any resultant alternating voltage induced by said first and second saturable reactor cores.

15. A variable impedance transformer as set forth in claim 12, wherein said equalizing winding is shorted for shunting any resultant alternating voltage induced by said first and second saturable reactor cores.

16. A variable impedance transformer as set forth in claim 12, wherein each of said first and second saturable reactor cores and said power core means provide a closed loop for said magnetic flux.

17. A variable impedance transformer as set forth in claim 12, said power core means comprises a first power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor cores;

said second power input winding being simultaneously wound about said first power core and said saturable reactor core; and

said power output winding means comprising a first power output winding wound about said first power core.

18. A variable impedance transformer as set forth in claim 12, wherein said equalizing winding is simultaneously wound about said first and second saturable reactor cores.

19. A variable impedance transformer as set forth in claim 12, wherein said equalizing winding comprises a first and a second equalizing winding;

and

said first and second equalizing windings being wound about said first and second saturable reactor cores, respectively.

20. A variable impedance transformer for controlling the power from an alternating input power source to a load, in accordance with a direct current control signal, comprising:

a first and a second saturable reactor core each having a first leg and a second leg;

said first and second saturable reactor core being substantially identical to one another;

a power core means having a primary leg and a secondary leg;

a first and a second power input winding each having a first end and a second end;

said first and a second power input windings being substantially identical to one another;

a power output winding means having a first end and a second end;

a control winding having a first end and a second end;

said first power input winding being simultaneously wound about said primary leg of said power core means and said first leg of said first saturable reactor core;

said second power input winding being simultaneously wound about said primary leg of said power core means and said first leg of said second saturable reactor core;

said power output winding being wound around said secondary leg of said power core means transferring power to the load;

said control winding being simultaneously wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core;

means connecting said first end of said first power input winding with said first end of said second power input winding and connecting said second end of said first power input winding with said second end of said second power input winding;

means connecting said first and second power input windings to the alternating input power source for establishing a magnetic flux in said power core means and said first and second saturable reactor cores;

means for positioning said first and second saturable reactor cores for enabling said magnetic flux in said second leg of said first saturable reactor core to substantially cancel said magnetic flux in said second leg of said second saturable reactor core;

means connecting said first and second ends of said control winding to the direct current control signal for controlling said magnetic flux in said first and second saturable reactor cores to control the saturation thereof;

an equalizing winding being wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core for shunting any resultant alternating voltage induced by any residual magnetic flux between said second legs of said first and second saturable reactor cores due to non-substantial physical variations therebetween;

said power core means comprising a first and second power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor cores; and

said second power input winding being simultaneously wound about said second power core and said second saturable reactor core.

21. A variable impedance transformer for controlling the power from an alternating input power source to a load, in accordance with a direct current control signal, comprising:

a first and a second saturable reactor core each having a first leg and a second leg;

said first and second saturable reactor core being substantially identical to one another;

a power core means having a primary leg and a secondary leg;

a first and a second power input winding each having a first end and a second end;

said first and a second power input windings being substantially identical to one another;

a power output winding means having a first end and a second end;

a control winding having a first end and a second end;

said first power input winding being simultaneously wound about said primary leg of said power core means and said first leg of said first saturable reactor core;

said second power input winding being simultaneously wound about said primary leg of said power core means and said first leg of said second saturable reactor core;

said power output winding being wound around said secondary leg of said power core means transferring power to the load;

said control winding being simultaneously wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core;

means connecting said first end of said first power input winding with said first end of said second power input winding and connecting said second end of said first power input winding with said second end of said second power input winding;

means connecting said first and second power input windings to the alternating input power source for establishing a magnetic flux in said power core means and said first and second saturable reactor cores;

means for positioning said first and second saturable reactor cores for enabling said magnetic flux in said second leg of said first saturable reactor core to substantially cancel said magnetic flux in said second leg of said second saturable reactor core;

means connecting said first and second ends of said control winding to the direct current control signal for controlling said magnetic flux in said first and second saturable reactor cores to control the saturation thereof;

an equalizing winding being wound about said second leg of said first saturable reactor core and said second leg of said second saturable reactor core for shunting any resultant alternating voltage induced by any residual magnetic flux between said second legs of said first and second saturable reactor cores due to non-substantial physical variations therebetween;

said power core means comprising a first and second power core;

said first power input winding being simultaneously wound about said first power core and said first saturable reactor cores; and

said second power input winding being simultaneously wound about said second power core and said second saturable reactor core; and

said means connecting said first and second power input windings in parallel across the alternating input power source for establishing a magnetic flux in said power core means connects said first and said second power input windings in parallel opposition.

22. The method of reducing a residual alternating voltage across a control winding of a variable impedance transformer having a first and a second saturable reactor core and a power core means;

winding identical first and second power input windings about the power core means and the first and second saturable reactor cores, respectively;

winding a control winding about the first and second saturable reactor cores;

winding a plurality of turns of an equalizing winding about the first and second saturable reactor cores having a number of equalizing winding turns that is greater than approximately six percent of the number of turns of the control winding for producing a magnetic flux proximate the control winding in a direction opposite to the non-substantial magnetic flux for reducing the voltage induced within the control winding by the non-substantial magnetic flux; and

connecting the equalizing winding to a low impedance for producing a magnetic flux proximate the control winding in a direction opposite to the non-substantial magnetic flux for reducing the voltage induced within the control winding by the non-substantial magnetic flux.