REGULATING POWER TRANSFORMER WITH MAGNETIC SHUNT

• US 3,622,868 A
• Filed: 02/06/1970
• Issued: 11/23/1971
• Est. Priority Date: 02/06/1970
• Status: Expired due to Term

• Current Assignee: Joachim H. Todt
• Original Assignee: Joachim H. Todt
• Inventors: Todt, Joachim H.
• Primary Examiner(s): Goldberg, Gerald
• Application Number:
  US05/009,143
• Time in Patent Office: 655 Days
• Field of Search: 323/6,44,56,57,58,62,89,89C,92 336/155,160 330/8
• US Class Current: 323/250
• CPC Class Codes: H01F 2029/143 with control winding for generating magnetic bias
• CPC Class Codes: H01F 29/146 Constructional details

Abstract

A regulating power transformer consisting of a primary winding and a secondary winding positioned coaxial on the center leg of an E-type stack of magnetic lamination pack which is separated by a layer of I-type laminations having two coils wound thereon, the latter fitting into the windows of the E-type lamination. The Itype laminations provide the function of the magnetic shunt for the flux generated by the primary coil and serve as the magnetic coupling between the E-type laminations on the primary side of the transformer and identical E-type laminations on the secondary side of the transformer. Saturation of the shunt path to various degrees through control of the excitation of the coils mounted on the I-type laminations varies the amount of bypassed or shunted magnetic flux making it available at the secondary coil in a substantially linear proportion to the DC excitation. The transformer uses less iron, is faster in response than conventional regulating transformers and has an improved output wave form.

Claims

1. A regulating power transformer comprising, a magnetic circuit having a principal flux path of substantially uniform cross section defined by a pair of symmetrical core members providing at least a pair of gaps therein separating the circuit into two portions, a magnetic shunt positioned in the gaps and abutting the core members to be held therebetween and having its principal flux path positioned normal to the flux path of the magnetic circuit, the flux path of the magnetic shunt having a cross section substantially reduced from the cross section of the principal flux path, a primary winding positioned on one portion of the magnetic circuit and adapted to be connected to an alternating current source of power, a control winding positioned on the magnetic shunt and distributed thereon such that no alternating current is induced in the control winding from alternating current flux in the magnetic circuit, said control winding being adapted to be connected to an adjustable direct current source of power to control magnetic saturation of the magnetic shunt, and a secondary winding positioned on the other portion of the magnetic circuit and inductively coupled to the primary winding, said secondary winding having a regulated alternating current induced therein.

2. The regulating power transformer of claim 1 in which the portions of the magnetic circuit are formed by stacked E-shaped laminations held together in abutting relationship with the magnetic shunt bridging the same.

3. The regulating power transformer of claim 2 in which the magnetic shunt is formed by stacked I-shaped laminations positioned normal to the E-shaped laminations.

4. The regulating power transformer of claim 1 in which the portions of the magnetic circuit are formed by pairs of C-shaped laminations in stacked relationship and held together in assembled relationship abutting the magnetic shunt.

5. The regulating power transformer of claim 3 in which the primary and secondary windings are preformed coils positioned on the center legs of the opposed E-shaped laminations.

6. The regulating power transformer of claim 4 in which the primary and secondary windings are preformed coils positioned over adjacent legs of the C-shaped laminations defining the main flow path through the transformer.

7. The regulating power transformer of claim 2 in which the magnetic circuit with the principal flux path of substantially uniform cross section is formed by making the center leg of the E-shaped lamination substantially twice the width dimension as the outside legs.

8. The regulating power transformer of claim 3 in which the stacked I-shaped laminations forming the magnetic shunt vary in ratio in cross section of from 5 to 20 percent of the cross section of the principal flux path defined by the center legs of the core members.

9. The regulating power transformer of claim 1 in which the control winding on the magnetic shunt is a pair of coils connected in opposition such that any alternating emf developed therein with alternating flux flow through the magnetic shunt flux path will cancel out.

10. The regulated power transformer of claim 9 in which the control windings are preformed and mounted on the magnetic shunt and connected in a series circuit without the polarity terminals of the coils being connected in common and with the coils being positioned between and within the core members of the magnetic circuit.

11. ThE regulated power transformer of claim 5 in which the control winding on the magnetic shunt is a pair of preformed coils connected in a series circuit and with opposite polarity terminals in common and adapted to be connected to a controlled DC source of power.

12. The regulated power transformer of claim 1 and including a feed back circuit means controlling the energization of the DC control winding in proportion to a characteristic of the output taken from the secondary winding.

13. The regulated power transformer of claim 12 in which the output characteristic of the secondary winding to which the energization of the DC winding is to be controlled may be current, voltage or power.

14. The regulated power transformer of claim 11 and including means for holding the stacked E-shaped laminations and the magnetic shunt in assembled relationship.

15. The regulated power transformer of claim 1 in which the magnetic circuit is formed by two E-shaped core members having a central leg and a pair of side legs positioned so that the legs align and with straight bar sections of the same cross section as the legs aligned therewith to define two sets of gaps, and in which the magnetic shunt is a pair of magnetic shunts positioned across each of the sets of gaps and between the E-shaped core members and the straight bar portions in contact with the same, and including a pair of control windings positioned on each magnetic shunt and connected in series circuit with opposite polarity terminals in common and with the pairs of control windings on the pairs of magnetic shunt being connected in series circuit and to a regulating DC source of power and in which the primary winding includes a primary winding on each of the central legs of the E-shaped core members and adapted to be connected to an alternating source of power with the respective windings being connected to sources of power 180* out of phase with one another and with the secondary winding being positioned on the straight bar section aligned with the central legs of the core members.

16. The regulating power transformer of claim 1 in which the direct current source is a pulsating direct current source which is variable with respect to the phase of the alternating current and variable in magnitude such as to produce a regulating control over the output of the secondary.

17. The regulating power transformer of claim 16 in which the DC regulating source has a complex wave shape to modify the alternating current wave shape generated in the secondary winding.

18. The regulating power transformer of claim 1 in which the primary and secondary windings positioned on the principal flux path of the magnetic circuit are distributed over various portions of the same.

19. The regulating power transformer of claim 1 in which the primary and secondary windings are electrically connected to provide an auto-transformer configuration.

20. The regulating power transformer of claim 1 in which the magnetic circuit and the magnetic shunt are made of magnetic materials having different magnetic permeability.

21. A regulating power transformer comprising, a pair of E-shaped core members each formed by a stack of E-shaped magnetic laminations positioned together in near abutting relationship, a layer of I-type laminations positioned in abutting contact with the E-shaped core members and separating the same, a primary and a secondary winding positioned coaxial of the center legs of the E-shaped core members and separated by the I-type laminations with the primary winding being adapted to be connected to an alternating current source of power, a pair of coils positioned around the I-type laminations fitted into the windows of the E-shaped core members in near abutting relationship and adapted to be connected to an adjustable direct current source of excitation, said I-shaped laminations serving as a magnetic shunt for the flux generated by the primary coil and as a coupling between the E-Shaped core members, circuit means energizing the coils on the I-type laminations to saturate the shunt path reducing the amount of bypassed alternating magnetic flux generated by the primary winding and directing it through the secondary winding in a direct proportion to the direct current excitation of the coils on the magnetic shunt.

22. The regulating power transformer of claim 21 in which the I-type laminations provide a magnetic path between the E-type cores and a shunt path between said cores with this shunt path being traversed by two sets of magnetic fluxes essentially perpendicular to one another with one of said fluxes being of controlled magnitude and fixed direction and the other perpendicular to it and of alternating fluctuation and of essentially constant magnitude, the alternating flux being varied by fluctuations in the energization of the primary winding and additionally altered by fluctuations in the load connected to the secondary winding with said output response in the secondary winding being substantially instantaneous due to change in flux direction being only a 90* angle.

23. The regulating power transformer of claim 22 in which the I-shaped laminations have a plurality of pairs of exciting coils mounted on the I-shaped laminations for controlling the flux flow through the shunt path with each pair of coils being adapted to be connected to separate energization circuits.

24. The regulating power transformer of claim 22 in which the number of magnetic shunts are two and a pair of primary windings connected to separate alternating current source 180* phase angle apart are positioned thereon with a secondary coil positioned in between the magnetic shunts and with the magnetic shunts having separate pairs of energization coils thereon such that phase angle output in the secondary coil may be varied by simultaneously increasing and decreasing the magnitudes of the DC control excitation in the respective coil pairs on the magnetic shunts.

25. The regulating power transformer of claim 21 in which the magnetic shunt formed by the I-shaped laminations may be made of a magnetic material different than the laminations forming the E-shaped core.

26. The regulating power transformer of claim 21 in which the adjustable direct current source of excitation is a pulsating direct current source which is adjustable in magnitude and phase angle with respect to the alternating current source of power connected to the primary winding.

27. The regulating power transformer of claim 26 in which the direct current source of excitation is a pulsating direct current source having a complex wave form adapted to modify the alternating current wave shape generated by the secondary winding.