CA2321436A1 - Clamping device for a core form transformer - Google Patents

Abstract

The present invention is an improved dynamic clamping device for retaining the coil assembly of a transformer under the appropriate compressive force throughout operational lifetime of the transformer. The modular clamping device comprises a cylinder having a lower portion for engaging a first structure in the transformer and a piston moveable within the cylinder. The piston and the cylinder define an internal chamber. The piston includes an upper portion for engaging a second structure in the transformer. At least one of the first and second structures is mechanically coupled to the coil assembly. A spring is disposed within the internal chamber and contacts the piston and the cylinder. The spring forces the piston away from the cylinder. The upper portion of the piston includes a threaded rod and nut combination allowing for it to be adjusted to the appropriate height in the transformer. The device also includes a compression retaining structure for retaining the appropriate force on the spring prior to installation.

Description

CLAMPING DEVICE FOR A CORE FORM TRANSFORMER
Field Of The Invention This invention relates generally to an electrical transformer and, in particular, to an improved clamping device for retaining the windings of the transformer under the appropriate compressive force throughout the operational lifetime of the transformer.
Background of the Invention Core form power transformers generally include a containment tank, a coil and insulation assembly, a magnetic core, a static clamping system to maintain compressive forces on the magnetic core and coil and insulation assembly, and electrical conduction assemblies to connect the coils to the exterior of the tank. After assembly of the major components, the containment tank is generally filled with an electrical grade mineral oil that becomes an integral part of the electrical insulation of the transformer, as well as a heat transfer medium.
During operation, the transformer is periodically subjected to electrical and mechanical transients as a result of electrical operating contingencies that occur in the electrical power system to which the transformer is connected. One of the common contingencies on the power system is that of short circuit faults. When a short circuit fault occurs on the power system, high magnitude currents flow from the various circuits to the short circuit location. If a power transformer is connected in the circuit path of high current, the high magnitude current flows through the power transformer and generates transient mechanical forces within the transformer components.
Under the stress of short-circuit currents, the magnetic interaction between the transformer windings increases the forces tending to expand the windings axially and radially with respect to the core.
The coil and insulation assembly is one of the components subjected to the transient mechanical forces during a short circuit event. The coils are constructed from highly conductive copper or aluminum that is insulated with an electrically nonconductive material. For several decades, the prominent non-conductive material utilized in power transformers has been an electrical grade paper. Many transformers have been observed as having loose coil and insulation assemblies which has been attributed to shrinkage of the insulating paper. If the coil and insulation assembly is loose and the transformer is CHICAGO 129083v1 47090-00002 subjected to a mechanical transient, the probability of transformer failure is much higher than if the assembly were tightly held together. As such, mechanical failure of a loose coil and insulation assembly is a common failure mechanism.
As previously mentioned, the transformer includes a static clamping system which applies clamping pressure on the coil and insulation assembly. This fixed clamping system contacts the ends of the coil and insulating assembly. However, this fixed clamp does not perform the clamping function adequately over time because the insulation shrinks over a period of time. Thus, the force on the windings brought about by this fixed clamping system is reduced, or even nonexistent, such that the windings are no longer tightly secured in position.
Spring-loaded devices have also been used in the past to obtain follow-up pressure on windings. 1n these devices, the springs are often large to directly resist the high deformation forces resulting from short circuit currents. Also, in many instances, many springs are needed to perform the function.
Other dynamic clamping systems have been available in the marketplace, such as the DynaCompTM device manufactured by ABB of St. Louis, MO. However, this device is to be installed only at the time the transformer is built and is permanently attached to the clamping system. It was not designed for retrofitting existing transformers in the field.
Further, it is relatively large and requires substantial springs to perform the desired function.
Summary of the Invention The present invention is a spring-loaded dashpot device which may be retrofitted into core form transformers to reestablish the mechanical tightness of the coil and insulation assembly that was present when the transformer was manufactured.
The inventive assembly includes a set of Belleville spring washers, a movable piston, and a cylinder. A small hole in the movable piston allows the cylinder to fill with the surrounding insulating oil when it is filled into the transformer container under vacuum. A
loading rod assembly is fixed to the moveable piston and engages the fixed clamping system of the core form transformer. The cylinder is positioned against the coil and insulation assembly. Consequently, the inventive device is sandwiched between the fixed clamping system and the coil and insulation assembly.
CHICAGO 129083v1 47090-00002 During steady-state operation of the power transformer, the spring washers maintain compressive forces on the coil and insulation assembly. The spring washers are designed so as to maintain pressure throughout the transformer service life even if the paper insulation continues to shrink. The movement is slow enough so that the displacement of oil from the cylinder is not impeded by the small size of the hole in the cylinder. Follow-up expansion is based on the design and compression capability of the device and can vary up to approximately one inch.
Another major feature of the device is that it does not compress during the mechanical transient events. During these transients, it is necessary for the device to act as a rigid component rather than as a spring. Because the transient events are too short in time duration to allow sufficient oil flow through the small hole in the cylinder, the oil volume within the cylinder is an incompressible volume which prevents rapid movement of the piston which, in turn, prevents rapid expansion or compression of the spring.
Therefore, the device becomes a rigid component during transient mechanical events and the compressive force is maintained on the coil and insulation assembly.
The device is relatively small and occupies a volume less than about 150 cubic inches while delivering up to 60,000 lbs. of force. A device delivering 15,000 lbs. of force will occupy less than about 35 cubic inches. The device incorporates compression retaining bolts that hold the spring washers under the appropriate pressure when assembled. After installation in the transformer, the compression bolts are removed such that the force of the spring washers is applied to the windings. Thus, the field installation of the present invention is quite simple. In summary, this invention provides an economical solution for re-establishing the appropriate compression on the coil and insulation assembly of core form power transformers, maintaining compression, and dampening axial movement.
Brief Description Of The Drawings In the accompanying drawings:
FIG. 1 is a cross-sectional view through the dynamic coil clamping device of the present invention;
FIG. 2 is a top view of the piston of the dynamic coil clamping device of FIG.
1;
FIG. 3 is a side view of the piston of the dynamic coil clamping device of FIG. 1;
FIG. 4 is a top view of the cylinder of the dynamic coil clamping device of FIG. 1;
CHICAGO 129083v1 47090.00002 FIG. 5 is a side view of the cylinder of the dynamic coil clamping device of FIG. 1;
FIG. 6 illustrates a side view of a typical core form transformer; and FIG. 7 illustrates the transformer of FIG. 6 with the inventive coil clamping device of FIGS. 1-5 installed therein.
Detailed Description Of The Drawings Refernng initially to FIGS. 1-5, a dynamic coil clamping device 10 includes a cylinder 12 and a piston 14 positioned within the cylinder 12. The lower surface of the piston 14 and the lower interior surface of the cylinder 12 define a chamber 15. At the base of the cylinder 12 and within the chamber 15, a plurality of spring washers 16 are disposed.
The spring washers 16 (e.g. disc springs) contact the lower inner surface of the cylinder 12 and also the lower surface of the piston 14. An alignment pin 18 is positioned within the cylinder 12 and is the structure around which the spring washers 16 are placed. While the alignment pin 18 is shown as a separate piece, it could be integrally formed with the cylinder 12.
A loading rod assembly 20 is located at the upper end of the coil clamping device 10. The loading rod assembly 20 includes a threaded rod 22 around which an upper nut 24 and a lower nut 26 are threadably engaged. Due to the inherent vibration (e.g.
60 Hz) that is present in a transformer, each of the nuts 24 and 26 includes a set screw 28 that is tightened after the coil clamping device 10 is installed in the transformer as will be described in more detail with reference to FIGS. 6 and 7. The threaded rod 22 could also be integrally formed on the piston 14.
Because of the necessity of having each electrically conductive component of a transformer grounded, a spring 30 is located between the alignment pin 18 and the piston 14 to ensure that the alignment pin 18 maintains mechanical contact with either the piston 14 or the cylinder 12. The spring 30 is a steel compression spring. The cylinder 12 and piston 14 are also generally made of steel, as is the alignment pin 18.
Additionally, the components of the loading rod assembly 20 are also preferably made of steel.
The coil clamping device 10 can be made relatively small while providing a substantial amount of force, for example, up to 60,000 lbs. of force. The outer diameter of the cylinder 12 is, for example, approximately 7 to 8 inches. The height of the cylinder 12 is approximately 4 inches. Thus, it occupies about 150 cubic inches. The distance that the CHICAGO 129083v1 47090.00002 loading rod assembly 20 extends above the surface of the piston 14 in such a device is approximately two inches. A device 10 delivering 15,000 Ibs. of force would have a cylinder 12 with an outer diameter of about 4 inches and a cylinder height of 2-3/4 inches.
Thus, the device 10 delivering about 15,000 Ibs. occupies about 35 cubic inches. Its 5 loading rod would have a height of about one inch.
As shown best in FIGS. 2 and 3, the piston 14 includes an alignment recess 42 that receives the alignment pin 18. The alignment recess 42 is also the internal structure of the piston 14 that receives the spring 30.
A rod recess 44 is located in the uppermost surface of the piston 14 so as to receive the loading rod assembly 20. The rod recess 44 of the piston 14 is primarily used to center the loading rod assembly 20 on the piston 14. As shown, the rod recess 44 is not threaded.
However, the rod recess 44 could be threaded to securely hold the threaded rod 22 of the loading rod assembly 20.
The piston 14 includes a circumferential recess 45 that receives a seal 46.
The seal 46 (FIG. 1) inhibits fluid from flowing between the outer circumference of the piston 14 and the inner wall of the cylinder 12.
Around its circumference, the piston 14 also includes a plurality of tapered recesses 47. Each of the tapered recesses 47 receives a compression retaining bolt 48 as shown in FIG. 1. The compression retaining bolts 48 are threaded through correspondingly aligned threaded bores 52 in the cylinder 12, as shown in FIGS. 4 and 5. The compression retaining bolts 48 are used during the assembly process to hold the coil clamping device 10 in a steady-state force condition prior to installation. Thus, when the appropriate compression force of the spring washers 16 is achieved, the compression retaining bolts 48 are threadably inserted through the cylinder 12 and engage the piston 14 to hold the assembly in a suitable position for storage and transportation.
The piston 14 also includes a fluid conduit 60 that includes a large region 62 and a small region 64. Because this coil clamping device 10 is installed into a transformer that has insulating fluid throughout its inner workings, the coil clamping device 10 will be exposed to this insulating fluid. As such, when the transformer is vacuum oil filled with the insulating fluid (e.g. mineral oil), fluid is allowed to flow from the exterior of the piston 14 through the conduit 60 into the chamber 15 where the spring washers 16 are located.
CHICAGO 129083v1 47090-00002 The insulating fluid would also flow up along the alignment recess 42 into the region occupied by the spring 30. Including an incompressible fluid within the chamber 15 and providing the small region 64 in the conduit 60 (e.g. 0.06 inch in diameter) allows the coil clamping device 10 to act as a rigid member when the transformer is subjected to transient mechanical shocks.
The spring washers 16 may include multiple sets of washers. For example, as shown in FIG. l, the spring washer 16 includes a first set of Belleville washers 72 and a second set of Belleville washers 74 positioned around the alignment pin 18.
The dimensions of the second set of Belleville washers 74 are such that they fit within the annularly-shaped gap defined by the alignment pin 18 and the first set of Belleville washers 72 after the first set of Belleville washers 72 has been placed in the cylinder 12. Also, the spring washers 16 can be replaced by standard springs.
Referring now to FIG. 6, a core form transformer 110 is illustrated which includes a container 112 and a coil assembly 114 which is comprised of a plurality of windings of an electrically conductive wire and its associated insulation. A top coil support 116 is located above the coil assembly 114 and a support block 118 is located above the top coil support 116. Because the coil assembly 114 has a round cross-sectional shape, as does the top coil support 116, the support blocks 118 are usually placed in a circumferentially symmetric fashion around the top coil support 116. It should be noted also that the transformer 110 includes a bottom coil support similar to the top coil support 116. However, in the drawings of FIG. 6, only the top coil support 116 is shown.
The entire coil assembly 114 is held in compression by a static clamping system 120 when it is manufactured. The static clamping system 120 includes a top clamp 122 and a corresponding bottom clamp that is not shown in FIG. 6. The top and bottom clamps are connected via an axially-extending tie rod. During the assembly of a typical transformer, the static clamping system 120 is positionally adjusted so as to place the coil assembly 114 under a predetermined amount of force. To accomplish this, an appropriately sized support piece 124 is positioned on the support block 118 below the top clamp 122.
Thus, the static clamping system 120 provides a known amount of force on the coil assembly 114.
The static clamping system 120 is also used to compress a yoke assembly of the magnetic core CH1CAG0 129083v1 47090-00002 that is not shown in FIG. 6. It should be noted that in some transformers, jack screws are used instead of support pieces 124.
Because of the electromagnetic nature of the transformer 110, the top coil support 116 and the support blocks 118 are made of an electrically insulative material. Examples of such material include wood, SpaulditeTM manufactured by the Spaulding Corporation, LebaniteTM, high density pressboard manufactured by Weidmann, or PermawoodTM
manufactured by Pernali Corporation. Additionally, the support piece 124 is often a piece of wood. And as previously mentioned, the windings of the coil assembly 114 are metallic structures having an insulative material therearound. Also, the coil assembly 114 may be comprised of multiple sets of concentric windings. Between those concentric windings, the coil 114 would include axially extending electronically insulative material that is commonly referred to as "fill material." Also, the entire contents of the transformer 110 located within the container 112 are surrounded by an insulative fluid 130.
Over time, the insulative material associated with the windings of the coil assembly 114, the insulative material of the top coil support 116, and/or the material comprising the support block 118 may begin to shrink. Further, adjacent turns of the windings, which are rectangular in cross-section, may shift slightly relative to each other over time. This shifting can cause additional shrinkage in the coil assembly 114. Any shrinkage will result in less material being compressively held which inherently reduces the compressive force on the coil assembly 114. When minimal shrinkage occurs, the support piece 124 may lose contact with the top clamp 122 as shown generally at line 132 (distance not to scale) such that the coil assembly 114 is no longer being held under the compressive force of the static clamping system 120. The gap left between the top clamp 122 and the support piece 124 due to shrinkage (i.e. the distance from line 132 to the top clamp 122) is usually about 0.002 inch to about 0.003 inch. Consequently, any electrical transients that occur may cause a high magnetic force in the coil assembly 114 and result in displacement of the coil assembly 114. Such an occurrence will inevitably result in damage to the transformer 110.
The present invention as described previously with respect to FIGS. 1-5 remedies this situation when installed into the transformer 110. In particular, the coil clamping device 10 can be retrofitted into existing transformers after the aforementioned shrinkage CHICAGO 129083v1 47090-00002 occurs, which usually takes several years after the transformer 110 has been placed into the field.
When retrofitting is needed, a field service technician places a jack or jacks between the top clamp 122 and the top coil support 116 after the fluid 130 has been drained from the transformer 110. It may be possible to remove the support pieces 124 even prior to the utilization of the jacks. However, if the support pieces 124 are still being held in place, the actuation of the jacks creates a force that tends to separate the top coil support 116 from the top clamps 122, thereby allowing the support pieces 124 to be removed with ease.
Referring now to FIG. 7, once the support pieces 124 are removed and the coil assembly 114 is being compressively held by the jacks, the technician then develops a generally cylindrical shallow recess 140 in each support block 118. The shallow recess 140 has a diameter slightly larger than the diameter of the cylinder 12 and serves to hold the dynamic clamping device 10 in place on the support block 118. The technician may develop these recesses 140 with a simple cutting tool such as a chisel.
At this point, the dynamic clamping devices 10 are placed in the recesses 140.
The loading rod assembly 20 is then positioned in the rod recess 44 on the piston 14. The lower nut 26 is rotated so as to have its lower surface engage the upper surface of the piston 14.
The upper nut 24 is rotated so that its upper surface is in tight contact with the top clamp 122. The set screws 28 (FIG. 1 ) are tightened to hold the lower and upper nuts 26 and 24 in place. This process is then repeated for each dynamic clamping device 10 in the transformer 110. Finally, the compression retaining bolts 48 are removed while reducing the jack pressure such that the force of the spring washers 16 is now on the coil assembly 114. Once the force is entirely on the coil assembly 114, the jacks are removed from the transformer 110. After the installation process is complete, the container 12 of the transformer 110 is refilled under vacuum with fluid 130 which also enters the chambers 15 of each device 10 via its conduit 60 (FIG. 3).
Because the dynamic clamping device 10 will be used on a variety of types of transformers, each of which has its own unique recommended pre-load manufacturing force, the present invention contemplates providing a kit that includes several sets of dynamic clamping devices 10. For example, a first set may have four devices 10, each of which provides 40,000 Ibs. of force. Thus, this set could be used on transformers with four CHICAGO 129083v1 47090-00002 support posts 118 that require about 160,000 lbs. of force on their coil assembly 114. The device 10 allows for up to about one inch of expansion.
A second set may have four devices, each of which delivers 30,000 lbs. of force.
Together, this second set could deliver 120,000 lbs. of force. The devices of a third set may each have 25,000 lbs. of force. The invention further contemplates appropriate labeling, whether by color coding or simple alpha-numerical statements, that reflects the available force for any specific device 10.
Because of the use of the compression retaining bolts 48, the dynamic clamping device 10 can be preloaded for easy transportation. Thus, the device 10 can be shipped to manufacturers of transformers for easy placement into new transformers, in addition to the retrofitting application previously referenced. The dynamic clamping device 10 can be installed between the static clamp and top coil support, as described previously without being fixedly attached to either structure. In other words, the dynamic clamping device 10 would be sandwiched between the two structures in the newly manufactured transformer.
While the present invention has been described with reference to one or more preferred embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention which is set forth in the following claims.
CH1CAG0 129083v1 47090-00002

Claims (44)

1. A modular clamping device for applying force to a coil assembly of a core fore transformer, comprising:
a cylinder having a central axis;
a piston moveable within said cylinder in a direction generally parallel to said central axis, said piston and said cylinder defining an internal chamber;
means, located within said chamber, for delivering a predetermined force on said piston so as to move said piston away from said cylinder; and a structure for holding said piston in a position relative to said cylinder to maintain said predetermined force on said piston prior to installation of said clamping device in said core form transformer.

2. The modular transformer clamping device of claim 1, wherein each of said piston and said cylinder has a surface defining an opening, said openings being aligned and said structure extending through said openings.

3. The modular transformer clamping device of claim 2, wherein said structure is a screw and one of said surfaces includes internal threads for mating with said screw.

4. The modular transformer clamping device of claim 3, wherein said screw has a tapered end portion and said surface defining said opening in said piston has a similar taper.

5. The modular transformer clamping device of claim 1, wherein said force-delivering means includes spring washers.

6. The modular transformer clamping device of claim 1, further including a loading rod assembly contacting an upper surface of said piston.

7. The modular transformer clamping device of claim 6, wherein said upper surface includes a recess and said loading rod assembly includes a threaded rod and two nuts, said threaded rod partially residing in said recess and extending away from said upper surface, one of said nuts engaging said upper surface of said piston and the other of said nuts for engaging a surface within said transformer.

8. The modular transformer clamping device of claim 1, further including an alignment pin within said chamber, said force-delivering means being positioned around said alignment pin.

9. The modular transformer clamping device of claim 8, wherein said piston includes a central recess exposed to said internal chamber, said alignment pin extending into said central recess.

10. The modular transformer clamping device of claim 8, wherein said alignment pin is a unitary component that is independent from said piston and said cylinder.

11. The modular transformer clamping device of claim 1, wherein said device is labeled to indicate said predetermined force.

12. The modular transformer clamping device of claim 1, wherein one of said cylinder or said piston includes a fluid conduit leading into said internal chamber for permitting fluid to enter said internal chamber.

13. The modular transformer clamping device of claim 12, wherein said fluid conduit is dimensioned to substantially inhibit fluid flow therethrough when said transformer is subjected to a short-circuit condition.

14. A modular clamping device for applying force to the coil and insulation assembly of a core fore transformer, comprising:
a cylinder;
a piston moveable within said cylinder, said piston and said cylinder defining an internal chamber; and a plurality of spring washers located within said chamber and contacting said piston and said cylinder.

15. The modular transformer clamping device of claim 14, wherein said plurality of spring washers includes at least two sets of washers, a first set being located adjacent to an inner periphery of said cylinder, a second set being located within said an inner periphery of said first set.

16. The modular transformer clamping device of claim 14, wherein one of said cylinder or said piston includes a fluid conduit leading into said internal chamber for permitting fluid to enter said internal chamber.

17. The modular transformer clamping device of claim 16, wherein said fluid conduit is dimensioned to substantially inhibit fluid flow therethrough when said transformer is subjected to a short-circuit condition.

18. The modular transformer clamping device of claim 17, wherein said spring washers deliver a predetermined force to said piston, said predetermined force being maintained prior to installation by a compression retaining structure.

19. The modular transformer clamping device of claim 18, wherein said compression retaining structure includes at least one screw.

20. A modular clamping device for applying force to a coil assembly of a core fore transformer, said transformer including two structures between which said device is inserted, one of said two structures being mechanically coupled to said coil assembly, comprising:
a cylinder having a lower portion for engaging one of said two structures in said transformer;
a piston moveable within said cylinder, said piston and said cylinder defining an internal chamber, said piston including an upper structure for engaging the other of said two structures in said transformer;
a spring within said internal chamber and in contact with said piston and said cylinder, said spring forcing said piston away from said cylinder; and means for adjusting the position of at least one of said upper structure of said piston and said lower portion of said cylinder.

21. The modular transformer clamping device of claim 20, wherein said adjusting means adjusts only said upper structure of said piston.

22. The modular transformer clamping device of claim 21, wherein said upper structure of said piston includes a threaded rod assembly, said adjusting means being said threaded rod assembly.

23. The modular transformer clamping device of claim 22, wherein said threaded rod assembly includes an upper nut for engaging said other of said two structures.

24. The modular transformer clamping device of claim 23, wherein said threaded rod assembly includes a lower nut for engaging a surface on said piston assembly.

25. The modular transformer clamping device of claim 20, wherein said adjusting means adjusts in a direction substantially parallel to a central axis of said piston assembly.

26. The modular transformer clamping device of claim 20, wherein said adjusting means is entirely removable from said clamping device.

27. The modular transformer clamping device of claim 20, wherein said piston includes a fluid conduit.

28. A method of retrofitting a transformer with a clamping device for applying force to a coil assembly of said transformer, comprising:
creating a region in said transformer for receiving said clamping device, said region being defined by an upper surface and a lower surface, one of said upper and lower surfaces being mechanically coupled to said coil assembly;
applying an installation force to said coil assembly;
installing at least one of said clamping devices into said region, said clamping device including a spring assembly within a piston assembly to maintain a desired operational force on said coil assembly and a fluid conduit for receiving fluid within said piston assembly;
adjusting the height of said clamping device so that said lower and upper surfaces are properly engaged by said clamping device; and removing said installation force from said coil assembly.

29. The method of claim 28, wherein said step of creating said region includes the step of utilizing a tool to apply force to said coil assembly.

30. The method of claim 29, wherein said tool is a jack.

31. The method of claim 29, wherein said tool also applies said installation force such that said steps of creating said region and applying said installation force are accomplished by the same tool.

32. The method of claim 28, wherein said step of installing said clamping device includes the step of removing compression retaining structure from said clamping device that maintains a preloaded force on said spring assembly.

33. The method of claim 32, wherein said compression retaining structure creating are screws, and step of removing includes rotating said screws.

34. The method of claim 28, wherein said installation force and said operational force are approximately the same.

35. The method of claim 28, wherein said step of adjusting said height includes the step of rotating at least one nut around a threaded rod, said nut for engaging one of said upper and lower surfaces defining said region.

36. The method of claim 28, wherein said piston assembly includes a piston and a cylinder for receiving said piston, said spring assembly including a plurality of spring washers positioned between said piston and said cylinder.

37. The method of claim 28, wherein said transformer includes a fixed clamping system for said coil assembly, at least one of said upper and lower surfaces being a part of said fixed clamping system of said transformer.

38. The method of claim 37, wherein said step of creating said opening includes the step of removing support pieces from said fixed clamping system.

39. The method of claim 28, wherein said step of creating said region includes the step of making a recess in one of said upper and lower surfaces for receiving said clamping device.

40. A method of installing at least one dynamic clamping device into a transformer that includes a fixed clamping system which applies an initial force to both ends of said coil assembly, said dynamic clamping device assisting to maintain approximately said initial force on said coil assembly over an extended period of time, said dynamic clamping device including a piston, a cylinder which receives said piston, and a spring device for creating a force between said cylinder and said piston, said dynamic clamping device including a retaining structure for holding said spring device at a predetermined force prior to installation, said method comprising:
creating a plurality of regions adjacent to or within said fixed clamping system, each of said regions being at least partially defined by an upper surface and a lower surface, at least one of said upper and surfaces being a part of said fixed clamping system;
installing said dynamic clamping device into each of said plurality of said regions; and releasing said retaining structure from said dynamic clamping devices so as to apply said predetermined force to said coil assembly.

41. The method of claim 40, further including the step of adjusting the height of each of said dynamic clamping devices so that said lower and upper surfaces are tightly engaged.

42. The method of claim 41, wherein said step of adjusting said height includes the step of rotating at least one nut around a threaded rod, said nut for engaging said upper or lower surface.

43. The method of claim 40, wherein said steps of creating, installing and releasing take place in the field so that said transformer is being retroffited with said dynamic clamping system.

44. The method of claim 40, wherein said dynamic clamping system is non-permanently attached to said fixed clamping system.