FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Arrangement former for multilayer winding in superconducting transformer
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Sathe Mahesh, of CG Global R&D Centre, Crompton Greaves Ltd., Kanjur (E), Mumbai 400042, Maharashtra, India, an Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention :

FIELD OF INVENTION
This invention relates to Arrangement former for multilayer winding in superconducting transformer.
BACKGROUND OF INVENTION
In prior art the conventional cylindrical former winding is difficult to do without sophisticated winding machine where as new invention eliminates the need of the sophisticated winding machine and projection for winding is provided on the former itself.
In conventional winding, winding turn lateral adjustment is essential to maintain the required winding coil length. However superconducting tape performance can be damaged with such rigid process and requires a good support to maintain its mechanical properties. Therefore, new design provides guide as well as support for each winding turn and layer and eliminates any lateral adjustments and guarantees the performance of the super conducting tape and do not affect the poperties of the tape. Conventional winding on horizontal winding machine was getting subjected to winding tensions rather some tension was required to avoid sagging of delicate HTS superconducting material tape Since the kapton insulation requirement is getting reduced due to use of formers between winding layers the kapton insulation cutting based and wrapping based waste is also getting reduced.
In HTS transformer, a normal cylindrical former was used for winding holding and conventional horizontal winding technique was used which had failed to deliver the right and correct quality of winding initially as well as after the transformer was


shifted from place to place and the need was felt to have former that shall support the winding properly and avoid the conventional horizontal winding and shall improve the cooling of winding first layer inner surface.
In the HTS super conducting tape, material thickness and width is standard which is very small hardly 0.3 mm and 4.58 mm respectively and due to this the total winding thickness in higher rating transformers having more winding layers do not exceed some few millimeters and winding height also after considering maximum winding turns was not exceeding some few millimeters and there was scope to increase the interlayer and inter turn insulation thickness which with 0.05 mm thick. Kapton insulation would have made the complete winding process more complicated and delicate and therefore the new former solution was worked out.
OBJECTS OF INVENTION
An object of the invention is to provide winding former with slits on peripheral surface allowing the liquid nitrogen a cool and insulates the HTS superconducting tape winding.
Another object of the invention is to provide winding former with helical projections on the periphery of the former for holding and guiding the winding tape during and after the winding operation and eliminating the possibility of user fiddling with the delicate HTS superconducting tape winding and assists in having error free winding.


Another object of the invention is to provide winding former with helical projections on the periphery of the former which maintains the specific spacing between the winding layers and allows cooling of the intermediate layers with liquid nitrogen.
Another object of the invention is to provide winding former allowing winding operation to take place with former and winding material spool being held vertically and without any winding tensions generation during winding.
Another object of the invention is to provide winding former with slots at the end faces allowing for winding HTS superconductor tape smooth switch over from layer to layer and maintaining the same switch over for all winding layers.
Another object of the invention is to provide winding former generating cage construction for holding winding and avoiding edge strips which are conventionally used for holding winding in place and thereby avoiding possibility of HTS tape getting damaged with edge pieces shifting and rubbing on the winding tape surface due to vibration.
Another object of the invention is to provide winding formers assembly one above the other annular to each other generating gap between layers due to helical projections on the former periphery and allowing insertion and fixing of different sensors on the intermediate surfaces of the winding for correct detection of hot spot region if required during experimentation.


Another object of the invention is to provide winding former reducing the capillary action based Liquid nitrogen soaking between the kapton insulation layers present between the layers as present in conventional winding by replacing kapton insulation between layers with former wall material having slits which opens up area below the winding tape by more than 50 % and thereby reducing down the initial thermal equilibrium achieving time.
DETAILED DESCRIPTION OF THE INVENTION
The Former is a FRP/PLASTIC component with helical slots for holding the HTS transformer winding in Place with required helical form. The former supports the winding and do not allow to deform it due to vibration or jerks. It also guides the winding material which is delicate super conducting tape while the tape is getting wound around the former and eliminates the need of counting winding turns during winding and lateral adjustments (which is undesirable as far as winding material performance guarantee is concerned.) of superconducting tape material required to maintain the required length of helically wound super conducting tape. This former also makes it possible to carry out winding operation with former and winding material spool held vertically avoiding simultaneous former and winding material spool turning torque based tensions getting generated during winding in case of conventional horizontal winding which affects the winding material performance whatsoever that has been quoted by winding material manufacturer. In vertical winding (here it is assumed that extra length of winding material is pulled over from winding material spool and with former (held vertically) rotation the winding operation takes place without any winding tensions. Since the former for each winding layer is present the winding is not suppose to seat tightly on the former


holding the former but instead is just allowed to seat over the former this again eliminates the tensions in winding and manufacturers winding material test data can be considered as base line for predicting or comparing transformer winding test results.
In addition to above the former which is carrying slits on the periphery allows the Die electric cum cooling media of HTS transformer that is Liquid Nitrogen to cool the HTS Super conducting tape effectively and avoiding possibility of any hot spot generation in the winding.
According to the present invention, winding former with slits on peripheral surface allowing the liquid nitrogen a cool and insulate the HTS superconducting tape winding.
In accordance to the present invention, winding former with helical projections on the periphery of the former for holding and guiding the winding tape during and after the winding operation and eliminating the possibility of user fiddling with the delicate HTS superconducting tape winding and assists in having error free winding.
In accordance to the present invention, winding former with helical projections on the periphery of the former which maintains the specific spacing between the winding layers and allows cooling of the intermediate layers with liquid nitrogen.
In accordance to the present invention, winding former allowing winding operation to take place with former and winding material spool being held vertically and without any winding tensions generation during winding.


In accordance to the present invention, winding former with slots at the end faces allowing for winding HTS superconductor tape smooth switch over from layer to layer and maintaining the same switch over for all winding layers.
In accordance to the present invention, winding former generating cage construction for holding winding and avoiding edge strips which are conventionally used for holding winding in place and thereby avoiding possibility of HTS tape getting damaged with edge pieces shifting and rubbing on the winding tape surface due to vibration.
In accordance to the present invention, winding formers assembly one above the other annular to each other generating gap between layers due to helical projections on the former periphery and allowing insertion and fixing of different sensors on the intermediate surfaces of the winding for correct detection of hot spot region if required during experimentation.
In accordance to the present invention, winding former reducing the capillary action based Liquid nitrogen soaking between the kapton insulation layers present between the layers as present in conventional winding by replacing kapton insulation between layers with former wall material having slits which opens up area below the winding tape by more than 50 % and thereby reducing down the initial thermal equilibrium achieving time.


Thus the former of the invention has vertical holding which eliminates winding tensions and helps in guarantying the same performance as that tested by manufacturer and further tape sagging problems also get eliminated as the tape during winding is almost vertical.