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 INVENTION
A mechanical system for protection of superconductor winding
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Sethumadhavan Thekkeveetil and Ramakichenan Vaithiyanathan, both of the Crompton Greaves Ltd., Product Technology Centre, CG Global R&D Centre, Crompton Greaves Limited, Kanjur (E), Mumbai 400042, Maharashtra, India, an Indian National
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention


The invention relates to a mechanical system for protection of superconductor winding.
In principle, transformer windings are subjected to radial and axial forces under short circuit condition. When transformer windings are made of superconductor tape, then the forces may damage the superconductor winding when adequate mechanical support is not provided. The prior arts US5107240 discloses coils that are secured to tank for withstanding radial forces thereby avoiding quenching deviation is in terms of (i) Ridges with axially-extending channel instead of perforations on former for cooling transformer (ii) No mention of Perforated former for withstanding radial forces(iii) No mention of cryogenic paste for outer surface of superconducting winding. Another prior arts WO1995024048 discloses the structural support to react all electromagnetic forces with cooling of coils Deviation is in terms of (i) Focus is on self support superconducting magnetic energy storage (SMES) system rather than perforated former on the outer surface of superconducting winding (ii) No mention of Perforated former for withstanding radial forces (iii) No mentioned of cryogenic paste for outer surface of superconducting winding. As per the literature in this technology, the mechanical support is provided to the superconductor winding by impregnating the winding by a suitable resin system. But this method will not provide adequate cooling to the winding because of complete coverage of the winding by the resin system and therefore quenching and other effects may damage the superconductor tape under short circuit or fault condition of the transformer. The radial force acting on the inner winding is automatically protected by the FRP former when the inner winding tend to move inwards, whereas the force

acting on the outer winding is not protected because this force will tend to move the outer winding outwards. The proposed invention by CG involving provision of perforated former attached to the outer surface of the superconducting winding using cryogenic paste In this particular invention, the radial forces acting on the outer-winding is prevented by means of perforated former slide down into the outer surface of the outer winding and kept in place by means of a cryogenic paste applied on to the surface of the winding. When this paste is applied continuously it will prevent the cooling of the winding from outer surface. This problem can be solved by having perforation on the former of the outer winding. Hence the cooling of the superconductor may take place from inside surface of the outer winding.
It is an object of the invention to provide a perforated former on the outer surface of the superconductor winding using cryogenic paste.
It is an object of the invention to apply cryogenic paste at regular intervals on the outer surface of the superconductor winding.
It is an object of the invention to provide perforated former on the outer winding of superconductor transformer.
A mechanical system for protection of superconductor winding of this invention discloses that the radial forces acting on the outer-winding is prevented by means of perforated former slide down into the outer surface of the outer winding and kept in place by means

of a cryogenic paste applied on to the surface of the winding. When this paste is applied continuously it will prevent the cooling of the winding from outer surface. This problem can be solved by having perforation on the former of the outer winding. Hence the cooling of the superconductor may take place from inside surface of the outer winding.
The invention is described in detail herein , a partial cross-sectional view of the winding assembly of a superconducting transformer along with a perforated former on the outer surface of the winding and a cryogenic paste is applied at regular intervals to enhance cooling of the superconductor winding according to an embodiment of the invention. The winding assembly comprises a plurality of layers of inner winding and a plurality of layers of outer winding made of superconducting material wire that are wound on non-magnetic material inner winding and outer winding formers and respectively. A perforated former is placed on the outer winding of the superconductor transformer by using cryogenic paste in such a way to enhance cooling of the winding. In this particular invention, the radial forces acting on the outer-winding is prevented by means of perforated former slide down into the outer surface of the outer winding and kept in place by means of a cryogenic paste applied on to the surface of the winding. When this paste is applied continuously it will prevent the cooling of the winding from outer surface. This problem can be solved by having perforation on the former of the outer winding. Hence the cooling of the superconductor may take place from inside surface of the outer winding.

In accordance to the present invention, a mechanical system for protection of superconductor winding comprises a perforated former provided on the outer winding of the superconductor transformer, said former is attached to the outer winding of the transformer by means of cryogenic paste
In accordance to the present invention, said former placed on the outer winding of the superconductor transformer to prevent the radial forces acting on the outer winding.
In accordance to the present invention, said former placed on the outer winding is having perforation to enhance cooling of the winding.
In accordance to the present invention, said perforated former placed on the outer winding using cryogenic paste to provide bondage between superconductor winding and former.
Dated this 18th day of March 2009
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