Electrical Bushing For High Voltage Application With Carbon Fibre As

Electrical Bushing For High Voltage Application With Carbon Fibre As Stress Grading Layer

Abstract: The invention relates to a process for fabricating/Impregnating a paperless electrical bushing for high voltage electrical application, the electrical bushing having at least one electrical copper conductor surrounded by a core material, the core comprising a sheet-like spacer, a plurality of equalization elements in appropriate radial positions from the center of the conductor, and having electrically conductive or semi-conductive layers, which layers having multitude holes/openings, to allow the matrix material to penetrate, and application of the equalization elements to the core separately from the spacer, the process comprising the steps of winding the core with a sheet like spacer in spiral form around an axis of the copper conductor, so as to form a multitude of neighboring layers, the axis being defined through the shape of the conductor; impregnating the core with said sheet like spacer and said equalization elements with a known un-filled low viscosity liquid epoxy resin system consisting of bisphenol “A” epoxy resin and/or neat epoxy filler materials mixed with a carboxylic acid anhydride based liquid hardener including a tertiary amine accelerator in pre-determined proportions; fabricating the mixed un-filled low viscosity liquid epoxy resin system of bisphenol “A” epoxy resin, carboxylic acid anhydride based liquid hardener and the tertiary amine accelerator in pre-determined proportions by pouring said mixture into a mould made in correspondence to the dimension/shape of the pushing including removal of air bubble in the composite body of the bushing through de-gassing during the fabrication process; conducting heat treatment of the impregnated body of the bushing in an air circulated oven in a temperature range of 80-90oC preferably at 80oC for a period of 1-2 hours, to produce a pre-cured electrical bushing; and carrying out heat treatment of the pre-cured electrical bushing with air circulated over at a temperature range of 140o – 150o C preferably at 140oC for a period of 4 – 6 hours, to obtain a fully-cured electrical bushing.

Patent Information

Application #

Filing Date

28 April 2015

Publication Number

45/2017

Publication Type

INA

Invention Field

ELECTRICAL

Status

Email

lsdavar@ca12.vsnl.net.in

Parent Application

Patent Number

Legal Status

Grant Date

2021-07-22

Renewal Date

Applicants

BHARAT HEAVY ELECTRICALS LIMITED

with one of its Regional offices at REGION CAL OPERATIONS DIVISION (ROD) Plot No.9/1, DJ Block 3rd Floor Karunamoyee, Salt Lake City, Kolkata-700091 having its Registered Office at BHEL HOUSE SIRI FORT, New Delhi – 110049, INDIA