Abstract:
A high-voltage DC cable joint comprising a multi-wall layered construction having individual concentrically arranged layers. The joint comprises, from inside to outside, an inner conductive rubber layer (1), a field grading rubber layer (2) made from a predetermined tailored formulation, an insulating rubber layer (3) and an outer conductive rubber layer (4). The field grading rubber layer separates and interconnects the conductive rubber layers, and wherein the rubber layers are cross-linked by a by-product-free manufacturing method. The cable joint is preferably made from platinum cured rubbers by moulding process steps. In a preferred embodiment the cable joint is made by injection moulding.
Abstract:
The subject of invention is a high-voltage (HV) instrument transformer based on a new type of combined dry insulation system. The HV instrument transformer is characterized in that the current transformer (1) has a head insulating body (7) in a form of a bushing for electrical insulation of the secondary winding assembly (5) from the primary winding conductor (6). The head insulating body (7) is placed within a conductive encapsulation (12) and being in contact with the insulating member (15), which the insulating member (15) is made of an elastic conformable material which tightly adheres to matching outer surfaces of the head insulating body (7) of the current transformer (1) and the conductive encapsulation (12) or (26) is made of electrically conductive polymer or electrically conductive elastomer material.
Abstract:
The subject of invention is a HV dry instrument transformer based on a new type of dry insulation system. High-voltage instrument transformer has a form of current transformer (1) or a voltage transformer (21). The column insulating body (1 1 ) or (29) of the instrument transformer has a form of a dry capacitor bushing wound as a block of spacer sheet (9) or (30), respectively. The current transformer (1 ) has a head insulating body (13) for electrical insulation of the secondary winding assembly (8) from the primary winding conductor (12), For the current transformer (1) the head insulating body (13) has a form of a capacitor bushing and is in contact with the insulating member (18). The voltage transformer (21) has a primary winding (24) which is in contact with the insulating member (32). The column insulating body (11) or (29) has an impregnation material having substantially the same coefficient of thermal expansion as the material of the insulating member (18) or (32), respectively.
Abstract:
The subject of invention is a high-voltage (HV) instrument transformer based on a new type of combined dry insulation system. The HV instrument transformer is characterized in that the current transformer (1) has a head insulating body (7) in a form of a bushing for electrical insulation of the secondary winding assembly (5) from the primary winding conductor (6). The head insulating body (7) is placed within a conductive encapsulation (12) and being in contact with the insulating member (15), which the insulating member (15) is made of an elastic conformable material which tightly adheres to matching outer surfaces of the head insulating body (7) of the current transformer (1) and the conductive encapsulation (12) or (26) is made of electrically conductive polymer or electrically conductive elastomer material.