Patent ID: 9329221
Filing Date: 2016-05-03
CPC Classification: G01R,H02B

Claim Text:
1. A partial discharge sensor comprising: a cylindrical structure which is formed to surround a high voltage cable and of which a surface is set to a ground potential; a cylindrical branch pipe of which one end is connected to the structure; a disc which is arranged in an interior of the branch pipe and of which one surface is arranged to be substantially flush with an inner surface of the structure; a post connected to the other surface of the disc; a cover member which has an opening to be inserted into by the post at a center thereof, and of which one surface is arranged to cover the other end of the branch pipe to be thus electrically connected with the structure through the branch pipe; and a short-circuit plate having an electrical length of ¼ wavelength of a specific frequency included in a frequency band to be detected, the short-circuit plate connecting the cover member with a portion of the post in a vicinity of the cover member, wherein the cover member comprises a ring-shaped projection member which is arranged in the interior of the branch pipe, which is formed to an upper end thee thereof in which a length from the inner surface of the structure to one surface of the cover member is subtracted by a predetermined length, and of which an opening having the same diameter as that of the opening of the cover member is formed to be extended up to the upper end face thereof.