Partial discharge detector of gas-insulated apparatus
AssigneeHitachi, Ltd.
InventorsTatsuro Kato, Youichi Ohshita
Life of this patent
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Abstract
With a circular signal receiving antenna unit (4) constituted by combining two pieces of semicircular conductive plates on a plane in a metallic vessel (3) for the gas insulated apparatus, the electromagnetic waves due to the partial discharge can be detected with a high sensitivity for a broad frequency band. The detected signals are measured by a measuring unit (10) via a hermetical seal coaxial terminal (7) and a coaxial cable (8). The antenna portions of the semicircular plates are designed to extend over a large area. Thus, a capacitance with a potential measurement portion can be increased and a potential measurement with high sensitivity can be performed.
Claims11
A partial discharge detector for a gas insulated apparatus having a metallic vessel, which is filled with insulation gas and accommodates therein a high voltage conductor supported by insulating members, comprising;
- a signal receiving antenna unit formed by disposing two pieces of plate shaped conductive electrodes arranged on a common plane with a gap in a symmetric manner with respect to the gap and forming a dipole antenna in combination;
- a coaxial cable coupled with said signal receiving antenna unit and electrically extending outside the metallic vessel through a hermetically sealing coaxial terminal;
- a measuring unit coupled with said coaxial cable;
- and
- wherein a center core wire and an outer grounding wire of said coaxial cable are directly connected to either one of the two plate shaped conductive electrodes at the center portion of the two pieces of the plate shaped conductive electrodes, and said measuring unit is coupled with said coaxial cable through a coaxial connector.
Dependencies are inferred from the claim text.