MEASUREMENT INSTALLATION FOR THE DETECTION OF PARTIAL DISCHARGES INSIDE HIGH VOLTAGE CIRCUIT INSTALLATIONS, WITH GAS INSULATION UNDER PRESSURE AND WITH METALLIC ENCapsulation

摘要

Partial discharges are to be detected within a metal-encapsulated, compressed-gas-insulated high-voltage switchgear using a capacitive voltage divider. The measurement device used for this purpose contains an electrode which is dish-shaped and is inserted flush in an opening of the capsule. A measurement cable leading to the display or measurement unit is built up coaxially and connected with a terminal element which is a supporting component and contains the electrode and the edge of the opening in the capsule. In addition, the terminal includes an outer connecting element in the shape of a hollow cone which extends to the edge of the opening and an inner connecting element in the shape of a cone that extends to the electrode, which are coaxially arranged, the ratio of whose diameters da/di is constant, and which have the characteristic impedance of the measuring cable.