Patent ID: 8718418

Claim:
A high-voltage AC/DC or DC/AC converter station, comprising: a converter that converts high AC voltage to high DC voltage or vice versa; a hall arranged around said converter; a bushing having a conductor for leading high DC voltage through a wall of said hall, said bushing comprising a base connected to said wall and arms extending from opposite sides of said base and carrying connecting electrodes; and at least one current sensor for measuring a current through said conductor at said high DC voltage, wherein said current sensor comprises a sensor head that includes an optical sensing fiber and an optoelectronic module, the sensor head having a housing mounted to said base or wall, an annular support body mounted on said base or wall within said housing, and a foam strip mounted to said support body, the sensor head being configured for measuring said current via a Faraday effect in said sensing fiber, wherein said sensing fiber is looped around said conductor and arranged at said base and/or said wall around said base, said sensor head forms a modular structure that can be added after assembly of the bushing, said sensing fiber forms an integer number of loops around said conductor so that the sensor measures a closed path integral of the magnetic field; and said sensor head is arranged at ground so that no high-voltage-proof fiber link is used.