Capacitive voltage transformer for a metal-enclosed, gas-filled high- voltage system

摘要

The capacitive voltage transformer is provided for a metal- enclosed, gas-filled high-voltage system. It has a cylindrical capacitor having two coaxially arranged, electrically conducting cylinders (12, 13), of which one internally arranged cylinder (12) is at a high voltage potential and outwardly bounds a current-carrying conductor (5) of the system. An externally arranged one of the two cylinders (13) is inserted in an electrically insulated fashion into the metal enclosure (4). In a first embodiment of the voltage transformer the internal cylinder (12) has an enclosing tube (16) formed from a material having a lower coefficient of linear thermal expansion than copper. In a second embodiment there is provided, for the purpose of correcting the transformed voltage values, a device which detects the value of the current carried in the conductor (5) , and in which the change in the capacitance of the cylindrical capacitor is determined as a function of a change in temperature caused by the current carried in the conductor (5). The accuracy of the transformed voltage values is increased by both embodiments.