Radio-interrogated, surface-wave technology current transformer for high-voltage systems

A current transformer assembly for current strength measurement on/in electrical devices at high voltage, comprising:

• two current-transformers each including:
• a surface-wave configuration having surface-wave structures and an antenna;
• a magnetosensitive element coupled to at least one of said surface-wave structures;
• a radiofrequency transmitter and receiver having a radio antenna and an electronic evaluation device, said transmitter constructed for radio transmission of an interrogation pulse and said receiver with said evaluation device constructed for radio reception and for evaluation of a change influenced by an instantaneous magnetic field in a high-voltage device, the change occurring in an impulse response of said surface-wave configuration;
• and
• a device with a DC magnetic field superposed with a magnetic field of a current to be measured;
• the DC magnetic field of one of said current-transformer devices having an opposite polarity to the DC magnetic field of the other of said current-transformer devices, relative to the magnetic field to be measured, for shifting an operating point in respectively mutually opposite directions.

A current transformer assembly for current strength measurement on/in electrical devices at high voltage, comprising:

• a high-voltage/medium-voltage cable;
• and
• current-transformer disposed in said cable, said current-transformer including:
• a surface-wave configuration having surface-wave structures and an antenna;
• a magnetosensitive element coupled to at least one of said surface-wave structures;
• and
• a radiofrequency transmitter and receiver having a radio antenna and an electronic evaluation device, said transmitter constructed for radio transmission of an interrogation pulse and said receiver with said evaluation device constructed for radio reception and for evaluation of a change influenced by an instantaneous magnetic field in a high-voltage device, the change occurring in an impulse response of said surface-wave configuration.