Compensation of simple fibre optic faraday effect sensors

A system for measuring high voltage current an electrical conductor, said system comprising:

• a light source selected from the group consisting of at least one of an LED based light source and an incandescent light source,
• a first optical conduit being a first optical fibre, said first optical conduit conducting light emitted from said light source,
• an optical electric current measurement device comprising:
• a housing defining a first open end and a second open end opposite said first open end,
• a first sealing means having an aperture, said first sealing means having an overall geometrical configuration corresponding to the overall geometrical configuration of said first open end of said housing, said first sealing means further comprising an aperture adapted for receiving said first optical fibre,
• a first fixture means for fixating said first optical fibre,
• a first optical lens having a reception part adapted for receiving said first fixture means for mounting said first optical fibre in optical continuation with said first optical lens, said first optical lens mounted in said housing,
• a first polarisation filter mounted in said housing in optical continuation with said first optical lens,
• a glass rod received in and encapsulated within said housing in optical continuation with said first polarisation filter, said glass rod being constructed from a material having magneto-optical properties,
• a second polarisation filter mounted in said housing in optical continuation with said glass rod,
• a second optical lens mounted in said housing in optical continuation with said second polarisation filter, said second optical lens adapted for receiving a second fixture means,
• a second fixture means for fixating a second optical fibre, said second fixture means received in said second optical lens,
• a second sealing means for sealing said second end of said housing, said second sealing means having an aperture for receiving a second optical fibre, said second sealing means mounted in said second end of said housing end, and
• a first and second lid adapted for fixation to said first and second end, respectively, of said housing, said first and second lid including an aperture for receiving said first and second optical fibre respectively, said optical electric current measurement device receiving said light from said first optical conduit,
• a second optical conduit being said second optical fibre, said second optical conduit receiving said light emitted from said optical electric current measurement device,
• a detection means for detecting said light emitted from said second optical conduit and converting said received light to an electrical signal,
• a processing means for processing said electrical signal from said detection means so as to determine said high voltage current in said electrical conductor,
• a current measurement system for performing calibration measurements for said system, and
• a first communications means.

A method of calibrating a system for measuring high voltage current in electrical conductors, said method comprising:

• providing an electrical conductor carrying high voltage current,
• providing a light source,
• providing a first optical conduit defining a first and a second opposite end, said light source connected to said first end of said first optical conduit, said light source emitting light into said first optical conduit,
• providing a Faraday current measurement device defining a first and a second opposite end said first end of said Faraday current measurement device connected to said second end of said first optical conduit, said Faraday current measurement device receiving said light from said first optical conduit,
• providing a second optical conduit, defining a first and a second opposite end, said first end connected to said second end of said Faraday current measurement device,
• providing an optical detection means for converting said light to an electrical signal, said optical detection means connected to said second end of said second optical conduit,
• providing a current measurement system performing a measurement of the current in said electrical conductor,
• performing said measurement of said electrical current in said electrical conductor, said system for measuring high voltage current in electrical conductors calculating a calibration constant, removing said current measurement system.