Optical fibers are widely used in power distribution networks for communication with protection, monitoring and control devices. Besides their electrical isolation, their immunity to EMI/RFI makes them ideal for harsh electrical environment and particularly for thyristor triggering.
Modern trend toward “smart grid” increases the need for sensors and communication offering an important opportunity for the development of fiber optics systems and components. Sensing current, temperature, isolation, vibrations, etc, are needed for network maintenance and security. New needs are also appearing with distributed generation associated with renewable energy such as windmills electric farms or solar energy.
For high voltage industrial environment SEDI-ATI has developed special cables combined with specific connector termination process adapted to high voltage avoiding sparkling risk. These cables have to be hermetic and totally made of dielectric materials. They are commonly used in high power plants to collect sensing information from the power line through the isolators.
Main issues: Pressure from 8 to10 bars, T° -40°up to 85°C, Mechanical resistance, Hermeticity, Dielectric…
Some High Voltage qualification: 35kV DC, with discharge current < 10pC (after 96h under 95% humidity).
2 KV over 20 mm distance and increase up to 5kV for 60 sec., without increase of discharge current