25 May 2005
An revolutionary new high DC current measurement system from ABB weighs 20 rather than 2,000 kilograms, takes four hours to install instead of 40, improves accuracy by a factor of 10, is immune to electromagnetic interference, and is as simple to install and use as the alternative is complex.

Designed for high-voltage substations and the electrochemical industries (aluminum, copper, magnesium, zinc, steel and chlorine), ABB's award-winning fiber-optic current sensor (FOCS) is a groundbreaking improvement on the conventional alternatives for these two applications.

Traditionally, measuring electrical current and high voltages requires current transducers that weigh as much as 2,000 kg and can take - in electrochemical applications - between one and two weeks to install.

Installation and commissioning in those applications is intricate and time consuming, because the transducers often require a magnetic field analysis and sophisticated magnetic centering, and are prone to electromagnetic interference and interference from nearby bus bars.

To overcome these drawbacks, ABB developed a lightweight, easy to install and more effective fiber optic alternative. Because the key components are dielectric and immune to electromagnetic interference, FOCS is ideal for the measurement of electrical currents in high-voltage substations and large power-consuming applications like aluminum smelters.

Protected by a dozen pending or already granted patents, FOCS measures currents of up to 500 kA and provides the following key benefits:

For high-voltage substations:

  • A thin optical fiber replaces hundreds or thousands of kilograms of copper, iron and insulation material

  • The sensor is easy to integrate into high voltage components like circuit breakers, eliminating the need for large current transformers and reducing installation costs

  • There is no electrical connection between high voltage components and secondary electronics - metering, substation control and protection devices - and no interference or damage from high voltage influences
For the electro-chemical industries:

  • Installation and commissioning takes about 4 hours, compared to as much as 40-80 hours for a conventional current transducer

  • The performance of FOCS does not deteriorate in asymmetric magnetic fields and FOCS is immune to local magnetic overload and interference from neighboring bus bars, both of which impair accuracy. This gives the customer unique flexibility when it comes to sensor placement

  • The sensor maintains better than 99.9 percent accuracy over a significantly larger current range and at temperatures of between -40 C and 80 C. The digital technology is considerably more accurate than the analog signals of conventional current transducers
FOCS was one of five technologies nominated for the prestigious Hermes Award at the Hanover Fair 2005, and was among the four finalists in the Swiss Technology Award for 2005.

-Ends-

By Editorial services

© Press Release 2005