Cover Story

Optical Instrument Transformers

Development of practical high-voltage optical current and voltage sensors based on the Faraday and Pockels effects started in the 1960s and 1970s.  Industrial R&D by technologists at various companies including General Electric, Square D, NGK, and Westinghouse yielded early prototypes in 1970s and 1980s.  More refined field prototypes and early products were introduced in the 1980s and early 1990s by a number of manufacturers.  In late 1990s, thanks to the telecom boom, the optical technology evolved rapidly resulting in the development of cost-effective and reliable components that, in turn, led to the introduction of industrial-grade optical instrument transformer products by the turn of the millennium. More

Relion advanced protection & control.
BeijingSifang June 2016