COSI Digital Instrument Transformers Alstom has developed a brand new range of digital instrument transformer solutions enabling full IEC 61850 implementation and contributing to transmission architectures for today’s and tomorrow’s smart grid networks. The innovative COSI (COmpact Sensor Intelligence) range of digital instrument transformers is designed to be accurate, intelligent, safe, cost-effective – and very importantly – core-less. The COSI products range is serving both AC (up to 1200kV) and DC (up to 800kV) transmission systems but also high current DC applications such as aluminum electrolysis companies. COSI sets the benchmark in transmission network architectures and counts on numerous references with major utilities around the world.