Electronic instrument transformers for integrated substation systems

In order to integrate primary equipment to digitized integrated substation systems, the digitizing procedure of instrument transformers is indispensable. Electronic current transformers (ECTs) and electronic voltage transformers (EVTs) have achieved high performance with a very small size. The ECTs and EVTs play a sensing and digitizing role for current and voltage information offered by Rogowski coils and capacitive voltage dividers respectively with the processing capabilities of digital electronics, and link up with protection relays and bay control units via process level LAN. The sensed current and voltage signals are transmitted as digital signals. This paper discusses the system construction of the electronic instrument transformers, which are applied for digitized substation systems integrated with primary equipment. The results of performance that can be achieved by the electronic instrument transformers are evaluated.