Electromagnetic Simulation of Split-Core Current Transformer for Medium Voltage ApplicationsN. Paudel , V. Siddharth , S. Shaw , D. Raschka ,
 ABB, Inc., Instrument Transformers & Distribution Components, Pinetops, NC, USA
In electric distribution network, current and voltage measurement for metering, monitoring, and protection & control applications is done via instrument transformers (current and voltage transformers). These measurement devices are deployed during the construction phase of the electric network. However, it is necessary from time to time to replace these devices due to failure or upgrade. Utility companies preferred to replace these devices without any power interruption. For the very same reason, this project focus to develop a clamp-on current instrument transformer with split ferromagnetic cores which can be easily installed around the primary conductor without service disconnection.
The design is focus to have the low voltage output that is proportional to the current input and, having a very low energy output, minimizes safety concerns associated with open circuited leads on an energized current transformer. The electromagnetic design is performed in the COMSOL Multiphysics® software using the AC/DC Module. The Magnetic Fields interface is coupled with Electrical Circuit interface to perform the FEA & Circuit co-simulation. Since, the split-core transformer is design for accuracy class of 1% (maximum error