Retrofitting Existing Distribution Networks
The current generation of electric power AC current sensors that are suitable for retrofitting existing distribution networks have obtained a level of accuracy capable of near revenue grade metering.
These split-core sensor designs permit the installation of the AC current sensor without taking the primary conductor off-line.
The standard solid-core AC current sensor used by electric power meters requires that the primary conductor be disconnected and threaded through the solid core current sensor for installation.
The split-core design is simply clamped around the primary conductor and physically secured to the primary conductor.
AC Current Transformer Sensors Most Widely Used
The technologies most widely used are the split-core AC current transformer sensors which incorporate advanced materials magnetic cores (e,g, silicon steel cold rolled grain oriented, Mn-Zn ferrite, …) and the Rogowski Coil current sensor “rope“ style split-core design.
AC current transformer sensors offer excellent price/ performance.
However, the AC primary current range and frequency response for each sensor design is relatively limited.
The rigid physical design is not conducive to irregular primary conductor profiles (something other than a circular or rectangular profile).
Benefits of Rogowski Coil AC Current Sensors
Rope style Rogowski Coil AC current sensors offer a very wide AC primary current range and frequency response.
The flexibility of the “rope” style split-core design can be used for irregularly shaped primary conductor profiles.
The Rogowski Coil current sensor does require additional electronics to perform the integration of the dv/ dt secondary output of the sensor.
See Specs on the Following:
AC Current Transformer Sensors
Rogowski Coil Current Sensors