HV DryShield Electronic Current Transformer With Rogowski Coil Current Sensing – Part 1

Using the robust and proven HV DryShield® insulation technology combined with a Rogowski coil sensor the evolution to a digital operation current transformer (CT) was a straightforward process. The HV DryShield® electronic CT uses a dead tank design that houses the sensor and primary converter in a grounded box which provides shielding from electromagnetic interference, temperature variations and vibration. A dead tank design also allows for quick “plug and play” installation at substation locations typically used for older electromagnetic CT installations and easy replacement and electronics maintenance.

 

Advantages of optical sensing in a dead tank construction

 

Conventional HV sensing configuration

Dead Tank Sensing Configuration

The sensing part is located at high voltage line level. Insulation is needed from the HV line to ground to protect connecting fibers Sensor needs power from ground to HV line Requires a specific installation. With sensing being at high voltage level it is exposed to climate rigors and complicates maintenance

Sensing is at the low voltage insulated end of CT Sensor & converter in grounded box, shielded from electromagnetic interference, temperature changes and vibration Sensor powered by grid at ground level CT can be installed at the same location and under the same configuration of older electromagnetic CTs Maintenance-free HV DryShield® insulation and easy replacement, maintenance and electronic upgrade