HV Dryshield electronic current transformer from RHM InternationalUsing 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 electronic current sensing in current transformer
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
