High Frequency Current Transformers (HFCT)

Our HVPD’s range of On-line Partial Discharge sensors can detect dangerous PD activity in rotating machines, cables, switchgear and transformers.

TYPES OF SENSORS

High frequency Current Transformers (HFCT) sensors are inductively coupled around the MV/HV cables to provide a means for On-line PD measurements to be made on in-service cables, transformers and rotating machines.

Figure 6 High Frequency Current Transformers (HFCT)

Each sensor inductively measures the high frequency current signals within the PD pulses flowing in the earth or the conductor of the cable without the need for any direct, galvanic connection to the HV.

The sensors can be installed permanently during a planned outage or at the build stage of a project to enable On-line PD monitoring or routine spot testing.

On the other hand, a temporary installation of the HFCT sensors can be carried out if the cable earth is available outside of the termination box, enabling On-line PD spot testing without the need for permanent sensors or outage.

HFCT Sensor installation at crutch the of 3-core cable. Belted cables or with individually screened conductors with earth straps looped back through the HFCT.