HVPD’s range of OLPD sensors can detect dangerous partial discharge activity in cables (HFCT), switchgear (TEV or AA) and transformers (HFCT, TEV and Bushing Taps).
All HVPD’s sensors are available in both portable and permanent versions and supplied with complete installation kits. Permanent OLPD sensor installations are now becoming more popular in industries where plant outages are rare (the oil & gas industry, for example) to facilitate periodic OLPD diagnostic spot‑testing at any time, without the need for an outage.
The installation, calibration and commissioning of sensor installations is always performed by either one of HVPD’s 15 Installation Engineers or by an HVPD‑Accredited Installation Engineer (refer to HVPD for details of our training course to become an HVPD-Accredited Installation Engineer).

  • High Frequency Current Transformer

    HFCT sensors are used to measure PD in HV cables, and (cable-fed) transformers. HVPD offer the widest range of HFCT sensors for OLPD measurement in the marketplace, including fully EMC-screened versions, high‑current (1000 A) versions, and Ex/ATEX‑certified versions for use in hazardous gas/explosive environments.

  • Transient Earth Voltage (TEV) Probe

    The TEV probe is a high-frequency capacitive sensor that is used to detect ‘local’ PD activity in metal‑clad MV switchgear. It is attached magnetically to the outside of the switchgear where it detects the transient earth voltages induced onto the earthed, metal-clad ‘skin’ of the switchgear from the PD source. HVPD supply indoor and outdoor versions of the TEV sensor.

  • Airborne Acoustic (AA) Probe

    The ultrasonic airborne acoustic (AA) sensor detects airborne acoustic signals from PD into air, including corona (in outdoor substations) and surface discharges and tracking (in indoor, air‑insulated switchgear (AIS)). The AA sensor is used in the HVPD’s MV Switchgear Monitoring Solution with the HVPD Multi™ Monitor and Linearplex AA Sensor Expansion Module. The AA sensors are ‘daisy-chained’ inside and along the AIS switchboard, typically with one sensor per switchgear panel.