SNAGS PARTIAL DISCHARGE (PD)
Keeping a cautious eye on your HV assets through continuous partial discharge monitoring.Failure of your high-voltage switchgear and cabling could cost millions in repairs, replacements and fines. But most failures don’t happen in a flash – they can be predicted from warning signs, most notably partial discharge (PD).By watching your cables and switchgear, SNAGSPD service can alert you to suspicious spikes and pinpoint which parts of your HV system should be investigated.
Partial Discharge Detection Equipment
Partial Discharges (PD) are evidences of a degrading insulation capacity, which will lead to cost-intensive repairs and can predictively lead to an electrical breakdown of the HV apparatus. Partial discharges are mainly caused by natural circumstances or by accelerated ageing of the HV insulation, but also manufacturing or installation failures can lead to harmful partial discharges. Therefore, the goal of partial discharge measurements is to detect the partial discharges in an early stage and to evaluate them in a proper way. Periodic, as well as permanent, partial discharge measurements have become one of the main criteria in assessing the quality and condition of HV equipment such as transformers, generators, switchgear and cable systems. With our vast experience in different PD measurement technologies, we are your expert source when trying to select the appropriate technology for your PD testing needs. We offer a variety of PD measurement equipment as well as PD accessories.
Commissioning
HV + EHV commissioning testingCommissioning tests are the final check on the cable system, performed to pinpoint eventual damages caused during the installation process. SNAGS or with PD Associate personnel will provide an accurate measurement in order to verify absence of dangerous Partial discharge phenomena discriminating between possible noise or disturbances.
For the commissioning of cable systems, SNAGS offers different methodologies:
AC Hi-Pot or 24-hour Soak Test and Partial Discharge commissioning testing of new HV and EHV underground cable installations as per IEC 60840 and IEC 62067
Access to a range of small and large Resonant Test Systems, and can test cables up to 500kV at 1.7U0, both short and long circuits
Installation and commissioning of permanent Partial Discharge sensors for on-line and remote PD monitoring
Site Testing & Commissioning
Type of testsOff-line Sequential & Simultaneous Tests for jointed and non-jointed cable systems
On-line 24-hour Soak Test
Other tests performed: Impedance Test, Sheath Current Test, Capacitance Test, Polarization Index, Tan-Delta, Insulation Resistance Test
PD localization (Time Domain Reflectometry & Arrival Time Analysis)
BENIFITS & FEATURES
- Locates PD activity before it leads to failure
- Ideal for pre-commissioning or post-repair
- Reduces the need for expensive excavations by identifying the location of the problem
- Reduces the risk of unplanned, expensive outages
Power rests with you
Together we’ll investigate the nature and magnitude of any issues, and advise you on whether you need to take urgent action or simply carry on monitoring the situation.
Either way, the fault is now under your control. You decide whether to undertake repairs during the next routine maintenance phase or to isolate part of the HV system while you do investigations, repairs and replacements.
On rare occasions, you might need a complete emergency shutdown, but again, it can be done properly with all safeguards and procedures observed, and with warning given to affected parties.
