On-line PD measurement and monitoring

On-line PD measurement and monitoring

Vol. 6 Issue 4

Easy on-line partial discharge measurement and monitoring


Effective in-service condition assessments

Periodic on-line PD measurement and monitoring are considered the most reliable methods of evaluating the insulation condition of power transformers when in service. They are performed to investigate potential faults when, for example, the results from a Dissolved Gas Analysis (DGA) provide evidence of PD activity. They also verify insulation condition after necessary repairs have been made. Because PD activity is often present well in advance of insulation failure, asset managers can assess it over time and make informed strategic decisions regarding the timely repair or replacement of the asset before an unexpected outage occurs. PD detection is therefore essential to ensure the reliable, long-term operation of power transformers and other electrical equipment.

Easier setup and use

Although users consider PD detection and monitoring as beneficial for trending insulation conditions in power transformers and other electrical assets, the system installation and data analysis has often been considered complicated and time-consuming. Users also tend to prefer a single on-line PD assessment system that is more flexible for short-term and long-term use on various assets, rather than having to invest in a separate system for each asset. That is why OMICRON decided to develop a portable on-line PD measurement and monitoring system that is easier to install and more flexible for use on various assets in the field.

One system for various applications

OMICRON’s MONTESTO 200 combines on-line partial discharge (PD) measurement and temporary on-line PD monitoring functions into one portable system. The IP65 rated MONTESTO 200 can be used both indoors and outdoors for insulation condition assessments on various medium-voltage and high-voltage electrical assets under load, including power transformers, motors and generators, as well as power cables. This versatility makes it possible for users to invest in only one system for assessing the insulation condition status of electrical assets throughout a utility or industrial plant.

Plug-and-play connections to various PD sensors

MONTESTO 200 is designed for use with a variety of PD measurement sensors from OMICRON and other suppliers, including bushing tap and UHF sensors for power transformers, coupling capacitors for rotating machines, and high-frequency current transformers (HFCTs) for power cables. These PD measurement sensors are permanently installed and connected to MONTESTO 200 via OMICRON’s Terminal Box, which is also permanently installed at the asset. This enables safe and convenient plug-and-play connections while the power transformer or other electrical asset is on line to avoid unnecessary downtime during setup.