Insulation faults can be traced back to be the leading cause of failures and eventual breakdowns of electrical equipment or assets such as generators, power transformers and motors, including power cables and switch gears.

Partial discharge (PD) measurement and monitoring are two popular and effective methods with the help of which the diagnosis of insulation condition of electrical assets can be conducted anytime. It can enable operators to detect localized faults or weak points in the insulation system effectively.

Continue to read till the end to learn all about partial discharge.

What is Partial Discharge?

It is a consequence of local electrical stress concentrations on the surface of the insulation or in the insulation itself. Partial Discharge is both the indicator and cause of a developing insulation defect in an electrical equipment.

Over the course of time, PD activity gets more hazardous and intense. The deterioration process tends to grow and develop until the insulation is no longer able to withstand the electrical stress and that leads to a flashover and financially hefty damage to the assets and unforeseen outages.

Why is Partial Discharge Measurement Important?

Partial Discharge measurement is a non-intrusive and reliable method that can be used anytime for the diagnosis of insulation condition in an electrical asset. In comparison to other dielectric diagnosis methods, the standard PD measurement and monitoring is better capable of collecting very sensitive data that can help in detecting localized weak points within the insulation system.

Since the PD activity is often present well in advance prior to the insulation failure, asset managers are able to assess it over time and take well-researched and informed strategic decisions related to the timely replacement or repair of the electrical equipment.

This helps in preventing any unexpected outage that might occur. Therefore, PD measurement is very much essential to ensure long-term, reliable operation of the equipment.

PD Measurement with On-line PD Monitoring System

With on-line partial discharge monitoring, the asset managers are capable of collecting a vast amount of data consistently without causing any interruptions in the normal services. This type of PD measuring and monitoring system records insulation condition data under the guidance of real load conditions.

Users can either choose between permanently or temporarily-installed systems. Regardless of the choice, the system allows continuous on-line assessments of PD activity levels along with insulation conditions during the time interval which the operator specifies.

When is the Ideal Time of PD Measurement?

The insulation integration in HV and MV equipment should be verified with the help of PD measurement and further analysis during the development, manufacturing and commissioning stage of the electrical equipment.

Once the asset is set into service, strategic decisions regarding the maintenance must be taken in order to ensure maximized availability.