OMICRON Magazine

Thereafter, on-line PD diagnostics play a role in insulation condition assessment for the rest of the asset’s service life. Using the grid voltage, PD measurements are performed during commissioning and in-service testing to see if the insulation is able to meet performance standards that can ensure reliable asset operation. Regular in-service PD measurements help you assess the insulation’s condition in order to make informed, strategic decisions about timely repairs or replacing equipment. This enables you to move from a time- based maintenance schedule to a more efficient condition-based one. This transition will save time and costs, while also helping you avoid unnecessary downtime. Post repair measurements that are taken over the course of a few days are able to confirm whether a repair was successful or not. What role does PD monitoring play? In addition to diagnostic on-line PD measurements, temporary and permanent PD monitoring both play an increasingly impor- tant role in ensuring the reliable, long-term operation of electrical equipment. PD monitoring lets you observe PD activity related to various operational conditions or loads in order to support your asset management decisions. When an asset is critical or aging, PD monitoring also provides you with reliable indications across the time span of a developing insulation fault. This allows you to perform timely maintenance procedures that prevent failure and unexpected outages. When it comes to temporary PD monitoring, on-line PD measurement is continued for a day, week, month or even a year in order to obtain a more detailed picture of potential progressive deterioration in the electrical insulation. Permanent, in-service PD monitoring follows the same procedure with long-term insulation condition assessments. This procedure is recommended for electrical assets towards the end of their service life. What advantages do our PD monitoring systems have? Our PD monitoring systems have many of the same features as our market-proven MPD PD measure- ment and analysis technology, including highly sensitive PD mea- surements, fiber optic connections for added safety; synchronous, multi-channel measurements; real- time data recording and playback; as well as highly effective noise sup- pression and PD source separation techniques that simplify analysis and defect localization. In addition, the flexible and scalable system architecture can be easily adapted to various applications – for continuous PD monitoring on a single electrical asset, a complete fleet of assets or a complete cable system with several distributed measurement points. You can use the same software with the same user interface to compare PD data from all of the connected acquisi- tion units. Automatic warnings and alarms immediately alert you when pre-set PD activity thresholds have been violated. «PD measurement offers a reliable and non-intrusive method for effectively locating weak points in the insulation system. It can be performed at any time from the factory to the end of the life cycle.» Samuel Scheller, Product Manager, OMICRON 22