Image for illustrative purposes
Substation Solutions, LLC, led by Bradley Webb, is emphasizing the importance of proactive transformer maintenance in the face of supply chain challenges, extended lead times, and the high costs associated with unexpected electrical failures. With over 16 years of expertise in medium and high voltage systems, Webb advocates for a structured approach to transformer care to ensure operational reliability and longevity.
A robust transformer maintenance program can be categorized into six key areas: insulating fluid, physical and mechanical condition, auxiliary controls and indicators, winding construction, winding insulation, and bushings. Among these, testing and monitoring the transformer’s insulating fluid is a cornerstone. Regular oil sampling—recommended annually—can detect abnormalities early, enabling timely corrective action. High-value transformers can further benefit from online oil monitoring systems that continuously analyze fluid conditions and provide early warnings.
Physical and mechanical inspections, such as checking for leaks, verifying gas pressures, and ensuring the functionality of fans, pumps, and coolers, are essential preventive measures. These tasks can often be performed with minimal disruption to operations by on-site personnel.
For more detailed assessments, offline testing every three to five years is advised. Key procedures include power factor testing, winding resistance testing, turns ratio testing, sweep frequency response analysis, and bushing power factor and capacitance tests. Special attention to bushing conditions is critical, as these components are often considered a transformer's weak point.
By implementing a comprehensive maintenance program, asset owners can extend the life of their transformers, reduce the risk of unplanned outages, and safeguard their investments.
This article was originally published in the November 2024 issue of the Power Systems Technology magazine, which you can access here.
To download the PDF version of this article, click here.
