frequency response analysis - Insulation Testing

SFRA Testing: A Practical Guide to Sweep Frequency Response Analysis

A transformer winding that has shifted 2 mm inside the tank will pass every conventional electrical test. The turns ratio is unchanged. The winding resistance is unchanged. The insulation resistance is unchanged. The DGA is clean if the movement hasn’t caused arcing yet. Energize the transformer, run it for years, and the shift slowly progresses — until one… Read More: SFRA Testing: A Practical Guide to Sweep Frequency Response Analysis »

Frequency Response Analysis (FRA) for Transformer Diagnostics: A Practical Guide

A power transformer survives a nearby short-circuit fault. It rides through the event, the protection clears the fault, and the transformer goes back to service. Oil tests come back normal. Insulation resistance is healthy. DGA shows no concerning gas evolution. Everything looks fine. But inside the tank, the windings have shifted. Not enough to fail immediately. Not enough… Read More: Frequency Response Analysis (FRA) for Transformer Diagnostics: A Practical Guide »