For FRA the company uses an Omicron FRAnalyzer, the FRAnalyzer is a sweep frequency response analyzer for power transformer core and winding diagnosis. Its concept – universal hardware controlled by software running on a computer –A sinusoidal voltage with constant amplitude and variable discrete frequencies is applied to the winding under test and the frequency of the input signal is successively increased.
The FRAnalyzer measures the frequency response of the transformer windings in a wide frequency range and compares it with that in a healthy condition. From the frequency response deviations, many different types of defects in the transformer winding and magnetic core can be diagnosed. These include:
- Faulty core grounds
- Partial winding collapse
- Broken or loose clamps
- Shorted turns and open windings
- Core deformation