Newtons4th – SFRA45 Sweep Frequency Response Analyzer

The SFRA45 is a Sweep Frequency Response Analyzer with a bandwidth of 5Hz to 45MHz, the SFRA45 offers a fully portable solution for the field of SFRA (Sweep Frequency Response Analysis) which fully complies with IEC60076-18 – Power Transformers Part 18 – Measurement of frequency response.

Featuring an inbuilt colour LCD screen as well as being battery powered, the tablet style instrument can be used with or without PC Software. The dedicated software available (SFRAComm) enables the user to create databases from which historical transformer sweeps can be recalled and compared to current sweeps for analysis. This offers the ability to perform the most common sweep frequency response analysis technique “Fingerprint Comparison” as well as all other comparison techniques.

Demystifying SFRA

The Sweep Frequency Response Analyzer simply injects a range of frequencies into a winding of a power transformer, when the power transformer is built correctly with no imperfections and faults the frequency response (of Gain Vs Frequency) plot of that particular type of transformer and winding on that particular transformer should exhibit a particular shape, this “shape” then becomes the transformers “fingerprint”.

Over the course of the transformers lifetime this “fingerprint” can be used in order to detect degradation of the transformer.

When is SFRA performed?

There are three main occasions when SFRA is performed

1. Upon factory quality checking
2. Before a short circuit test
3. Before and After transportation
4. Ongoing scheduled maintenance

Features & Benefits