The recent upsurge in solar flare activity ushers in a new season of risk for critical grid infrastructure – particularly EHV Transformers.  The Solar Flare Index for the current Solar Cycle 25 has increased from approximately 15 in 2020 --  to over 100 in 2023!  NOAA scientists are forecasting that in 2025 we could experience another similar event – with some experts believing it will happen by mid-to-late 2024.

How is your critical grid infrastructure protected? And how can you protect your EHV Transformers from induced neutral DC from Geo-magnetically Induced Currents? These Geo-magnetically Induced Currents induce DC current on the Transformer neutral, but in the presence of much larger AC currents.

OSI’s device detects a rise in neutral DC current -- free from the masking effects of the much larger AC currents, which delivers the early alerts necessary to make informed protection decisions.  More importantly, a Utility may accomplish installation without taking an outage on the transformer.  The split-core, outdoor-rated design enables simple installation without requiring neutral disconnection.  

Ohio Semitronics has worked with a number of utilities to measure DC currents in the neutral and would be happy to share potential solutions with you.

Geomagnetic induced currents from coronal mass ejections are forecast for 2025.  Are You Prepared?