Wilson Transformer Company and GridON have delivered the first proven, fully tested commercial Fault Current Limiters (FCLs) that are scalable to extra high voltage ratings. Our solution utilises existing transformer technology and manufacturing practices which provides a robust product range, scalable from distribution to transmission networks. Extensive computer simulation and a pre-saturated core design methodology have resulted in multiple successful installations in the United Kingdom.
Placing a FCL in a transformer feeder location offers great flexibility in reducing substation fault levels to accommodate switchgear ratings. One or more FCLs may be installed depending on the fault reduction required and with minimal changes to existing protection settings. A FCL may be included in a transformer protection zone with no additional relays or CTs required. FCLs may also be used to improve load balancing between feeder transformers with different impedances and/or rated power. FCLs enable capacity increase on existing grids.

Key features and benefits of our design approach include:

Suppressing fault currents flowing through the grid, thus enabling uninterrupted operation, and reliable connection of additional generation
Enabling network meshing and connection of generation & low carbon energy sources
Increasing grid quality, reliability and stability
A reduction in capex by millions of dollars, while extending the useful life of existing network assets
An immediate increase of impedance during the first peak of a fault current and reducing it as soon as the fault is cleared, thereby enabling power supply to be maintained