Fault current limiter

A fault current limiter (FCL) comprising:

• a core structure in the form of a polygonal shaped ring having connected sides of the polygon, the core structure comprising
• i) a first magnetisable core member, and
• ii) a second magnetisable core member, spaced from the first core member;
• an AC magnetomotive force source configured to generate a varying magnetic flux in at least a portion of the first and second magnetisable core members;
• and
• a plurality of static magnetomotive force (mmf) sources being positioned to provide a magnetic circuit within at least part of the magnetisable core members,
• wherein each static mmf source has a body, which includes limbs extending in different directions following the shape of the adjacent core member, and
• wherein the static mmf sources are positioned at corners/vertices of the core structure and wherein the limbs extend at inclined angles corresponding to the angle between the connected sides of the polygon.