Three phase saturated core fault current limiter performance with a floating neutral

High power demands in electricity grids are continually increasing. This increasing trend coupled with the introduction of renewable energy sources, which require energy storage devices, poses significant problems to fault current levels. To improve network availability and grid resilience, superconducting saturated core Fault Current Limiters (FCL) are a suitable solution to reduce high fault currents in distribution level electricity grids. These devices have the characteristic of low impedance to the network during normal operation and high impedance during a fault event. However, this change in impedance is nonlinear and can lead to an imbalance in a three phase saturated core FCL. In this paper, the effects on fault current limiting performance due to the unbalanced instantaneous impedance between the 3 phases are investigated. The FCL fault transients of a grounded fault and a floating fault are simulated and compared using Finite Element Analysis (FEA) techniques. The presented results are also validated against a real world distribution level saturated core FCL under high power testing.