A novel bridge-type hybrid saturated core fault current limiter based on permanent magnets

Due to the increase of electric power consumption and the development of distributed generations (DGs), the short-circuit levels are rapidly rising which may exceed the maximum short-circuit capacity of grid equipment. Fault current limiter (FCL) is one of the most effective methods to limit excess current. Various types of FCLs such as superconducting, solid state, saturated-core and hybrid topologies are being developed in the past decades [1]. Superconducting FCLs are costly and need high maintenance requirements, while solid state FCLs are limited by rated power of semiconductor devices. Saturated-core FCLs require high magneto-motive force (MMF) from DC coils with uncertain fault clipping performance. Permanent magnet (PM) biased FCLs is only suitable for applying in the low voltage system for the finite flux density of PM.