A fault current limiter (FCL) has a core structure with a first and second magnetisable core members and 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. Static magnetomotive force sources being positioned to provide a magnetic circuit within at least part of the magnetisable core members. The FCL may have a ring core structure and the static magnetomotive force sources may include a mitered or tapered joint interface with the core member.

A converter device comprising a converter and a coil arrangement that contains a number of coils. The coil arrangement has a plurality of interconnected coils. Torroidal cores of a soft magnetic nanocrystalline material are associated with each of said coils. A coupling toroidal core (11) is provided with a core opening (12) through which at least two windings (8, 9) of different coils can be guided and mounted. At least the winding of one coil is guided and mounted through a core opening of an individual toroidal core (13, 14). An an open/closed-loop control device is provided with a current controller that acts on the coils such that direct current components are compensated by currents flowing through the windings of the coils.

A device for limiting a fault current for a generator, in particular of a wind turbine is provided. A first frame is made of a ferromagnetic material, wherein the first frame comprises a first frame section and a further first frame section, wherein a first gap is formed between the first frame section and the further first frame section. A first coil is wound around the first frame section, wherein the first coil is connectable to a first stator winding of a stator of the generator. A further first coil is wound around the further first frame section, wherein the further first coil is connectable to an electronic device. A first permanent magnet element is arranged inside the first gap. The first frame section and the further first frame section are formed with respect to each other such that an electromagnetic interaction between the first coil and the first permanent magnet element and the further first coil and the first permanent magnet element is provided.

An inductor includes a magnetic core composed of a magnetic material having variable permeability characteristics based on at least one of design parameters or operational parameters of the inductor that includes one or more air gaps. A coil is wound through the one or more air gaps and is configured to be excited by an electric current.

The present invention provides a fault current limiter apparatus comprising: a fault current limiter including: a magnetically saturable core, at least one AC coil wound on at least a portion of the magnetically saturable core, and a magnetic biasing arrangement for magnetically biasing at least a portion of the magnetically saturable core; a source terminal for electrically connecting the fault current limiter to a power source, and a load terminal for electrically connecting the fault current limiter to a load, wherein the at least one AC coil of the fault current limiter is electrically connected between the source and load terminals, and wherein the fault current limiter has a first inductance in normal conditions and a second inductance in fault conditions; a first capacitance electrically connected between the source and load terminals, wherein the first capacitance is electrically connected in series with the fault current limiter, and wherein the first capacitance has a capacitance that is arranged to have a reactance value that compensates for at least some of the first inductance.

A fault current limiter (FCL) includes at least one magnetisable core member and at least one AC magnetomotive force source configured to generate a varying magnetic flux in at least a portion of the at least one magnetisable core member. At least one static magnetomotive force source is positioned to provide a magnetic circuit within at least part of the at least one magnetisable core member and the AC magnetomotive force source and the static magnetomotive force source are relatively positioned to be orthogonal to each other. Typically the static magnetomotive force source may be a permanent magnet and the AC magnetomotive force source configured to generate a varying magnetic flux in both of first and second spaced core members.

A method protects an electrical modular unit from overcurrent damage by virtue of an inductive component converting electrical energy into magnetic and thermal energy, in which a bypass bypasses the inductive component during regular operation of the modular unit and current flows via the bypass. In order to reduce current spikes in the event of a surge current without significantly enlarging the semiconductor switching the circuit inductance for the commutation circuit, it is proposed that the bypass is opened by an overcurrent flowing through the bypass which is above a current value that can be achieved during fault-free operation of the modular unit, with the result that more current is forced through the inductive component than residual current flows through the bypass.

A current limiting device including a transformer including an element made from a magnetothermal material, a primary conductor, and a secondary winding. Heat is generated by the current flowing through the primary conductor and when the current exceeds a certain threshold it modifies the coupling coefficient of the transformer, which makes it possible to limit the current in the primary conductor.

A system is provided for transferring power between a stator and a rotor of an excitation system. The stator and the rotor may form part of a rotary transformer that includes a primary winding and a secondary winding, where power is transferred from the primary winding to the secondary winding or conversely from the secondary winding to the primary winding.

A fault current limiter (FCL) includes at least one magnetisable core member and at least one AC magnetomotive force source configured to generate a varying magnetic flux in at least a portion of the at least one magnetisable core member. At least one static magnetomotive force source is positioned to provide a magnetic circuit within at least part of the at least one magnetisable core member and the AC magnetomotive force source and the static magnetomotive force source are relatively positioned to be orthogonal to each other. Typically the static magnetomotive force source may be a permanent magnet and the AC magnetomotive force source configured to generate a varying magnetic flux in both of first and second spaced core members.