A circuit arrangement for reducing a magnetic unidirectional flux component in a core of a transformer includes a measuring device that provides a sensor signal corresponding to the magnetic unidirectional flux component, a compensation coil magnetically coupled to the core of the transformer, and a semiconductor switching device which is electrically arranged in a current path in series with the compensation coil to feed a current into the compensation coil, such that current is directed opposite the unidirectional flux component, where the semiconductor switching device is controlled via a control signal provided by a controller, and includes an inductive voltage divider having a first impedance component arranged in a current circuit in series with the compensation coil and the semiconductor switching device and a second impedance component arranged in parallel with the semiconductor switching device, where the first impedance component is connected in parallel with a parallel resonant circuit.

An electrical power distribution network is disclosed, the network can include: a plurality of electrical power control apparatuses, each of the electrical power control apparatuses including: one or more signal conversion components receiving electrical power in the form of a corresponding first signal having a corresponding first fundamental frequency and a corresponding first characteristic voltage, and generating a corresponding second signal having a corresponding second fundamental frequency and a corresponding second characteristic voltage; and a controller that controls operation of the signal conversion components to determine an output voltage and an output frequency of an output signal of the electrical power control apparatus; electrical power generation components acting as sources of electrical power to at least some of the electrical power control apparatuses; and electrical power consumption components acting as sinks of electrical power from at least some of the electrical power control apparatuses.

An apparatus for reducing a magnetic unidirectional flux component in the core of a transformer with at least three legs, in particular a three-phase transformer having at least one compensation winding per transformer leg, wherein the compensation windings are magnetically coupled to the core of the transformer, where two compensation windings are provided per leg, the first compensation windings of a leg are each electrically connected together in a first delta connection, in each case the second compensation windings of a leg are each electrically connected together in a second delta connection, the compensation windings of at least one leg have different numbers of windings, and where at least one switching unit is arranged in series with the compensation windings for phase angle control.

Magnetic flux valves can be used in electromagnetic (EM) power converters to electronically control output signals of the EM power converters. An input signal is provided to an EM power converter that includes two or more core sections in which at least one core section includes a magnetic flux valve having an adjustable reluctance. The EM power converter has one or more primary windings and one or more secondary windings wound around one or more core sections. One or more control signals are provided to the one or more magnetic flux valves to control a reluctance or reluctances of the one or more magnetic flux valves, affecting magnetic coupling between the primary and secondary windings. An output signal is generated, in which the output signal is a function of the input signal and the one or more control signals.

An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

In the reactor in which the wiring board with the main winding formed thereon and the wiring board with the control winding formed thereon are incorporated in layers into the planer core, the magnetic flux generated by the main winding and the magnetic flux generated by the control winding are brought into the following states in order to equalize the density of the magnetic flux generated by the control current. A main winding current of high-frequency current flowing through the main winding generates an AC magnetic fluxes, each of the fluxes having a magnetic field in a direction opposite to each other so as to cancel each other out, and a control current of direct current flowing through the control winding generates a DC magnetic flux with a uniform magnetic flux density around the pair of the inner legs of which AC magnetic fluxes are cancelled out each other.

A tunable inductor has a first magnetic core and a second magnetic core wound with a direct current (DC) winding and an alternating current (AC) winding. A first portion of the AC winding is wound around a first portion of the first magnetic core, and a second portion of the AC winding is wound around a first portion of the second magnetic core. The DC winding is wound simultaneously around the first magnetic core and the second magnetic core in a second portion that does not overlap the first portion of the first magnetic core and the second magnetic core. The DC winding is connected to a DC control circuit that applies a DC voltage to control permeability of the first magnetic core and the second magnetic core, which allows inductance value of the tunable inductor to be adjusted.

Magnetic flux valves can be used in electromagnetic (EM) power converters to electronically control output signals of the EM power converters. An input signal is provided to an EM power converter that includes two or more core sections in which at least one core section includes a magnetic flux valve having an adjustable reluctance. The EM power converter has one or more primary windings and one or more secondary windings wound around one or more core sections. One or more control signals are provided to the one or more magnetic flux valves to control a reluctance or reluctances of the one or more magnetic flux valves, affecting magnetic coupling between the primary and secondary windings. An output signal is generated, in which the output signal is a function of the input signal and the one or more control signals.

Various embodiments of the teachings herein include a charging station for an electric vehicle. An example charging station may include: a connection for an electrical energy source; a control device; an inverter; and an electronic coil connected to the inverter via a compensation circuit having a variable inductive device to wirelessly couple energy to the electric vehicle. The inverter applies an AC voltage to the electronic coil. The variable inductive device comprises a first winding arranged on a magnetic core and connected into the current path of the AC voltage. The variable inductive element comprises a second winding arranged on a second magnetic core in an air gap of the magnetic core. The second winding is connected to an auxiliary power supply to supply an auxiliary voltage having a DC component to the second winding.

Disclosed herein is an inductor comprising a primary winding. The inductor further comprises a secondary winding wound around the same core as the primary winding. The secondary winding is connected to an excitation stage that causes the secondary winding to selectively generate flux at one or more frequencies in order to vary the magnetic behaviour of the inductor.