A tunable inductor arrangement includes a first winding part connected at one end to a first input of the inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the inductor arrangement, and a fourth winding part connected at one end to the other end of the third winding part. For tuning, the inductor arrangement includes a switch arrangement switchable between a first setting series-connecting the first and third winding parts between the inputs, and a second setting series-connecting the first, second, fourth and third winding parts between the inputs. The first and third winding parts are arranged on a chip or substrate with essentially common magnetic fields, and the second and fourth winding parts are arranged to cancel electro-magnetic coupling with the first and third winding parts.

A system includes conductive windings extending around a magnetic core and impedance-varying windings extending around the magnetic core. The impedance-varying windings include positive windings and negative windings. The conductive windings and the impedance-varying windings conduct electric current around the magnetic core. The system includes a first impedance tap changer that is electrically coupled with the positive windings of the impedance-varying windings and a second impedance tap changer electrically coupled with the negative windings of the impedance-varying windings. A controller controls the first impedance tap changer and the second impedance tap changer to change an impedance of the system by changing which portion of the positive windings and which portion of the negative windings are conductively coupled with the conductive windings, and which portion of the positive windings and which portion of the negative windings are disconnected from the conductive windings.

Primary-side windings of the transformers (T1,T2,T3) are connected in parallel to each other. A switch (SW) turns on/off primary side currents of the transformers (T1,T2,T3). Each transformer (T1,T2,T3) includes a plurality of secondary-side windings.

A tunable inductor arrangement includes a first winding part connected at one end to a first input of the inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the inductor arrangement, and a fourth winding part connected at one end to the other end of the third winding part. For tuning, the inductor arrangement includes a switch arrangement switchable between a first setting series-connecting the first and third winding parts between the inputs, and a second setting series-connecting the first, second, fourth and third winding parts between the inputs. The first and third winding parts are arranged on a chip or substrate with essentially common magnetic fields, and the second and fourth winding parts are arranged to cancel electro-magnetic coupling with the first and third winding parts.

A container arrangement for a transportable power transformer unit includes at least one container in which a first cable drum is situated. A first high-voltage cable having a first length and being configured for an operating voltage A, is wound on the first cable drum. In order to further shorten the commissioning of the power transformer unit, at least one further cable reel is disposed in the container. A further high-voltage cable having a different length is wound on the at least one further cable reel. Each further high-voltage cable is configured for the operating voltage A.

A transformer assembly and method(s) of use thereof is described. Embodiments of the transformer assembly can include, but are not limited to, a transformer, a plurality of secondary bushings located on a secondary side of the transformer, a plurality of secondary probe blocks, and a plurality of secondary parking ports. The plurality of secondary probe blocks are each configured to be inserted into either one of the plurality of secondary bushings or one of the plurality of secondary parking ports. When inserted into the secondary bushing, the secondary probe block and associated service wires can be energized at a secondary voltage. When inserted into the secondary parking port, the secondary probe block and associated service wires will be de-energized.

A tunable inductor arrangement includes a first winding part connected at one end to a first input of the inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the inductor arrangement, and a fourth winding part connected at one end to the other end of the third winding part. For tuning, the inductor arrangement includes a switch arrangement switchable between a first setting series-connecting the first and third winding parts between the inputs, and a second setting series-connecting the first, second, fourth and third winding parts between the inputs. The first and third winding parts are arranged on a chip or substrate with essentially common magnetic fields, and the second and fourth winding parts are arranged to cancel electro-magnetic coupling with the first and third winding parts.

This present disclosure discloses a transformer. The transformer comprises a lithium battery pack, a transformer coil and 2N switches. The lithium battery pack comprises N single batteries connected in series. The transformer coil comprises a magnetic core, N first windings and N second windings. The N first windings combined into one strand, the N second windings combined into one strand, are then wound on the magnetic core respectively. The N first windings and the N second windings have same number of coil turns, same homonymous ends and same common ends. Two ends of each single battery are connected with one first of the first windings and one of the second windings in parallel respectively. Each first winding is connected with one switch in series. Each second winding is connected with one switch in series. N is a natural number greater than or equal to 1.

An electronic circuit of an electronic pen includes an integrated circuit, and a resonant circuit that is formed of a parallel circuit of a coil and a first capacitor and is externally connected to the integrated circuit. The integrated circuit includes a variable-capacitance circuit which, in operation, adjusts a frequency of the resonant circuit, and has a connection pin connecting the variable-capacitance circuit to outside of the integrated circuit. A first end of the parallel circuit is grounded and a second end of the parallel circuit is connected to a first end of a second capacitor externally connected to the integrated circuit. A second end of the second capacitor is connected to the connection pin of the integrated circuit and is connected to a diode which, in operation, clamps a potential of the second end of the second capacitor to a predetermined value.

Provided is a method for servicing a transformer, especially a transformer of a wind turbine, wherein a lifting device is used to lift a lid that closes a case of a transformer from the case to expose at least one electrical component of the transformer that is connected to the lid for exchanging or servicing the electrical component, wherein the lifting device includes at least one fixed component that is fixed with respect to the case and at least one moveable component that is coupled to the lid, wherein the moveable component is moveable with respect to the fixed component by at least one actuator to lift the lid.