An on-load tap-changer uninterruptedly operates a diverter switch between different winding taps of a tap-changing transformer. The on-load tap-changer has an on-load tap-changer plate; a selector; and a diverter switch. The selector and the diverter switch are mounted on the on-load tap-changer plate.

An isolated power converter and a hydrogen production system are provided. An electrical connection structure in the isolated power converter includes N secondary winding output bus bars, N rectifier circuit input bus bars, and a positive-negative bus bar, where N is greater than or equal to 1. A secondary winding may include M tapping points, and the secondary winding output bus bar and the rectifier circuit input bus bar that correspond to the secondary winding each include M copper bars that are insulated and stacked. The M tapping points of the secondary winding overlap the M copper bars of the secondary winding output bus bar at input ends of the M copper bars, respectively. The positive-negative bus bar includes two copper bars that are insulated and stacked.

An electromagnetic induction device includes: a main tank, a magnetic core arranged in the main tank, an On-Load Tap Changer, OLTC, comprising: an OLTC tank mounted to the main tank, a fine selector, a diverter switch, a change-over selector, and a customer interface; and a barrier separating the main tank from the OLTC tank, wherein the diverter switch and the change-over selector are arranged in the OLTC tank, and the fine selector and customer interface are arranged in the main tank, and wherein the barrier comprises a plurality of electrical connections configured to connect the diverter switch and the change-over selector to the fine selector.

An electrical device (10, 13), in particular a power transformer (13), a shunt reactor, or an on-load tap changer (10), comprises a housing (101, 131) that is filled or fillable with insulation oil (11, 11′); and a sensor (12) that comprises a piezo element (16) in the housing (101, 131) on a level with a minimum fill level (19, 19′) of the insulation oil (11, 11′); and an evaluation device (18) that is connected to the piezo element (16); wherein the evaluation device (18) is formed such that it can induce an oscillation of the piezo element (16);
and it can determine the fill level from a measurement of a characteristic of the oscillation, in particular the half-life period of the amplitude of the oscillation.

The present invention relates to a contact unit for changing over between winding taps on a control winding of a tapped transformer. Such a contact unit can be used particularly preferably for electrical switchgear in high-voltage engineering, such as selector switches or changeover switches. A common feature of both kinds of device in this case is that the changeover between the winding taps on the control winding of the tapped transformer is accomplished without load current. The general inventive concept is to include the contact element of the contact unit in a separate contact housing, so that the contact element and the contact housing form a separate assembly and so that the contact housing, including the contact element, can be fixed in a recess provided in the contact mounting by means of a retaining element.

Disclosed is a phase shift transformer for supplying voltage to a plurality of unit power cells in a medium voltage inverter system. The phase shift transformer according to the present invention comprises a first bushing arranged by the side of a tank and connected to a first winding to apply high voltage and a plurality of second bushings arranged on the top of a cover and connected to each of a plurality of second windings to output low voltage, wherein three outputs of the plurality of second bushings can be applied to unit power cells.

A visual status indicator for an electrical apparatus is disclosed. The status indicator can be mounted within a lower cover of the electrical apparatus such that various display faces of the indicator are visible through one or more viewing windows of the lower cover. The status indicator can comprise a mounting base with protrusions and at least one wing, wherein the wing comprises at least one display face. At least one swing arm can be attached to the mounting base via the protrusions and the at least one swing arm can comprise at least one display face. The swing arm can be actuated such that either the display face on the wing or the display face on the swing arm is visible through the viewing window to indicate the status of the electrical apparatus.

The invention relates to a switch assembly (1), in particular a preselector, for a variable transformer (4) having a first winding (2) and a second winding (3) with a first and a second tap (3.3, 3.4), said switch assembly comprising: a first connection terminal (2.1) that can be connected to the first winding (2); a second connection terminal (3.1) that can be connected to the first tap (3.3); a third connection terminal (3.2) that can be connected to the second tap (3.4); a first, second, third and fourth fixed contact (5.1, 5.2, 5.3, 5.4); a vacuum interrupter (6); a first moving contact (7) that can be contacted selectively with the first or second fixed contact (5.1, 5.2); a second moving contact (8) that can be contacted selectively with the third or fourth fixed contact (5.3, 5.4), wherein the second and the fourth fixed contact (5.2, 5.4) are connected to the second connection terminal (3.1), the first and the third fixed contact (5.1, 5.3) are connected to the third connection terminal (32), the first moving contact (7) is connected to the first connection terminal (2.1) via the vacuum interrupter (6), and the second moving contact (8) is connected to the first connection terminal (2.1).

Disclosed is a suspensible external combined on-load tap changer, including: a switch box, a switch body and a motor mechanism, a top box wall of the switch box being opened with a top opening, a top box cover being mounted on the top opening, wherein the switch body is detachably mounted in the switch box and is entirely lifted in and lifted out by the top opening; and the motor mechanism is connected with the switch body in a driving manner. The switch body in the present invention uses a hoisting structure, and the top box wall of the switch box is opened with a top opening with a size large enough, so that the switch body is directly lifted in and lifted out of the switch box from the top opening, and installation and maintenance are easier.

A switching arrangement (1), in particular a polarity switching means, for a control transformer (10) which comprises a first winding (2) for a phase of an AC power supply system, which phase is to be controlled, comprises—a first connection terminal (1.1) which can be connected to the winding (2);—a second connection terminal (1.2) which can be connected to a discharge line (3);—a vacuum interrupter (4);—an isolator (5);—a resistor (6) which is connected in series with the vacuum interrupter (4) and the isolator (5); wherein—the first connection terminal (1.1) is connected to the second connection terminal (1.2) by means of the series circuit.