An instrument transformer for high current and/or high voltage conversion has a housing and at least an active part, which is electrically insulated by an isolation material. The isolation material includes particles. A method for the instrument transformer includes the filling of a housing of the instrument transformer with particles, particularly with particles of paper material and/or cellulose, which were impregnated by an insulating fluid, particularly mineral oil and/or a synthetic oil, and/or ester, particularly vegetable esters.

The present disclosure relates to a transformer system comprising a power transformer including a metal tank filled with an electrically insulating liquid, and a wireless sensor arrangement submerged in the insulating liquid within the tank. The sensor arrangement includes a radio transmitter for wirelessly transmitting sensor readings to the outside of the transformer through an opening in the tank, said opening being provided with a liquid-tight seal comprising a solid insulator for preventing leakage from the tank of the insulating liquid and wherein the radio transmitter is configured for transmitting the sensor readings using a carrier frequency within the range of from 100 kHz to 1 MHz.

The present invention relates to gas-insulated electrical apparatuses, in particular gas-insulated transformers or reactors, comprising a housing enclosing an interior space, in which an electrical component comprising a winding is arranged, at least a portion of the interior space defining an insulation space which is filled with an insulation fluid electrically insulating at least a part of the electrical component from the housing. According to the invention, the electrical apparatus further comprises a cooling element comprising a condenser, an evaporator and a cooling fluid to be circulated between the condenser and the evaporator. The evaporator is designed such that at least a part of the electric component is immersed in the cooling fluid in its liquid state, thus being in direct contact with the cooling fluid.

Multiple methods are provided to paint a body of an inductor so that there is no residual glue remained in the lead that may cause extra cleaning work and soldering issues when the lead is soldered with an external circuit.

A current converter with fluid or oil paper insulation for high voltage, with a head housing through which a primary conductor passes. A measurement device through which the primary conductor passes is arranged in the head housing. The primary conductor includes two different primary conductor types, more specifically an outer tube primary conductor as the first type and one or more inner conductor primary conductors as the second type. The outer tube primary conductor surrounds an interior that is designed to receive the inner conductor primary conductor, and the inner conductor primary conductors can be inserted into the interior. The outer tube primary conductor is used to transmit power and creates an encasement for the inner conductors. Only the outer tube primary conductor needs to be sealed with respect to the head housing. Inner conductors therefore can be easily inserted or re-moved subsequently, without the need for sealing measures.

An electric device, for example a track transformer, connects to a high-voltage line. The electric device has a magnetizable core, at least one winding which is arranged in the vicinity of the core, and a housing which is filled with an insulating fluid and in which at least one winding is arranged. The core is arranged at least partly outside of the housing. In order to allow a stable mounting of a core formed of two halves, the core is arranged completely between two opposing pressing plates, between which tension elements for clamping the core extend.

A pressboard for high-voltage devices is disclosed. The pressboard has a density of 0.6-1.3 g/cm.sup.3 according to IEC60641-2, and includes 1-15% microfibrillated cellulose (MFC) based on the total dry weight of the pressboard. The pressboard also includes an insulation element. For example, the pressboard is impregnated with an electrically insulating compound. The insulation element may be used in a high-voltage device, such as a power transformer.

A method of manufacturing an electrical device includes providing a composition comprising a mixture of vegetable oil fatty acid esters as a dielectric fluid in an electrical apparatus. The mixture of castor oil fatty acid methyl esters can contain the methyl stearate in a mass content of 1 to 20% to total amount of the mixture, the methyl oleate in a mass content of 1 to 90% to total amount of the mixture, the methyl linoleate in a mass content of 1 to 80% to total amount of the mixture, the methyl palmitate in a mass content of 1 to 50% to total amount of the mixture, the methyl ricinoleate in a mass content of 0 to 4% to total amount of the mixture, and the 10-undecylenic acid in a mass content of 0 to 1%.

An electrical device for connection to a high-voltage system has a tank filled with insulating fluid. The tank has at least one side wall forming a planar wall portion and a radially outwardly curved bulging/convex portion, which increases the interior volume of the tank. An active part with a core and at least one winding is arranged in the tank. A winding barrier system encloses one or more windings. The convex bulging portion has a shape that complements a portion of the winding barrier system and lies opposite it at a distance, such that the electrical device has increased dielectric strength. An additional barrier is disposed between the winding barrier system and the convex bulging portion which has a round portion, bent radially outwards and facing the convex bulging portion, and two planar flat portions, which at an axial crease respectively extend out of the round portion towards a free end.

The present invention relates to an On-Load Tap Changer (OLTC) for connection to a regulating winding of a transformer, the regulating winding enclosed in a transformer tank, wherein the transformer tank includes insulating liquid, the OLTC comprising: a switching device including: a main contact, and a resistor contact, wherein the main contact and the resistor contact are configured to be arranged directly in the insulating liquid and that they are configured to be physically separated from the insulating liquid, and wherein the main contact is enclosed in a main contact enclosure and the resistor contact is enclosed in a resistor contact enclosure. The present invention further relates to a transformer comprising the OLTC as disclosed herein.