Abstract: The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system for an electrical machine. For example, a corona shielding system may include: an outer corona shield and an overhang corona shielding. The outer corona shielding and the overhang corona shielding may comprise a first corona shielding material having a nonlinear field strength-dependent electrical resistance.

Abstract: The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially for an electrical machine, e.g., a high-voltage machine, such as a generator for generation of electrical energy, an electric motor, or another piece of electrical equipment having a relatively high rated voltage, e.g., a transformer or a bushing or a cable. A corona shielding system may include: a polymeric matrix; and filler particles comprising mica surrounded by a layer of at least one ceramic metal oxide. The filler particles may be distributed throughout the polymeric matrix.

Abstract: The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially an outer corona shielding system, for an electrical machine. For example, a corona shielding system may include: a polymeric matrix; particles disposed in the matrix, including a mica-coated core and a layer of metal oxide disposed on the core; and a surface functionalization material disposed on a surface of the particles for binding to the matrix.

Abstract: An electric switching device may include at least two conductor elements that can be placed at a distance from one another and contacted with each other using a moving mechanism, and a housing that defines a circuit breaker chamber, wherein the housing is made of an insulator, and at least partly surrounds the conductor elements. At least one face of the housing may have a resistive coating made of a matrix material filled with a filler, wherein the coating has a sheet resistance between 108 and 1012 ohm at the operating field strength, and is conductingly connected to the conductor elements.

Abstract: The invention relates to a heating circuit for induction heating coils of an induction cooking hob and to an induction cooking hob including such a heating circuit. In the heating circuit, there are in each case two auxiliary half bridges interconnected to excite a respective resonant circuit for an induction heating coil such that the resonant circuit is excited by a full bridge. Thereby, lost heat is considerably reduced. Via a connecting device the auxiliary half bridges can be controlled to excite induction heating coils, which are partly or fully covered by a cooking vessel.

Abstract: An insulating tape in the form of a particle composite for an electrical insulating tape, use of such insulating tape as insulation, and the production of the insulating tape are disclosed. To produce the insulating tape, electrically insulating, platelet-shaped particles are connected by an electrically insulating binder to an electrical insulating material in the form of an at least partially porous insulating tape. The insulating tape may be windable on a conductor structure when wound under exerted tension force, namely without addition of a materially additionally impeding heat flow. A thermal conductivity which is greater relative to the prior art may help prevent heat accumulation and total failures, e.g., of main insulation.

Abstract: A rotary tool for machining workpieces, comprising at least one main body with a clamping segment, a tool head comprising a cutting region, and at least one coolant channel for feeding a cooling and lubricating fluid into the cutting region. At least one partial surface section of the cutting region forms a hardened region, which covers and/or defines the coolant channel and is surface-hardened. A method for producing a rotary tool.

Abstract: By performing a method for transmitting to a reading device data of a sensor that is allocated to an inductively heated cooking vessel, a high frequency control voltage is generated from a mains alternating voltage by means of a converter, wherein the high frequency control voltage is applied to an oscillator circuit having an induction heating coil in order to generate a high frequency magnetic alternating field for heating the cooking vessel.

Abstract: A corona shielding paper for use in a corona shielding system for an electric machine, e.g. a high-voltage machine, may be produced by compacting partial discharge-resistant, planar, conductive particles but can include both reinforcement fibers and a woven fabric.

Abstract: A surface coating for lightning protection is embodied as a composite material including a matrix formed from a polysilazane or of a polysiloxane, and filled with lamellar, ceramic particles having an electrically conductive coating of metal oxide. The surface coating may be applied to a blade of a wind turbine by applying the conductive coating in liquid form to the blade, allowing the surface coating to harden at room temperature, and pyrolyzing the surface coating via short periods at temperatures up to 700° C. to form a glassy, electrically conductive coating that is resistant to temperature changes.

Abstract: A corona shielding system for an electric machine, for example a high-voltage machine, such as a generator, for generating electrical energy, an electric motor or else other electric operating means having a relatively high rated voltage, such as transformers, bushings, cables, etc, is disclosed. The corona shielding system may include a filler mixture including both planar and spherical particles. Therefore, the electrical conductivity, which is good in the presence of only planar particles in two spatial directions but is very poor in the third, can be adjusted anisotropically in a targeted manner.

Abstract: A varistor, or voltage-limiting composition has a polymer matrix and a particulate filler containing a partially conductive material applied to an electrically non-conductive carrier material. The carrier material has a lower density than the partially conductive material, so that the settling rate of the filler in the polymer matrix is reduced. The voltage-limiting composition can therefore also be used as a lacquer or for prepreg materials. A body which acts as a varistor may be produced using a composition of this kind by a method that includes annealing. The varistor may be used for surge arresters, in particular in medium-voltage systems, low-voltage systems, cable connections and cable fasteners.

Abstract: An electrical conduction device is provided having an electrically conductive conduction element and an electrically insulating sheathing surrounding said conduction element at least in regions. An overhang corona shielding in the form of a coating composed of a material having a resistivity that increases towards an end of the sheathing is arranged on the sheathing at an outer side. An overhang corona shielding arrangement and a method for producing an overhang corona shielding are also provided.

Abstract: A resistance covering for a DC insulation system may be a matrix material with particles embedded therein, the particles having an aspect ratio greater than 1. The matrix material is flexible to such an extent that the particles align depending on an electric field strength. The particles can align in the electric field and thus a breakdown voltage of the resistance covering is increased. A DC insulation system may have the resistance covering.

Abstract: A widening bar, which has main insulation with first and second layers is used as an insulation arrangement for a high-voltage machine. The first layer has platelet-shaped mica particles and the second layer has platelet-shaped aluminum oxide particles. The insulation arrangement may be used in a generator and the method of producing the insulation arrangement is described.

Abstract: A method and device for forming corona shielding on a winding bar for high-voltage machines has end corona shielding in a first section and outer corona shielding in a second section that adjoins the first section. The method includes providing a first composition, including a carrier material and a first filler therein and a first electrical resistance; providing a second composition, including the same carrier material and a second filler therein and a second electrical resistance, wherein the first and second fillers contain an identical dopable semiconductor material, doping of which determines electrical resistance of the first and second fillers, and wherein the second resistance differs from the first resistance; applying the first composition in the first section to form the end corona shielding; and applying the second composition in the second section to form the outer corona shielding.

Abstract: A thermoelectric generator pipe for producing electrical energy, surrounds a heat source or a heat sink. The generator pipe is formed by a helix structure having an inner and outer conductor strips that are electrically conductive. The conductor strips have substantially the same width and are wound with the same pitch. Between the inner and outer conductor strips, first and second intermediate axial spaces are formed, which are each arranged between one edge of the inner conductor strip and the edge of the immediately adjacent outer conductor strip. The intermediate spaces are formed as a double helix. First and second layers are arranged respectively in the first and second intermediate spaces. The first and second layers are formed respectively from n-doped and p-doped, thermoelectric and percolating particles. The generator pipe is slit subdivided in the axial direction to produce sections that form thermoelectric elements connected in series.

Abstract: A method is provided for producing an electrical insulation paper having a particle composite. The method involves mixing a dispersion of particles in platelet form, a carrier fluid and a functionalizing agent which is distributed in the carrier fluid and has a proportion by mass in the dispersion corresponding to a predetermined mass ratio based on the proportion by mass of the particles. The dispersion is sedimented, such that the particles in platelet form are arranged in essentially plane-parallel layers in the sediment. The carrier fluid is removed from the sediment. Energy is introduced into the sediment to overcome the activation energy of that chemical reaction of the functionalizing agent with the particles which forms the particle composite from the sediment with coupling of the particles via the functionalizing agent. The mass ratio is predetermined such that the particle composite has a porous structure. The insulation paper is thereby produced.

Abstract: By performing a method for transmitting to a reading device data of a sensor that is allocated to an inductively heated cooking vessel, a high frequency control voltage is generated from a mains alternating voltage by means of a converter, wherein the high frequency control voltage is applied to an oscillator circuit having an induction heating coil in order to generate a high frequency magnetic alternating field for heating the cooking vessel.

Abstract: An electrical conduction device is provided having an electrically conductive conduction element and an electrically insulating sheathing surrounding said conduction element at least in regions. An overhang corona shielding in the form of a coating composed of a material having a resistivity that increases towards an end of the sheathing is arranged on the sheathing at an outer side. An overhang corona shielding arrangement and a method for producing an overhang corona shielding are also provided.