Abstract: The subject of the application is a power electronic tap changer module for transformer using power electronic elements connected to sections of a primary winding of the transformer. The power electronic tap changer module is equipped with valves having a pair of a thyristor or transistors connected with a controller and the valves are connected in series with the fuses, respectively. The module is equipped with an additional oversized tap line having an oversized valve rated for short circuit current, which valve is connected with an overvoltage triggering circuit. The oversized valve is equipped with a pair of thyristor or transistors connected with a thermally protected voltage suppressing device.

Abstract: The subject of the application is a power electronic tap changer module for transformer using power electronic elements connected to sections of a primary winding of the transformer. The power electronic tap changer module is equipped with valves having a pair of a thyristor or transistors connected with a controller and the valves are connected in series with the fuses, respectively. The module is equipped with an additional oversized tap line having an oversized valve rated for short circuit current, which valve is connected with an overvoltage triggering circuit. The oversized valve is equipped with a pair of thyristor or transistors connected with a thermally protected voltage suppressing device.

Abstract: A coil assembly for a dry high-voltage transformer, having at least one coil with hollow cylindrical electrical winding and with taps, wherein the coil is surrounded at least on its radial outer surface by stiff insulation material, wherein a tap-changer is casted on the outer surface of the insulation material, which is electrically connected to the taps, wherein the electrical connection of at least some of the taps is guided at least in part through the insulation material. The tap-changer may be surrounded by a casting material.

Abstract: The invention relates to a device for measuring the direct component of alternating current, applicable in current measuring systems where a low direct component of alternating current and a high amplitude of the alternating component of alternating current occur. The device for measuring the direct component of alternating current comprises a current-carrying wire (1) around which there is located a magnetic core (2) provided with a gap (3) in which a magnetic field sensor (4) with insulated terminals (5) is located and it comprises a shorted compensating winding (6) or (9) which is made in the form of a single turn coil placed on the core (2).

Abstract: A device for suppressing very fast transients, applicable in protecting electric and/or electric power equipment, and especially transformers operating in electric power substations and in wind power plants, connected in a supply network circuit downstream of a circuit breaker and upstream of the protected equipment is disclosed. The device is a component of an induction character, comprising a high-frequency magnetic core arranged around the current-conducting lead. On the magnetic core is wound at least one winding with at least one pair of terminals used for connecting at least one damping resistor. The inventive device contains an insulating body in which there is a magnetic core, a damping resistor and a winding, or an insulating body in which there is a magnetic core together with a damping resistor, a winding and a section of a current-conducting lead.

Abstract: The invention relates to a device for measuring the direct component of alternating current, applicable in current measuring systems where a low direct component of alternating current and a high amplitude of the alternating component of alternating current occur. The device for measuring the direct component of alternating current comprises a current-carrying wire (1) around which there is located a magnetic core (2) provided with a gap (3) in which a magnetic field sensor (4) with insulated terminals (5) is located and it comprises a shorted compensating winding (6) or (9) which is made in the form of a single turn coil placed on the core (2).

Abstract: The subject of the invention is a device for suppressing very fast transients (1, 1a, 1b), applicable in protecting electric and/or electric power equipment, and especially transformers operating in electric power substations and in wind power plants, connected in the supply network circuit downstream of the circuit breaker and upstream of the protected equipment. The device according to the invention is a component of an induction character (1, 1a, 1b), comprising a high-frequency magnetic core (2) arranged around the current-conducting lead (3). On the magnetic core (2) there is wound at least one winding (4, 4a) with at least one pair of terminals (6) used for connecting at least one damping resistor (7).