Abstract:
The subject of the invention is an on-load power electronic tap changer with passive power electronic valves, having application in power or distribution transformers. The on-load power electronic tap changer comprises a control module (7) and a power electronic tap-changer module (1), which comprises a plurality of power electronic valves (V1... Vn). Each of the power electronic valve (V1... Vn) is connected with the control module (7) by an optical connector (C1... Cn) and comprises a main valve module (8) for current conduction between a first and second terminal. The first terminal is connected to a voltage source and the second terminal is connected to a transformer tap. Every single power electronic valve (V1... Vn) of the on-load power electronic tap changer is galvanically isolated from the control module (7) by optical connections (C1... Cn). The power electronic valve (V1... Vn) is adapted for triggering the main valve module (8) through the optical connector (C1... Cn) by a triggering circuit (9). The triggering circuit (9) is powered from voltage between the first and the second terminal. The power electronic valve (V1... Vn) can be also adapted for triggering the main valve module (8) directly through the optical connector (C1... Cn).
Abstract:
The present invention relates to a disconnecting system (1;1') for current interruption in a transformer which transformer has vacuum interrupter (7) as current interrupting element placed inside the tank (2) of the transformer filled with the insulation medium (3).The vacuum interrupter (7) is equipped with a fixed contact (7b) and a movable contact (7a) and the movable contact (7a) of the vacuum interrupter (7) is connected mechanically with an elastic membrane (9) closing the compartment (10) of a bi-stable actuating device (8; 8') and the membrane (9) is in contact with a compressible medium (11) filling the compartment (10) and being in contact with the insulation medium (3) of the transformer.
Abstract:
The present invention relates to a primary coil suitable to use in a transformer and a method for manufacturing a primary coil suitable to use in a transformer. A primary coil suitable to use in a transformer comprising a primary winding bobbin (4) on which a layer of a primary winding (5) and at least one layer, preferably a fixed number of 1 to 3 layers, of an interlayer insulation material are wound alternately, wherein the interlayer insulation material and the primary winding (5) are impregnated with an epoxy (11), wherein the interlayer insulation material is a nonwoven material or a crepe paper.
Abstract:
The present invention relates to an overvoltage protection circuit for power electronic devices. The circuit comprises a thermistor being either a positive temperature coefficient thermistor (PTC) or a polymer fuse (CTR). The thermistor is connected in series with a thyristor crowbar circuit, a triac crowbar circuit or a breakover diode crowbar circuit. Such arrangement provides a new way of overvoltage protection to power electronic devices such as power electronic tap changers or power supplies.
Abstract:
The subject of the invention is a conductive screen for power electronic elements enclosed in insulating medium and working on high voltage potential having an application in energetic industry, specially designed for HV transformer. Conductive is characterized in that the power electronic element (1) is electrically connected with a heat radiator (8) having an external surface (8a) and a first conductive screen (10) is placed on the surface (8a) of the radiator (8). The first conductive screen is electrically connected with high voltage potential derived through a HV terminal (3). The conductive screen is adapted for shaping an electric field distribution between the potential of the screen (10) and a ground potential of the housing (5) filled-in with the insulating medium (6). The screen (10) is attached to the flat surface (8a) of the heat radiator (8) in such a way that the sharp edges of the radiator (8) and the power electronic device (1) are encircled by the screen (10) and a second conductive screen (10') is placed in the insulating medium (6) and the second screen (10') is electrically connected with the first screen (10).
Abstract:
A magnetic actuator for low-voltage electric systems, wherein magnetic actuator comprises a magnetic circuit including: - a fixed magnetic armature and a movable magnetic armature, said movable magnetic armature being movable between a first position and a second position relative to said fixed magnetic armature; - a permanent magnet configured to feed said fixed and movable magnetic armatures with a first magnetic flux having a predefined direction, when said permanent magnet is in a magnetized condition; wherein said magnetic actuator further comprises an excitation coil magnetically coupled to said magnetic circuit and configured to be fed with an electric current, when a tripping manoeuvre of said magnetic actuator is required, wherein the magnetic circuit has three branches forming two magnetic loops having a branch in common.
Abstract:
The subject of the invention is a split-core coupler for inductive power transfer, and more specially the invention relates to the split-core coupler used in wireless charging system in which the supply and receiving side are separated by some insulating gap having a specially designated thickness ensuring relatively large value of the coupling coefficient and, at the same time, enabling for movement of a transmitter relatively to a receiver or vice versa in an improved way. The invention is characterized in that the two parts (A) and part (B) of the split-core transformer are movable connected together during the matching and also during a charging process. The second core column (4) which is placed between the yokes (1) has at least three degrees of freedom in horizontal, vertical and torsional directions or combinations of all these directions during the charging process when the magnetic circuit of the split-core coupler is closed.
Abstract:
The subject of the invention is a catenary line test device (7) for a main circuit breaker (6) of an AC catenary line system (1). The invention is used for detection of short circuit in AC catenary line system (1) prior to closing, the main circuit breaker (6). The catenary line system (1) is powered by through connecting terminals first (4) and second (5) and the main circuit breaker (6) is connected to the overhead line (2) and a load (8) is connected between the overhead line (2) and a return grounding line (3). The catenary line test device (7) is adapted to prevent of closing the main circuit breaker (6) on short-circuited overhead line (2), and the test device (7) comprises a capacitor circuit (103) and an impulse generator circuit (104) connected in series. To the capacitor circuit (103) a measuring and control circuit (105) is connected for providing a half period of an electrical impulse generated in the impulse generator circuit (104), causes the flow of the supply current into the catenary line system (1) through the first connecting terminal (4).