SU1007141A1 - High-voltage safety cutout - Google Patents

Description

power industry, and more specifically to emergency devices to disconnect high-voltage devices and sources of electricity. A high-voltage fuse is known, comprising a housing in which a gas-generating (paraffin) cylindrical tube is installed, in the cavity of which is an arc-suppressive l channel, with a gap in relation to the inner walls of the tube, the exploding conductor is fixed l arcing channel and explosive conductor, which reduces the reliability of operation and complicates the manufacturing technology of the fuse, since it is necessary to withstand a certain diameter new handset. Due to the fact that there is a gap between the explosive conductor and the tube walls, unfilled with the gas-generating material, and in order to avoid repeated breakdowns, the fuse must have a greater length with a voltage of 50 KB and its length reaches 0.9 m). Due to the large length of the arcing channel, which is also a channel for exhausting gases (explosion products) into the exhaust chamber located at the end of the channel, the exit time of the explosion products becomes longer, and the explosion products are concentrated near the current path, which contributes to repeated breakdown of the fuse. Also known is a high-voltage fuse containing a fuse-insert installed in the gas-generating tube, which is located with a gap in the housing, provided with an end opening through which the gap between the gas-generating tube and the housing communicates with the atmosphere, and the gas-generating tube is formed with transverse cylindrical holes for exhaust gas in specified clearance; The presence of these transverse holes increases the breaking capacity of the fuse 2. However, the location of the exhaust from the body version at its end makes it difficult for gases to exit the specified gap and reduces the efficiency of the transverse gas blowing. The disadvantage of these fuses is the occurrence of overvoltages due to the high rate of current change when an electrical circuit is broken with a fuse, which leads to insulation breakdown and short circuits in the protected sources and devices. The high-voltage fuse containing the installed fuses is the closest to the invention. in an insulating body, at least two electrostatically destructive inserts with equal specific sublimation energies and with different resistances and are full and energies E sublimation, and arc excipient. In this fuse, the inserts are located in a common case covered with quartz sand. The inserts are made of the same material, but have different lengths and cross sections, which ensures their sequential operation and reduction of overvoltages when the inserts operate in the 3J melting mode. A disadvantage of the known fuse is a significant amount of overvoltages occurring during switching off, especially when the fuse is operating in the mode of explosion of the inserts. The purpose of the invention is to reduce overvoltages in the process of shutdown in the explosion mode by reducing the rate of decay of the current to be switched off. The goal is achieved by the fact that in a high-voltage fuse containing at least two inserts destroyed by an electric current with equal specific sublimation energies and different electrical resistances and full sublimation energies installed in an insulating body, the body is made with arcing analog 1 and according to the number of destructible inserts, completely filled with arcing filler, each of which has a corresponding insertion, as arcing on the gasifier material is selected, the electrical resistances of the inserts differ by an order of magnitude, and the ratio of the total sublimation energy of the insert with lower electrical resistance to the total sublimation energy of the insert with high electrical resistance is selected in the range from 1.05 to 1.3. 31 In addition, in order to increase the breaking capacity, the casing is made with an exhaust channel connecting the arcing channels to the atmosphere and located perpendicular to the arcing channels, with the diameters of the exhaust and arcing channels being comparable. FIG. 1 shows the fuse in perspective, the general view; in fig. 2 - fuse housing cover, top view; in fig. 3 shows section A-A in FIG. in fig. - fuse with removed housing cover, top view; FIG. 5 is a section BB in FIG. if; in fig. 6 is a sectional view BB in FIG. k, The fuse contains a composite case, made in the form of a cover 1 and a lower part 2, interconnected by bolts 3. In the lower part 2 of the case there are current conductors k connected by inserts destroyed by electric current (explosive with conductors) 5i installed in arcing channels 6 , made in the lower part 2 of the case and completely filled with gas-generating arcing filler. Perpendicular to the arc extinguishing channels Lam 6 there is an exhaust channel 7, also made in the lower part of the housing. The housing cover 1 (Fig. 2 and 3) is made with holes 8 for bolts 3. The bottom part 2 of the case (Fig. K is made with holes 9 for bolts 3. Current leads k are attached to the bottom part 2 of the case with screws 10 and have holes 11 for attachment to external elements (not shown). When an overload current occurs in a protected circuit, a conductor with higher conductivity and less resistance first begins to explode due to an increase in resistance of this conductor during an explosion (by about an order) most of the current branches second conductor te The most slowing down is the supply of energy J4 to the first conductor and the speed of its explosion decreases. In the process of explosion the second conductor in turn increases its resistance and most of the current branches into the first conductor. This is how energy is transferred from one conductor to another. Experiments have shown that the choice of conductors with the same specific energy of sublimation and exceeding the total energy of sublimation of a conductor with a lower electrical resistance by one, allows us to provide practical ski simultaneous occurrence of explosion ustano- processes and build the necessary priority to explosion; Wah one of the conductors. The combined explosion of conductors reduces the steepness of the drop-off current, and thereby eliminates the occurrence of dangerous overvoltages on the disconnected devices. In this case, the off time is slightly increased compared to the off time of the fuse with parameters other than the specified parameters of this fuse. As experiments have shown, when choosing the ratio of total energies of sublimation of conductors smaller than 1.05, the necessary priority for the explosion of one of the conductors is not ensured, and when choosing this ratio, greater than 1.3. the second conductor explosion occurs after the end of the explosion of the first conductor. In either case, the slope of the current increases, and overvoltages occur on the protected equipment. The use of a transverse exhaust duct allows for the effective removal of ionized gases from arcing ducts and increases the breaking capacity of the fuse. Thus, the proposed fuse favorably differs from the known one and allows to ensure the arc-free disconnection of high-current circuits without overvoltages.

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Claims (2)

1. HIGH-VOLTAGE SAFETY CURRENT, containing at least two inserts with equal electrical sublimation energies and different sublimation energies and an arcing filler, installed in the insulating casing, with equal specific sublimation energies, characterized in that, in order to reduce overvoltages during shutdown in explosion mode by reducing the decay rate of the disconnected current, the housing is made with arcing channels by the number of destructible inserts, completely filled by the specified arc extinguishing filler, in each of which there is a corresponding insert, gas-generating material is chosen as the arcing filler, the electrical resistances of the inserts differ by an order of magnitude, and the ratio of the total sublimation energy of the insert with lower electrical resistance to the total sublimation energy of the insert with high electrical resistance is selected within 1 , 05 “o '> J” | 2. Fuse pop. 1, due to the fact that, in order to increase the breaking capacity in accordance with I *, the housing is made with an exhaust channel connecting I arcing channels with an at-2 atmosphere and perpendicular to the arcing channel, and the diameters of the exhaust and the arcing channels are selected commensurate. about 1067141>