Electrotechnical current limitation device
SUBSTANCE: electrotechnical current limitation device includes primary winding, secondary winding containing suppressed superconductor which is characterised by transition from condition with low resistance to condition with high resistance when electric current exceeds critical value. Secondary winding is connected to primary winding with common part of magnetic flow. In addition, secondary winding includes metal element (6) creating closed circuit, and cryostat (5) providing cooling of secondary winding. Besides it includes at least one element (3) arranged on considerable part of non-suppressed conductor characterised with minimum dependence of its resistance on current and magnetic field, and some part of suppressed superconductor. At least one loop of non-suppressed superconductor (3) and suppressed superconductor (2) are electrically connected in series, thus forming closed circuit.
EFFECT: reducing response time and providing the possibility of controlling it.
17 cl, 8 dwg
The present invention relates to the electrical device for limiting an electric current.
Electrical device for limiting an electric current is known from U.S. patent 5379020. The device current limit is sometimes referred to as a current limiter or current limiters damage or short circuit current. In U.S. patent 5379020 the current limitation is provided by the electrical device consisting of a primary winding, secondary winding, containing suppressed superconductor, for which a transition from a state with low resistance, usually denoted as the superconducting state, in the state of high resistance, if the electric current exceeds a critical value. The secondary winding is connected with the primary winding on the General part of the magnetic flux. The secondary winding further comprises a metal element forming a closed loop. The secondary winding is located in the cryostat, which provides cooling. Magnetic connection of the two windings is provided a ferromagnetic core.
The device current limit damage it is also known from U.S. patent 5,694,279. The device comprises a primary winding containing metal or alloy, and a secondary winding, comprising suppressed superconductor, characterized the clinical transition from a state with low resistance state with a high resistance when excess electric current critical value. Both of these windings are connected in the General part of the magnetic flux in the ferromagnetic core. The secondary winding is placed on a number of thin and flat disk substrate coated with a layer of suppressed superconductor, namely high-temperature superconductor. The discs are provided with Central holes, allowing you to install them in a cryostat and placed around the magnetic core. The secondary winding may also include a cylindrical substrate, covered with suppressed high-temperature superconductor.
Both the above-mentioned devices are designed to limit the electric current in the external circuit that is connected in series with the primary winding. They are suitable for restrictions over primary current. However, for some applications, the previous designs of the devices are too large response times and may be too slow for effective power management.
It is desirable to improve the characteristics of the device current limit to provide a more efficient power management for when you want a shorter response times, not only for providing fast protection schemes, but also to ensure the required performance when such protection.
The technical task of the present is asego invention is to provide a device for limiting an electric current with a low response time. Another object of the present invention is to provide a device with a controlled time of hail, which allows you to install, reinstall the response time. Another object of the invention is the creation of an electrical device having optimum cost.
The task is solved by creating a device, as claimed in the independent claims. The embodiments of the invention claimed in the dependent claims.
In accordance with the present invention, the electrical device comprises a primary winding, a secondary winding, containing suppressed superconductor. Suppressed superconductor is characterized by a transition from a state with low resistance state with a high resistance when excess electric current critical value. The secondary winding is connected with the primary winding of the General part of the magnetic flux. The secondary winding further comprises a metal element forming a closed loop. The electrical device further comprises a cryostat, providing cooling of the secondary winding.
The secondary winding includes at least one element or area that contains a significant portion nepotoplyaemogo Explorer and the suppressed part of the superconductor. Nepotoplyaemyi Prov is'dnik has a minimal dependence of its resistance to the current and magnetic field. Nepotoplyaemyi the conductor can have metallic properties. In this case, a substantial part of it must be more than 50% of the total volume. Part f nepotoplyaemogo conductor element of the secondary winding is 50%≤f≤95%, preferably 60%≤f≤95%, more preferably 75%≤f≤95%, even more preferably 80%≤f≤90% by volume. The total volume of the element represents the sum of the parts nepotoplyaemogo Explorer and suppressed superconductor.
The secondary winding includes at least one coil containing nepotoplyaemyi Explorer and suppressed the superconductor, electrically series-connected to provide a closed loop.
The design or layout of the secondary winding in accordance with the invention provides more uniform suppression suppressed superconductor and reducing the response time of the device as a whole.
The electrical device may also optionally contain an iron core.
Nepotoplyaemyi guide in this electrical device can be a metal with high conductivity, such as Cu, Ag, Au, Al, In or the superconductor. In one embodiment, the implementation suppressed superconductor is a so-called low-temperature superconductor such as Nb3Sn or NbTi, if the device is intended to work is at low temperatures, that is, at temperatures of 2-10K.
In another embodiment, the implementation suppressed superconductor composition contains, based on the connection ReBa2Cu3O7-xor fine mixture, where Re represents one or more rare earth elements, preferably one or more elements from the group of Y, Ho, Nd, La, Pr, Gd, Tb, Dy and Yb. Suppressed superconductor in this electrical device can be formed as a monolayer or may contain multiple layers forming the multilayer structure.
Layer ReBa2Cu3O7-xor the corresponding multilayer structure preferably are in the form of a coating on a metal tape substrate. One side or two opposite sides of the tape substrate can be covered with one layer based on ReBa2Cu3O7-xor a multilayer structure consisting of several monolayers ReBa2Cu3O7-x. The tape substrate may contain stainless steel or Hastelloy, or an alloy based on Ni or NiCr, so that its resistance was more than 80 µohm·cm (microohm per centimeter). Tape-substrate may also optionally contain one or more additional buffer layer located between the surface of the metal substrate film and the superconducting layer. The buffer layer can prevent nagulat the global chemical reaction between the metal tape substrate and the superconductor.
Electrical connection suppressed conductor nepotoplyaemyi conductor is achieved by applying a layer of the normal conductor, for example, In, Cu, or Pb, or a layer of a superconductor, for example, BiSCCO, i.e. Bi2Sr2CaCu2Oxor (BiPb)2Sr2CaCu2Ox, Eu(Bi)CO., or mixtures thereof, having a composition different from compositions used or suppressed in the superconductor, or nepotoplyaemomu Explorer.
In an additional embodiment, the implementation of the secondary winding of the electrical device contains a series of coils, each of which contains nepotoplyaemyi Explorer and suppressed the superconductor, in accordance with one variant of the invention.
In another embodiment, the implementation nepotoplyaemyi Explorer and suppressed conductor, forming a round, ensure the direction of the current along the perpendicular to the main axis of the magnetic flux. The magnetic flux may be provided with an iron core, which is surrounded by the primary and secondary windings.
In another implementation, at least one nepotoplyaemyi conductor and one suppressed conductor contains at least one plot to the current direction along the main axis of the magnetic flux. This allows you to reallocate current between the various coils and, thus, to get the desired response time condition the device as a whole.
In another embodiment, the implementation of the ratio of the geometric dimensions of various parts nepotoplyaemogo Explorer or/and different parts suppressed superconductor varies for different orbits nepotoplyaemogo Explorer and suppressed superconductor. This embodiment provides an effective opportunity to achieve a given response suppression.
In yet another variant of realization of the relationship of the geometric dimensions of various parts nepotoplyaemogo Explorer or/and different parts suppressed superconductor followed by a numeric sequence or form a smooth distribution function. This helps to avoid surges during the crackdown.
In the latter case the implementation of the width of the distribution function determines the temporal characteristic of the device, i.e. the response time of the device. In the case where the secondary winding has a number of turns, suppressed the superconductor may contain multiple tapes, coated with the composition ReBa2Cu3O7-x.
If the secondary winding has many tapes coated with the composition ReBa2Cu3O7-xthen the secondary winding may contain at least two ribbons, characterized by different threshold values of the electric current that causes the process of suppression. At m is re, two tapes may have different superconducting properties, such as the Jc(critical current density) or Twith(the critical temperature). This provides additional freedom in the management of the response function of the device and, thus, provides the desired response time.
In a variant implementation of the invention cryostat contains at least one metal wall forming a closed path containing at least a portion of the total magnetic flux.
The metal element and the metal wall of the cryostat can be one and the same element of the electrical device.
The response time may be subject to replacement, or partial replacement, the metal element of the secondary winding of the "external" element of the cryostat.
Electrical device in accordance with the invention may have an optimum value if the number of suppressed superconductor device significantly, by 50-90%, compared with the known technical solutions. Superconducting tapes and, in particular, the superconducting tape with a coating manufactured through steps of vacuum deposition, are relatively expensive to manufacture. Since the secondary winding of the device current limit according to the invention contains significant is the preliminary part nepotoplyaemogo Explorer, the suppressed part of the superconductor is reduced. In addition, the manufacturing cost of the cryostat is reduced due to the fact that, in accordance with the present invention part of the cryostat can be made of conventional metal elements.
Described below are preferred examples of the implementation of the electrical device to limit current in accordance with the present invention with reference to the accompanying drawings, in which
Figure 1 depicts the scheme of the first implementations of electrical device according to the invention;
2 is a diagram of one turn of the secondary winding formed by the electrical connection nepotoplyaemogo Explorer and suppressed superconductor, according to the invention;
Figure 3 diagram of the ring-variant coil secondary winding formed by the electrical connection nepotoplyaemogo Explorer and suppressed superconductor, according to the invention;
Figa-section of a second variant implementation of the electrical device according to the invention;
Fig.4b is a view along arrow x in figa, according to the invention;
5 is a layout of a number of turns of the secondary winding, according to the invention;
6 is another variation of the composition of a number of turns of the secondary winding, according to the invention;
Fig.7 is a variant of the "heterogeneous" layout number witch is in the secondary winding, according to the invention.
Figure 1 shows the scheme of the first implementations of electrical device in accordance with the present invention. The device comprises a primary winding 1, consisting of a normal metal conductor, for example, Cu or Al, and a secondary winding consisting of a number of turns. Each round contains nepotoplyaemyi conductor 3, representing in this case the wire or tape, and suppressed the superconductor 2, which in this case is a tape coated YBCO. Superconducting YBCO tape can be biaxially textured YBCO film or coating that can be deposited on one side or on opposite sides of the flexible, made of metal or alloy substrate film. One or more buffer layers also having biaxial texture can be placed between the tape substrate and the YBCO superconductor. Nepotoplyaemyi conductor 3 is suppressed, the superconductor 2 is electrically connected in series so that they form a closed circuit. The connection of these conductors is provided with the connecting pads 4. The connecting pad 4 facing towards the ends of the superconducting tapes 2 and the edges of the copper wire 3. In this embodiment, the implementation of the superconducting tape 2 is longer than the gap between the two ends of the copper wire, so that kr is I superconducting tape overlapping the edge of the copper wire. Thus, connecting the space formed by these overlapping areas. The connection between nepotoplyaemyi conductor 3 is suppressed, the superconductor 2 is achieved by the layer normal In used in the form of a thin layer of solder. In this embodiment, the implementation of one side of a metal substrate coated with superconductor YBCO. The connection between the superconducting tape 3 and the copper wire 2 is formed between the bare metal substrate of the superconducting tape 3 and the copper wire 2.
Experiments have shown that a satisfactory electrical connection can be achieved using pressed or soldered contacts on the basis of layers of Cu, Pb or high-temperature superconductors, such as BiSCCO, Eu(Bi)CO. Many turns 2-4 can provide a current flow perpendicular to the main axis of the magnetic flux (indicated by the dashed line in figure 1). Rounds 2-4 are placed in the cryostat 5. The device is equipped with item 6 of Cu, forming a closed loop. The secondary winding of the device also contains a metal separator 7, is electrically connected with nepotoplyaemyi conductor 3 between adjacent turns of the secondary winding to provide current flow along the main axis of the magnetic flux (dashed line in Figure 1), passing in the iron core 8, creating effective the complete connection of the primary winding with the secondary winding through items 2-4 and 6. In practice, the primary winding 1 can be placed not only in the way shown in figure 1, but in any other place on the iron core 8. This winding can be placed both inside and outside of the secondary winding on the right shoulder of the iron core 8. Other elements of the design of electrical devices according to the invention are insulating cylindrical core 9 that serves as a frame of the primary winding 1, and current inputs 10, the supply current to the primary winding 1.
During operation, current inputs 10 are attached sequentially to the circuit of AC power (not shown). Cryostat 5 is filled with liquid nitrogen or other liquefied gas. If flowing in the primary winding current reaches a threshold, the voltage drop across the electrical device is very small and, accordingly, small energy loss. Small energy loss of 0.03% was observed in model tests on samples at a power of 6 kW.
If the current in the primary winding exceeds a threshold value, then the suppressed superconducting secondary winding enters a state with a high resistance, and electrical device starts to add additional impedance in the associated external electrical circuit. While flowing in the external circuit current is limited. Device de is there partially as inductive load and partly as a resistive load, limiting the current in the primary circuit, respectively, the amplitude and phase. One of the known problems to be solved in such a current limiter, is actually limiting the current.
For electrical devices containing 8 turns of tape coated YBa2Cu3O7-xas suppressed superconductor, the current is limited to 1600 A (effective current value) in the secondary winding and, respectively, 14 And (effective value of the current in the primary circuit 380 C. Each ribbon coating had a width of 1 cm and a thickness of 10 mm, the thickness of the YBCO layer was about 2 μm. The critical current of a single tape was about 280 A (at 77 K and their own field); the current density in YBa2Cu3O7-xamounted to 1.4 mA/cm2. The outer surface of YBa2Cu3O7-xwas covered with silver or gold protective layer thickness of 0.5 μm, electrically connected with the metal substrate. Arising in the secondary winding current is additionally specified metal element 6, which when full power load functions as an effective shunt protecting suppressed superconductor from excessive overcurrent. The response time of the device was 45 microseconds. The device is characterized by a very short recovery time, i.e. the time required to return electrotechnics the CSOs device in the initial state. The recovery time was less than 50 MS at full power load, when compared with the value of 0.5-20 seconds to known devices.
Further options are shown in figure 1 electrical devices can be implemented at another location of the primary winding 1 relative to the iron core 8 and relative to the secondary winding. The primary winding can be placed in any position, including coaxial position relative to the secondary winding. In the latter case, the primary winding 1 may be located or outside the outer surface of the cryostat 5, or between the cryostat 5 and iron core 8. Another implementation option is to use another form of core 8, for example, instead of the core is rectangular in shape (Figure 1) can be used toroidal core.
Figure 2 and 3 shows two kinds of the single coils. Figure 2 shows round rectangular shape, and 3 refers to the circular coil. Each of the coils has a plot nepotoplyaemogo conductor 3 and the plot suppressed superconductor 2 is connected mechanically and electrically, forming a closed loop.
The second embodiment of the electrical device is schematically shown in Figa and 4b. Nepotoplyaemyi conductor 3 of Cu in this case has the shape of a toroid with a notch on the outer walls of the E. To the borders of the 14 slots attached tape coated YBCO, so that a semi-enclosed ring 12. Metallic element 16 is formed as a bridge from Cu soldered to the same boundaries 14. The secondary winding containing parts 3, 12, 16, placed in the cryostat 5. The primary winding and the iron core 8 as a whole is shown in Figa and 4b.
During operation of the device is similar to the first variant of realization in figure 1, but with a different response time, which in this case is even less: it is less than 35 microseconds.
Figure 5 presents the design of a number of turns of the secondary winding. In this embodiment, there are no inter-turn connection in the direction parallel to the direction of the magnetic flux. All the coils are basically the same and contain suppressed superconductor 22 and nepotoplyaemyi conductor 23 is electrically connected to pads 24. Nepotoplyaemyi conductor 23 has a U-shaped form with superconducting tape 22 that is located between the two ends of the U-shaped, forming a closed loop. In this embodiment, the implementation of the U-shaped nepotoplyaemyi conductor 23 has approximately the same wall thickness as the width of the superconducting tape 22 and the superconducting tape 22 is stretched between the upper surfaces of each of the shoulders of the U-shaped nepotoplyaemogo conductor 23. Electrical device is the primary objective of this design is characterized by a response time less than 50 microseconds.
Figure 6 presents another variant of the design of a number of turns of the secondary winding. All the coils are basically the same. Each round contains a plot suppressed superconductor 32, electrically connected with nepotoplyaemyi conductor 33 at sites 34. Nepotoplyaemyi conductor 33 has a common part 35, which connects the various coils in the direction of the magnetic flux. Some parts nepotoplyaemogo conductor 33 are not interconnected, as by conductor 33 has a series of slots 36. Nepotoplyaemyi conductor 33 can be considered as a rectangular block with a channel located on one face of the block on the two protruding shoulders. Nepotoplyaemyi conductor 33 has a U-shaped cross-section. The sequence of slots that have basically the same dimensions, are located on the outer surface of both shoulders to ensure consistency of turns, basically, the same width and height, which are mechanically and electrically connected through the base of the unit. Thus, two sequences of the grooves in the generally elongated one relative to another.
Thus, nepotoplyaemyi conductor is in this case, the current direction along the main axis of the magnetic flux. This leads to the redistribution of power between the various coils and to improved temporal stability of the device, while QCD is onine local settings suppressed tapes 32 coated have a lesser impact on the electrical characteristics of the device as a whole.
A similar effect can be achieved by using partial paths are suppressed through the superconductor. The response time of as little as in the case discussed for Figure 5.
7 shows the scheme of "heterogeneous" the location of a number of turns of the secondary winding in accordance with the present invention. In this case, different coils 42, 43, 44 have different width w1and the length h of sections 45 round. These sites do not provide electrical connections with other coils. This interconnect is provided in the "General" part 46 nepotoplyaemogo Explorer. In the described example, the geometric parameters w1and h is determined by the position and depth of the slots 47. Similarly to the previous example nepotoplyaemyi conductor 43 can be considered as a rectangular block with a channel located on one face of the block on the two protruding shoulders. Nepotoplyaemyi conductor 43 has a U-shaped cross-section. The sequence of slots are located on the outer surface of the two arms, providing a series of turns. In this embodiment, the implementation of the slots have different sizes. 7 shows that the depth of the slot decreases from the front to the rear of the unit shown in orientation. Two sequences of slots located on each shoulder, mostly stretched one relative to the other is, forming a sequence of pairs of slits. Each pair is the same size to provide a sequence of projections, each of which forms a section of a coil. Therefore, the height and width of the protruding sections vary and can be considered as heterogeneous.
It is experimentally shown that the response time and the time dependence of the increase in impedance during current limit is strongly dependent on the distribution of these geometric parameters for a given number of turns. If permanent tape options suppressed superconductor 42 change w1in the range from 10 mm to 17 mm with a pitch of 1 mm, is provided for the secondary winding on the basis of 8 turns. Increased response time of the device as a whole from 40 MS to 110 MS. Thus, the electrical response of the device during a current limit can be adjusted by the choice of the secondary winding geometry suppressed superconductor and nepotoplyaemogo Explorer, which determine the desired response time.
The smoothness of the distribution function of such variation leads to smooth temporal variations of impedance during current limiting. This can be understood if we take into account the geometric parameters of the channels in nepotoplyaemomu Explorer, which determine the distribution of current between the various coils and, in affect, is, the sequence of their suppression when current overload. Thus, the width of the distribution function of the geometric parameters (which, in turn, determines the amplitude of the variations of these parameters) determines the time width of the electric response of the device as a whole, i.e. the response time in General. In addition, the "smoothness" of the distribution function allows to avoid current surges during operation of the device as a whole.
Similar results can be achieved by variation of the electrical parameters of the suppressed parts of the superconductor used in the various coils. In practice both possibilities, i.e. change the settings nepotoplyaemogo conductor and settings suppressed superconductor, can be used in conjunction with the additional advantage that the total response time can be not only increased, but also reduced in a controlled way due to the compensation of the internal heterogeneity of the critical current in the suppressed superconductor with appropriate selection of the geometric nepotoplyaemogo conductor within each loop.
The use of multiple short suppressed superconductors in the examples, provides a cost optimization of the production and maintenance of electrical devices, so that the installation and obnovlyayuschemusya less costly in time and materials.
1. Electrical device for current limiting, containing a primary winding, a secondary winding, containing suppressed superconductor, characterized by the transition from a state with low resistance state with a high resistance when excess electric current critical value, and the secondary winding is connected with the primary winding on the General part of the magnetic flux and additionally contains a metal element (6), forming a closed loop, and a cryostat (5), which provides cooling of the secondary winding, thus
the secondary winding includes at least one element (3), placed on a significant part nepotoplyaemogo Explorer, which will have a minimal dependence of its resistance to the current and the magnetic field, and the suppressed part of the superconductor;
at least one coil nepotoplyaemogo conductor (3) and suppressed superconductor (2) electrically connected in series, forming a closed loop.
2. Electrical device according to claim 1, characterized in that nepotoplyaemyi conductor (3) contains a metal with a high conductivity selected from the group consisting of cu, Ag, Au, Al, In or the superconductor selected from the group consisting of Nb3Sn And NbTi.
3. Electrical device according to claim 1, characterized in that suppressed sverkhprovod is to (2) contains the connection R 2C3O7-xor fine mixture, where Re is one or more elements from the group consisting of Y, But, La, Pr, Nd, Gd, Tb, Dy and Yb.
4. Electrical device according to claim 1, characterized in that the suppressed superconductor (2) formed as a monolayer or multiple layers in a multilayer structure.
5. Electrical device according to any one of claim 3 or 4, characterized in that the coated composition R2C3O7-xthe tape contains a metal tape substrate, preferably containing stainless steel or alloy based on Ni or NiCr, or Hastelloy, preferably having a resistance of 80 µohm·see
6. Electrical device according to claim 1, characterized in that the electrical connection is provided by a layer of a normal conductor selected from the group consisting of In, Cu, Pb, or a superconductor selected from the group consisting of BiSCCO, Eu(Bi)CO., or mixtures thereof, having a composition different from compositions used either suppressed, or in nepotoplyaemomu superconductor.
7. Electrical device according to claim 1, characterized in that it contains a lot of turns, each of which contains nepotoplyaemyi conductor (3) and suppressed the superconductor (2).
8. Electrical device according to claim 1, characterized in that nepotoplyaemyi Explorer and suppressed the superconductor, abrazos the e the same round, designed for current direction along the perpendicular to the main axis of the magnetic flux.
9. Electrical device according to any one of claims 1 to 4 and 6 to 8, characterized in that at least one of nepotoplyaemogo Explorer, and suppressed conductor contains at least one plot to the current direction along the main axis of the magnetic flux.
10. Electrical device according to claim 9, characterized in that the ratio of the geometric dimensions of various parts nepotoplyaemogo Explorer or/and different parts suppressed superconductor varies for different orbits nepotoplyaemogo conductor (3) and suppressed superconductor (2).
11. Electrical device of claim 10, wherein the relationship of the geometric dimensions of various parts nepotoplyaemogo Explorer or/and different parts suppressed superconductor followed by a numeric sequence or form a smooth distribution function.
12. Electrical device according to claim 11, characterized in that the width of the distribution function determines the temporal characteristic of the device.
13. Electrical device according to any one of claims 7, 8 and 10-12, characterized in that the suppressed Explorer contains many tapes coated with the composition R2C3O7-x.
14. Electrical device according to item 13, on the tives such as those what many tapes coating contains at least two ribbons, characterized by different threshold values of the electric current that causes the suppression of superconductivity.
15. Electrical device according to claim 1, wherein the cryostat contains at least one metal wall forming a closed path containing at least a portion of the total magnetic flux.
16. Electrical device according to claim 1, characterized in that the at least one metallic element and at least one metallic wall of the cryostat represent the same element of the electrical device.
17. Electrical device according to any one of claims 1 to 4, 6-8, 10-12 and 14-16, characterized in that the part f nepotoplyaemogo conductor element of the secondary winding is 50%≤f≤95%, preferably 60%≤f≤95%, more preferably 75%≤f≤95%, even more preferably 80%≤f≤90% of the volume element, the volume element is the sum of the parts nepotoplyaemogo Explorer and suppressed superconductor.
SUBSTANCE: when nominal current in electric network is exceeded, retention of short circuit current impulse is performed with current limiting device in two stages: at the first stage there performed is quick limitation of shock short circuit current during T1 time with multiple-element resistance with active element based on hall effect with non-linear current-voltage characteristic, and at the second stage there maintained is nominal short circuit current during T2 time with multiple-element resistance with active element with positive temperature coefficient of resistance with non-linear current-voltage characteristic. Both limitation stages are performed at voltage grading. Time T1 is chosen not more than 2 ms, and time T2 is chosen not less than 500 ms. The proposed device for limiting short circuit current in network includes two current limiting devices, the first one of which includes at least two shunted semi-conducting magnetoresistors, the active element of each of which is made in the form of Corbino disc from semi-conducting material of n-type AIIIBV, which are located inside solenoid, and the second current limiting device consists at least of two shunted resistors, the active element of each of which is made from material with positive coefficient of temperature resistance.
EFFECT: increasing switching speed, decreasing power loss in networks in nominal mode and forming the specified shape of short circuit current impulse.
3 cl, 4 dwg
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering, particularly to a superconducting resistive current limiter module and its versions, meant for protection from overloading and short circuit current in a network. In the first version the superconducting resistive current limiter module includes a pipe-like superconducting element, shunt solenoid, terminal current-conducting switching elements and a ring made from soft magnetic material, placed on the inner and outer surface of the pipe-like superconducting element. In the second version the superconducting resistive current limiter module includes a pipe-like superconducting element, shunt solenoid and terminal current-conducting switching elements. Part of the pipe-like superconducting element contains at least one metal sheath, insulated from the terminal current-conducting switching elements of the module. The pipe-like superconducting element can be made with an inner and/outer metal sheath. A ring made from soft magnetic material can be put on the surface of at least one metal sheath of the pipe-like superconducting element.
EFFECT: invention increases reliability of the current limiter module and reduces the size of the module while maintaining high electric field intensity.
5 cl, 2 dwg
FIELD: electrical engineering.
SUBSTANCE: voltage commutator with the current overload protection comprises a current pickup, an electronic gate composed of a two-step follower feeding the load unit. The additional aperiodic component, a transistor and a diode connected in series to the source-emitter junction of the said transistor are connected in the gate control circuit as an electronic shunt to interrupt current flowing through the load.
EFFECT: expanded performances thanks to current overload protection.
2 cl, 2 dwg
SUBSTANCE: device contains load current sensor, electronic key, load block, RS-trigger, OR circuit and current overload protection unit, connection input of voltage switchboard, disconnection input of voltage switchboard, data output, exclusive OR circuit and D-trigger, data input D-trigger is connected to output of voltage source corresponding to logic 1, clock input of D-trigger is connected to RS-trigger output, reset input of D-trigger is connected to output of OR circuit, D-trigger output is connected to driving input of electronic key, the first input of exclusive OR circuit is connected to output of RS-trigger, the second input of exclusive OR logic is connected to D-trigger output, and output of exclusive OR logic is connected to data output of voltage switchboard.
EFFECT: increased functional reliability.
SUBSTANCE: invention may be used in commuted power supply sources with over-current protection. Voltage switch board with load bank protection from over-current includes electronic bug, which supplies power to load bank via current load sensor. Relay element connected to current load sensor output de-energises load bank though logical element OR and trigger if current overload is detected while unit is under transient or steady-state conditions. Thresholds for over-current protection actuation are adjusted by control unit with combinatory logic, voltage switch board connection and disconnection inputs being connected to control unit inputs.
EFFECT: widening of application area and extension of functional capabilities.
SUBSTANCE: invention may be used in commuted power supply sources with over-current protection. Voltage switch board with load bank protection from over-current includes controlled switch, which supplies power to load bank through current load sensor, as well as the second controlled switch. Relay element connected to current load sensor output de-energises load bank though logical element OR and trigger if current overload is detected while unit is switched on or under steady-state conditions. Thresholds for over-current protection actuation are adjusted by control unit, voltage switch board connection and disconnection inputs being connected to control unit inputs.
EFFECT: widening of application area and extension of functional capabilities.
FIELD: electronic engineering.
SUBSTANCE: the device has series-connected load current sensor and an electronic switch connected to the load unit, R-S flip-flop, OR gate and an overcurrent protection unit, the "on" input of the R-S flip-flop is connected to the "on" input of the voltage switch, the "off" input of the flip-flop is connected to the "off" input voltage switch, the output of the load current sensor is connected to the input of the overcurrent protection unit, the output of the overcurrent protection unit is connected to the first input of the OR gate, whose second input is connected to the "off" input of the voltage switch, provision is made for a D-flip-flop, whose data input is connected to the output of the voltage source corresponding to the voltage of the logic unity, its synchronizing input is connected to the output of the R-S flip-flop, the "off" input - to the output of the OR gate, and he output - to the control input of the electronic switch.
EFFECT: enhanced functional reliability due to prevention of a repeated switching after the actuation of the overcurrent protection unit.
FIELD: commutating power equipment, possible use for protecting electric equipment from short circuit currents.
SUBSTANCE: ultra-conductive short circuit current limiter contains following parts connected in parallel: high temperature superconductor with resistance R in normal state and circuit with capacitor with capacity C, serially to which a switch is connected, which disables the current after high temperature superconductor transitions to normal state. In the circuit which is parallel to superconductor, serially with the capacitor, linear resistance Z is connected, and in parallel to section of circuit, which contains switch and capacitor, a circuit is connected with serially connected inductiveness L and controllable commutator, which is enabled immediately after switch contacts are opened. To disable currents in switch and commutator, following ratios must be fulfilled: R>Z; where Lc - inductivity of undamaged section of circuit.
EFFECT: reduced volume of superconductor, ensured capability of limiter to endure several short circuits following one another with short time intervals, ensured independency of high temperature superconductor resistance from parameters of external circuit and reduced costs of the limiter.
FIELD: microelectronics; protection of wire communication equipment against heavy currents due to occurrence of unwanted voltages in communication line.
SUBSTANCE: proposed protective device has switching unit transferred from low-resistance state to current-limiting mode in response to signal coming from overcurrent control unit or from current-limiting mode to high-resistance state in response to signal arriving from unit controlling overvoltage with respect to peak value of AC or DC voltage and overvoltage with respect to RMS value of AC voltage. Switching unit uses inertia optoelectronic switch circuit arrangement with normally closed contacts. Protective device is inserted in series with communication line. Circuit arrangement of communication-line overcurrent protective device units can be optimized for each polarity of emergency voltages or separately for DC and DC overcurrent levels.
EFFECT: enhanced operating reliability.
1 cl, 4 dwg
FIELD: electrical engineering; short-circuit protective gear.
SUBSTANCE: proposed short-circuit current limiter built around controlled reactor has at least one pair of separate magnetic cores carrying magnetizing and demagnetizing windings. This pair of magnetic cores carries main winding designed for connection to phase line under protection and auxiliary winding. Main and auxiliary windings are made in the form of series-connected semi-windings disposed on separate magnetic cores of pair. Magnetizing winding is designed for connection to dc current supply. Semi-windings of main winding are connected differentially and those of auxiliary winding, cumulatively; they pass current to rectifier connected via threshold switch to demagnetizing winding.
EFFECT: enhanced speed of response and short-circuit current limiting efficiency.
3 cl, 2 dwg
FIELD: physics; radio.
SUBSTANCE: invention relates to high frequency equipment, particularly to devices for switching signals in the centimetre, millimetre and sub-millimetre ranges. The high-speed superconducting switch has a thin-film switching element with submicrometre dimensions on an insulating substrate and conducting electrodes. The superconducting switching element is connected across a microwave transmission line and is made in form of a superconductor nanobridge with on impedance much greater than on impedance of the line and small impedance much less than off impedance of the line and conducting electrodes are connected to the microwave transmission line transversely.
EFFECT: increase in operating frequency of the modulator signal to gigahertz, over 90% increase of modulation depth, reduction of real losses to less than 1 dB, increase in modulation frequency (switching) to hundreds of megahertz.
6 cl, 4 dwg
SUBSTANCE: invention pertains to devices for registering individual photons in the visible and infrared ranges. The superconducting single photon detector consists of a substrate, terminal pads on the substrate, and stripes made from superconductor films, put on the substrate between the terminal pads. The ends of the stripes are joined to the terminal pads. Each stripe is joined to one of the terminal pads through the corresponding stripe resistor. Resistors for all stripes are the same, and the resistors have resistance of 0.5-500 Ohm. Depending on the kinetic inductance of the superconductor stripes, the resistance are chosen in such a way that, switching into resistive state of one of the stripes does not lead to the other stripes also switching into resistive state i.e. the value of current in these stripes does not exceed the value of the critical current.
EFFECT: increased response speed of the detector.
6 cl, 2 dwg, 1 tbl
SUBSTANCE: invention is mainly related to transport electric power engineering and designed for powering superconducting magnet (SM) to frozen-in flux mode, mainly in order to create magnetic levitation and driving and stabilizing forces of high speed transport together with electric magnets of rail trucks. It is also designed to power SMs in geomagnetic torque motor to orientate and stabilize space crafts and electrophysical instrumentation. SM powering system includes: energized SM with winding from high-temperature superconductor (HTSC) inserted into cryostat; superconducting bypass with primary two-circuit winding from HPSC and thermal control winding of superconducting bypass are also inserted into cryostat; cryo refrigerator (CR); SM feed current meter; SM powering subsystem itself including adjustable frequency inverter with transformer output. Transformer input is linked with power supply buses. Three transformer outputs form the beginning, end and lead-out from the middle point of secondary transformer winding. SM powering subsystem also includes single-cycle two-phase rectifier based on two diode gates. Gates anodes are connected to the beginning and end of secondary transformer winding. Their cathodes are attached to the one of SM winding leads; the other lead is coupled with lead-out from the middle point of secondary transformer winding. Both SM winding leads are linked with primary winding of superconducting bypass by means of HPSC wires enclosed into heat-insulated connecting pipes with wire cooling channels. Power subsystem of thermal control superconducting bypass winding with outputs connected to thermal control winding leads via controllable turn-off switch is also available in the subsystem as well as threshold detector, current meter in primary superconducting bypass winding and powering system control unit. According to the invented method, each SM with superconducting bypass cool cryo refrigerator until stable superconducting state and supply current to thermal control winding. Primary winding of superconducting bypass is then transferred to resistive state by heating to the temperature higher than critical HPSC temperature. Adjustable frequency inverter is switched to maximum invariable frequency and transformer is switched to output voltage for the period until SM powering with invariable nominal power will start. From this moment frequency is decreased which means that output transformer voltage will be also decreased based on analytical dependences on powering time which are specified in invention description and formulas. Analytical dependencies correspond to SM powering mode with invariable nominal power. When SM powering current will achieve the required maximum value Ism, superconducting bypass of thermal control winding is de-energized and cryo refrigerator is switched on to operate in augmented rating mode. Output transformer voltage and frequency are abruptly decreased to their nominal values to be maintained constant during cooling time of primary superconducting bypass winding to the temperature below critical HPSC temperature. At the moment of primary superconducting bypass re-transition to superconducting state, current Ism is short-circuited via superconducting bypass; adjustable frequency inverter is switched off while cryo refrigerator is transferred to the nominal mode of operation.
EFFECT: decrease of weight; decrease of power supply cost and power in superconducting magnets powering system in frozen-in flux mode.
2 cl, 4 dwg, 1 tbl
FIELD: electric engineering.
SUBSTANCE: in accordance to method for changing amount of energy in magnetic system, current is measured in at least one pair of windings of magnetic coil, while changed in one coil is electric current of one direction of current density vector, and in another winding electric current of opposite direction of current density vector is measured. Device contains magnetic coil containing at least one magnet with winding. Magnetic system contains at least one more winding, while at least two windings are made with possible connection as one pair of windings and are made with possibility of joint powering by currents of opposite directions, while it is possible to inject energy into at least one pair of windings and to eject energy from at least one pair of windings.
EFFECT: increased efficiency of parameter changes in magnetic system.
2 cl, 14 dwg
FIELD: cryoelectronics; thin-film cryogenic devices built around superconductors.
SUBSTANCE: proposed film-type weak-magnetic-field superconducting sensor incorporating magnetic flux transformer has magnesium oxide based insulating substrate in the form of high-temperature superconducting strip inserted between two magnetic flux transformers made of same high-temperature superconducting film. This sensor built around high-temperature superconducting film of material system Y-Ba-Cu-O operating at liquid nitrogen boiling temperature has magnetic-field threshold resolution of -20-50 pT which is higher than that of prior-art sensors, except for superconducting quantum interface devices.
EFFECT: reduced magnetic-field threshold sensitivity of superconducting film material.
1 cl, 1 dwg
FIELD: cryoelectronics; developing thin-film electronic devices around superconductors.
SUBSTANCE: proposed weak magnetic field sensor has insulating substrate made of sapphire and magnetically sensing element in the form of heteroepitaxial niobium film.
EFFECT: reduced threshold response of sensor to magnetic field and magnetic flux.
1 cl, 2 dwg
1 cl, 2 dwg
SUBSTANCE: invention relates to electrical engineering, specifically to thermo-stabilised superconductors based on the Nb3Sn compound and methods of making the said superconductors. The thermo-stabilied superconductor based on the Nb3Sn compound is made in form of a matrix from a metal or alloy, containing superconducting material fibre, metal tubes filled with a rare-earth metal compound with extremely high heat capacity at low temperatures, an outer hollow copper cylinder and a thin cylindrical shell made from titanium and/or niobium placed coaxially between the matrix and the outer hollow copper cylinder. The metal tubes are tightly pressed to each other in the gap between the cylinder and the shell in the first version, or in a gap made in the radial direction in the wall of the cylinder in the second version. The method of making such thermo-stabilised superconductors is described.
EFFECT: wider functional capabilities of a thermally insulated superconductor due to presence in the superconductor of a rare-earth intermetallic compound with extremely high heat capacity at helium temperatures, which increases mean heat capacity of the superconductor by 5-6 times.
12 cl, 11 dwg