RU2396630C1 - Explosive current pulse shaper - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: in comparison to the device containing breakable conductor located between riffled dielectric obstacle and explosive charge with its initiation system, in the proposed shaper the breakable conductor is made in the form of the fragments located along the generatrix of cylindrical surface of explosive charge and connection straps between them, located along the arc of circle, or in the form of fragments located along the arc of circle of explosive charge and connection straps located along the generatrix of cylindrical surface, and edges of end fragments are connected to power supply and load. ^ EFFECT: increasing pulse strength in load, decreasing pulse length, and possibility of compact location of breakable conductor in restricted space, considerable simplification, improving manufacturing accuracy. ^ 8 dwg

Description

The invention relates to the field of electrical engineering and can be used as a device for opening high-current electrical circuits and forming a current pulse with a rise time of less than one microsecond.

The famous “Explosive current breaker” by A.I. Pavlovsky, V.A. Vasyukov, A.S. 490381 USSR, MKI H01H 39/00, claimed 15.10.73, No. 1965660 / 24-7, BI No. 39, 165, 1976, containing a dielectric substrate, a thin layer of a conductor sprayed on its surface, explosive charge (BB) and explosive charge initiation system. The principle of operation of the circuit breaker is based on the quenching by the products of detonation (PD) of the explosive charge (explosive) of electrical discharges arising from the explosion of a thin layer of the conductor under the action of the current flowing in the circuit breaker.

The disadvantage of this device is the large initial ohmic resistance, as a result of which a significant part of the source energy is lost (converted into heat) until the circuit opens. To reduce heat loss, either a high-speed energy source is used, which is not always feasible, or an additional intermediate current breaker, which is also associated with losses.

It is known a disconnect device in which a massive hollow conductor consists of two cylindrical segments, on the inside of which along the generators grooves (grooves) are arranged with a constant step, and which is destroyed by a cylindrical explosive charge placed inside the conductor and initiated along the axis - “Magnetocumulative generators "/ Larry L. Altgilbers et al., 2000, Springer-Verlag. New York

The disadvantage of this device is the large opening time and low electric field along the destructible surface due to the conductivity of explosives in large volumes.

A multi-gap switching device is known consisting of a hollow cylindrical body made of dielectric material, on the inside of which there are grooves along the generatrix, a conductive destructible conductor in the form of a pipe with a longitudinal through cut inserted into the dielectric body, a cylindrical dielectric element filled inside with an explosive, in which the axis is the axial system of initiation of this charge. In such a shaper, the explosion products are separated from the gaps formed by opening with an intermediate insulating layer of paraffin, which is additionally used to extinguish arcs arising in the gaps at the initial stage of opening, - Andreev V.R. et al. “An experimental study of mock-ups of multi-gap explosive switching devices” / USSR-USA Seminar “Inductive Energy Storage and Switching Equipment for Thermonuclear Installations”, 1974. Review journal “Physics”. Issue No. 7, 1975.

The disadvantage of this explosive shaper is that the opening time occurs within hundreds of microseconds. This is due to the fact that, due to the presence of an insulating medium, the destruction of the destructible conductor into the grooves occurred more smoothly and longer than when it was in direct contact with the explosive, because part of the explosion energy is directed to compressing a thick layer of paraffin. This leads to a sharp decrease in the rate of destruction of the conductor due to the weakening of the shock wave and the alignment of its front, which goes to the inner surface of the destructible conductor. This practically eliminates the vortex nature of the destruction, which is one of the main mechanisms that affect the rapid opening of the electric circuit. Vortices arise in inhomogeneities occurring in a destructible conductor, in a cylindrical body made of dielectric material and explosives, and also due to the presence of some asymmetry in the detonation of the explosive charge, due to the assembly technology and design features of the device.

Closest to the claimed is a cylindrical explosive current pulse shaper on a ribbed barrier (RP) - Chernyshev V.K. et al. Current magnetic field pressure effect on explosive opening switch operation // Megagauss-9 / Eds. V.D. Selemir, L.N. Plyashkevich. - Sarov, VNIIEF, 2004. p. 310-313.

An explosive current pulse shaper according to the prototype of FIG. 1 contains a destructible conductor 1 located between the dielectric ribbed barrier 2 and the explosive charge 3 with its initiation system 4, usually consisting of a chain of radial electric detonators 5, a cylindrical explosive charge 6, a reverse current conductor 7 (in a particular case the tube above the cylindrical charge 6) and the insulator 8. In this case, all the elements of the former are aligned with each other.

In this device, an energy source (explosive magnetic generator (VMG) is not shown) was connected to terminals 9, and the load to terminals 10 located at opposite ends of the destructible conductor 1. The destruction of the destructible conductor (foil) in the shaper with a ribbed barrier occurs as a result of that at normal incidence of the detonation wave front, the velocity of the sections of the destructible conductor under the action of the pressure of the PD in the grooves of the RP is greater than the speed of the destructible conductor resting on the edges of the barrier.

The disadvantages of this device include the difficulty in manufacturing an extended (tens of centimeters) thin-walled (tens to hundreds of microns) cylindrical destructible conductor with preserving its predetermined thickness and diameter along the entire length, rather complicated installation of an extended destructible conductor with an explosive charge, as well as the fact that it is not always possible to place it compactly in a limited spatial volume while preserving, not to mention improving, the performance of the circuit breaker. In addition, the manufacture of an extended cylindrical explosive current driver (for example, more than 10 cm), starting with a certain small diameter, for example less than 30 mm, seems impossible due to the complexity of manufacturing the initiation system, a thin-walled extended explosive charge and a destructible conductor.

When creating the present invention, the task was to develop an explosive current pulse shaper, the design of which would provide stable (repeatable from experience to experience) operating parameters and allow the compact use of a destructible conductor in a limited spatial volume. Thus, the prerequisites would be created for the reliable formation of powerful high-voltage pulses from an explosive magnetic energy source for a wide class of loads used in physics of high energy densities: plasma-dynamic generators, high-energy liners, microwave devices, etc., with relatively small time costs for installing the entire working device .

The technical result in solving this problem is to increase the pulse power in the load by increasing the amplitude of the current pulse and voltage and to reduce the pulse duration by changing a sufficiently wide range of design parameters of the explosive current pulse shaper and the possibility of a compact arrangement of the destructible conductor in a limited space, for example, in length or in diameter depending on the tasks, when instead of a single extended destructible conductor uetsya breakable conductor configured as fragments and jumpers. In addition, the manufacturing technology of the shaper parts is significantly simplified due to the smaller dimensions, the manufacturing accuracy is increased, which primarily affects the efficiency of the device, and therefore, the pulse parameters in the load.

The specified technical result is achieved in that, in comparison with the known device of the explosive current pulse shaper, which contains a destructible conductor located between the dielectric ribbed barrier and the explosive charge with its initiation system, in the inventive device, the destructible conductor is made in the form of fragments arranged along a cylindrical generatrix the surface of the explosive charge, and jumpers between them, located along an arc of a circle, or in the form of individual fragments located along the circumference of the explosive charge, and jumpers located along the generatrix of the cylindrical surface, and the ends of the extreme fragments are connected to the power source and load.

The execution of the destructible conductor in the form of fragments located along the generatrix of the cylindrical surface of the explosive charge, and jumpers between them, located on an arc of a circle, or in the form of fragments located along the arc of the circumference of the explosive charge, and jumpers located along the generatrix of the cylindrical surface, allows to increase the manufacturing accuracy the geometrical dimensions of the parts involved in the explosive former (explosive charge, ribbed barrier, thin-walled destructible conductor and initiation system) and will provide a coaxial arrangement between the conductor erodible barrier rib and an explosive charge to initiate the system.

To create a current pulse in a load with the same or better parameters than in the prototype, it is necessary that the destructible conductor has the same thickness d as in the prototype, and the width T _F in the claimed device should be equal to the perimeter of the destructible conductor in the prototype. Thus, the destructible conductor must be divided into fragments whose width should be equal to the perimeter of the destructible conductor, and their total length - the length of the destructible conductor of the prototype. Due to this, when solving certain problems, you can change the overall dimensions of the device (reduce the length or increase its diameter). When the fragments of the destructible conductor are located along the generatrix of the cylindrical surface of the explosive charge, the explosive former will have a significantly shorter overall length while maintaining the same level or even increasing the length of the destructible conductor, since fragments connected by jumpers are on a larger diameter than the cylindrical destructible conductor in the prototype. Thus, all the details of the current driver can be manufactured on existing machine tool equipment with greater accuracy, which, in turn, will allow it to receive a pulse with a larger amplitude and shorter duration in the load due to more efficient and stable operation of the driver as a result of providing more simultaneous and uniform destruction of the conductor.

If the fragments of the destructible conductor are located along the arc of the explosive charge circumference and the terminals are located on the open ends of the fragments, the explosive former will have a smaller diameter, but somewhat larger length. Typically, for the effective use of such an explosive shaper when working at high impedance loads, which are often the majority of devices used in high energy density physics, its destructible conductor has a rather small width. For its destruction, cylindrical charges and barriers are used, located around individual fragments and having lengths that are in accordance with the width of the conductor. If only the conductor belonging to the fragments is destroyed, then due to the insignificant size of the charges from the SI and obstacles above the fragments, it is possible to fabricate parts for such an explosive shaper quite simply and with greater accuracy. A destructible conductor located only in a specific sector of a cylindrical charge can be used. Or the destructible conductor has a stepped shape and is located along the length of the cylindrical charge. This expands the possibility of more flexible use of such explosive shapers in small-sized devices, where the volume is limited and the elements of this device are closely located.

The use in the explosive shaper of additional cylindrical charges with SI under the jumpers, and over the jumpers having a thickness and width corresponding to the thickness and width of an individual fragment, ribbed barriers whose edges are perpendicular (orthogonal) to the direction of the jumper between the individual fragments, allows you to create a conductor, destructible along its entire length. And this, in turn, allows you to generate a more powerful energy pulse in the load than for the case when the jumpers are not destroyed. Ribbed barriers both above the fragments and above the jumpers can be assembled from separate units (Fig. 3) or made as a single monoblock (Fig. 4).

Figure 1 shows the device of the prototype.

Figure 2 shows the inventive explosive shaper of the current pulse with the axial direction of the current in the fragments.

Figure 3 shows the inventive explosive current driver with the azimuthal direction of the current in fragments.

Figure 4 shows the inventive explosive current driver with a destructible conductor with an azimuthal direction of the current in the fragments and the ribbed barrier of Fig. 8.

Figure 5 shows the destructible conductor of the inventive explosive current driver with the axial direction of the current in fragments.

Figure 6 shows the destructible conductor of the inventive explosive current driver with the azimuthal direction of the current in fragments.

Figure 7 shows the stepwise configuration of the destructible conductor of the inventive explosive current driver with the azimuthal direction of the current in the fragments.

On Fig shows a ribbed barrier used for the simultaneous destruction of fragments and jumpers.

Figure 1-8 indicated:

1 - destructible conductor;

2 - dielectric ribbed barrier;

3 - explosive charge (BB);

4 - initiation system;

5 - electric detonator;

6 - cylindrical explosive charge;

7 - reverse current lead;

8 - insulator;

9 - terminals for connecting a power source;

10 - terminals for connecting the load;

11 - a separate fragment of a destructible conductor;

12 - jumper;

13 - grooves of the ribbed barrier.

Other designations in figures 1-8:

T _f - the width of the fragment destructible conductor; T _p - the width of the jumper; d is the thickness of the fragment;

------ - the profile of the destructible conductor.

The claimed explosive current pulse shaper (Fig. 2,3) contains a destructible conductor 1 located between the dielectric ribbed barrier 2 and the charge 3 of the explosive with its initiation system 4, which are all placed coaxially relative to each other. In this case, the destructible conductor is made in the form of fragments 11 located along the generatrix of the cylindrical surface of the charge 3 of the explosive, and jumpers 12 between them, located along an arc of a circle (Figure 2), or in the form of fragments 11 located on the arc of a circle of a charge of 3 explosives, and jumpers 12 located along the generatrix of the cylindrical surface (Figure 3). In this case, the ribs of the ribbed barrier 2 are always perpendicular to the direction of the location of the individual fragments 11. In addition, for the case when the jumpers 12 have a thickness (d) and a width (T _p ) corresponding to the thickness (d) and width (T _f ) of the fragment 11, then a ribbed barrier 2 is placed above them, the ribs and grooves 13 of which are located perpendicularly (orthogonally) to the direction of placement of the bridge 12 between the individual fragments 11 (Fig. 8).

In the example implementation of the inventive device of FIG. 2, an explosive current pulse shaper with axial current spreading in a fragment was fed from a spiral explosive magnetic generator with an internal spiral diameter of 60 mm. In the normal operating mode of the generator, the energy stored in the final inductance is ~ 200 nH, is ~ 6 kJ at a rise time of the current pulse with an amplitude of ~ 300 kA at a level of 0.1-0.9 of the order of 2 μs. The thickness of the two fragments of the destructible copper conductor was 0.2 mm; the width was 90 mm with the length of each fragment being 100 mm. The length of the bridge was about 50 mm, the thickness was 2 mm, and the width was 2 cm. The thickness of the explosive charge shell for the destructible conductor was 5 mm. The initiation system (SI) was used with a chain of electric detonators mounted along the axis. In the experiment, a load of the order of 100 nH was obtained with a current of the order of 180 kA with a characteristic rise time of the current at a level of 0.1-0.9 of the order of 400 ns and a voltage of the order of 50 kV. In this case, the pulse power was about 10 GW.

In the example implementation of the inventive device of FIG. 3, an explosive current pulse shaper with azimuthal current spreading in fragments was fed from a spiral explosive magnetic generator with an internal spiral diameter of 60 mm (VMG-60). The outer diameter of the cylindrical charge for SI is 90 mm. His detonation came from a chain of electric detonators. Two fragments of destructible copper conductor were located on a diameter of 100 mm with a thickness of 0.036 mm, a width of 15 mm and a length of 157 mm. The web was 200 mm long, its width and thickness were like that of a fragment, and it was also located at a diameter of 100 mm. The explosive charge for breaking the destructible conductor had a thickness three times less than the thickness of the destructible conductor from the previous example. A dielectric ribbed barrier was used with an outer diameter of 110 mm and was made of organic glass.

The operation of the devices shown in figure 2, 3 and 4, begins with the moment the start of operation of the power source connected to the terminals (9). The current from the power sources flows through the individual fragments 11 of the destructible copper conductor (1) and the jumpers 12 connecting them. At a given point in time, electric detonators (5) undermine the cylindrical charge (6), which initiates the explosive charge (3) through the cylindrical insulator ( 7). Its detonation leads to rupture of the destructible copper conductor on a dielectric ribbed barrier (10). At this moment, the load was also connected. In an experiment with an experimental model of the claimed device (azimuthal current spreading in fragments) at a spiral current VMG-60 of the order of 32 kA in a load with a resistance of 27 Ohms and an inductance of ~ 500 nH, a current of ~ 12 kA was obtained with a characteristic rise time of -100 ns, and a voltage pulse was generated ~ 420 kV. Thus, the power of the device was ~ 5 · 10 ⁹ W. In the experiment with the device, when the destructible copper conductor had a thickness of 0.036 mm, was placed on a diameter of 200 mm and had a length of ~ 320 mm (the destructible conductor did not contain fragments), a voltage of 1.4 times less was obtained, and the pulse formation time in the load amounted to about 120 ns.

Thus, the use of the inventive device with the axial direction of the current in accordance with the claims allowed to destroy the conductor with a thickness of 0.2 mm and a width of 90 mm, located on a charge with a diameter of 100 mm, and to form a pulse in the load, which was not possible to do with a cylindrical destructible conductor with a diameter of 30 mm and a length of 200 mm. This was achieved due to the fact that the torn conductor of a given width was located at a diameter of 100 mm. This ensured the possibility of guaranteed fulfillment of the dimensions of the explosive current pulse shaper, its efficiency, as well as the possibility of using SI, which allowed simultaneously and with good accuracy to undermine the charge under two fragments of the conductor being destroyed.

The use of the inventive device with azimuthal current spreading made it possible to break a 0.036 mm thick breakable conductor, consisting of two fragments and a jumper, and to generate a pulse with a power 1.8 times greater in load than a device using a single 0.036 mm thick conductor located on a larger twice the diameter. In this case, the current in the load is increased by 1.3 times, and the voltage is increased by more than 1.4 times.

Claims (1)

An explosive current pulse shaper containing a destructible conductor located between the dielectric ribbed barrier and the explosive charge with its initiation system, characterized in that the destructible conductor is made in the form of fragments located along the generatrix of the cylindrical surface of the explosive charge, and jumpers between them located along circular arc, or in the form of fragments located along the circular arc of the explosive charge, and jumpers located along the generatrix of the cylinder surface, and the ends of the extreme fragments are connected to a power source and load.

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