Compact pulse voltage generator

Abstract

FIELD: high-voltage pulse technology.SUBSTANCE: invention can be used in the creation of small-sized Arkadyev-Marx cascade generators. In a compact pulse voltage generator, the dielectric column is made from a single dielectric plate with sections of smaller and larger thickness. On the section with a smaller thickness, the cascade capacitors are secured in pairs. In the thicker section, holes are made in which cascade arresters are installed. Each arrester is secured with a dielectric screw through a polyurethane insert. The dielectric column is secured to a metal plate using metal corners. The opposite end of the dielectric column is secured in the housing using a supporting conical insulator. The charging inductors are made separately for each stage of the pulse voltage generator. Each coil is provided with a pair of end contacts for connection to the busbars using a threaded connection. The coils are positioned at an angle to the generator axis. A capacitive voltage divider is installed on a sealed metal housing opposite the last stage, the high-voltage electrode of which is made spherical and is installed on the busbar of the last stage of the generator.EFFECT: expansion of operational capabilities, while maintaining the weight and size characteristics, due to the simplification of the technology for connecting parts and units, as well as the presence of a voltage divider for recording nanosecond pulses of the generator output voltage.3 cl, 4 dwg

Description

[0001] Field of technology to which the invention relates

[0002] The invention relates to high-voltage pulse technology and can be used in the creation of small-sized Arkadyev-Marx cascade generators.

[0003] Technology Level

[0004] A compact Arkadyev-Marx pulse voltage generator (VPG) is known (RU Patent No. 2091980, IPC H 03 K 3 / 00, H 05 K 7 / 02, H 05 G 1 / 24, "Voltage pulse generator", Elyash S.L., Moskvin N.I., Korolev V.N., Kalinovskaya N.I., published on September 27, 1997), in each cascade of which the capacitors are collected in a package, the spark gap axis is parallel to the axis of the capacitor package, the axes of all capacitor packages are located in one plane, and in another plane, parallel to the first, there are axes of the spark gaps, all elements of the generator are located in a sealed metal casing. The spark gaps are made with two electrodes, the generator cascades are charged by a pulse transformer.

[0005] Using this layout allowed the generator's weight and volume to be reduced by approximately 50% while maintaining the same output parameters. Furthermore, the generator is easy to assemble, disassemble, and maintain due to the use of K15-10 energy-storing capacitors and long charging inductors, which are soldered to all generator stages, as well as the central pillar constructed from two insulating plates.

[0006] The closest to the claimed one is the compact Arkadyev-Marx generator (Patent RU No. 2576383, IPC H 03 K 3 / 00, 3 / 02, 3 / 53, H 05 G 1 / 00, 1 / 02, published 03 / 10 / 2016), containing several cascades with capacitors and a spark gap in each cascade, as well as a pulse charging transformer, all elements of the generator are located in a sealed metal casing, the generator casing is divided into two sections with flanges, in one section the pulse charging transformer is located, the generator cascades are installed in the other section and are fixed on a metal plate, wherein the plate is clamped between adjacent flanges of the casing sections until the end adjacent surfaces of the plate and flanges are closed and has an opening for wiring the high-voltage terminal of the pulse transformer to the charging inductance coils. A rubber oil expansion compensator is installed in the bottom of the housing.

[0007] Thanks to the stated design features, as well as the use of UHV-12A capacitors as energy storage, this generator is more technologically advanced in terms of assembly and maintenance compared to its predecessor. However, its design retains some of its predecessor's shortcomings: long charging inductors, which are soldered to all generator stages, and the central post, which is also made of two plates (which complicates assembly and access to the capacitors and spark gaps). Furthermore, there is no channel for recording nanosecond output voltages.

[0008] The objective of this invention is to create a high-tech Arkadyev-Marx generator with increased operational reliability and ease of assembly, setup and maintenance.

[0009] The technical result is the expansion of operational capabilities, while maintaining the weight and size characteristics, due to the simplification of the technology for connecting parts and units, as well as the presence of a voltage divider for recording nanosecond pulses of the generator output voltage.

[0010] Disclosure of the essence of the invention

[0011] This technical effect is achieved by the fact that, in comparison with a compact pulse voltage generator containing several cascades with capacitors and a spark gap in each cascade, charging inductors and conductive buses connecting the spark gaps to the capacitors, as well as a pulse charging transformer connected to the first cascade, all elements of the generator are located in a sealed metal casing, the generator cascades are fixed on a dielectric stand mounted on a metal plate, the spark gaps and capacitors form two rows with an equal pitch along the generator axis, the axes of the spark gaps are parallel to the axes of the capacitors, a row of spark gaps is shifted along the generator axis relative to the row of capacitors by half a pitch, an oil expansion compensator is installed in the bottom of the casing, what is new is that the stand is made of a single dielectric plate with sections of smaller and larger thickness,in the section with a smaller thickness, the cascade capacitors are fixed in pairs, in the section with a larger thickness, holes are made in which the cascade arresters are installed, each arrester is fixed with a dielectric screw through a polyurethane insert, the rack is fixed on a metal plate with the help of metal corners, the opposite end of the rack is fixed in the housing with the help of a supporting conical insulator, the charging inductance coils are made separate for each cascade of the PVG, and each coil is provided with a pair of end contacts for connection to the conductive buses using a threaded connection, the coils are located at an angle to the axis of the generator, in addition, a capacitive voltage divider is installed on the housing opposite the last cascade, the high-voltage electrode of which is made spherical and is installed on the busbar of the last cascade of the PVG.

[0012] In addition, fittings for vacuum pumping, draining and filling oil are installed along the edges of the housing, and the conductive buses and arresters are equipped with units for compensating for the beating of the interaxial distances of the arresters and capacitors, as well as the non-flatness of the conductive buses.

[0013] Making the rack from a single dielectric plate allows for easy access to all components and assemblies of the generator stages without disassembling the entire generator, significantly simplifying inspection, adjustment, or replacement of any generator component. A thinner section in the capacitor mounting area allows for increased thickness and strength of the main rack section without increasing the transverse dimensions of the generator column. Attaching the rack to a metal plate with metal angles increases the generator's resistance to axial and lateral impacts and vibrations during handling and transportation, and ensures strength during assembly of the generator stages, which must be performed without the housing when the rack is cantilevered.

[0014] Securing the opposite end of the rack in the housing using a conical insulator helps to increase the electrical strength of the GIN due to a more uniform distribution of the electric field strength along the surface of the conical insulator and the greater length of its generatrix compared to a traditional disk insulator.

[0015] In the prototype accelerator, the charging inductors are made as long, solid columns with taps. These coils are very inconvenient both to manufacture and to secure in the PVG using soldering. Furthermore, if even one section fails, the entire long coil must be replaced. In the proposed PVG, the coils are separate for each stage. Their manufacture and winding are significantly simpler, and the presence of end contacts for connection to the conductive busbars via a threaded connection allows for quick and secure attachment and removal of the coils during assembly and disassembly of the PVG. The use of end contacts results in the coils becoming longer, so to maintain the same length of the PVG column and the entire generator, the coils are positioned at an angle to its axis.

[0016] The presence of a built-in capacitive voltage divider (VCD) in the high-voltage terminal area enables recording of the MG output voltages, which is necessary for determining its output parameters and the causes of malfunctions during generator maintenance. Typically, the high-voltage electrode of the capacitive divider is formed by metal components of the MG's final stage, forming a structural capacitance with the divider's low-voltage electrode. A disadvantage of this solution is the small value of this capacitance (approximately 0.01 pF), resulting in a relatively low useful signal level and significant interference. Furthermore, the capacitive coupling of the divider with the spark gap of the final stage at the moment of its operation (resulting in a voltage surge with a subnanosecond rise time) can cause resonance of the natural oscillation frequency of the low-voltage section of the divider, which will also distort the recorded voltage pulse.Installing a spherical high-voltage electrode on the busbar of the PVG's final stage increases the capacitance between the high-voltage and low-voltage electrodes of the divider by approximately an order of magnitude (up to ≈0.1 pF), shields the influence of the remaining PVG stage elements, and thus ensures high-quality recording of the generator's output voltages. Designing the high-voltage electrode as a spherical electrode reduces the requirements for its positioning accuracy relative to the low-voltage section of the divider, simplifying generator assembly.

[0017] Installing fittings at the extreme points of the housing allows for vacuum pumping, filling, and draining of oil with the generator in a horizontal position. The prototype device does not have fittings, so these operations must be performed only with the generator in a vertical position with the cover removed, in the following order:

[0018] - partial pumping of oil through a tube that is inserted into the generator with the risk of damaging the elements of the generator;

[0019] - final draining of oil by tilting and then turning the generator over some container;

[0020] - placing a stop under the rubber compensator to fix its shape in the presence of pressure from a vertical column of oil (approximately 0.1 atm.).

[0021] This technology is quite inconvenient and labor-intensive, requiring 2-3 people. Furthermore, the presence of oil column pressure makes it impossible to completely evacuate the air from the bottom of the generator. When the generator is positioned horizontally, servicing the compensator is simplified, as the low oil pressure (the oil column height does not exceed the housing diameter) does not cause excessive expansion of the compensator, and all the above operations—vacuum pumping, filling, and draining the oil—can be performed through fittings and hoses by a single worker.

[0022] The arrangement of the arresters in holes drilled in the thick section of the rack, and the fixation of each arrester with a dielectric screw through a polyurethane insert, ensures simple and secure attachment and removal of the arresters during servicing of the GIN. Polyurethane also offers the advantages of providing high-quality adhesion to the arrester surface, preventing jamming after long periods of operation, and electrical strength, which is essential when the insert is located in areas of intense electric fields.

[0023] Brief description of drawings

[0024] Fig. 1, Fig. 2 shows the design of the claimed generator with an accelerating tube as a load, Fig. 3 shows the design of the arrester fixing unit, Fig. 4 shows the design of the charging inductance coil, where:

[0025] 1 - metal case;

[0026] 2 - cover;

[0027] 3 - bottom;

[0028] 4 - rubber oil expansion compensator;

[0029] 5 - metal plate;

[0030] 6 - dielectric stand;

[0031] 7 - a section of smaller thickness of the dielectric stand;

[0032] 8 - metal corners;

[0033] 9 - pulse charging transformer;

[0034] 10 - Cascade energy-storing ceramic capacitors (UHV-12A);

[0035] 11 - cascade arresters;

[0036] 12 - charging inductor coils;

[0037] 13 - conductive buses;

[0038] 14 - fittings;

[0039] 15 - low-voltage electrode of the built-in capacitive voltage divider (LVED);

[0040] 16 - high-voltage electrode VEDN;

[0041] 17 - design capacity of the high-voltage arm of the VEDN;

[0042] 18 - conical insulator;

[0043] 19 - fixing dielectric screws of conical insulator;

[0044] 20 - arrester dielectric fixing screw;

[0045] 21 - polyurethane insert;

[0046] 22 - high voltage terminal;

[0047] 23 - connector for supplying pulse power to the charging transformer 9;

[0048] 24 - dielectric frame;

[0049] 25 - screen;

[0050] 26 - contact;

[0051] 27 - winding.

[0052] The claimed Arkadyev-Marx cascade generator (Fig. 1, Fig. 2) is assembled in a sealed metal casing 1, which, in addition to the shell, contains a cover 2, a bottom 3 with a rubber oil expansion compensator 4 and a metal plate 5, dividing the casing into two sections. The PVG column is located in the upper section, and the pulse charging transformer 9 is in the lower section. A stand 6 is secured to the plate 5 using metal corners 8. In addition to increased resistance to impact and vibration, such a fastening is very convenient for assembling the PVG column, which is carried out with the casing removed and stand 6 cantilevered on the plate 5. Fastening the stand 6 with metal corners 8 (unlike the prototype, where the stand plates are secured with threaded bolts) allows for assembling the PVG column without fear of breakage of the fasteners and accidental fall of the column.

[0053] Each cascade of the PVG contains two UHV-12A ceramic capacitors connected in series. The capacitors are covered on both sides with screens to prevent breakdowns from the sharp plates of the capacitors to the housing 1 and are secured in pairs with studs on the section 7 of the rack 6 with a thinner thickness. In the thick part of the rack 6, there are holes in which the arresters 11 are located. The arresters and capacitors are electrically connected by conductive buses 13. Charging inductors 12 with connecting contacts 26 are connected to the buses (Fig. 4). These units are connected with bolts, which ensures ease of assembly and disassembly - both complete and partial, when only one or more units need to be disconnected.The use of compensation units for the center-to-center spacing of arresters and capacitors, as well as for busbar flatness, based on contact pairs with spherical sections, allows for the virtual elimination of mechanical stress on the rods of high-pressure gas-filled arresters. This ensures high generator reliability by reducing the risk of insulator failure and arrester leakage due to misalignment of fasteners, flatness of conductive busbars, etc.

[0054] The arresters are secured in the holes of the post 6 (Fig. 3) using fixing dielectric screws 20 through elastic inserts 21 made of polyurethane (VITUR material). Polyurethane has good elastic properties and high electrical strength, and therefore ensures reliable fixation of the arresters in the area of ​​high electric field strength (in the gap between arresters 11 and housing 1).

[0055] To secure the generator column in the final stage area, a conical insulator 18 is installed at the end of the column, eliminating the possibility of radial movement of the column under lateral impacts and vibrations. Rigid fixation of the insulator in housing 1 is ensured by clamping screws 19. High voltage from the generator is supplied to the load via high-voltage terminal 22.

[0056] The generator operates as follows. A voltage pulse from the primary supply is applied to the primary winding of transformer 9 via connector 23. This creates a voltage pulse with an amplitude of 100-120 kV on its secondary winding, which charges the capacitors 10 of the PVG stages via charging inductors 12. After the spark gap of the first stage breaks down, the spark gaps of the remaining stages sequentially break down, which leads to the sequential connection of all capacitors and the formation of a voltage pulse at high-voltage terminal 22, the amplitude of which is approximately equal to U вых ≈ U зар ⋅N where Uзар - amplitude of the charging voltage of the cascades, N - number of cascades.

[0057] Implementation of the invention

[0058] In this specific example, a ten-stage compact pulse voltage generator was developed and manufactured to power TMKE-1200 pulsed accelerator tubes manufactured by Impulse Technologies LLC in Ryazan. The generator's surge capacitance is 85 pF, and the voltage pulse amplitude at the specified load is 1 MV. The tubes provide an electron dose outside the window of 1.5-2 Mrad with a pulse duration of 3.5-4 ns. The proposed accelerator features high manufacturing efficiency and ease of maintenance compared to the prototype.

Claims

1. A compact pulse voltage generator comprising several cascades with capacitors and a spark gap in each cascade, charging inductors and conductive buses connecting the spark gaps to the capacitors, as well as a pulse charging transformer connected to the first cascade, all elements of the generator are located in a sealed metal casing, the generator cascades are fixed on a dielectric stand mounted on a metal plate, the spark gaps and capacitors form two rows with an equal pitch along the generator axis, the axes of the spark gaps are parallel to the axes of the capacitors, the row of spark gaps is shifted along the generator axis relative to the row of capacitors by half a pitch, an oil expansion compensator is installed in the bottom of the casing, characterized in that the stand is made of a single dielectric plate with sections of smaller and larger thickness, the capacitors of the cascades are fixed in pairs on the section with a smaller thickness, and holes are made on the section with a greater thickness,in which the cascade arresters are installed, each arrester is fixed with a dielectric screw through a polyurethane insert, the rack is secured to a metal plate using metal corners, the opposite end of the rack is secured in the housing using a supporting conical insulator, the charging inductance coils are made separate for each generator cascade, and each coil is provided with a pair of end contacts for connection to the conductive buses using a threaded connection, the coils are located at an angle to the axis of the generator, in addition, a capacitive voltage divider is installed on the housing opposite the last cascade, the high-voltage electrode of which is made spherical and is installed on the bus of the last cascade of the generator.

2. A compact pulse voltage generator according to paragraph 1, characterized in that fittings for vacuum pumping, draining and filling oil are installed along the edges of the housing.

3. A compact pulse voltage generator according to paragraph 1, characterized in that the conductive buses and arresters are equipped with units for compensating for the beating of the interaxial distances of the arresters and capacitors, as well as the non-flatness of the buses.

Images