RU2682305C1 - High-voltage pulse generator - Google Patents

Abstract

FIELD: physics.SUBSTANCE: invention relates to the high-voltage pulse equipment. Technical result is achieved due to the pulse voltage generator, containing the coaxial single forming line, discharging unit, the transmission line and the load, in the proposed generator, the coaxial single forming line and the discharging unit are functionally divided into two independently functioning elements, as the discharging unit, the uncontrolled discharger is used, the uncontrolled discharger is connected to the electrical circuit between the single forming line and the load, at that, the uncontrolled discharger is located in the strip line, which one end is connected to the DC voltage generator through the charging resistance, and at its other end the shorting discharger is located, wherein the uncontrolled discharger axis is oriented along the strip line, the uncontrolled discharger is located at a distance l=τν/2 from the shorting discharger, where τ is the generated electric pulse required duration, ν is the electromagnetic wave propagation speed along the strip line, and the single forming line (SFL) length is l=2l=τν.EFFECT: technical result consists in the discharger switching time control simplification due to the design simplification.1 cl, 2 dwg

Description

The invention relates to high-voltage pulse technology and can be used in accelerator technology, plasma physics, radiation physics, in atomic physics, medicine, chemistry, solid state physics, and other pulsed high-current devices.

A device is known (Vorobev G.A., Rudenko N.S. Generator of nanosecond voltage pulses 500 kV // PTE. 1965. No. 1 from 109-111.).

The generator includes a Marx generator, connected to an additional inductance, which in turn is electrically connected to a low-inductance capacitor, which is a segment of a coaxial long forming line consisting of two cylindrical plates with a space between them filled with glycerin. The inner lining of the capacitor is also the housing of the discharge chamber, filled with nitrogen, into which the switching arrester is placed. On the other hand, a noninductive uncontrolled arrester is connected to the transmission line, which is a brass tube filled with transformer oil. At the opposite end, the feed line is connected to the load.

The disadvantage of this generator is:

1. The inconsistency of the wave impedances of the low-inductance capacitor, which is a segment of a coaxial long line, and the transmission line, due to the difference in the ratio of the diameters of the internal and external electrodes of the low-inductance capacitor and the transfer line.

2. The presence of an uncontrolled arrester, instability in the times of its operation. It cannot be synchronized with the spark gap of the Marx generator, since each uncontrolled spark gap has its own delay time (not always stable).

3. In the circuit, the compensation capacitor is charged by a pulse voltage generator (GIN) - a Marx generator with a capacity many times higher than the capacitance of the capacitor itself. Therefore, only a small part of the energy stored in the GIN enters the load.

Closest to the claimed device is a high-voltage pulse generator (Kovalchuk B.M., Mesyats G.A., Shpak V.G. PTE (6) 73 (1976)).

It consists of a Marx generator, electrically connected to a coaxial single forming line (OFL) with high-pressure gas insulation connected to a single common reservoir filled with gas at a certain pressure, with a block of a discharge unit that combines sharpening and cutting arresters, the so-called slicer. serving to form the trailing edge of the high voltage pulse. The slicer design allows in the operating mode to change the gap of the arresters using eccentric mechanical drives.

на обостряющем разряднике. Сама же скорость нарастания фронта напряжения задавалась генератором Маркса. Срезающий разрядник работал в условиях «бегущей волны» и при более высоком значении

и поэтому задний фронт сформированного импульса был в два-три раза короче переднего.When the Marx generator is triggered, the coaxial forming line is charged, when the breakdown value of the electric field is reached, the gap of the sharpening spark gap breaks down and then the pulse propagates along the transmission line to the load. The duration of the leading edge of the pulse was determined by the rate of rise of voltage

on a sharpening spark gap. The rate of rise of the voltage front itself was set by the Marx generator. The cutting arrester worked in the conditions of the "traveling wave" and at a higher value

and therefore, the trailing edge of the generated pulse was two to three times shorter than the leading one.

The main disadvantages of this system are:

1. The presence in the design of the pulse generator of a complex device - slicer. Its design includes eccentric drive mechanisms. The movable potential electrode of the sharpening spark gap was driven through a thin-walled insulator located in the gap of a gas-filled coaxial forming line with high-pressure gas insulation. The gaps of the arresters were regulated with an error of 10 μm. Using a slicer greatly complicates the design as a whole.

где р-давление газа. Е - напряженность электрического поля. При неизменном напряжении статического пробоя газонаполненного межэлектродного промежутка обостряющего разрядника согласно закону Пашена произведение давления газа на длину промежутка pd тоже должно оставаться неизменным (для обостряющих разрядников очевидно рассматривается правая ветвь закона Пашена), а следовательно, неизменной будет и величина

здесь

- пробойные значения напряженности и напряжения. Это значит, что время t_к уменьшается с ростом давления. Поэтому в данном генераторе, для достижения коротких передних фронтов импульсов необходимо поддерживать давление газа до 100 атмосфер. Это сильно усложняет конструкцию генератора из-за необходимости поддержания высокого давления в слайсере, что важно для уменьшения времени коммутации. Кроме того, высокоточное регулирование межэлектродных зазоров серьезно усложняет конструкцию разрядного узла - слайсера. Все вышесказанное соответственно усложняет управление временем коммутации разрядника.2. The dependence of the switching time t _to for breakdown of the interelectrode gap according to the Rompe and Weinel models: the switching time t _{to is} proportional to

where p is the gas pressure. E is the electric field strength. Under the constant voltage of the static breakdown of the gas-filled interelectrode gap of the sharpening spark gap according to the Paschen law, the product of the gas pressure and the length of the gap pd must also remain unchanged (for sharpening spark gaps, the right branch of the Paschen law is obviously considered), and therefore the value will also be unchanged

here

- breakdown values of tension and voltage. This means that the time t _k decreases with increasing pressure. Therefore, in this generator, to achieve short leading edges of pulses, it is necessary to maintain a gas pressure of up to 100 atmospheres. This greatly complicates the design of the generator due to the need to maintain high pressure in the slicer, which is important to reduce the switching time. In addition, high-precision regulation of interelectrode gaps seriously complicates the design of the discharge unit - slicer. All of the above, respectively, complicates the management of the switching time of the arrester.

The technical result consists in simplifying the management of the switching time of the arrester by simplifying the design

от закорачивающего разрядника, где τ - требуемая длительность формируемого электрического импульса, ν - скорость распространения электромагнитной волны по полосковой линии, а длина одинарной формирующей линии (ОФЛ) составляет

The technical result is achieved by the fact that, in contrast to the known high-voltage pulse generator, containing an electrically coupled pulse voltage generator, a single forming line, a discharge unit, a transmission line and a load, in the proposed generator, the single forming line and the discharge unit are functionally divided into two independently functioning element, an uncontrolled arrester is used as a discharge unit, an uncontrolled arrester is included in the electric circuit between forming line and the load, the discharger is uncontrollable in the strip line, one end of which is connected to the generator via the DC resistance of the battery, and at the other end thereof is placed shorting arrester, wherein the unsteered arrester axis oriented along the stripline, uncontrollable discharger located at a distance

from a short-circuit arrester, where τ is the required duration of the generated electric pulse, ν is the propagation velocity of the electromagnetic wave along the strip line, and the length of the single forming line (OFL) is

The proposed approach to controlling the switching time of the spark gap is to control the switching time of the spark gap on the “new physical principle” —magnetize charge carriers (electrons and ions) by means of a transverse magnetic field, so that the longitudinal displacement of charged particles equal to the double Larmor radius is much smaller than the interelectrode gap arrester. With the involvement of the corresponding mathematical apparatus, the formulas of which are important, since they determine the parameters of the physical processes underlying this device, this idea looks as follows.

2R _L << d (Fig. 1), where R _L is the Larmor radius of the electron, d is the width of the discharge gap of the spark gap, or

where m is the mass of the electron, and

- дрейфовая скорость электронов в газе, М - масса ионов газа, m=9,1⋅10^-31 [кг] - масса электрона, λ - длина свободного пробега электрона, U₀ - напряжение, приложенное к межэлектродному промежутку разрядника.

is the electron drift velocity in the gas, M is the mass of gas ions, m = 9.1 910 ^-31 [kg] is the mass of the electron, λ is the mean free path of the electron, U ₀ is the voltage applied to the interelectrode gap of the spark gap.

- ток протекающий по линии U_} - напряжение приложенное к ПЛ,

- волновое сопротивление полосковой линии b - ширина линии, а -расстояние между пластинами ПЛ,

Теперь соотношение (1) примет вид:The magnitude of the induction of the magnetic field B inside the strip line (PL) is

- current flowing along the line U _} - voltage applied to the submarine,

- the wave impedance of the strip line b is the line width, and the distance between the plates of the submarine,

Now the ratio (1) will take the form:

A single forming line (OFL) is connected at one end to a pulse voltage generator (GIN), and at the other end to a load resistance. In the claimed design, there may be a synchronization unit, which is connected via communication lines through a short-circuit arrestor and a GIN to the OFL.

The physical basis of the approach for creating a high-voltage pulse generator relates to the organization of the switching control process. The proposed scheme allows you to control the start and end switching times of an uncontrolled arrester and, which is very important, with small leading and trailing edges of the generated pulse.

This is organized due to the fact that the "uncontrolled" arrester is controlled by an external magnetic field created by electric pulses propagating in the submarine. This becomes possible due to the fact that the coaxial single forming line and the discharge unit are functionally divided into two independently functioning elements (and not combined, as in the prototype, into a total volume filled with gas at a certain pressure) and it is possible to place a spark gap in a submarine in which electrical impulses propagate. These pulses in a certain way “turn on” or “turn off” the magnetic field in the submarine; the magnetic field at those times when it “turns on”, closes the arrester, and when the field “turns off”, the arrester opens, since it is under voltage more than the breakdown voltage. Thus, a voltage pulse is formed at the load resistance of the desired duration and with short leading and trailing edges.

In the claimed design from an external static power supply, the submarine is charged through the charging resistance. At certain times, the synchronization unit starts the GIN and the short-circuit arrestor. After the short-circuit arrester is triggered, charging and discharging waves begin to propagate in the submarine.

The proposed technical solution allows us to abandon the complex design of the slicer, which is used in the prototype, and use an uncontrolled arrester for switching a high-voltage pulse at low pressures, which will simplify the design and simplify the control of the pulse formation process with short fronts by controlling the arrester switching time.

In FIG. 1 schematically shows the trajectory of the movement of charged particles.

In Fig 2. presents a circuit diagram of a high voltage pulse generator, where

1 - GIN - pulse voltage generator;

2 - charging resistance;

3 - single forming line (OFL):

4 - strip line (GS);

5 - uncontrolled arrester;

6 - block synchronization;

7 - short-circuit arrestor;

8 - load resistance;

9 - external static power source;

10 - charging resistance.

от закорачивающего разрядника 7, где τ - требуемая длительность формируемого электрического импульса, ν - скорость распространения электромагнитной волны по полосковой линии, а длина одинарной формирующей линии (ОФЛ) 3 составляет

Одинарная формирующая линия (ОФЛ) 3 одним концом подсоединена к генератору импульсного напряжения (ГИН) 1, а другим концом к сопротивлению нагрузки 8. В заявляемой конструкции может быть блок синхронизации 6, который посредством линий связи подсоединен через закорачивающий разрядник 7 и ГИН 1 к ОФЛ 3.In the high-voltage pulse generator (Fig. 2), the single forming line 3 and the discharge unit 5 are functionally divided into two independently functioning elements, an uncontrolled arrester is used as the discharge unit 5, an uncontrolled arrester 5 is connected to the electric circuit between the single forming line 3 and the load 8, while the uncontrolled arrester is located in the strip line 4, one end of which is connected to a constant voltage generator (external static power source) 9 through the charging resistance 2, and at its other end there is a short-circuit arrester 7, the axis of the uncontrolled arrester is oriented along the strip line, the uncontrolled arrester is located at a distance

from a short-circuit arrestor 7, where τ is the required duration of the generated electric pulse, ν is the propagation velocity of the electromagnetic wave along the strip line, and the length of the single forming line (OFL) 3 is

A single forming line (OFL) 3 is connected at one end to a pulse voltage generator (GIN) 1 and at the other end to a load resistance 8. In the inventive design, there can be a synchronization unit 6, which is connected via short-circuit arrestor 7 and GIN 1 to the OFL 3.

пока волна разрядки по полосковой линии достигнет неуправляемого разрядника 5, за это время t₁ ГИН 1 успевает зарядить ОФЛ 3 до напряжения U=0,8÷0,9U_{пробойное}. В момент времени равный t₁ в межэлектродном промежутке неуправляемого разрядника возникает магнитное поле

где U₁ - напряжение, до которого заряжена полосковая линия. При этом происходит замагничивание носителей заряда. Разрядник будет заперт, вследствие выполнения неравенства (2). В дальнейшем волна разрядки по полосковой линии движется в сторону, где установлено сопротивление зарядки 10. Поскольку R_{зарядки}>>ρ на этом конце полосковой линии происходит отражение падающей волны разрядки, которая превращается в волну зарядки для полосковой линии. Когда волна зарядки достигнет неуправляемого разрядника в момент времени

где

расстояние от неуправляемого разрядника до конца ПЛ 4, подключенного к зарядному сопротивлению 10 (время отсчитывается от начала коммутации закорачивающего разрядника и ГИН), то к этому моменту времени ГИН должен зарядить ОФЛ до напряжения значительно большего, чем U_{пробойное}, а магнитное поле в межэлектродном зазоре исчезнет. Как следствие, неуправляемый разрядник пробьется и сформирует импульс напряжения на нагрузке 8 с коротким передним фронтом, благодаря тому, что к нему будет приложено напряжение значительно большее, чем пробойное. В дальнейшем волна разрядки будет двигаться к концу полосковой линии, где размещен закорачивающий разрядник, а в неуправляемом разряднике магнитное поле будет отсутствовать. Подойдя к этому концу полосковой линии, волна зарядки отразится от закороченного конца линии и по ней в противоположную сторону начнет движение волна разрядки. При достижении этой волной неуправляемого разрядника в момент времени

в нем опять скачком возникнет магнитное поле, удовлетворяющее условию (2), ток через разрядник прекратится и вместе с ним импульс напряжения на нагрузке с резким задним фронтом. В итоге на нагрузке сформируется импульс напряжения длительностью

The device operates as follows. At the initial time, the synchronization unit 6 commutes the GIN 1 and the short-circuit arrester 7 located at the end of a charged submarine 4 with wave impedance p. When shorting a submarine charged from an external static power source 9, a discharge wave is formed in it. During

until the discharge wave along the strip line reaches the uncontrolled spark gap 5, during this time t ₁ GIN 1 manages to charge OFL 3 to the _breakdown voltage U = 0.8 ÷ 0.9U. At time equal to t ₁ in the interelectrode gap of an uncontrolled spark gap a magnetic field occurs

where U ₁ is the voltage to which the strip line is charged. In this case, magnetization of charge carriers occurs. The arrester will be locked due to inequality (2). Subsequently, the discharge wave along the strip line moves to the side where the charging resistance is set to 10. Since the _charging R >> ρ at this end of the strip line, an incident discharge wave is reflected, which turns into a charging wave for the strip line. When the charging wave reaches an uncontrolled discharger at a point in time

Where

the distance from the uncontrolled arrester to the end of the PL 4 connected to the charging resistance 10 (the time is counted from the beginning of the switching of the short-circuit arrestor and the GIN), then by this time the GIN must charge the OFL to a voltage much larger than U _breakdown , and the magnetic field in the interelectrode gap will disappear. As a result, an uncontrolled arrester will break through and form a voltage pulse at load 8 with a short leading edge, due to the fact that a much larger voltage than the breakdown voltage will be applied to it. Subsequently, the discharge wave will move to the end of the strip line where the short-circuit discharger is located, and there will be no magnetic field in the uncontrolled discharger. Approaching this end of the strip line, the charging wave will be reflected from the shorted end of the line and a discharge wave will begin to move along it in the opposite direction. When this wave reaches an uncontrolled arrester at a time

again, a magnetic field appears in it abruptly, satisfying condition (2), the current through the arrester will stop, and with it the voltage pulse at the load with a sharp trailing edge. As a result, a voltage pulse of duration

то к ко времени t₃ ОФЛ разрядится и процесс прекратится.Due to the fact that the length of the OFL is

then by the time t ₃ OFL will be discharged and the process will stop.

The electron accelerator is made as follows. The forming line is made of five equal lengths of coaxial cable KVI-100 with a wave impedance of 60 Ohms,

For switching submarines, the control arrester RU-78 was used. The submarine is charged from a standard external power supply SpelJman CZE 1000R. As a GIN, BING-45 was selected with the following characteristics:

• Output voltage: from 60 to 80 kV;

• Front of pulse formation: up to 5 ns.

The submarine has a wave impedance ρ = 50 Ohms. As an uncontrolled arrester, a PO-48 arrester with a breakdown voltage of 50 kV was used. By the time the spark gap was locked by the PL magnetic field, the voltage on it was about 45 kV, and by the time the charge wave arrives, when the magnetic field disappears, the voltage on the spark gap is about 80 kV.

Thus, the high-voltage pulse generator allows you to generate high-voltage pulses of a certain duration and with short leading and trailing edges on the load while simplifying the control of the switching time of the spark gap due to the simplification of the design in comparison with the prototype.

Claims (1)

A high-voltage pulse generator containing an electrically interconnected pulse voltage generator, a coaxial single forming line, a discharge unit, a transmission line and a load, characterized in that the coaxial single forming line and a discharge unit are functionally divided into two independently functioning elements, as the discharge unit is used uncontrolled arrester, uncontrolled arrester is included in the electric circuit between the single forming line and the load, while The discharged arrester is located in a strip line, one end of which is connected to the DC voltage generator through a charging resistance, and a short-circuit arrester is placed at its other end, the axis of the uncontrolled arrester being oriented along the strip line, the uncontrolled arrester is located at a distance

from a short-circuit arrester, where τ is the required duration of the generated electric pulse, ν is the propagation velocity of the electromagnetic wave along the strip line, and the length of the single forming line (OFL) is

.

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