RU2714739C1 - Non-uniform forming long line (versions) - Google Patents

Abstract

FIELD: pulse engineering.

SUBSTANCE: group of inventions relates to pulse engineering and can be used in power circuits of pulse sources operating in pulsed and pulse-periodic modes. Non-uniform forming long line is forming long line with lumped or distributed parameters, ratios of lumped parameters of the first of which depend on the serial number of the capacitor, throttle or LC circuit, capacity of the capacitor of the first LC-circuit, inductance of throttle of the first LC-circuit and sequence number of the last LC-circuit, as well as on the ratio of distributed parameters of the other line, which depend on the sequence number of the section on which the line is broken, on the length of the non-uniform line with distributed parameters, on the number of sections on which the line with distributed parameters is broken, and on the length of sections on which the line with distributed parameters.

EFFECT: reduced duration of output voltage pulse of inhomogeneous shaping long line with lumped or distributed parameters with simultaneous increase of its amplitude, which can find application in electric pulse technology at treatment of various materials by high-voltage discharges.

2 cl, 7 dwg

Description

The invention relates to the field of the electrical industry, in particular to pulsed technology, and can be used in power circuits of pulsed light sources, spark chambers, lasers and accelerators operating in both pulsed and pulsed-periodic modes.

In addition, the invention may find use in electrical pulse technology in the processing of various materials by high-voltage discharges.

Inhomogeneous forming long lines with concentrated or distributed parameters are known, in which the capacitors of the capacitors and inductances of the chokes vary along the length of the line.

The group of inventions a non-uniform forming line with lumped parameters (option 1) and a non-uniform forming line with distributed parameters (option 2), belong to objects of the same type, have the same purpose and provide the same technical result.

Despite the fact that the equivalent electrical circuits of lines with lumped and distributed parameters can be the same, the processes in them are fundamentally different, since the processes in lines with lumped parameters are not wave-like.

Such lines are used in generators for the formation of powerful electric pulses of a given duration at a coordinated or inconsistent load, as well as for the transformation and transmission of electrical or magnetic energies from power sources to the load.

Pulse generators usually form pulses close to rectangular in shape, which are used in charged particle accelerators when it is necessary to obtain a stream of particles with the same energy spectrum in time, as well as in radar. Such pulses are obtained by shorting a pre-charged long line through a switch or a surge arrester to a load resistance.

However, in many cases when using pulse generators using long lines, for example, for supplying pulsed light sources or for generating a volume discharge in electric-discharge gas lasers, it is not necessary to obtain a rectangular pulse with a flat top on the load, it is enough to generate an output pulse with a maximum voltage amplitude and a minimum duration, so that, switching it to the load, to allocate on it in the shortest possible time all the electrical energy that is initially stored hay in a long line capacity.

Known inhomogeneous forming a long line with lumped or distributed parameters, in which the capacitance of the capacitors and inductance of the chokes vary exponentially along the line length:

where L (0) is the linear inductance at the beginning of the line;

L (x) is the linear inductance at a distance x from the beginning of the line;

C (0) is the linear capacity at the beginning of the line;

C (x) is the linear capacity at a distance x from the beginning of the line;

[G.A. Month, ““ Pulse energy and electronics ”/ M .: Nauka, 2004. 704 p. (p. 38-43), / O.N. Litvinenko, V.I. Soshnikov, / “Theory of inhomogeneous lines and their application in radio engineering” / M. Sovetskoe Radio, 1964, 536 s, (p. 26-29) /].

The equivalent electrical circuit of this inhomogeneous forming line with lumped or distributed parameters contains a power source, N series-connected L-shaped four-terminal devices, including N capacitors and N chokes, capacitors are connected in series to a chain, all chokes are connected to a common bus with one terminal, other terminals connected to the connection points of two capacitors, while the last line choke is connected to the end of the capacitor chain, and the beginning of the capacitor chain a terminal connected to a potential source.

The equivalent electrical circuit of this inhomogeneous generating line differs from the equivalent circuit of the claimed heterogeneous generating long line with lumped or distributed parameters, although the choice of dependences by which the inductors of the inductors and capacitance of the capacitors change leads to the voltage along the line increasing in dependence U (x) = U (0) e ^{kx / 2} , where (U0) is the voltage at the beginning of the line, e ^{kx / 2} is the transmission coefficient of the long line by voltage at a distance x from the beginning of the line. However, the duration of the output voltage pulse will be equal to the time of double passage of energy along the line, which is a drawback.

изменяется по параболическому закону. [/ О.Н. Литвиненко, В.И. Сошников, / «Теория неоднородных линий и их применение в радиотехнике»/ М. Советское радио, 1964, 536 с, (с. 17, с. 377, Рис. XIII.5)/]. Данная неоднородная формирующая длинная линия применяется в генераторах импульсов для получения на ее выходе прямоугольных импульсов с плоской вершиной и ее электрическая схема содержит источник питания, N последовательно соединенных Г-образных четырехполюсников, включающих в себя N конденсаторов и N дросселей, дроссели соединены последовательно в цепочку, все конденсаторы одним выводом подсоединены к общей шине, а другими выводами подключены к точкам соединения двух дросселей, при этом последний конденсатор линии подключен к концу цепочки из дросселей.Known inhomogeneous forming a long line with lumped or distributed parameters, in which the capacitance of the capacitors C _n and the inductance of the chokes L _n vary along the length of the line so that its wave impedance equal to

varies according to a parabolic law. [/ HE. Litvinenko, V.I. Soshnikov, / “Theory of inhomogeneous lines and their application in radio engineering” / M. Sovetskoe Radio, 1964, 536 s, (p. 17, p. 377, Fig. XIII.5) /]. This inhomogeneous forming long line is used in pulse generators to obtain rectangular pulses with a flat top at its output and its electrical circuit contains a power source, N series-connected L-shaped four-terminal devices, including N capacitors and N chokes, chokes are connected in series in a chain, all capacitors are connected to a common bus with one terminal, and connected to the points of connection of two chokes with the other terminals, while the last capacitor of the line is connected to the end of the circuit Kidney of chokes.

The disadvantage of this inhomogeneous forming long line is that for its operation, an additional capacitor with a capacity equal to the static capacitance of the parabolic line must be connected in front of the power source. In this case, the amplitude of the pulse of the output voltage of the line is almost halved and the multiplication coefficient of the line (transmission coefficient) in voltage is low. The pulse duration of the output voltage and current signals is equal to the time of double passage of energy along the line. [G.A. Month, ““ Pulse energy and electronics ”/ M .: Nauka, 2004. 704 p. (p. 62, Fig. 4.8) /].

The closest in technical essence to the claimed solution and selected as a prototype is a hyperbolic heterogeneous forming a long line with lumped or distributed parameters, in which the capacitors C are equal to each other, and the inductors of the chokes, or the inductance per unit length of the line (linear inductance), change along the length of the line, based on the ratio:

where L (0) is the linear inductance at the beginning of the line;

L (x) is the linear inductance at a distance x from the beginning of the line;

T is the time of a single passage of energy along the line.

[/HE. Litvinenko, V.I. Soshnikov, / “The theory of inhomogeneous lines and their application in radio engineering” / M. Sovetskoe Radio, 1964, 536 s, (p. 381) /]. An equivalent circuit diagram of such a line is given in the same place on p. 373.

The equivalent electrical circuit of this inhomogeneous forming long line also contains a power source, N series-connected L-shaped four-terminal devices, including N capacitors and N chokes, chokes are connected in series in a chain, all capacitors are connected to a common bus with one terminal, and connected to other terminals to the connection points of two chokes, while the last line capacitor is connected to the end of the chain of chokes.

The disadvantage of this inhomogeneous forming long line is that, when used in pulse generators, the duration of the voltage and current output signals is equal to the time of double passage of energy along the line, which is not suitable for solving the required problems, and the voltage transfer coefficient does not exceed unity. Moreover, reflected pulses appear at the junction of the L-shaped four-terminal networks, which reduce the efficiency of energy transfer to the load, since their wave impedances are not consistent with each other. However, the equivalent circuit of this line coincides with the equivalent circuit of the claimed heterogeneous forming a long line with lumped or distributed parameters

The technical problem to be solved by the claimed invention is directed is the creation of a non-uniform forming long line with concentrated or distributed parameters, which will be used in pulse generators to generate pulses with increased voltage amplitude and short duration.

The technical result of the present invention is to reduce the pulse width of the output voltage of a nonuniform forming long line with concentrated or distributed parameters while increasing its amplitude.

Another technical result provided by the invention is to increase the efficiency of transmission of electric energy, originally stored in a non-uniform long line forming, to the load.

Both for an inhomogeneous forming long line with lumped parameters, and for a long line with distributed parameters, the problem posed is solved essentially in the same way with achieving the same result, however, the specifics of equivalent electrical circuits and the technical design of lines with lumped and distributed parameters does not allow to combine them into a common point, they are independent options.

The technical result of the invention of an inhomogeneous long line with lumped parameters is ensured by the fact that its electric circuit contains a power source, N series-connected L-shaped four-terminal devices, including N capacitors and N chokes, chokes are connected in series in a chain, all capacitors are connected to one terminal common bus, and other leads connected to the connection points of two chokes, while the last capacitor of the line is connected to the end of the chain of chokes, a chain of inductors connected to the power source potential terminal. According to the invention, N capacitors and N chokes form N resonant LC circuits, capacitors and chokes of resonant LC circuits use capacitors whose capacitances are C _n and chokes whose inductances L _n are selected from the following relations:

where n = 2, 3, ... N is the serial number of the capacitor, inductor or LC circuit;

C ₁ is the capacitance of the capacitor of the first LC circuit;

L ₁ is the inductance of the throttle of the first LC circuit;

N is the sequence number of the last LC circuit.

формирующей длинной линии разбита на N участков длиной

имеет погонную емкость С_р и погонную индуктивность L_p, источник питания. Согласно изобретению емкости n-го участка длинной линии C_n=C_p⋅Δ

и индуктивности n-го участка длинной линии L_n=L_p⋅Δ

выбирают из соотношений (1) и (2),The technical result of the invention of an inhomogeneous forming long line with distributed parameters is ensured by the fact that the length

forming a long line is divided into N sections of length

has linear capacitance C _p and linear inductance L _p , power source. According to the invention, the capacitance of the n-th section of the long line C _n = C _p ⋅Δ

and inductance of the n-th section of the long line L _n = L _p ⋅Δ

choose from relations (1) and (2),

where n = 1, 2, 3, ... N is the serial number of the section into which the line is divided;

= длина неоднородной линии с распределенными параметрами;

= length of an inhomogeneous line with distributed parameters;

N = number of sections into which the line with distributed parameters is divided;

= длина участков, на которые разбита линия с распределенными параметрами.Δ

= length of sections into which the line with distributed parameters is divided.

The application of these patterns of change in capacitances of capacitors and inductances of chokes of an inhomogeneous forming line with concentrated or distributed parameters leads to the appearance of a new property of the generator in which the line is used, namely: the absence of reflection of electric and magnetic energies when they move along the forming line from its beginning to the end when closure of the generator switch located in front of the line. This leads to the fact that the electric energy stored at the beginning of the line, or in its first capacitor, flows through the switch, and the remaining stored energy propagates to the end of the line under the influence of the voltage drop in neighboring capacitors caused by the discharge of the capacitor at the beginning of the line, the principle of the "raked snow" or "snow plow" model. At the same time, at the output of a long line, a voltage pulse appears with an increased amplitude and a significantly shorter duration than the time of double energy passage along the line, which takes place in the prototype.

Since the loss of electrical energy that occurs during the formation of the output voltage pulse of the generator is mainly determined by the resistance of the switch, the absence of reflected electrical energy during the passage of the pulse along the resonant inhomogeneous forming line leads to a decrease in the duration of the current pulse through the switch, which means that the energy loss on it resistance and increases the efficiency of transmission of electrical energy from long line capacitors to the load.

In the case associated with the implementation of the claimed invention in the form of an inhomogeneous long line with distributed parameters, the capacitances of capacitors C _n and the inductances of the chokes L _n should be understood as the capacitance and inductance of the nth portion of the long line into which the inhomogeneous long line with distributed parameters is divided.

The invention is illustrated by drawings.

In FIG. 1 shows an electric circuit of an inhomogeneous long line with concentrated parameters according to claim 1, which corresponds to an equivalent electric circuit of an inhomogeneous long line with distributed parameters according to claim 2, where: U ₀ is the line power source, C _n are capacitors, L _n - chokes, I _Ln - currents through chokes.

In FIG. 2 a) graphs of the time variation of the voltages on the capacitors of the long line during one period of resonant oscillations T for six resonant LC circuits of the long line according to claim 1, FIG. 2b) are graphs of the time variation of currents through long line chokes. The values of the capacitors and chokes are calculated with an accuracy of ≈ 0.1%, and the graphs are constructed according to specific equations using the standard program.

In FIG. 3 a) graphs of the time variation of electric energy on long-line capacitors under the same conditions, FIG. 3 b) graphs of the time variation of magnetic energy in long line chokes are shown.

In FIG. Figure 4 shows an electric circuit of an inhomogeneous long line with lumped parameters, the operation of which was studied using a standard software package. The values of the capacitors and chokes are calculated according to the above formulas and differ from the exact values by ≈ (3-5)%.

In FIG. Figure 5 shows the graphs of the time variation of the voltages on the capacitors U _Cn (t) and currents through the inductors I _Ln (t) of the long line for N = 6, constructed using the standard software package.

In FIG. 6 is a schematic drawing of an inhomogeneous long line with distributed parameters according to claim 2 of the claims (option 2), which explains the transition to an inhomogeneous long line with concentrated parameters according to claim 1.

In FIG. 7 is an exemplary graph of the time variation of the Voltage in the last section of a non-uniform long line with distributed parameters according to claim 2, when all the electric energy of the long line passes at time t ₁ to the end of the line.

The inhomogeneous forming long line with lumped parameters according to claim 1 of the claims is an integral part of the pulse generator and works as follows.

The concentrated capacitance of the capacitors of the long line C _n through the corresponding chokes L _n are charged from the power source to the value U ₀ . Further, if you close the switch of the generator, which is located before the start of the forming line, in N connected resonant LC circuits of the long line, the oscillation process begins with N independent frequencies ω _n , which are in relation ω ₁ : ω ₂ : ω ₃ : ...: ...: ω _n : ...: ω _N = N: N-1: ...: n: ...: 3: 2: 1. At the same time, at the beginning of the oscillatory process, a current passes through the switch and inductance L ₁ , which is determined mainly by the electric energy stored in the capacitor C ₁ , which passes into the magnetic field energy of the inductor L ₁ (see U _C1 , I _L1 in Fig. 2 a) and b) and E _C1 E _L1 in FIG. 3 a) and b)), transmitted further to the capacitor C ₂ . Then, with some delay, the discharge of the capacitor C ₂ begins through the inductor L ₂ and the capacitor C ₁ . In this case, the inductor L ₂ already stores electric energy from the capacitor C ₂ and the remainder of the energy from the capacitor C ₁ into the energy of the magnetic field (see U _C2 , I _L2 in Fig. 2 a) and b) and E _C2 E _L2 in Fig. 3 a) and b)), which is then transferred to the capacitor C ₃ . This process continues until time t ₁ , when electric energy reaches the end of the line, that is, to the capacitor C _N , is reflected from the open end of the line, and a similar process of energy movement towards the beginning of the line begins, but with the currents through the inductors inverse in direction.

Since the capacitance values of the capacitors C _n and the inductances of the chokes L _n are selected according to the above patterns, which determine the resonant nature of the oscillations in the coupled LC circuits of the generator, and also ensure the matching of the input and output wave impedances of the circuits, the appearance of reflections of the pulse energy during its passage along line excluded. This is clearly seen from the graphs in FIG. 3a), b), which were obtained by the exact solution of the equations describing the behavior of electric and magnetic energies in an inhomogeneous long line for N = 6. Moreover, all the electric energy initially stored in the capacitors of the long line after a time equal to the half-period of the oscillatory process t ₁ goes to the last capacitor of the long line C _N (see U _C6 in FIG. 2a) and E _C6 in FIG. 3 a)), which, if you turn on the spark gap-sharpener of the generator at time t ₁ , transfers it to the load. The capacitance of the last capacitor of the line is significantly less than the total capacitance of all capacitors of the line, so the voltage on it increases significantly, and the time of its discharge to the Load, determined by the time constant τ = R _H ⋅C _N (R _H is the load resistance), is noticeably reduced, that is, the peak the power of the generator transmitted to the load, compared with the known generators, increases.

As follows from the type of dependencies in FIG. 2, the duration of the output voltage pulse of the generator for N = 6 is significantly less than the time of double passage of the pulse along the line, in this case equal to T. The shape of the output voltage pulse is close to triangular, and the pulse width at the base is approximately equal to the duration of the current pulse through the switch and inductor L ₁ .

The inhomogeneous forming long line with distributed parameters according to claim 2 of the claims is an integral part of the pulse generator and works as follows.

, имеющая погонную емкость С_р и погонную индуктивность L_p, разбивается на N участков длиной

(см. Фиг. 6) и [/ О.Н. Литвиненко, В.И. Сошников, / «Теория неоднородных линий и их применение в радиотехнике» / М. Советское радио, 1964, 536 с, (с. 372)/], а емкости C_n=С_р⋅Δ

и индуктивности L_n=L_p Δ

выбирают из соотношений (1), (2),Inhomogeneous forming long line with distributed parameters of length

having linear capacitance C _p and linear inductance L _p , is divided into N sections of length

(see Fig. 6) and [/ O.N. Litvinenko, V.I. Soshnikov, / “Theory of inhomogeneous lines and their application in radio engineering” / M. Sovetskoe Radio, 1964, 536 s, (p. 372) /], and capacitances C _n = С _p ⋅Δ

and inductances L _n = L _p Δ

choose from relations (1), (2),

where n = 1, 2, 3, ... N is the serial number of the section into which the line is divided;

= длина неоднородной линии с распределенными параметрами;

= length of an inhomogeneous line with distributed parameters;

N = number of sections into which the line with distributed parameters is divided;

= длина участков, на которые разбита линия с распределенными параметрами.Δ

= length of sections into which the line with distributed parameters is divided.

The distributed capacitance of the capacitors of the long line C _n through the corresponding chokes L _n are charged from the power source to a voltage of U ₀ . Next, the generator switch closes, which is located in front of the start of the forming line, and the oscillation process begins in the line similar to that which occurs in a nonuniform long forming line with lumped parameters. Since at time t _{1 the} voltages in the intermediate sections of the long line, except the last, vanish, a voltage pulse will be formed at the output section of the long line as on the last capacitor of the long line with lumped parameters (see Fig. 7).

The experimental confirmation of the operability of the claimed invention with a resonant inhomogeneous forming line with lumped parameters for the number of resonant LC circuits of the line N = 4 was carried out. The ratio of the capacitances of the capacitors of the long line was C ₁ : C ₂ : C ₃ : C ₄ = 1: 0.43: 0 , 28: 0.28, and the inductances of the chokes L ₁ : L ₂ : L ₃ : L ₄ = 1: 1.92: 3.38: 7.06. The amplitude of the output voltage pulse increases, a voltage multiplication factor of ≈ 2.5 for a long line according to claim 1 is obtained, and the voltage pulse duration at half maximum decreases ⋅ ≈ 4 times compared to the prototype pulse.

The performance of the claimed invention with a non-uniform forming line with distributed parameters for a long line according to claim 2 of the claims for the number of sections of a long line N = 6 is confirmed by modeling its operation using a standard software package (see Fig. 5). The parameter values of the sections of the forming long line are shown in FIG. 4 and were calculated according to the above formulas. From the figure in FIG. 5 it can be seen that until time t ₁ , when the energy switches to the load, the voltages and currents in the intermediate sections of the long line practically coincide with those calculated exactly (see Fig. 3 a, b). In this case, the amplitude of the output voltage pulse increases, the voltage multiplication factor is ⋅≈ 3.4, and the voltage pulse duration at half maximum decreases ⋅≈ 5 times compared to the prototype pulse.

Claims (14)

1. A non-uniform forming long line, which is a forming long line with lumped parameters, the electric circuit of which contains a power source, N series-connected L-shaped four-terminal devices, including N capacitors and N inductors, inductors are connected in series in a chain, all capacitors are in one output connected to a common bus, and other leads connected to the connection points of two chokes, while the last line capacitor is connected to the end of the chain of chokes, beginning epochki of inductors is connected to the potential conclusion that the power source, characterized in that the N series connected L-shaped two-port form N resonant LC-circuits, as capacitors and inductors of the resonance LC-circuits using capacitors whose C _n capacitance and inductors, the inductance of which L _n choose from the following ratios:

, where n = 2, 3, ... N is the serial number of the capacitor, inductor or LC circuit; C ₁ is the capacitance of the capacitor of the first LC circuit; L ₁ is the inductance of the throttle of the first LC circuit; N is the sequence number of the last LC circuit. 2. Inhomogeneous forming a long line, representing a forming a long line with distributed parameters, length

which is divided into N sections of length

having linear capacitance C _p and linear inductance

, a power source, characterized in that the capacitance of the n-th section of the long line C _n = C _p ⋅Δ

and inductance of the nth section of the long line Ln = Lp⋅Δ

choose from the ratios:

where n = 1, 2, 3, ... N is the serial number of the section into which the line is divided;

= length of an inhomogeneous line with distributed parameters; N = number of sections into which the line with distributed parameters is divided; Δ

= length of sections into which the line with distributed parameters is divided.

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