JPH0667219B2 - High voltage pulse generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-voltage pulse generator that generates a high voltage with high efficiency and a high repetition frequency, and particularly to a capacitance and an inductance connected in parallel with each other. A parallel resonant circuit of one stage or a plurality of stages connected in series, and a switch provided between the power source and the consuming device,
The present invention relates to a high voltage pulse generator used in a TEA-designed gas laser.

[Prior Art and its Problems] Pulse generators of the type described above are known. This pulse generator is used especially for TEA energy lasers.
In a laser, electrical energy with a high peak power is converted into excitation energy that leads to laser emission during a gas discharge. Not just a laser device,
In the technical field of using high voltage pulses, it is necessary to be able to utilize high speed, high voltage, high energy pulses.

In the pulse generator described above, in order to obtain a very high peak power, it is absolutely necessary that all the components used and their mechanical components have a very low inductance. Moreover, it is essential to use a fast switch to supply the load with the energy stored in the capacitor. In addition to various other requirements,
This switch requires a particularly high sustaining voltage, the ability to switch high peak currents with low losses, and it must have a long life. Although the thyratron used as a conventional switch has the ability to meet the above-mentioned requirements, it has drawbacks such as limitation of switching voltage, current, and limit peak output with respect to a load. Furthermore, the life of a thyratron depends sensitively on its mode of use. The service life under very high peak currents is much shorter than when carrying the same charge at low currents. Since the switch is the weakest part among the conventionally used parts, efforts have been made to reduce the load on the switch as much as possible.

One solution to that problem is Appln.
Phys. Lett 40 (7) by I. Smilanski et al.

This prior art is shown in FIG. In addition to the resistance R, switch S and energy consumption load RL of the device shown in FIG.
It has an HV.

In addition, the series connection of capacitors C0 to CN and the coils LDC and L1
And a saturable inductance (coil) SI1 and SIN connected in series and in parallel.

Energy is stored in capacitor C0 and transferred by switch S to capacitor C1. In this case, the magnitude of the inductance of coil L1 is adjusted so that it does not exceed the switch maximum current ratings dI / dt and Imax.

The reload time, or charge transfer time, is Made up.

The saturable inductance SI1 causes a very small current to flow in the capacitor C2 due to its high inductance.

By setting the saturable inductance SI1 correctly,
Saturates when capacitor C0 is almost completely discharged. Recharging from the current charge of capacitor C1 to capacitor C2 is much shorter than τ _1. The saturable inductance SI1 of SI1, which is designed to be performed in the time of, must be low.

As shown in Fig. 3, one capacitor and one saturable inductance form a single-stage resonant circuit (SI1, C1), (SI2, C
2), ..., (SIn, Cn), and the current is compressed in the resonant circuit at each stage, that is, the current value becomes small as described above. Here, when the capacitors have the same capacitance in each stage (each stage), the current compression factor Ki per resonance circuit of one stage (one stage) is expressed by the following equation.

Here, i is a natural number indicating the stage number of the resonance circuit.

That is, the current is compressed according to the compression coefficient Ki expressed by the above equation.

If the loss in the switch S and the saturable inductance SI is negligible, the resonance circuit is recharged (hereinafter referred to as resonance recharge), and the voltage in the circuit state of the subsequent stage is It becomes equal to the voltage in the circuit state of the stage.

The above design completes a resonant recharge with current compression, but does not change the voltage on the capacitor.

However, when the system demands that a voltage different from the voltage used in the first-stage resonance circuit must be used in the n-th resonance circuit, for example, when a higher voltage is required in the next stage, Capacitance must be lowered, and conversely increased when lower voltage is needed. The basic drawback of this device is that the recharging of energy does not take place in the resonant charging mode, the energy is the same as in the resonant circuit of the preceding stage and returns again, thus leading to unwanted oscillations.

OBJECT OF THE INVENTION The object of the invention is to increase the peak current as well as the peak voltage in a pulse generator of the kind described above by improving the maximum efficiency with a minimum burden, and without the drawback of partial energy transfer. It is to provide a high-voltage pulse generator capable of multiplication.

The above-mentioned object is achieved by the configurations described in the claims.

[Main Points and Effects of Configuration of the Invention] The present invention provides a high-voltage pulse generator that efficiently generates a pulse having a high voltage and a high pulse repetition frequency.

Specifically, a saturable inductor and a cascaded circuit composed of capacitors connected in series-parallel are provided, and the capacitors are charged in the parallel circuit. Resonant oscillations occur in the parallel charging circuit in order to invert the voltage of one capacitor, and in addition a switching device, preferably in the form of a saturable inductance, is timed to generate the maximum potential developed on the capacitor. The charge energy of the charged parallel capacitors is transferred in series to the resonance circuit or energy utilization device of the next stage, such as a gas laser.

The high-voltage pulse generator of the present invention is effectively used when it is required to operate at a high frequency and the allowable loss of the switch S is particularly limited. Apart from being able to raise the voltage in the resonant circuit of each stage, it is also possible to compress the current, which makes it possible to adjust the maximum current in the resonant circuit of each stage.

This current compression coefficient can be selected independently for each stage, and depends on the capacitance and inductance of adjacent stages. The device of this invention can be conveniently used for various types of gas lasers,
It can operate at the above frequencies. In addition to improvements in the field of electrical components, the operation of lasers can also be improved. Overall efficiency can be doubled. As a result, electrode wear can be greatly reduced and the life of the gas mixture can be extended. Generally, as a result of the above, as well as prolonging the life of the various components of the circuit, the use of the device of the present invention allows for high capacitance,
The partial or overall efficiency of a system using high voltage pulses can be increased.

It is therefore a primary object of the present invention to provide a high voltage pulse generator with the ability to generate high voltage pulses at high frequencies that make efficient use of charge energy. Other objects and scope of use of the present invention will become apparent from the detailed description below.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In addition, in the drawings, the same reference numerals are given to the equivalent portions.

[Embodiment] The circuit shown in FIG. 1 is based on the basic principle of the circuit shown in FIG.

Saturable inductance SI ^S ₁ to S connected in series-parallel
I ^S _N , SI ^P ₁ , SI ^VM ₁ to SI ^P _N , SI ^VM _N are capacitors C ^S ₀ to C
^S _N , C ^P ₀ to C ^P _N are connected in series over a plurality (N + 1) stages.

The capacitors C ^P ₀ and C ^S ₀ are charged to the voltage U0 by the high voltage power supply HV. By closing the triggerable switch S, oscillation occurs through inductance L0 and a capacitor C ^P _0, the voltage rises up to (2 × U0). The same voltage drop occurs in the saturable inductance SI ^S ₁ . The time integral ∫U × dt of the voltage U is calculated as follows. That is, recharge time Saturable inductance SI ^S ₁ saturates just before reaching, and energy flows to capacitors C ^P ₁ and C ^S ₁ .

The saturable inductance SI ^VM ₁ which is pre-magnetized by the direct current to near the saturation point plays an important role in charging the capacitor C ^S ₁ . That is, it has the same effect as a diode, and in the saturable inductance SI ^VM ₁ ,
A very small forward current saturates the saturable inductance core material sufficiently. On the other hand, the reverse current of the saturable inductance SI ^VM _{1 in} the saturable state is the above voltage U
Is suppressed according to the time integration ∫U × dt of, that is, the energy is prevented from returning toward the circuit composed of the inductance L 0 and the capacitor C ^P ₀ .

Here, for optimal charge transfer without loss in the recharge process, the capacitor value of the series circuit of capacitor C ^P ₀ and capacitor C ^S ₀ is set to be equal to the input capacitor C ^P ₁ of the next stage. It That is, capacitor C ^P ₁
Is the capacitor value of the series circuit of capacitor C ^P ₀ and capacitor C ^S ₀ for resonance recharge. Is equal to

By setting C ^S ₀ = C ^P ₀ and C ^G ₀ = 1 / 2C ^S ₀ , the voltage of the capacitor C ^P ₁ rises to the maximum value 2Uu. Saturable inductance SI ^S ₁ becomes a reasonable value at current reversal, the time constant according to the voltage time integral, since blocking period current, energy of the saturable inductance SI ^S ₁ from the capacitor C ^P ₁ to capacitor C ^P ₀ Feedback current is prevented. In this method, CI is supplemented by the supersaturation inductance SI ^P _{1 which} leads to a voltage rise on the saturable inductance SI ^S _2.
Oscillating between the ^P ₁ and SI ^P ₁ becomes possible. This voltage pattern is repeated for the saturable inductance SI ^S _{2 in the} same way as for SI ^S ₁ above.

The efficiency of the device is determined by the losses in switch S and the total losses in saturable inductance SI. The loss per pulse in these components can be kept negligibly low by proper wiring design and proper choice of capacitor type. By using the configuration of the apparatus described above, the pulse repetition rate and the pulse repetition rate are set high by setting the pulse repetition frequency as high as the amount of loss per pulse reduced in the switch S. The loss product of (which corresponds to the total loss). Can be set to be held constant.

When using multiple saturable inductances SI,
The saturable inductance core is placed between two pulses (ie, 1
(After one pulse) it is necessary to reset or return to the opposite polarity remanence point, ie the point of negative remanence.

This is done in two different ways:

In one method, an insulating winding is arranged around the core of the saturable inductance, and a pulse current or a constant direct current is applied to the insulating winding to reset to a point of negative residual magnetic flux density. it can.

Also, in the other method, it is possible to design a plurality of capacitors as follows. That is, a capacitor having an electrostatic capacity for disturbing the resonance state for charge transfer is used, that is, a capacitor having an electrostatic capacity set when the resonance charge transfer is set slightly apart from the tuning state.
In this case, for a short time after recharging, a negative voltage of opposite polarity is supplied and a small reverse current flows. This allows resetting to a point of negative residual magnetic flux density.

The saturable inductance core material is substantially perpendicular to B
With the -H hysteresis characteristic, this small reverse current is sufficient to reach the point of remanence of opposite polarity, ie the point of negative remanence.

FIG. 2 shows the one-stage resonant circuit of the circuit configuration of FIG. A thyristor is used as the switch S, and the capacitors C1, C2 and C3 are ceramic capacitors. Air-core coils are used as the inductances L0 and LDC, and saturable inductance SI uses amorphous metal as the core material.

The capacitances C1 and C2 are charged to the voltage U0 via the resistor R. Oscillation occurs in the circuit S-L0-C1 after closing the switch S, and voltage reversal occurs in the capacitor C1. At the same time, the saturable inductance SI raises the voltage from 0 to the total voltage of the capacitors C1 and C2. The saturable inductance SI is designed such that its value collapses just before the maximum voltage is reached and charge carrier exchange takes place between the capacitors C1, C2 and C3. 3 to guarantee the transfer of resonant energy
There are two conditions that must be met.

1. The capacitance of series capacitors C1 and C2 must be equal to the capacitance of capacitor C3.

2. The charge stored in capacitor C1 after oscillation in circuit S-L0-C1 must be equal to the charge in capacitor C2.

3. At the "switching point" of the saturable inductance SI, the oscillation of the circuit S-L0-C1 ends with the proper transfer relationship with the energy transfer from the capacitors C1-C2 to C3, and after the energy transfer, the capacitors C1 and C2 The voltage is set equal to zero.

The above requirements are met by proper adjustment of the individual components so that no energy remains on capacitors C1 and C2 after recharging. The return flow of energy is blocked by the high inductance with respect to the reverse current so that the energy of the capacitor C3 is dissipated in the charging resistor. Even a slight discrepancy in the recharge current phases will result in only a very small reverse current. Therefore, additional external wiring automatically enables resetting to the remanence point, which is unnecessary for reset purposes.

As can be seen from the above description, according to the present invention, it is possible to provide a high voltage pulse generator capable of achieving a predetermined purpose with high efficiency.

It should be noted that various modifications can be made from the illustrated embodiment within the scope of the present invention. The specification and the drawings show preferred embodiments, and the present invention is not limited to these embodiments. The scope of the present invention should be defined by the description of the claims.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example in which a plurality of resonant circuits are connected in series in a high-voltage pulse generator showing an embodiment of the present invention, and FIG. 2 is provided with a single-stage resonant circuit of the present invention. FIG. 3 is a circuit diagram showing an embodiment of a pulse generator, and FIG. 3 is a circuit diagram showing a conventional pulse generator. C ^P ₀ , C ^P ₁ , C ^P ₂ , ..., C ^P n, C ^S ₀ , C ^S ₁ , C ^S ₂ , ..., C ^S n, C1, C2, C3 ……
Capacitor, L0, LDC …… Inductance, SI ^S ₁ , SI ^S ₂ ,…, SI ^S n, SI ^P ₁ , SI ^P ₂ ,…, SI ^P n, SI ^VM n, SI… Saturable inductance, S… ... switch, R ... resistance.

Claims (2)

[Claims] 1. A first capacitor and a second capacitor which are connected to each other and are connected to a power source so as to be charged in parallel, and the first capacitor, the inductance and the switching means which are connected to each other in series. Following the switching of the switching means, a resonance circuit that causes circuit oscillation so that the voltage of the first capacitor is inverted, and a resonance circuit that is connected in series with the first and second capacitors, A high-voltage pulse generator comprising a saturable inductance that transfers from the first and second capacitors to the energy use device via a third capacitor connected in parallel with the energy use device. 2. A first capacitor and a second capacitor which are connected to each other and are connected to a power source so as to be charged in parallel, and the first capacitor, the inductance and the switching means which are connected in series to each other. Following the switching of the switching means, a resonance circuit that causes circuit oscillation so that the voltage of the first capacitor is inverted, and a resonance circuit that is connected in series with the first and second capacitors, A saturable inductance that transfers a pulse from the first and second capacitors to the energy using device via a third capacitor connected in parallel with the energy using device, and electromagnetically to the saturable inductance. A winding wound in close proximity to the saturable inductance to be coupled, after the generation of one pulse and A high voltage pulse characterized by comprising a direct current power supply for supplying a predetermined direct current to the winding at a timing before the generation of the next pulse to reset the saturable inductance to a point of a negative residual magnetic flux density. Generator.