Low-pressure gas-discharge current interrupters in a generator of high-voltage nanosecond pulses with an inductive energy storage

Designs of grid units with slotted and multiple-aperture configurations of holes that allow an increase in the stability of the current-cutoff process and a reduction in the time to turn the device off in a high-voltage pulse generator with an inductive energy storage were created. Compared to a TGI2-500/20 thyratron, these designs made it possible to reduce the time instability of the instant of the current interruption by factors of 2 and 5 for switches with the multiple-aperture and slotted configurations of the grids, respectively. These constructions allowed the minimum time for disabling a device to be reduced by 25%.     

用于激光器的电感储能发生器

研制了适用于激光器的电感储能发生器(GIES),并研究了它在高压混合气体中的放电和激光参数.研究表明,电感储能发生器可产生高压预脉冲并引起放电电流的突然增大,可在不同的混合气体中形成长时间的稳定放电,从而方便地控制和优化每一种气体混合物的预脉冲参数.在未知IES击穿电压和首次放电幅度下的参数时,电流尖峰会按因子1.5-...     

A current source with an inductive energy storage for measuring pulse impedances of grounding connections

A pulse generator with an inductive energy storage for measuring pulse impedances of grounding connections is developed. The generator produces current pulses with a rise time of 200–300 ns and an amplitude of up to 8 A. In contrast to the capacitive storage sources, it is fully controllable, allows one to adjust the amplitude, and ensures a constant current-pulse shape regardless of the load parameters. The different operation modes of the source are described. The experimental load-current waveforms are presented.     

Output voltage adjustment of a pulsed high-voltage nanosecond generator with inductive energy storage and a solid-state switching system

The possibility of adjusting the output voltage of a high-voltage nanosecond pulse generator with inductive energy storage and a solid-state switching system was investigated. All components of the adjustment system are installed in the low-voltage input circuit of the generator, whose voltage was less than 1000 V. The smooth adjustment of the output voltage in the range of 70–115 kV was achieved. The experimental setup and the obtained results are described.     

Compact inductive energy storage pulse power system

An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.     

A current-pulse generator with an intermediate storage for inductive-resistive load operation

The design and results of tests of a generator developed for obtaining a current of positive polarity with a duration of the first half-period of 110–130 ns, an amplitude of 40–70 kA in the single-pulse mode, and an amplitude of 30 kA at a pulse repetition rate of 10 Hz for 5 min in an inductive-resistive load of 300 nH, 1 Ω are presented. The setup has been assembled according to a scheme with an intermediate energy storage. The primary storage is a 10-stage Marx generator, and a capacitor with water insulation performs the function of the intermediate storage.     

A generator of gas-metal plasma based on an electron-injection discharge

An earlier developed plasma generator based on a nonself-sustained gas discharge with electron injection was modernized and ensured production of gas-metal plasma and, correspondingly, multielement composite (including oxide) coatings with controlled compositions and fractional ratios of components. The characteristics of the discharge system are investigated, and the optimal ways to increase the coating-deposition rate are determined. The device developed stably operates in an oxygen atmosphere for a long service life and is characterized by the absence of a microparticle fraction.     

A shaper of gigawatt nanosecond microwave pulses with time domain compression of magnetron radiation energy

For boosting the peak power of microwave radiaton pulses emitted by a mass-produced magnetron, a two-stage series-resonance microwave pulse compression system is connected to its output. The magnetron generated pulses with a power of up to 2.5 MW, a length of 3 μs, and a repetition rate of up to 400 Hz. After the first compression stage, microwave pulses with a peak power of 150 MW and a length of 11 ns at a 3-dB level were obtained; after the second stage, these parameters were 1 GW and ∼1 ns.     

脉冲诱导放电气体激光器

研究了一种实现新放电方法:诱导圆筒放电的可能性.该放电方法基于不同的粒子数反转机理,使用不同的原子和分子传能模式泵浦气体激光器.研制了用于气体中的脉冲诱导圆筒放电(脉冲感应耦合等离子体)激励系统,并对其进行了实验研究.首次实现了基于原子和分子不同传能模式的4种脉冲诱导激光器,其激励特性是光束发散角小,不同脉冲间的非稳定...     

Electrical discharge machining with ultralow discharge energy

The possibility of electrical discharge machining (EDM) with ultralow discharge energy has been investigated. EDM using an RC discharge circuit was performed at low open-circuit voltages and a capacitance of approximately 30 pF. Workpieces were ultrasonically vibrated to remove debris and bubbles from the discharge gap, thus preventing short-circuiting. The machining proceeded at voltages lower than 15 V at a vibration amplitude of 0.4 μm. The maximum discharge energy per pulse is as small as approximately 3 nJ under these conditions. The volumetric electrode wear ratio can be 0.2% at voltages lower than 40 V, while it is normally more than 1% for EDM using an RC discharge circuit. Workpiece surfaces processed at voltages of 20 V or lower are smooth and free of observable discharge craters, and show no typical features of surfaces machined by EDM.     

A high-current pulse generator for gas discharge pumping

A generator has been designed for pumping a pseudospark gas discharge in xenon with the aim of generating UV radiation at a wavelength of 13.5 nm. The output parameters of the generator are as follows: the pulse energy is 10 J, the voltage is 6 kV, the peak current when short circuited is 40 kA, the base current pulse duration is 200 ns, and the frequency is as high as 500 Hz.     

Electric spark discharge as an ultrasonic generator in flow measurement situations

In this paper, a gap discharge approach to create acoustic signals for ultrasonic low pressure gas flow measurements is investigated. The objective is to develop an ultrasonic gas flow meter system that is capable of operation in extreme industrial environments. These environments might have extremely high temperatures (1200 °C), moisture, steam, dust, low gas pressure and large transmission distances.Most other types of ultrasonic transducers found show sensitivity to such conditions: their operation suffers, or they may even stop functioning if exposed to such environments. The development of new transducer technology is therefore crucial to allow ultrasonic flow measurements in extreme industrial environments. In this paper, the gap discharge emitter is evaluated as a candidate to be used in these applications. Its capabilities as a sound source are investigated, and its impact on flow meter performance is estimated. It can be concluded that, despite the uncertainties it introduces to a flow meter system, it stands out as a strong candidate to be used as an acoustic emitter in a gas flow meter system for extreme environments.     

A high-voltage nanosecond pulse generator based on a barrier discharge

One of the specific features of the barrier electric discharge is the short duration of microdischarge processes that last about tens of nanoseconds. A high-voltage nanosecond pulse generator based on a barrier electric discharge is presented. A voltage of tens of kilovolts is usually applied to electrodes of the discharge cell. The peak values of the current pulse may be very high (from a few amperes to several tens of amperes). The presented high-voltage nanosecond pulse generator, having a sufficiently simple design, ensures quite good pulse repetition stability, and, when necessary, allows one to easily tune characteristics of pulses and their repetition rates by changing the geometrical, electrical, and physical-chemical parameters of the setup.     

A high-voltage semiconductor rectangular-pulse generator for powering a barrier discharge

A semiconductor rectangular-pulse generator with smoothly controlled output parameters for powering a barrier discharge was developed and investigated. The generator allows the formation of voltage pulses with the smoothly regulated amplitude (0–16 kV) and duration (600 ns–1 ms) across the discharge gap. The pulse rise and fall times can be varied from 40 ns to 1 μs. The generator pulse repetition rate can be smoothly varied from 0 to 50 kHz. The generator can operate in the manual-triggering mode and in the mode of pulse trains with an effective frequency of up to 500 kHz. The generator is intended for initiating and investigating a barrier discharge in millimeter-wide air gaps at the atmospheric pressure.     

A plasma generator based on nonself-sustained low-pressure glow discharge with a large-volume hollow cathode

The results of studying nonself-sustained glow discharges in an electrode system with a hollow cathode with a volume of 0.25 m³ are presented. A high-current (up to 35 A) nonself-sustained glow discharge at low pressures (0.3–1.0 Pa) is initiated and sustained with the help of an auxiliary cold-hollow-cathode arc discharge. When the current of a nonself-sustained glow discharge increases from 2 to 35 A, its burning voltage changes from 40 to 300 V. These values are much lower than the voltage for a self-sustained glow discharge in the same electrode system. At a discharge current of 30 A, the electron concentration at the center of the hollow cathode is n _e ∼ 10¹⁰–10¹¹ cm⁻³ and the electron temperature is T _e ≈ 2 eV. The discharge considered can be used in the system for modification of materials and products.     

A 1-MJ capacitive energy storage

A capacitive energy storage is intended for generating high-power current pulses. The setup consists of two capacitive energy storage modules, a control console, and a cable collector for connecting a load to the setup. Each module is a capacitive energy storage with a 0.5-MJ stored energy and 18-kV voltage, which is based on eight capacitor cells with reverse switch-on dynistors as switches. The module volume is 1.3 m³. The semiconductor switches in the capacitor cells are activated by light pulses, which are transmitted from the control console through fiber-optic cables. The unit is designed for operating in the programmable discharge mode, at which the semiconductor switches in the capacitor cells are switched on nonsimultaneously but in accordance with a specified program. When the discharge of all the cells is switched on simultaneously and the load is short-circuited, the maximal amplitude of the output current pulse is 800 kA. The rise time of the discharge current pulse of the cell is 150 μs.     

A high-power,high-frequency pulse generator based on a hollow-cathode discharge

A high-power high-frequency generator based on a hollow-cathode gas discharge is described. This simple device, equipped with a cold cathode, produces high-frequency pulses with up to 200-kW of power in a frequency band of 20–60 MHz. The duration of the high-frequency pulses varies from 0.5 to 1.5 s.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 86–89.Original Russian Text Copyright ¢ 2004 by Vyalykh, Dubinov, Lvov, Sadovoi, Selemir.     

一种基于飞轮储能系统的新型动态电压恢复器

为了克服传统动态电压恢复器无储能装置的不足,提出了一种基于飞轮储能系统(FESS)的新型动态电压恢复器(DVR)。根据飞轮充电要求,对DVR拓扑结构进行了研究,给出了DVR在不同工作模式下的控制策略:在飞轮充电过程中,采用脉宽调制(PWM)整流技术,实现了单位功率因数控制;在补偿电压暂降时,电机采用半桥能量回馈控制,以保持直流母线电压恒定,逆变器采用双环控制策略,补偿电压暂降的同时有效地抑制负载干扰和参数变化。实验结果验证了拓扑结构和控制策略的正确性。     

A compact repetitive high-voltage nanosecond pulse generator for the application of gas discharge

Uniform and stable discharge plasma requires very short duration pulses with fast rise times. A repetitive high-voltage nanosecond pulse generator for the application of gas discharge is presented in this paper. It is constructed with all solid-state components. Two-stage magnetic compression is used to generate a short duration pulse. Unlike in some reported studies, common commercial fast recovery diodes instead of a semiconductor opening switch (SOS) are used in our experiment that plays the role of SOS. The SOS-like effects of four different kinds of diodes are studied experimentally to optimize the output performance. It is found that the output pulse voltage is higher with a shorter reverse recovery time, and the rise time of pulse becomes faster when the falling time of reverse recovery current is shorter. The SOS-like effect of the diodes can be adjusted by changing the external circuit parameters. Through optimization the pulse generator can provide a pulsed voltage of 40 kV with a 40 ns duration, 10 ns rise time, and pulse repetition frequency of up to 5 kHz. Diffuse plasma can be formed in air at standard atmospheric pressure using the developed pulse generator. With a light weight and small packaging the pulse generator is suitable for gas discharge application.