A generator of high-voltage nanosecond pulses with a subnanosecond rise time

A generator of high-voltage pulses of nanosecond duration with a subnanosecond rise time is described. The generator contains a nanosecond-pulse shaper based on an assembly of drift step-recovery diodes (DSRDs) connected in series and a sharpening switch based on an assembly of deep-level dynistors (DLDs) connected in series. The results of tests of this generator at a pulse repetition rate of 100 Hz are presented. Voltage pulses with an amplitude of 20 kV, a rise time of 0.3 ns, and a duration of 10 ns are formed across a load with a resistance of 50 Ω.     

Low-jitter generators of high-voltage pulses with a subnanosecond rise time and an increased actuation accuracy

Two low-jitter high-voltage pulse generators with a subnanosecond rise time are described. The generators are connected in the Marx circuit and have the following characteristics: the amplitude of the output pulse developed across a 50-Ω load is 50 and 70 kV, respectively; duration of the pulse edge is no more than 0.3 ns; operating frequency is up to 10 pulses/s. The instability of the delay of the pulse edge relative to the edge of the low-voltage triggering pulse does not exceed 10 and 30 ns for the first and second generator, respectively. The generators are designed for exact synchronization of the facility used in experiments on the subnanosecond pulsed breakdown.     

A high-power semiconductor switch of high-voltage pulses with a rise time of nanosecond duration

The results of studies of new fast-acting semiconductor devices—deep-level dynistors intended for use in high-power devices of nano-and microsecond pulsed-power technology—are presented. The possibility of switching multikiloampere current pulses having a rise rate of 200 kA/μs with the use of a single device with a 12-mm-diameter structure is shown. A high-power switch based on an assembly of dynistors with an operating voltage of 12 kV connected in series is described. The switch is capable of switching current pulses with a 1200-A amplitude and a 4-ns rise time.     

Semiconductor formers of high-voltage pulses of nanosecond duration

A small former of high-voltage pulses of nanosecond duration based on new semiconductor devices—deep-level dynistors (DLDs)—is described. The former has been developed on the basis of the Marx voltage-multiplication principle and allows formation of 8-kV voltage pulses across an 8-Ω load at a 2.5-kV input-voltage level. A DLD-based former with an output diode opening switch based on assemblies of drift step-recovery diodes connected in series is described. The results of its being tested are presented. Voltage pulses with an amplitude of 25 kV and a rise time of 1 ns are obtained across a 100-Ω load.     

A high-frequency semiconductor generator of high-voltage nanosecond pulses

A generator of high-voltage rectangular nanosecond pulses equipped with switches in the form of assemblies of deep-level dynistors connected in series is described. A control circuit for dynistors based on an assembly of inversely switched-off diodes connected in series is considered. The generator can operate at a frequency of 10 Hz and form (at a 20-pF load) rectangular voltage pulses with short (4 ns) leading and trailing edges and a short (25 ns) delay relative to an external control signal. The amplitude and duration of output pulses are controlled smoothly in the ranges 7–9 kV and 100–600 ns, respectively. The spread of moments of operation is within 0.5 ns.     

A high-frequency semiconductor generator of high-voltage nanosecond pulses

A high-frequency generator of high-voltage nanosecond pulses based on an assembly of drift step-recovery diodes is described. A circuit that includes parallel transistor chains for the formation of forward and reverse currents of drift diodes is presented. The results of tests of this generator are presented. Voltage pulses with an amplitude of 2.5 kV, a duration of 2 ns, and a pulse repetition rate of 300 kHz were obtained across a 50-Ω load.     

Generators of high-voltage pulses with a repetition rate of 50000 pulses per second

We study the schematic and mechanical features of frequency (∼50000 pulses/s) generators of high-voltage (up to 10 kV) pulses of the microsecond range. We analyze (with the purpose of decreasing energy consumed from the power network) the energy transfer process from a low-voltage discharge circuit (with insulated-gate bipolar transistors as commutators) by means of a step-up pulse transformer to the load. We implement the design of a generator with pulse front sharpening in the load (into a reactor with pulsed corona discharge) using a multigap air discharger. The maximum achieved pulse repetition rate with a sharpened front was ∼27 000 pulses/s and a voltage of ∼3 kV.     

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%.     

Optimization of high-voltage devices for energy compression of nanosecond pulses

Designs of compact converters intended for compression of high-voltage pulses with durations of a few nanoseconds and operating in a traveling wave mode were examined. The energy compression unit contained two lines-high-impedance and forming-with a high -pressure gas spark discharger used as a switch. A traditional serial connection of lines was replaced by a parallel connection to increase the energy compression efficiency. The power of the initial pulse (amplitude, 145 kV; half-height duration, 4 ns; and rise time, 1.5 ns) at a load of 45 Ω was increased by a factor of 1.8, while the calculated value was 2.5. The amplitude was as great as -195 kV, and the power was 17% higher relative to the circuit with a serial connection of lines. When shaped, the pulse was compressed in time to 0.8 ns. Two modifications of devices converting the initial pulse with an amplitude of -160 kV and a rise time of 0.3 ns into pulses with amplitudes of -210 and -250 kV and durations of 0.80 and 0.45 ns, respectively, were tested. Waveguide components of the converters were developed, with which it was possible to minimize the dimensions of the device in order to avoid excitation of higher harmonics while maintaining the electric strength.     

高压开关柜温升自动巡检仪的设计

针对高压开关设备出厂前温升试验手工完成效率低的问题,设计了一套自动温升巡测系统,该系统采用T型热电偶采集柜内母线排的温度信号,利用隔离热电偶变送器,将温度信号放大后送入TLC2543进行A／D转换,单片机（MCU）AT89S52对A／D转化结果进行处理后在液晶显示器（LCD）显示温升值,本系统还对测量误差曲线进行拟合后,在单片机软件中加以修正以提高测试精度。研究结果表明,该系统具有测量准确、抗干扰能力强等优点,能大幅度提高检测效率。     

Ferrite-filled coaxial lines for sharpening pulse leading edges of high-voltage nanosecond generators

Fast deflecting units (kickers) energized by high-voltage thyratron generators are used to inject and eject charged particles in e ⁺ e ⁻-colliders and synchrotron radiation sources. Thyratron generators can ensure rise times of pulses on kicker plates of no less than 30–40 ns. An increase in the discharge development time in thyratrons is especially noticeable when currents of >5 kA are switched. A method for producing high-voltage nanosecond pulses, in which the initial leading edges of thyratron pulses are shortened by coaxial lines filled with ferrite rings, is proposed. This method of obtaining steep leading edges can be useful when it is necessary to extract charged particles from the booster synchrotron into the basic experimental storage.     

在GSM网络中实现高压电力线路检测

根据目前高压输电线路分布广、作业环境恶劣的现状。本文介绍了基于GSM网络的无线检测系统,以现有成熟的GSM系统作为数据无线传输网络,在各分机与控制中心间采用AT指令集以短消息方式实现数据传输,实现了高压电力线路污秽情况的远程自动化实时监测,为线路状态检修提供了决策依据,大大提高了线路运行的安全性和输电线路技术管理水平。该系统具有精度高、稳定性强、抗干扰能力强、应用范围广、操作简便、免维护等优点,在实际检测中达到了良好的效果。     

高压线路带电作业智能化自动工具研究

为了解决现有手动工具劳动强度大,作业风险高,自动化水平低的情况。研制出高压带电自动剥皮器、电动扳手、断线钳、破螺母工具、并股线夹、导线遮蔽罩等六种作业工具,具有统一的机械连接和电气控制接口,并进行了电磁兼容设计,采用差分式无线接收模块实现可靠通讯,应用积分分离PID算法进行电流闭环控制,实现过载保护,在高压大电流环境下保证工具的可靠运行。由机械手或人工遥操作完成常规的带电作业任务,作业风险低、效率高,为配电网可靠运行提供了技术保障。     

A coaxial broadband detector of high-power nanosecond microwave pulses on the hot-electron effect

The design and characteristics of a liquid-nitrogen-cooled hot-carrier detector of microwave pulses detecting electromagnetic radiation in the range 2–10 GHz with a resolution no worse than 1 ns are considered. The conversion coefficient of the voltage at the input cable into the output amplitude of a detected signal is 1.2 × 10⁻².     

Mechanism and characteristic of rain-induced vibration on high-voltage transmission line

Under the rainy weather, rain-induced vibration on high-voltage (HV) transmission line often occurs, which intensifies fatigue conductors and tower callapses. Mechanism and control measures of the rain-induced vibration have aroused wide attention in power engineering. The mechanism can be explained that the droplets suspended to the conductors amplify corona discharges with ionic wind, forms non-circular cross-sections, and the rain-induced vibration is due to the coupling action of vortex-induced vibration by ionic wind and galloping vibration by external wind force. Based on the mechanism, a valid model on the rain-induced vibration on high-voltage transmission line is proposed based on the finite element theory and the Newmark algorithm. Taking the conductor LGJ-240 as an instance, we investigate the effects of ionic wind and non-circular cross-sections with different parameters on amplitude of the conductors. The result shows non-circular cross-sections have obviously effects, and the ionic wind have a certain influence and easily to coupling with wind force. Mechanism and conclusions in this paper can be used as references to construct High-voltage transmission lines, upgrade the existing lines and control vibration.     

Characteristic times in transient thermal elastohydrodynamic line contacts

For practical applications, there are several points of interest in the numerical simulation of transient Thermal Elastohydrodynamic (TEHD) lubrication. Among others, is the possibility to investigate the impact of transient effects depending on the dynamic characteristics of the contact. In this regard, the paper presents an original study on the characteristic times involved in a generic line contact lubricated with a non-Newtonian fluid. The paper highlights the dependency of the dominant heat transfer mode on the Slide-to-Roll Ratio (SRR), leading to the formulation of new thermal characteristic times. Based on results from time-dependent computations, it also provides a criterion linking the onset of transient effects to the dominant thermal characteristic time which has been validated on various operating conditions.     

Investigation of the electrical strength of liquid dielectrics in vacuum under the action of high-voltage nanosecond pulses

The results of an experimental study of the electrical strength of insulators that are coated with a thin liquid-dielectric layer (1?C2 mm) are presented. Studies were performed in a vacuum at a pressure of 10^?4?C10^?5 Torr and a high-voltage pulse duration of ??100 ns on an experimental setup, which is based on a PG-1 high-voltage nanosecond generator with an output voltage of up to 500 kV at a load of up to 40 ??. It was established that a castor or transformer oil coating on an insulator allows an increase in the amplitude of a voltage pulse, which is applied to the insulator, by a factor of at least 1.7 as compared to the clean insulator without its breakdown over the surface in vacuum.     

Applications of comber-type coaxial lines with a built-in charging transformer for generating high-power nanosecond pulses

A high-power nanosecond pulse generator, based on a comber-type coaxial line section, which is charged by a high-voltage transformer built into this line, is described. Experimental data on its test results are given. It is stated that the considered approach can be used for decreasing the geometrical sizes of the generators. In the experiment, when 2-GW power pulses were generated, an extension of produced pulses by a factor of 1.8 was reached without substantial deterioration of the generated pulse shapes, as compared with a standard coaxial forming line of the same length.