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The high-voltage pulse modulator based on the modern semiconductor elements is described. The modulator is intended for use in the power supply system of LINAC helium ions injector and has the ability to smoothly adjust the amplitude (110…150 kV) and the pulse duration (0.5…1 ms). The use of a pulse-to-peak stabilization scheme, made on the basis of a parametric stabilizer with parallel switching of the load, made it possible to increase the accelerated current at the accelerator output by 2 times.

The nanoscaled profiling of a silicon 5 (111) n-type substrate surface is studied by the local anodic oxidation (LAO). Varying the voltage pulse amplitude from 5 to 12.5 V and the humidity from 30 ± 1 to 70 ± 1% during the LAO is a promising way to form oxide structures with heights from 0.5 ± 0.3 to 2.1 ± 0.1 nm and profiled structures with depths from 0.4 ± 0.3 to 1.5 ± 0.2 nm on the substrate. The results can be applied to the development of technological processes of the element base of silicon-based nanoelectronics using the probe nanotechnologies.

Protection of buildings and structures by means of lightning rods having different heights with the preset reliability level Pr does not have hitherto a sufficient scientific substantiation. The article presents the results of investigations on determining the limit distance Lmax between lightning rods having different heights used to protect an arbitrarily shaped facility. For analyzing the striking probability of a facility protected by means of lightning rods having different heights, the protection angle a is used, which is determined by the ratio of protection radius rx to the lightning rod active part height ha above a facility having the height hf. The dependence characterizing the striking probability of a facility protected by lightning rods having different heights has been determined by carrying out tests of a long spark gap using a 250/2500 μs switching voltage pulse.

In this work, we present an integrated read and programming circuit for Resistive Random Access Memory (RRAM) cells. Since there are a lot of different RRAM technologies in research and the process variations of this new memory technology often spread over a wide range of electrical properties, the proposed circuit focuses on versatility in order to be adaptable to different cell properties. The circuit is suitable for both read and programming operations based on voltage pulses of flexible length and height. The implemented read method is based on evaluating the voltage drop over a measurement resistor and can distinguish up to eight different states, which are coded in binary, thereby realizing a digitization of the analog memory value. The circuit was fabricated in the 130 nm CMOS process line of IHP. The simulations were done using a physics-based, multi-level RRAM model. The measurement results prove the functionality of the read circuit and the programming system and demonstrate that the read system can distinguish up to eight different states with an overall resistance ratio of 7.9.

In spintronics, magnetization switching based on voltage control of magnetic anisotropy (VCMA) continues to attract attention, because it reduces the write power in magnetoresistive random-access memory (MRAM). Further reduction of the write power is required for next-generation MRAM. Conventionally the magnetic anisotropy (MA) is $e\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$ during the voltage pulse, but here the authors propose a scheme in which the MA is $e\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}h\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$, to induce precession around an almost perpendicular axis. They show that pulse duration can be reduced to a few tens of picoseconds, without deteriorating thermal stability. Such a short pulse helps to reduce energy loss by Joule heating.

Converter feed synchronous generators have some important advantages in pump storage hydro power stations compared to conventional synchronous generators with fixed speed. Due to the converter voltage pulses with large du/dt and high frequency content the winding insulation is electrically and thermally stressed different than for power frequency. As known from MV motors especially the stress grading system is very sensitive regarding these voltage pulse trains. In this feasibility study the electric and thermal stress resulting of the stress grading system is analyzed via a FEM-model. This is done for different for voltage characteristics, i.e. sinusoidal and impulse voltages. The intention is to compare and assess the field strength distribution along the bar surface and the hot-spot temperature in the stress grading layer depending on the voltage signal. Finally, some conclusions and recommendations are given for converter feed windings in hydro-generators.

Carbon nanotubes (CNT) resistance-change memory devices were assessed for neuromorphic applications under high frequency use conditions by employing the ultra-short (100 ps -10 ns) voltage pulse technique. Under properly selected operation conditions, CNTs demonstrate switching characteristics promising for various NN implementations.

This paper mainly concentrates on the analysis of different charging techniques adopted in the solid-state Marx generator. The unipolar Marx topology has been simulated using resistance, inductive and input switch charging methods. Results obtained by simulations are validated from experimental set-up for a two-stage Marx generator circuit. The characteristics (traits) of each charging method are investigated based upon the parameters such as current drawn by source during charging and discharging instant of capacitors, voltage across the input charging elements, output voltage, load current, degree of isolation provided by each method. Finally, a comparison between all charging methods is carried out for all above-mentioned parameters. Resistance charging is simple and less complex method. Boosting phenomenon of the output voltage pulse is obtained from the RL charging method. This method also limits the source current too few milliamperes as compared to the other two methods. Switch charging method provides complete isolation from the high-voltage source during the erection of Marx generator.

Данная работа посвящена изучению частичных разрядов в кабеле. Были рассмотрены возможности их регистрации и выявлению места повреждения изоляции. В ходе работы решались следующие задачи: 1. Анализ существующих методик по измерению и выявлению частичного разряда. Были сформулированы определения для параметров. Изучение уже существующих способов регистрации частичных разрядов. 2. Сформулирован принцип распространения частичного разряда и описан его физический смысл. Проведено исследование методов измерения частичных разрядов в кабеле. Плюсы и минусы различных методов выявления . 3 .Была разработана методика по регистрации импульсов частичного разряда. Сконструировали лабораторную схему для фиксации частичного разряда. Получили графические результаты. Разработанная схема и методика по регистрации импульса частичного разряда может помочь при выявлении повреждения в кабельной линии. Проблемы, которые могут возникнуть были решены, непосредственно введением оборудования для помехоподавления., This work is devoted to the study of partial discharges in the cable. Possibilities of their registration and identification of the place of insulation damage were considered. During the work the following tasks were solved: 1. Analysis of existing methods for measuring and detecting partial discharge. Definitions for parameters were formulated. The study of existing methods of registration of partial discharges. 2. the principle of partial discharge propagation is Formulated and its physical meaning is described. A study of methods for measuring partial discharges in the cable was conducted. Pros and cons of various detection methods . 3 .Methodology was developed for the registration of partial discharge pulses. We designed a laboratory circuit for fixing a partial discharge. Got graphic results. The developed scheme and method for registering a partial discharge pulse can help in detecting damage in the cable line. Problems that may arise have been resolved directly by the introduction of interference suppression equipment

Effective polarization of ferroelectric materials can be achieved by utilizing a conventional high-voltage polarization equipment with a high voltage but a large volume. Here, we report that the polarization of a ferroelectric BaTiO3 material can be realized by using a triboelectric nanogenerator (TENG) to scavenge ambient wind energy, where the TENG is ideal for providing a higher voltage, a smaller current, and especially a smaller volume. Both the output voltage and current signals of TENG can be adjustable by controlling different wind speeds, where the TENG can deliver an output voltage pulse (

This paper deals with the development of a voltage nanosecond pulse generator for electrical discharge micromachining. The generator is based on the usage of a half-bridge circuit in the output stage and the RC–circuit in the control chart for the formation of a working voltage pulse. A computer simulation of the generator and an experiment on the implementation of the electrical discharge micromachining were performed.

The cavitation is directly related to the safety of many large water conservancy projects. There are two types of cavitation bubbles, one is generated by the gas nucleus, called the non gas-bearing cavitation bubble, and another is generated by the gas bubble, called the gas-bearing cavitation bubble. They have significantly different collapsing characteristics. This paper studies the cavitation bubbles, generated by a high voltage pulse bubble generation system, and discusses the gas-bearing cavitation bubble’s characteristics a from the aspects of the collapse process, the cycle, the size and the collapse strength. It is shown that: (1) the collapse of the gas-bearing cavitation bubbles can be divided into two types: the centripetal collapse and the bisected collapse, (2) the cycle period and the size of the gas-bearing cavitation bubble increase significantly, and the increase norm has a certain relationship with the bubble diameter ratio, (3) the collapse strength of the gas-bearing cavitation bubble decreases significantly. The larger the bubble diameter ratio, the greater the effect will be.

Electrostriction mechanism of breakdown in polar liquid caused by high-voltage nanosecond pulse is studied. Nonstationary motion of liquid in the pin-to-plane system exposed to a pulse with peak voltage of 30 kV and 6-ns duration is numerically analyzed. Cavities in which the breakdown can be initiated are formed in the vicinity of the tip electrode. Dimensions of such cavities are estimated, and the conditions for formation are formulated. Profiles of voltage and current pulses are measured for breakdown in water and air. The velocity of breakdown development in air is determined using the time delay of the pulse measured by the shunt of discharge current at several interelectrode distances. The proposed method has limitations in the measurement of breakdown in water due to the effect of displacement current that exceeds the discharge current.

In this paper, GeTe and Sb4Te layers were alternately deposited to form superlattice-like structure (SLL) for multilevel phase change memory (PCM). It is shown that SLL GeTe/Sb4Te film can realize a multilevel storage with various appropriate thickness ratios between GeTe and Sb4Te layers. The crystallization behavior of SLL GeTe/Sb4Te film can be tuned by the thickness ratios which is associated closely with the thermal stability. GeTe(4 nm)/Sb4Te(6 nm)-based device demonstrated the minimum voltage pulse for the RESET operation of 3.2 V-5 ns, suggesting the low power consumption in comparison with that of Ge2Sb2Te5 (4.1 V). An electric pulse as short as 5 ns can trigger different operations among three stable resistance states for GeTe(4 nm)/Sb4Te(6 nm)-based device, which can be explained by the asynchronous crystallization of GeTe and Sb4Te. These results demonstrate that SLL GeTe/Sb4Te films are promising candidate for multilevel phase-change memory.

This paper dealt with the application of transient earth voltage (TEV) sensors for the online measurement and analysis of partial discharge (PD) in medium-voltage switchboards. To simulate the typical insulation defects in the switchboards, four types of artificial electrode systems, including high-voltage protrusion, low-voltage protrusion, particle-on-conductor, and void inside cast-resin potential transformer were fabricated. A TEV sensor with a frequency range of 1–150 MHz and a non-inductive resistor were used to detect the PD-induced TEV signal and the PD voltage pulse, respectively. The frequency spectrums of TEV signals were analyzed, and it was found that they had a mutual frequency range of 5–50 MHz. However, the amplitude of TEV signal was not proportional to the apparent charge specified in IEC 60270, resulting the difficulty of quantification of PD. The phase-resolved partial discharge patterns were acquired using the TEV sensor and the developed measuring algorithm, by which distinguishable patterns were obtained from different defects.

Hydrogen-free diamond-like carbon (DLC) films with thickness of 36 μm and 50 μm have been prepared on Si and AISI 304L stainless steel substrates, respectively, by filtered cathodic vacuum arc (FCVA) together with a high-voltage pulse power. The structure, chemical bonding state, mechanical properties and wear, corrosion resistance and anti-erosion performance were evaluated. The thick DLC films with compressive stress of 0.71 GPa and hardness of 3160 HV were obtained. The preparation of the low stress but high hardness coating mainly due to the appropriate high negative bias and short pulse duration, which could result in an alternate ion bombardment and deposition. The 50 μm-thick coating showed corrosion resistance with high polarization resistance of 4.69 × 108 Ω·cm2 and low corrosion current density of 5.47 × 10−8 A·cm−2. Thick coating exhibited outstanding sand particle erosion resistance with low average mass loss rate of 0.035 mg g−1. Under high-speed sand erosion conditions, the coating remains unbroken, without peeling or cracking were observed on the erosion center. In addition, DLC coatings showed good tribological performance under dry, water- and oil-lubricated condition.

This paper presents a more economically advantageous method of obtaining high amplitude current impulses having a high voltage generator (GIT) as a power source. This method consists in the realization of a current impulse testing system for high voltage equipment. To obtain impulse currents with GIT, they were introduced into the circuit of the LC pulse delay cell circuit. A current impulse generator (GIC) circuit has been developed to meet current standards. This system has enabled new test methods to be developed and improved equipment developed. The methods and procedures can be applied to extend the fields of research by using current impulses to determine the dynamic and thermal stability of the electrotechnical and electroenergetic equipment, as well as the functional stability of the electronic devices in electromagnetically disturbed environments.

The high dv/dt associated with Wide-Bandgap (WBG) devices will lead to more serious reflected wave phenomenon, resulting in overvoltage at the load side. This paper proposes an active reflected wave canceller (ARWC) for SiC motor drives. The proposed solution mitigates the reflected wave phenomenon by injecting a controlled nanoseconds voltage pulse. The proposed ARWC can achieve smaller size and light weight utilizing WBG devices. A testbed has been built to experimentally demonstrate the operation principle of the proposed ARWC circuit.

One of the main contributors to the nontechnical power losses is the loss due to electricity theft. In developing countries like Pakistan, the financial losses due to electricity theft are very high and pose a very serious threat to the country's economic stability. The most common form of electricity thefts in Pakistan is the theft done at the consumer end due to meter tampering such as bypassing the meter, and at the line end due to “Hooking” system. In order to put a stop to these thefts and to reduce the damage done to our country's economy, we propose a novel solution to detect and then prevent electricity theft. Our theft detection algorithm is able to detect electricity thefts at both the consumer line (meter tampering) and at the distribution line (Hooking) with the help of consumer load profiling. Once a theft is detected, our prevention algorithm firstly disconnects all legal consumers and then a high voltage pulse is sent at the distribution line which will make all illegal consumers in-operational.

The HfO2-based ferroelectric field effect transistor (FeFET) with a metal/ferroelectric/insulator/semiconductor (MFIS) gate stack is currently being considered as a possible candidate for high-density and fast write speed non-volatile memory. Although the retention performance of the HfO2-based FeFET with a MFIS gate stack could satisfy the requirements for practical applications, its memory window (MW) and reliability with respect to endurance should be further improved. This work investigates the advantage of employing ZrO2 seed layers on the MW, retention, and endurance of the Hf0.5Zr0.5O2 (HZO)-based FeFETs with MFIS gate stacks, by using fast voltage pulse measurements. It is found that the HZO-based FeFET with a ZrO2 seed layer shows a larger initial and 10-year extrapolated MW, as well as improved endurance performance compared with the HZO-based FeFET without the ZrO2 seed layer. The results indicate that employing of a direct crystalline high-k/Si gate stack would further improve the MW and reliability of the HfO2-based FeFETs.

The effect of applying a positive voltage pulse (Urev = 10 - 150 V) directly after the negative high power impulse magnetron sputtering (HiPIMS) pulse (bipolar HiPIMS) is investigated for the reactive sputter deposition of TiN thin films. Energy-resolved mass spectroscopy analyses are performed to gain insight in the effect on the ion energy distribution function of the various ions. It is demonstrated that the energy of a large fraction of the ions can be tuned by a reverse target potential and gain energy corresponding to the applied Urev. Microscopy observations and x-ray reflectometry reveal densification of the films which results in an increase in the film hardness from 23.9 to 34 GPa as well as an increase in compressive film stress from 2.1 GPa to 4.7 GPa when comparing conventional HiPIMS with bipolar HiPIMS (Urev = 150 V).

The effect of pulse-on and pulse-off times on the efficiency of micro/nano ECM with ultra-short voltage pulses is theoretically analyzed. A new approximate analytical equation for the time of charging electrical double layer (EDL) is obtained. The equation takes into account all main parameters of the process. It enables one to determine the pulse-on time that provides a high localization of Faradaic process in the zones with small interelectrode gap and a high productivity of ECM process. The results of numerical calculations agree well with the data calculated by the proposed approximate analytical equation. The numerical calculations of the pulse-off time are performed. The effect of reverse voltage pulse imposed in the pauses on the EDL relaxation time is analyzed. The amplitude of reverse voltage pulse is limited by the condition of the absence of the tool-electrode wear. The proposed algorithm for calculating the pulse-off time and amplitude of reverse voltage pulse provides the required high coefficient of metal dissolution localization in the zone of small interelectrode gaps at a given pulse-on time.

The results of experimental study of streamer and spark processes under a standard lightning voltage pulse are shown for different degrees of electric-field nonuniformity in sphere–plane and sphere–sphere electrode systems. The possibility of introducing similarity relations for streamer processes is considered. The applicability of various numerical methods for determining the breakdown voltage is analyzed.

In this paper, we study the characteristics of atmospheric-pressure pulsed dielectric barrier discharge (DBD) under the needle-plate electrode configuration using a one-dimensional self-consistent fluid model. The results show that, the DBDs driven by positive pulse, negative pulse and bipolar pulse possess different behaviors. Moreover, the two discharges appearing at the rising and the falling phases of per voltage pulse also have different discharge regimes. For the case of the positive pulse, the breakdown field is much lower than that of the negative pulse, and its propagation characteristic is different from the negative pulse DBD. When the DBD is driven by a bipolar pulse voltage, there exists the interaction between the positive and negative pulses, resulting in the decrease of the breakdown field of the negative pulse DBD and causing the change of the discharge behaviors. In addition, the effects of the discharge parameters on the behaviors of pulsed DBD in the needle-plate electrode configuration are also studied.

The voltage pulse injection method is widely used at the starting and low-speed sensorless operation of the rotary switched reluctance machine (SRM) and the linear SRM (LSRM). The conventional methods for the inductance estimation in voltage pulse injection, the current peak value method, and the current slope difference method have a limitation that the iron losses in the controlled SRMs/LSRMs should be negligible. In this study, a new inductance estimation method in the voltage pulse injection is proposed considering the iron losses. Assuming that the iron-loss currents in the energising and de-energising intervals are almost equal, the inductance estimations in the two intervals are conducted, respectively, and the actual inductance values without the influence of the iron losses can be obtained by a special operation of the two calculated inductance values. Take a designed LSRM as a test object, the results of the proposed method coincide well with the actual values as compared with the conventional methods. The novel inductance estimation can be utilised in the SRMs/LSRMs without the limitation of the iron losses, and then it can further improve the accuracy of the sensorless control in the voltage pulse injection method.

The time effects of electrical breakdown at the leading and trailing edges of a voltage pulse applied to an interelectrode gap are studied. The pulsed dielectric strengths of limestone, sandstone, clay, paraffin, and water are determined experimentally at fixed parameters of the voltage pulse and different lengths of the dielectric-filled interelectrode gap. Experimental data are explained in terms of a structure–time approach based on the incubation time criterion. It is found that breakdown occurs when a sufficient power impulse (electric energy) arises within a characteristic time rather than when the electric field reaches a limit.

A simple circuit that produces a voltage pulse analogous to the pulse generated in the neuron was developed. This circuit is suitable for an introductory physics lab experiment to improve students understanding of applications to real life. By including a simple description of how neurons send electrical signals, a direct connection is made between physics and the human body. This is especially relevant to students pursuing careers in biology, medicine, and other pre-health areas, but also important to any student who is curious about the role physics plays outside of the lab.