Some electrical and optical studies of a pulsed high current discharge.

by Christopher Hugh Gillen

Written in English
Published: Downloads: 344
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Edition Notes

Thesis (Ph. D.)--The Queen"s University of Belfast, 1966.

The Physical Object
Pagination1 v
ID Numbers
Open LibraryOL20195851M

To summarize, the electric current is the continuous flow of charge, while electric discharge is a one-time movement of the charge. Approved by eNotes Editorial Team Posted on May 8, at PM. Partial discharges are small electrical pulse caused by a electrical breakdown in a defect in the insulation system. This discharge at local inhomogenities emits a spectrum of electromagnetic waves or radiation and transmits information about the energy level of the discharges. For the measuring physical effects like optical, electrical and. Electric breakdown in air occurs for electric fields exceeding 34 kV/cm and results in a large current surge that propagates along unpredictable trajectories. Guiding such currents across specific paths in a controllable manner could allow protection against lightning strikes and high-voltage capacitor discharges. Such capabilities can be used for delivering charge to specific targets, for. A thyratron is a gas discharge tube that can be triggered. The solid state equivalent is, of course, the thyristor (SCR, et al.) The reason this came immediately to mind is because physicists have been researching high current, high voltage pulses for quite some .

What is Partial Discharge (PD) •PD only occurs where there is a gas (air, SF6, hydrogen) between the two conductors •The conductors must have a high voltage between them, creating an electric stress •If the electric stress in the gas exceeds 3 kV/mm of spacing (for most dry gases at kPa), then electrons are stripped from the gas atoms. • Maximum sec Discharge Pulse Current –The maximum current at which the battery can be discharged for pulses of up to 30 seconds. This limit is usually defined by the battery manufacturer in order to prevent excessive discharge rates that would damage the battery or reduce its capacity. Along with the peak power of the electric motor, this. The discharge is most stable if the power supply has a relatively high output impedance, since the current drawn by the discharge is a sensitive function of the applied voltage. The tube can be evacuated by means of a water aspirator, but a mechanical vacuum pump capable of a producing a vacuum of a few millitorr is preferred. Although electrical discharge machining (EDM) is one of the first established non-conventional machining processes, it still finds many applications in the modern industry, due to its capability of machining any electrical conductive material in complex geometries with high dimensional accuracy. The current study presents an experimental investigation of ED machining aluminum alloy Al

Capacitor Discharge Ignition System Working principle a CDI System. A capacitor discharge ignition works by passing an electrical current over a capacitor. This type of ignition builds up a charge quickly. A CDI ignition starts by generating a charge and storing it up before sending it out to the spark plug in order to ignite the engine. To generate the microsecond high energy pulsed plasma discharge, our concept uses existing components of a drilling bottom hole assembly (BHA) such as the mud motor and alternator to generate power in situ. This project focuses on the design, assembly and characterization of the major electrical circuit required to generate the electrically. Abstract The fast pulsed electric discharge current drives all physical processes in the plasma focus device; in turn all physical processes in the focus affect the current wave-form. Thus the discharge current waveform is the most important indicator of plasma focus performance. This underlies the importance of properly measuring, processing. High Energy Storage, Pulse Discharge These capacitors are an energy storage device. Many applications demand a product that is slowly charged but then discharges in a very short period of time (less than milliseconds), thus generating a pulse of electrical energy.

Some electrical and optical studies of a pulsed high current discharge. by Christopher Hugh Gillen Download PDF EPUB FB2

This is an up-to-date review of studies in the physics of pulsed electrical discharges in a vacuum. It gives the reader detailed information on the processes occurring at electrodes and in vacuum gaps and on the mechanisms of discharge initiation and development.

Modern techniques and equipment are described in detail. After that, the discharge always happens when the following pulses are applied separately.

Moreover, the discharging time T d is μs when the third high voltage pulse is applied, while it decreases quickly to minimum when the following high voltage pulses are applied, as shown in figure 6.

The minimum discharging time means that the Author: Rui-Qiang Zhang, Qiong Hu, Shao-Jun Liu, Xiao-Zhou Hu. In the present paper, the voltage‐current characteristics and the time‐dependent arc resistance of the high‐current pulsed discharge in SF 6 are obtained accurately from the arc current and the breakdown voltage by solving the circuit equation.

The electrode separation and the pressure are changed from to 1 cm and from to torr Cited by: 1. A current transducer based on a Rogowski coil is developed to detect nanosecond pulse signals of the discharge current with a wide bandwidth of kHz– MHz and high sensitivity of V A−1.

Pulsed electrical discharges in water: fundamentals and applications A. Belkind1, S. Gershman2, O. Mozgina1, C. Christodoulatos1, K. Becker1 1 Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ USA 2 Department of Physics and Astronomy, Rutgers, the State University of New Jersey, Piscataway, NJ USA Time-resolved spectroscopy has been conducted using a.

While evaluating pulse current wave form, rising time, falling time, overshoot and undershoot are four critical indicators (see figure 5). For optimized pulse functions, all indicators should be close to zero. However, in real-world practice, due Some electrical and optical studies of a pulsed high current discharge.

book bandwidth limitation of control systems, the wave form gets affected and then distorted easily. high-speed photography) 2) the pulse shape of the applied voltage 3) oscillograms of electric current 4) the surface charge density and electric field on the surface of the insulator 5) dust (Lichtenberg) figures.

Unfortunately, there is no works on the spectroscopic investigation of surface discharge plasma in the. electrical measurements have been performed in order to study the discharge propagation and breakdown phenomena in water according to the two parameters.

A single high voltage of duration between µS and 1 ms is applied between two µm diameter platinum tips separated by 2 mm and immersed in the aqueous solution.

Furthermore, with R within the discharge circuit, the current pulse will be lengthened, as the charge transfer even with C D 0 will be delayed by a time constant RCtCK/Ct C CK.

Both effects are influencing the shape of the original current pulse, and thus the measurement of i is a tedious task and is only made for research purposes. partial discharges. Partial Discharge can be described as an electrical pulse or discharge in a gas-filled void or on a dielectric surface of a solid or liquid insulation system.

This pulse or discharge only partially bridges the gap between phase insulation to ground, or phase to phase insulation. These discharges might occur in any void. (Color online) A series of discharge images of BNPDBD at Hz pulse repetition rate and 3 mm discharge gap distance.

(a) Single-pulse images with the exposure time of ms at 26 kV pulse. Optical Diagnosis of Pulsed Streamer Discharge under Atmospheric Pressure Ryo Ono1 and Tetsuji Oda2 1High Temperature Plasma Center, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba,Japan 2Department of Electrical Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo,Japan Abstract—This paper introduces recent optical measurements of.

Persephonis P., Ioannou A., Parthenios J., Georgiades C., Giannetas V. () The time evolution of the electric characteristics of a laser discharge through their waveforms of the voltage and the current. In: Kossowsky R., Jelinek M., Walter R.F. (eds) High Power Lasers — Science and Engineering. NATO ASI Series (Series 3: High Technology.

We present the results obtained using time‐resolved optical emission spectroscopy and time‐ and energy‐resolved mass spectroscopy in high‐power unipolar pulsed dc magnetron discharges at a repetition frequency of 1 kHz, an argon pressure of 1 Pa and an average target power loading in a pulse up to W/cm 2.

Most falling water film reactors generate plasma by DBD, either with AC or monopolar pulsed high voltage. Pulsed DBD in coaxial configuration using O 2 is considered as one of the most efficient electrical discharge systems evaluated because of the large surface area and small electrode distance.

Several configurations are possible, but in the. Wen et al. study the individual shock fronts created by pulsed positive streamer discharge in water.

Using a high-speed camera system that included four intensified charge coupled device (CCD) imagers and a light splitter, the authors were able to take four successive images of a discharge with 10 nanosecond exposures at intervals of 30 nanoseconds.

A high-voltage pulse has wide application in fields such as chemistry, physics and biology and their combinations.

The high-voltage pulse forms two kinds of physical processes in water, namely (a) a pulsed electric field (PEF) in the parallel electrode configuration and (b) plasma generation by a pulsed discharge in the water phase with a concentrated electric field. Typically, there is a very high electric field adjacent to a sharp electrode, and a net production of new electron-ion pairs occurs in this vicinity.

The Corona typically has a very low current, and very high voltage. The Glow Discharge typically has a voltage of several hundred volts, and currents up to 1 A. A small electron current is emitted. An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy.

Such a pulse's origin may be a natural occurrence or man-made and can occur as a radiated, electric, or magnetic field or a conducted electric current, depending on the source.

EMP interference is generally disruptive or damaging to electronic equipment. 1 Time-resolved diagnostics of a pin-to-pin pulsed discharge in water: pre-breakdown and breakdown analysis C. Rond 1,a, J.M.

Desse 2, N. Fagnon 1, X. Aubert 1, M. Er 1, A. Vega 1 and X. Duten 1 1LSPM - CNRS UPR, Université PaVilletaneuse,France 2ONERA - Department of Applied Aerodynamics,5 Boulevard Paul Painlevé, BPLILLE Cedex, France. A unipolar current pulse would result in a perfect magnetic charge if the hard magnetic material, for example, a sintered magnet had no electrical conductivity.

However, in a conductive magnet, a current is induced by the rise and decay of current in the magnetizing coil, and this result in. The review is devoted to studies of the processes and mechanisms of ignition of a glow discharge in tubes whose length significantly exceeds their diameter (long discharge tubes) at low pressures (~10 Torr and lower) and moderate voltage rise rates (~1 kV/μs and lower).

The electric field in such tubes before a breakdown is substantially nonuniform. High-power impulse magnetron sputtering (HIPIMS or HiPIMS, also known as high-power pulsed magnetron sputtering, HPPMS) is a method for physical vapor deposition of thin films which is based on magnetron sputter utilises extremely high power densities of the order of kW⋅cm −2 in short pulses (impulses) of tens of microseconds at low duty cycle (on/off time ratio) of.

Scheme of a pulsed electric field system for food processing. The high intensity pulsed electric field processing system is a simple electrical system consisting of a high voltage source, capacitor bank, switch, and treatment chamber.

Generation of pulsed electric fields requires a fast discharge of electrical energy within a short period of time. Pulse forming network The circuit illustrated below shows the simplest network. L, CB forms a resonant circuit, which is damped by the tube. The reversal of current can be suppressed by a diode D.

In comparison to the free capacitor discharge, the current rise and peak current imax are reduced. Pulsed-laser deposition (PLD) (Eason, ) is a relatively new physical vapour deposition technique, which has nevertheless been used for deposition of a vast range of materials including CHG thin PLD, laser pulses of high-energy density are focused onto a target, the material of which is vaporized after the laser power reaches the ablation threshold and forms a plasma plume.

Constant Current discharge ends at about 2 s while pulsing results in a total on time of 16 s increasing the discharge capacity by 8 times." It, obviously, won't give any benefit where the constant load is applied to a single battery, however, by distributing the constant load in pulse form within the battery pack should prolong its capacity as.

This book comprehensively describes the phenomena that occur in liquid dielectrics under the influence of an inhomogeneous pulsed electric field.

Written by leading experts in the field, it is the first of its kind to address numerous potential applications such as the technology of high-voltage insulation in pulsed inhomogeneous fields, and. What is Partial Discharge.

When speaking of partial discharge, the most important standard that every expert will refer to is IEC High-voltage test techniques – Partial discharge standard applies to the measurement of PD in electrical apparatus or systems when testing with AC voltage up to Hz or with DC voltage.

In this study, the machining characteristics of AISI stainless steel have been investigated in thermal erosion process. Taguchi method based experiments have been conducted with conventional and modified pulse generators using electric discharge machining.

Investigation of a pulse circuit design and pulse condition for the high energy efficiency on water treatment using pulsed power discharge in a water droplet spray IEEE Transactions on Dielectrics and Electrical Insulation, Vol.

18, No. 4. Research from the IEEE Gold Book, Ta indicates that cables, switchgear, and transformers suffer the greatest losses from insulation failure. For more than 50 years, companies have performed Partial Discharge Testing on electrical assets .The current discharge pulse pattern have been captured by a Tektronix CT-1 current probe coupled into a Tektronix Digital Oscilloscope with a GS/s sampling rate and a bandwidth of MHz.

A schematic test setup is shown in Figure 1.