Breakdown Voltage Prediction Research Articles

Study of discharge in air from the tip of an icicle

Electric discharge between the tip of an icicle and a plane electrode has been studied because of its relevance to the flashover of high voltage ice-covered insulators. A photomultiplier was used to scan the high voltage rod simultaneously with current measurement technique. The basic properties of streamers, namely the onset voltage, leakage current, mean propagation velocity and breakdown voltage, have been measured and compared with propagation from a metal rod as a reference. The effects of several experimental parameters such as freezing water conductivity, surrounding temperature and air gap length on the discharge characteristics have been examined. Possible mechanisms, which control discharges from ice points, have also been discussed and empirical relationships to predict breakdown voltage have been derived.

A Particle-in-Cell Simulation of the High-Field Effect in Devices With Micrometer Gaps

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Devices with micrometer and submicrometer gaps can face a serious challenge due to electrical breakdown during manufacturing, handling, and operation. Therefore, it is necessary to be aware of the breakdown voltage at different gaps. Since the Paschen's law is not valid for gaps smaller than several micrometers, modified Paschen curve should be used to predict breakdown voltage for microdevices. One of the possible mechanisms responsible for the reduction of the maximum operation voltage at small gaps is the field emission (FE). In this paper, particle-in-cell/Monte Carlo collision simulations, including the ejection of electrons from the cathode due to a high electric field, have been carried out to estimate the significance of the FE effect on the breakdown voltage in microgaps. </para>

Artificial neural network-based prediction technique for transformer oil breakdown voltage

This paper presents an artificial neural network (ANN)-based modeling technique for prediction of transformer oil breakdown voltage. This model comprises transformer oil service period, total acidity and water content while preserving the nonlinear relationship between their combinations for predicting transformer oil breakdown voltage. The model results are compared with those obtained by various modeling techniques such as ANN-based model for transformer oil breakdown voltage as a function of its service period, a polynomial regression model for transformer oil breakdown voltage as a function of its service period and a multiple linear regression model for transformer oil breakdown voltage as a function of its total acidity, water content and service period. A quantitative analysis of various modeling techniques has been carried out using different evaluation indices; namely, mean absolute percentage error and actual percentage error at each service period. The results showed the effectiveness and capability of the proposed ANN-based modeling technique to predict transformer oil breakdown voltage and justified its accuracy.

Prediction of breakdown voltage of transformer oil from predischarge phenomena

Complex experimental studies of the discharge mechanism in transformer oil under positive lightning impulse were carried out using alternative diagnostic methods. An attempt to establish a connection between the macroscopic features of discharge and the breakdown voltage was made.

Analysis of the breakdown voltage in SOI and SOS technologies

The aim of the paper is to analyse the breakdown voltage performance of lateral power devices in silicon on insulator (SOI) technologies. Both silicon on oxide (termed SOI as per the convention) and silicon on sapphire (SOS) technologies have been considered. Detailed numerical modelling together with analytical evaluation has been carried out on lateral devices employing uniformly doped and variation in lateral doping drift regions. The results indicate that existing theories to predict breakdown voltage are valid only in the case of ultrathin insulator layers and fail when ultrathick layers are considered. Predicted results for devices with ultrathick dielectric layers, as it is the case in SOS technology, are presented. Moreover, the breakdown voltage sensitivity with respect to the SOI layer and dielectric thickness is also analysed.

Equivalent doping profile transformation: a new analytical method to predict breakdown voltage of the composite pn junction

This paper describes a new analytical method called the equivalent doping profile of a composite p–n junction, that is, a simplified diffused junction with a linear gradient G L on the diffused side and a constant concentration N sub on the substrate. The analytical results for various combinations of the substrate doping concentration and the diffused side gradient levels agree well with the numerical analysis, showing the validity of the method presented here.

A method for predicting breakdown voltage of power devices with cylindrical diffused junctions

A method for predicting breakdown voltage of power devices with cylindrical diffused junctions

Characterization of bipolar snapback and breakdown voltage in thin-film SOI transistors by two-dimensional simulation

A two-dimensional finite-difference simulator for silicon-on-insulator (SOI) MOSFETs is presented. The simulator is derived from the MINIMOS4 simulator and incorporates additional features which permit the characterization of the bipolar snapback effect, which has been observed as a limiting feature in ultra-thin-film transistors. The snapback effect is illustrated as a hysteresis mechanism whereby, for a given bias condition, there are two different solutions to the semiconductor equations, depending on the starting condition. Examples of the application of the simulator to predict breakdown voltage in submicrometer devices are considered. Excellent agreement with measured values of breakdown voltage has been achieved for submicrometer n-channel transistors, both with and without the use of lightly doped drains. >

The effects of ionizing radiation on the breakdown voltage of p-channel power MOSFETs

The effects of ionizing radiation on the breakdown voltage of p-channel power MOSFETs were examined through two-dimension simulation. The breakdown-voltage performance of p-channel power MOSFETs was found to be very different from that of corresponding n-channel power MOSFETs. In p-channel devices, simulation showed breakdown-voltage enhancement for low values of positive oxide-trapped charge, N/sub ot/, whereas for high values of N/sub ot/, the breakdown voltage may or may not continue to increase, and may actually decrease in some topologies. For comparison, in n-channel devices, increases in N/sub ot/ always cause breakdown-voltage degradation. The uncertainties stem from the interaction of the depletion region of the device (which is a function of its termination method) with its isolation technology, making it difficult to predict breakdown voltage for large N/sub ot/. However, insights gained through analysis of depletion-region spreading in p-channel devices suggest a termination/isolation scheme, the VLD-FRR, that will enhance p-channel device reliability in radiation environments. >

Inhomogeneous field breakdown in GIS-the prediction of breakdown probabilities and voltages. I. Overview of a theory for inhomogeneous field breakdown in SF/sub 6/

Inhomogeneous field breakdown in SF/sub 6/ has been investigated, and a theory has been developed which predicts the breakdown voltage for fast-rising (rectangular) waveforms applied to arbitrary electrode geometries and gas pressures. This theory facilitates the analytical design aspects of many GIS components where previously, engineering judgement and development testing were necessary. It is suggested that extensions of the theory, will permit breakdown voltage prediction for an arbitrary surge waveform, which will facilitate the assessment of test waveform efficacy and the development of a more reliable field, factory, and type tests.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Inhomogeneous field breakdown in GIS-the prediction of breakdown probabilities and voltages. II. Ion density and statistical time lag

For pt.I see ibid., vol.3, no.3, p.923-30 (1988). An improved model for the calculation of statistical time lags in SF/sub 6/ insulated electrode arrangements for positive impulse voltage is presented. On the basis of physical considerations, the production rate of initial electrons is ascribed to the local density of negative SF/sub 6/ ions and to field dependent electron detachment. Values of negative ion densities are measured directly, while the detachment coefficient is determined by a fitting procedure to measurements of statistical time lags.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Inhomogeneous field breakdown in GIS-the prediction of breakdown probabilities and voltages. III. Discharge development in SF/sub 6/ and computer model of breakdown

For pt.II see ibid., vol.3, no.3, p.931-8 (1988). Extensive investigations into various phases of discharge development in SF/sub 6/ (corona formation, streamer to leader transmission, leader, and propagation) are summarized, with the goal of familiarizing the engineer with the theoretical and empirical basis of a quantitative model SF/sub 6/ breakdown, including breakdown in highly inhomogeneous fields. The quantitative predictive capability of this model is tested for a number of examples, which demonstrate the correct prediction of geometry and pressure dependencies of the breakdown voltage. Combined with the modified volume-time 'law', the breakdown model becomes a valuable tool for the power engineer, capable of predicting statistical breakdown characteristics for a wide range of gap geometries and positive voltage waveforms as a function of pressure. The model does not cover negative polarity waveforms and becomes increasingly inaccurate as the waveform risetime increases over about 10 mu s. Future research planned to address both of these limitations and practical applications are outline. >

Second breakdown prediction by two-dimensonal numerical analysis of BJT turnoff

An isothermal two-dimensional numerical calculation of the potential and current distribution in an n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -p-n-n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> bipolar power transistor driving an inductive load during its turnoff transient has been carried out. The transistor is initially considered to be in a heavily saturated ON-state and is then turned off by extracting a nearly constant base current. The simulation shows that during the turnoff transient, current constriction to the center of the emitter together with the increasing collector-emitter voltage produce a high electric field near the collector n-n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> junction which can initiate avalanche injection. It has been found that the collector-current density is not uniform vertically (from collector to emitter) due to the current spreadout in the collector n-region. Previous one-dimensional analytical analyses of second breakdown did not consider this important effect. Thus, for an accurate prediction of reverse second breakdown voltage, the two-dimensional current flow should be considered.

Prediction of Breakdown Voltages of Binary Gas Mixtures in Uniform Electric Fields

Prediction of Breakdown Voltages of Binary Gas Mixtures in Uniform Electric Fields

Prediction of Breakdown Voltages of Binary Gas Mixtures in Uniform Electric Fields

A simple equation to predict the breakdown voltages for binary mixtures (Vmix) of electronegative gases (SF6, CCl2F2) and buffer gases (N2, N2O, CO2, air) under uniform electric field has been proposed. Values of Vmix evaluated using this equation for mixtures of SF6-N2, SF6-air, SF6-N2O, SF6-CO2 and CCl2F2-N2 over a wide range of pd show an excellent agreement with the experimentally measured data available in the literature.

Computer analysis of breakdown mechanism in planar power MOSFET's

Breakdown mechanism in planar power MOSFET's having high breakdown voltage is investigated. Precise electric field distribution is obtained by two-dimensional numerical analysis. This field distribution is used to optimize device structure and to predict breakdown voltage. A technique for reducing the electric field on the silicon surface by equalizing its distribution is presented.

マイカ絶縁コイルの残存破壊電圧の予測

マイカ絶縁コイルの残存破壊電圧の予測

Transient Behavior in Transformer Oils: Prebreakdown and Breakdown Phenomena

A quantitative correlation between streamer velocities and impulse breakdown voltages has been established for point-plane geometries. We have extended these studies to less divergent fields (rod-plane) where we have identified two regions for impulse breakdown in liquids, oneiationinitiation-Inintrolled and a second controlled by streamer propagation rate. Which controls breakdown is determined by electrode geometry (field divergence), liquid composition, and wave shape. The influence of these parameters has been determined and a general model for the prediction of impulse breakdown voltage is proposed.

Limiting Values of Critical Electric Stress, and the Design Prediction of EHV/UHV SF6 Insulation Breakdown

An analysis of SF6 Paschen curves in the EHV/UHV range has been made. It is observed that the limiting value of critical electric stress is not the stress at which the apparent ionization and attachment coefficients are equal, that is, it is not the limiting value found for lower voltage treatments. Paschen departures, concluded to be a genuine phenomenon, are found to occur as an hyperbolic function of gap spacing. The Paschen curve, including departures, yields two new values of limiting critical stress. From those values, an equation is developed which may be used to predict insulation breakdown in uniform field configurations. Using a field intensification factor, the equation is adapted to the important engineering configuration of coaxial cylinders. The resultant equation gives good correlation with the breakdown behavior found by several groups using differing electrode geometries. Prediction of breakdown voltage is more accurate than that obtained by the widely used law of similarity. The breakdown equation is in a form suitable for use in prediction of EHV/UHV SF6 breakdown in engineering insulation design situations.

Maximum surface and bulk electric fields at breakdown for planar and beveled devices

Techniques previously presented for predicting breakdown voltage on planar devices with and without a field ring and in negative beveled devices are greatly extended so that the peak bulk and surface electric fields at breakdown can now be predicted. In addition, new techniques are described which for the first time allow the peak bulk and surface electric fields to be predicted for all positive and double positive beveled devices. Using this paper it becomes possible to predict peak bulk and surface electric fields as well as breakdown voltage for all planar and beveled devices. This is accomplished by the use or normalization procedures which allow dependencies on the substrate doping, junction depth, surface concentration, junction curvature, and bevel angle to be reduced to a single dependence. It is shown that the positive bevel is most effective in reducing surface electric fields with the negative bevel, double positive bevel, and the field ring for planar devices in decreasing order of effectiveness.