Static Breakdown Voltage Research Articles

Impact-Ionization Switching of High-Voltage Thyristors Connected in Parallel

Thyristors triggered in the impact-ionization wave mode is a promising switching method in pulsed power technology. This triggering approach enhances the current capability of standard thyristors, allowing switching a current pulse with an amplitude of 200 kA and a current rise time rate-of-change (dI/dt) of 58 kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> s. Thyristor wafer area can be considered as one of the factors that are limiting the peak current amplitude and dI/dt. Switching thyristors in parallel is a possible solution to overcome these limitations. However, no evidence was found in the literature for successful parallel switching of standard thyristors in the impact-ionization wave mode. In this research, the possibility of parallel switching of two standard thyristors rated for 2.2 kV with a wafer diameter of 32 mm was investigated. A Marx generator equipped with a peaking module was used to charge the thyristor equivalent capacitance (1 nF) up to double its static breakdown voltage with a voltage rise time rate-of-change (dV/dt) of more than 1 kV/ns, as required for impact-ionization triggering. The diagnostic system includes two wideband voltage probes (VPs) with a subnanosecond time response, which allows simultaneous measurement of a voltage drop across each thyristor connected in parallel. Two stages of thyristor operation were investigated: 1) a triggering stage, without energy switching, when a dc bias voltage is applied; and 2) a current flow stage, with energy switching, when an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$RLC$</tex-math> </inline-formula> discharge circuit is connected. In these experiments, thyristors change from blocking to conducting state within 400 ps, switching a current pulse with an amplitude of 11 kA and a dI/dt of 6 kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> s (circuit limits). The current imbalance between the thyristors was less than 10%. To the best of the authors’ knowledge, it is the first time reported that high-voltage thyristors connected in parallel have been successfully triggered in the impact-ionization wave mode.

Study of trigger mechanisms of a pseudospark switch configuration with a steady-state auxiliary glow discharge

This paper presents data on investigation of the pseudospark switch whose trigger unit uses a low-current auxiliary glow discharge with hollow cathode and hollow anode. The electrode system of this unit communicates with the main high-voltage gap of the switch due to the aperture in the flat part of one of the trigger electrodes. It is shown that when the electrode with the aperture plays of role of the hollow cathode of the auxiliary discharge, a low parasitic current through the aperture is provided by the ion flow. This ion current does not practically influence on the static breakdown voltage of the main gap. Applying the trigger pulse between the trigger electrodes leads to the pulsed trigger discharge with an enhanced current. At a negative polarity of the trigger pulse, the cavity with aperture turns out into the hollow anode so that the current is able to be intercepted through the aperture to the grounded cavity of the main gap. The plasma is generated in the cavity and the switch is triggered. With the proper selection of the geometry of the trigger electrodes, the delay time to trigger at a level of several tens of nanoseconds is achievable.

Simulation of Pulse Sharpening Mechanism of Vertical Diamond Avalanche Diode

The extremely low leakage, fast response, and excellent thermal conductivity of diamond facilitate its potential application in pulse power switching devices. In this study, we investigated the static and transient characteristics of diamond avalanche diodes (DADs) via 2-D device simulation. DAD is based on a Schottky barrier diode (SBD) structure. The static breakdown voltage is 590 V. Under an input pulse voltage with a peak voltage of 2400 V and a rise time of 2 ns, the output voltage on a 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> load driven by the device has a peak value of 1.83 kV and a rise time of 1.282 ns. The behavior and mechanism of the sharpened rising pulse response waveform are analyzed phase by phase. The generation and dynamic changes in carrier plasma inside the device and their effect on the altered electric field, impact generation, and carrier density, as well as the transient output of the device are investigated.

Direct comparison of silicon carbide and silicon diode avalanche shaper in multi-pulse applications

This paper compares the pulse shaping characteristics of SiC and Si Diode Avalanche Shaper (DAS) under quasi-uniform triggering with the help of Technology Computer-Aided Design (TCAD) software. Under the same static breakdown voltage (VSB), the opening speed of SiC DAS does not show obvious advantages over that of Si DAS. With the same device structure, SiC DAS has a higher breakdown voltage than Si DAS, so it has a faster dV/dt in the triggering process. In addition, compared to Si, SiC DAS delayed breakdown voltage (VDB) is less affected by the input pulse rise rate. This is because the SiC DAS avalanche generation rate is more sensitive to the device voltage in the vicinity of VDB. Then, the multi-pulse operating characteristics of SiC and Si DAS with the same VSB were compared by continuously triggering the SiC and Si DAS 50 times at the 1 MHz frequency. It is revealed that the VDB of the SiC DAS is low but has excellent multi-pulse consistency. At the same time, under multi-pulse operation, the temperature rise speed of SiC DAS is slow, and the temperature distribution in the device is more uniform. It can be concluded that SiC DAS has significant advantages in high voltage and multi-pulse shaping.

Influence of low dose rate gamma radiation on breakdown voltage and electrical breakdown time delay of working gas Geiger-Muller chamber

This paper presents the experimental data on the dynamic breakdown voltage and electrical breakdown time delay of commercial Geiger-Muller chamber manufactured by PHILIPS. The distributions of these data were determined. Static breakdown voltage was estimated based on the mean value of dynamic breakdown voltage as the function of voltage increase rate, for the cases when gamma radiation was not presented and in its presence. In order to separate the mechanisms that predominantly influence the initiation of breakdown for different values of relaxation time, the dependences of mean value of electrical breakdown time delay as the function of relaxation time was analyzed. It has been shown that during the relaxation times up to 3 ms positive ions plays a dominant role in initiating the breakdown while for relaxation times from 3 ms to 30 s initiation of the breakdown is caused by electrically neutral active particles. The effect of gamma radiation on electrical breakdown time delay was observed for relaxation time greater than 7 s.

Robustness of Cascode GaN HEMTs in Unclamped Inductive Switching

Surge-energy robustness is essential for power devices in many applications such as automotive powertrains and electricity grids. While Si and SiC <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s can dissipate surge energy via avalanche, the GaN high-electron-mobility transistor (HEMT) has no avalanche capability and withstands surge energy by its overvoltage capability. However, a comprehensive study into the surge-energy robustness of the cascode GaN HEMT, a composite device made of a GaN HEMT and an Si <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> , is still lacking. This article fills this gap by investigating the failure and degradation of 650-V-rated cascode GaN HEMTs in single-event and repetitive unclamped inductive switching (UIS) tests. The cascode was found to withstand surge energy by the overvoltage capability of the GaN HEMT, accompanied by avalanche in the Si <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> . In single-event UIS tests, the cascode failed in the GaN HEMT at a peak overvoltage of 1.4–1.7 kV, which is statistically lower than the device's static breakdown voltage (1.8–2.2 kV). In repetitive UIS tests, the device failure boundary was found to be frequency dependent. At 100 kHz, the failure boundary (∼1.3 kV) is even lower than the single-event UIS boundary. After 1 million cycles of 1.25-kV UIS stresses, devices show large but recoverable parametric shifts. All these failure and degradation behaviors can be explained by the buffer trapping in the GaN HEMT and the resulted change in its dynamic breakdown voltage. Moreover, the GaN buffer trapping is believed to be assisted by the Si <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> avalanche. An analytical model was also developed to extract the charges and losses produced in the Si avalanche in a UIS cycle. These results provide new insights into the surge-energy and overvoltage robustness of cascode GaN HEMTs.

FIELD DISTORTION ARRESTERS WITH IMPROVED TIME LIMITS FEATURES AND INCREASED RELIABILITY

The article considers the features of the design of four-channel rail arresters with field distortion with improved time characteristics and presents the results of studies of their time characteristics. The need for these studies is associated with the widespread use of such dischargers in capacitive energy storage devices that serve as power sources for electrodynamic mass accelerators. At the present stage of the development of science and technology, the use of such accelerators is the most promising for creating experimental stands for modeling in laboratory conditions the processes of high-speed interaction of structural elements of aircraft with particles of different masses and different origins. According to the operating conditions of the experimental stands, in a wide range of changes in both particle masses and interaction velocities, the amplitude values of currents through the low-inductive load of the mass accelerator can vary from kiloamperes to several megamperes at acceleration times from units to hundreds of microseconds. With this in mind, capacitive energy storage devices are performed in a multi-module design. Each module of a capacitive energy storage device is switched to the load by its own switch. To expand the range of operation of the spark gap of the storage device, to obtain the time characteristics of the spark gap with small delay times, to exclude the probability of spontaneous operation of the spark gap, and to provide the stability of the discharge formation during parallel operation of the switches, the designs of four-channel rail spark gaps with field distortion with improved characteristics were developed, their experimental and theoretical studies were carried out.&#x0D; &#x0D; The results of the conducted studies show that the smallest value of the delay time and, accordingly, the spread of the delay time are obtained for a spark gap with field distortion with two control electrodes.&#x0D; &#x0D; It is shown that the obtained analytical expressions presented in the article and the empirical expression calculated for a spark gap with a field distortion with two control electrodes make it possible to determine the values of threshold voltages and delay times, taking into account the statistical delay time and the time of discharge formation.&#x0D; &#x0D; The value of the threshold voltage is determined, at which the process of direct transformation of the streamer into a spark discharge with high conductivity followed by a breakdown of the interelectrode gap is observed.&#x0D; &#x0D; The dependences of the static voltage on the pressure in the inner chamber of the spark gap with field distortion with improved time characteristics are given. It is shown that at a certain distance between the main electrodes at a pressure of 0,3-0,5 MPa, the arresters operate with a margin of electrical strength when the static breakdown voltage is 1,5-2 times higher than the operating voltage applied to the electrodes of the gas gap of the arrestor. This eliminates the possibility of spontaneous triggering of the dischargers of the capacitive energy storage.

Xenon-filled diode performance under influence of low doses of gamma radiation

This paper presents a detailed statistical analysis of experimental results of dynamic breakdown voltage and electrical breakdown time delay for xenon-filled diode. These quantities have a stochastic nature and they were measured in the cases when the xenon-filled diode was and was not exposed to a gamma radiation source, with exposure dose rate 7.7⋅10−12 C/(kg⋅s). The static breakdown voltage was estimated based on dynamic breakdown voltage as a function of voltage increase rate. The applicability of certain distributions to experimental dynamic breakdown voltage and electrical breakdown time delay data was also analyzed.

8/20 and 10/350 surges behaviour of a Gas Discharge Tube according to gas pressure

This paper presents some results about the behaviour of a Gas Discharge Tube (GDT) under high surge currents. GDTs are amongst the components used to protect electrical equipment against electrical surges from atmospheric or other sources. The end-of-life of these components is an important feature for safety reasons. This paper shows that the end-of-life of GDTs depends on the type of electrical stress, which should be taken into account during the normative tests. Two normalized waveforms (8/20 µs and 10/350 µs) were applied to GDT. For each waveform, the resistance of the GDT to increasingly high currents was verified by measuring the static and dynamic breakdown voltages. Then, the resistance of the GDT to multiple shocks at a defined current level was also measured in the same way. It was thus possible to determine the associated destruction modes. These tests were validated for GDT which are filled with different gas pressures in order to determine the influence of the gas pressure.

Study on the Mechanism of Microparticle-Initiated Breakdown in the Air Gap

The microparticle-initiated breakdown plays a key role in the failure of gas switches and has become an active area of investigation in gas discharge recently. The mechanism of the microparticle-initiated breakdown in a 2-mm air gap is studied by experiments and simulations in this article. The dynamics of the microparticle in the electric field is obtained, and four breakdown modes are acquired from the picture of the high-speed camera. The probabilities of breakdown for the 200-, 300-, and 500- $\mu \text{m}$ Cu microparticles under different voltages are presented, and the corresponding lowest breakdown voltages reduce to 65%, 56%, and 47% of the static-breakdown voltage. The relation between the breakdown voltage and position of the microparticle is calculated based on the Townsend theory. The simulated results agree well with the experimental results. The breakdown process and evolution of the plasma are also revealed with PIC simulations.

Experimental Analysis of Breakdown With Nanosecond Pulses for Spark-Ignition Engines

The influence of pulse rise rate and pulse duration for ignition purposes in engines is investigated. A constant volume cell is used to characterize the breakdown voltage under nanosecond pulsed voltages with automotive sparkplugs having electrode gaps ranging from 0.2 mm to 1 mm. Two pulse generators are used to compare pulses with durations of 10 ns and 50 ns. Different pulse amplitudes are used, and air gaps with breakdown voltages ranging from 4 kV to 15 kV are investigated. The cell is filled with synthetic air with densities gap distances products that are relevant for internal combustion engines. This study shows that the pulse shape and rise rate influence the breakdown voltage. Under pulsed discharge, the breakdown voltage is always above the static breakdown voltage. The probability of pulsed discharge breakdown increases as both the pulse amplitude and duration increases. Furthermore, the breakdown voltage value increases with increasing pulse rise rate. The delay time between reaching the static breakdown voltage and the actual breakdown voltage decreases with increasing overvoltage. The delay time is constituted by statistical and formative times. Both the statistical and formative times decrease with increasing overvoltage. For ignition purposes, the pulse rise rate should be as high as possible to deliver a larger energy input in the breakdown phase. Furthermore, for reduced electrode erosion, the pulse duration should be short (10-20 ns) to reduce the probability for a transition to an arc.

О минимальном напряжении статического пробоя газоразрядного промежутка

Based on the self-sustaining condition of the discharge, a theoretical analysis was carried out in order to identify the minimum possible breakdown voltage. It is shown that a weak nonuniformity of the electric field in the discharge gap leads to an increase in the static breakdown voltage in comparison with the Paschen’s law. A strong nonuniformity of the field in diodes of coaxial and spherical geometry also cannot provide a decrease in the minimum breakdown voltage in comparison with the case of a plane-parallel gap. It is proved that of all symmetric geometries of a gas-filled diode, the planar geometry has the lowest breakdown voltage.

The evolution of breakdown voltage and delay time under high overvoltage for different types of surge arresters

The results of the reliability testing of Littelfuse and EPCOS gas-filled surge arresters for different overvoltages under DC discharge will be presented in this paper. The static breakdown voltage of these gas components was estimated using voltage increase rates ranging from 1 to 10 V/s. A detailed statistical analysis of experimental data has also been done. The delay time of these components for different nominal overvoltages has been investigated as an additional aspect important for component reliability. In addition, the delay time method was used as a statistical method which can give neither ion nor neutral active states number density in the glow and afterglow. It can be employed for qualitative observation of ions and neutral active states decay in the afterglow to such low concentrations where the other methods cannot be applied. Finally, a comparison has been done between the characteristics of two gas-filled surge arresters which have the same nominal overvoltage (Littelfuse and EPCOS) from different manufacturers.

Analysis of the Influence of Silicon-on-Insulator Lateral Double-Diffused MOS Device Substrate Deep Depletion on the Transient Breakdown Voltage

With two-dimensional device simulation software, the influence of the deep depletion (DD) of the silicon-on-insulator (SOI) lateral double-diffused metal-oxide-semiconductor (LDMOS) device substrate on the transient breakdown voltage (TrBV) was analyzed. Based on the changes in the characteristics of the charge distribution and the depletion layer in the device substrate with time and the related parameters in the off state, the mechanism of their action on the transverse and vertical breakdown voltages (BVs) was studied. TrBV demonstrates completely different characteristics from the static breakdown voltage (StBV) due to the DD effect of SOI LDMOSs. Low drift region concentration (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> ) and substrate doping concentration (P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sub</sub> ) are conducive to obtaining a high maximum TrBV. With increasing drain voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> ), the turn-off nonbreakdown time (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nonbv</sub> ) of the device with higher P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sub</sub> decreases faster. However, the T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nonbv</sub> with higher P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sub</sub> is higher at low V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> . Therefore, the maximum T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nonbv</sub> can be obtained by optimizing N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> and P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sub</sub> under a given V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> . In addition, T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nonbv</sub> is greatly reduced with increasing temperature.

Separation of vacuum and gas breakdown processes in argon and their influence on electrical breakdown time delay

Research presented in this paper is dealing with the determination of static breakdown voltage Us in an argon-filled tube at 0.5 mbar pressure, for different inter-electrode gaps d with the aim of separating vacuum and gas breakdown processes contribution in electrical breakdown time delay. The Us determination was performed using data on the dynamic breakdown voltage experimental data obtained for different voltage increase rates. It was shown that up to d≈9 mm estimated value of Us is relatively small change corresponds to breakdown which is vacuum-like, where as for d > 9 mm, breakdown takes place as in normal gas discharge. For d≈1 1 mm, Us has the minimal value, when gas ionization process induced by secondary electron emission from the cathode is maximal. The measurement of electrical breakdown time delay td was performed for three different values of inter-electrode gap: 0.1, 4 and 11 mm. On the basis of memory curve (mean value of electrical breakdown time delay t‾d as a function of relaxation time) behavior and statistical analysis of td data, mechanisms which make main impact to breakdown initiation were estimated for different values τ. Also, the impact of additional electron yield originating from UV radiation with wavelengths 302, 312.5 and 313.1 nm on the memory curve were investigated.

Role of Prebreakdown Currents in a Static Breakdown of a Two-Sectioned Cold-Cathode Thyratron

The data on prebreakdown currents and static breakdown voltages measured in two-sectioned sealed-off thyratron with a cold cathode TPI1-10k/50 are presented. The temporal behavior of the anode voltage and of the voltage at the separate sections has been investigated at the prebreakdown and breakdown stages. It is demonstrated that the prebreakdown current presented in the separate sections causes redistribution of the anode voltage between the sections. Due to this effect, a maximum thyratron breakdown voltage can be obtained. The other method to increase the breakdown voltage is based on the forced distribution of the anode voltage between the sections using a capacitive divider. Special features of transition from the prebreakdown to breakdown current are discussed for different thyratron-switching circuits.

Numerical and Experimental Study of an Optimized p-SOS Diode

We report on the results of experimental investigation and numerical simulation of switching of SOS diode with p+P0n+ structure and with reduced thickness of P0-base. The proposed 1D diffusion-drift model of electron–hole plasma dynamics is found to be in good agreement with the experiment. The reduction of the P0-base thickness has allowed us to double the output pulse voltage with the same switching current density. This has been reached by a considerable reduction of switching losses as well as due to the formation of the domain of a strong quasi-rectangular electric field at the P0n+ junction during the current interruption. As a result, output pulse amplitude considerably exceeds the static breakdown voltage of P0n+ junction. This effect has been observed for the first time for high-voltage semiconductor opening switches.

Численное и экспериментальное исследования оптимизированного p-SOS-диода

AbstractWe report on the results of experimental investigation and numerical simulation of switching of SOS diode with p ^+ P _0 n ^+ structure and with reduced thickness of P _0-base. The proposed 1D diffusion-drift model of electron–hole plasma dynamics is found to be in good agreement with the experiment. The reduction of the P _0-base thickness has allowed us to double the output pulse voltage with the same switching current density. This has been reached by a considerable reduction of switching losses as well as due to the formation of the domain of a strong quasi-rectangular electric field at the P _0 n ^+ junction during the current interruption. As a result, output pulse amplitude considerably exceeds the static breakdown voltage of P _0 n ^+ junction. This effect has been observed for the first time for high-voltage semiconductor opening switches.

Investigation of statistical behaviour of electrical breakdown voltage distribution for nitrogen‐filled diode at 13.3 mbar pressure

The results of statistical analysis of the electrical breakdown voltage distribution in nitrogen are presented in this paper. For obtaining the experimental results, a nitrogen‐filled diode at 13.3 mbar pressure was used. The dynamic method was used for estimating the static breakdown voltage. One‐hundred voltage measurements were carried out for each value of the increase in the voltage rate from 1 up to 10 V/s. Wilcoxon test was used for checking the measurements' randomness for each rate. The experimental distribution functions are fitted with the three‐parameter Weibull distribution function. The coefficients of the Weibull distribution are also estimated.

Investigation of the Static Breakdown Voltage of the Lubricating Film in a Mechanical Ball Bearing

In this paper, the current pulse (discharge) activity in a small bearing is investigated when current-limited DC voltages of different levels are applied to the shaft under varying rotational speeds and mechanical loads. The measurements show that the inception voltage of discharges in the bearing is higher than the extinction voltage. However, when the discharge activity has been intense the bearing exhibits difficulties to recover its insulating properties when the voltage is decreased to a low voltage level and thus the discharge activity continues. The measurements also show that at low voltages the bearing acts as an insulator but if the voltage is increased the bearing starts to act as a conductor. This transition occurs during a narrow voltage interval. The time interval between two consecutive current pulses decreases significantly with increasing shaft voltage.