Arc Breakdown Research Articles

Testing the operation of protection devices against parallel arc breakdown and spark gaps in the event of a ground fault

Testing the operation of protection devices against parallel arc breakdown and spark gaps in the event of a ground faultTHE PURPOSE. Develop a laboratory rig for testing parallel arc fault and spark gap protection devices for tripping in the event of a ground fault. Conduct laboratory rig tests with subsequent development of requirements for the use of parallel arc fault and spark gap protection devices for tripping in the event of a ground fault.METHODS. Mathematical and statistical methods of analysis were used to achieve the stated objective. Laboratory tests of parallel arc fault and spark gap protection devices for different network parameters for correct tripping in the event of a ground fault.RESULTS. Laboratory tests of parallel arc fault and spark gap protection devices for correct tripping in the event of a ground fault were conducted with different network parameters. The oscilloscope recorded the shape of the voltage and current curve in the event of a ground fault and the tripping time of the devices. The tested devices demonstrated the ability to recognize and disconnect a ground fault. The tripping time of the devices varies, however, does not exceed the established requirements.CONCLUSION. A laboratory stand has been developed for testing parallel arc breakdown and spark gap protection devices for operation during a ground fault. This stand makes it possible to test devices for adequate operation during a ground fault with subsequent certification. The tests conducted demonstrate the need to develop mandatory requirements for the device to standardize their operating algorithm. Therefore, the use of this protection device can contribute to safer operation of low-voltage electrical networks by preventing emergency situations and reducing the risk of fires. This is an important technical aspect for improving the reliability and safety of power supply.

Research on arc evolution law of arc extin‐ction device under high‐speed large current

AbstractThe lifespan of the guide rail is a bottleneck restricting the operational life of electromagnetic railguns. A well‐designed arc extinguishing device can reduce the arcing erosion caused by residual currents within the guide rail. The CuW alloy is widely used in the high‐pressure arc extinction field due to its excellent electrical and thermal conductivity, high strength, and hardness. Based on the theory of equilibrium state arc plasma, a finite element model of the air arc‐CuW electrode coupling in the arc extinction device was established to study millisecond‐level arc initiation, evolution, extinguishing characteristics, and distribution patterns under extreme and harsh operational conditions with a current input of 110 kA. The highest temperature in the arc column region was found to exceed 50,000 K. The study elucidated the influence of arc extinction device parameters on arc evolution, breakdown time, and breakdown voltage. Consequently, it established that the R70 spherical electrode exhibits optimal arc extinguishing characteristics. The aim of this research is to provide theoretical support for optimizing the arc suppression device. Additionally, experiments on high‐speed and high‐current arc extinction device discharges were conducted to validate the finite element analysis results regarding arc diffusion patterns and electrode erosion.

Venting particle-induced arc of lithium-ion batteries during the thermal runaway

Thermal runaway of lithium-ion batteries will release a large amount of particles with elevated temperature and high velocity, probably resulting in arc failures. In this study, we adopted an 117Ah fully-charged prismatic battery with Li(Ni0.8Co0.1Mn0.1)O2 cathode to collect the vented particles in an inert atmosphere after thermal runaway. All settled particles were classified into six groups to investigate the influence of electrode spacing, particle size and load resistance on the critical breakdown voltage as well as arc characteristics. As a result, a novel breakdown arc failure called venting particle-induced arc was firstly revealed and verified in the battery system. These settled particles significantly decrease the critical breakdown voltage for arc failure. The critical breakdown voltage exhibits a positively quadratic correlation with electrode spacing within 1–8 mm, while it is negatively correlated with particle sizes. Furthermore, a critical voltage map for breakdown arc under various particle sizes and electrode spacing was proposed. The results provide guidance to electrical hazards prevention in the battery system.

ПРОБЛЕМА АДМИНИСТРАТИВНЫХ БАРЬЕРОВ ПРИ ОСУЩЕСТВЛЕНИИ ТРУДОВОЙ ДЕЯТЕЛЬНОСТИ ПРЕДПРИНИМАТЕЛЯМИ И СОТРУДНИКАМИ СТРУКТУРНЫХ ПОДРАЗДЕЛЕНИЙ ОРГАНОВ НАДЗОРНОЙ ДЕЯТЕЛЬНОСТИ В СИСТЕМЕ МЧС РОССИИ

The problems of administrative barriers for both executive authorities and controlled persons were considered. A partial analysis of the situation with fires and their consequences on the territory of the Russian Federation in recent years in the field of fire safety is given. It is stated that a significant part of the causes of fires occurring in buildings and structures falls on the emergency mode of operation of power grids. It is noted that arc breakdown or sparking is one of the most common causes of «electric» fires. The issue of responsibility for the serviceability and integrity of electrical wiring at the protection facility was touched upon. It was concluded that the progress of the goal to improve the quality of life of citizens, among other things, is achieved by the use of experimental methods of legal regulation.

Influence of Ti2SnC content on arc erosion resistance in Ag–Ti2SnC composites

Abstract In this work, an Ag–Ti2SnC composite was fabricated by the hot-pressing sintering method, and the erosion behavior of Ag–Ti2SnC with volume percentages of 10–40% was studied at a load voltage of 10 kV. The arc life and breakdown current were observed at about 31–36 ms and 39 A, respectively. The cathode spot traveled the fastest on the surface of the Ag–40 vol% Ti2SnC composite. Due to emission center model, the temperature of the minor protrusions on the cathode surface increased, resulting in Ag ions, Ti ions, and Sn ions being generated. Combining with the ionized oxygen, Ag2O, AgO, TiO2, and SnO2 were formed on the eroded Ag–Ti2SnC surface after arc erosion. The research results will broaden the application range of Ag–Ti2SnC electrical contact material and enrich the arc erosion mechanism.

Analysis of internal material characteristics of cathode crater of micro-cathodic arc thruster

In this study, the material loss relationship between the electrodes of a micro-cathodic arc thruster was investigated by adjusting the input voltage. The crater morphology of the micro-cathodic arc thruster was observed with a scanning electron microscope. The internal crater material was analyzed with an energy spectrum analyzer. On this basis, the arc path is obtained and the material loss of the structure between the electrodes of the micro-cathodic arc thruster was studied through further numerical simulation. The experimental and simulation results show that with a change in the Power processing unit (PPU) input voltage of the micro-cathodic arc thruster, the material distribution in the cathode crater and the discharge channel between the electrodes changed, affecting the bombardment of ions between the electrodes of the thruster on the insulating structure and conductive coating. In engineering applications, regulation of the arc breakdown path can effectively reduce the total energy of ion bombardment on the wall.

Investigation of Interface Discharge Characteristics for Cable Accessories After Moisture Penetration Into the XLPE–SiR Interface

For cable accessories, environmental moisture inevitably gradually diffuses into the XLPE-SiR composite interface. The penetrated moisture always causes interface insulation degradation and failure. In this paper, to investigate the discharge characteristics at the interface insulation, a composite interface discharge experimental unit is performed, and the insulation deterioration when the interface remains dry or becomes damped are discussed and analyzed. Combined with optical tests, discharge signal tests, SEM and EDS tests, the interface discharge characteristics are studied. In addition, several analysis models are established, and the discharge processes of the interface insulation are discussed in detail. Moreover, several field cases are discussed and compared to better understand the interface discharge. It is found that the discharge trace is mainly concentrated in one channel when the insulation remains dry. Moisture-induced early deterioration of the interface insulation is characterized by the emergence of non-conductive regions and weak dendritic discharge. As the interfacial water content increases, weak dendritic discharge turns into a macroscopic one. The occurrence and development of discharge after interface wetting can be attributed to two main factors. On one hand, interface discharge is related to the interface electric field distribution and interface contact morphology. On the other hand, the discharge performance is strongly influenced by the electric field distortion caused by water droplets, size of the dry area between water droplets, and increase in electrical losses ascribed to the invading moisture. The ultimate damage to the interface insulation takes two forms: continuous thermal breakdown that erodes the insulation, and instantaneous arc breakdown at the interface.

Research on the energy consumption mechanism and characteristics of the gallium indium tin liquid metal arcing process

For high-voltage direct current (HVDC) power grid transmission with higher voltages, the energy-consuming branch of the DC circuit breaker is required to dissipate huge energies of more than megajoules in a short time in the case of a fault and short circuit. The requirements for huge volume and weight are difficult to meet with energy-consuming equipment based on ZnO. In this paper, a new energy consumption method is proposed based on gallium indium tin (GaInSn) liquid metal in the arcing process, and a test platform with adjustable short-circuit current is built. The mechanism triggering GaInSn liquid metal arcing energy consumption is studied. It is found that short-circuit current and channel aperture are the key parameters affecting the energy consumption of liquid metal arcing. The characteristics of GaInSn liquid metal energy consumption are investigated, and four stages of liquid metal energy consumption are found: oscillatory shrinkage, arc breakdown, arc burning phase change and arc extinction. The influence of short-circuit current and channel aperture on the energy consumption characteristics of GaInSn liquid metal is investigated. To further explore the physical mechanism of the above phenomena, a magneto-hydrodynamic model of energy consumption in the GaInSn liquid metal arcing process is established. The influence of short-circuit current and channel aperture on the temperature distribution of the liquid metal arc is analyzed. The mechanism of the effect of short-circuit current and channel aperture on peak arc temperature and the temperature diffusion rate is clarified. The research results provide theoretical support for this new liquid metal energy consumption mode DC circuit breaker.

Modeling and Simulation of a Transient Process and an Analysis of Transient Characteristics in the Switching Operation of Disconnectors

High-voltage switchgears can generate high-frequency and high-amplitude electromagnetic interference during their operation, which may lead to abnormal outputs of the measurement devices, thus giving rise to measurement errors or protective relay malfunctions and impacts on the stable running of the power grid. Considering the air breakdown delay, a dynamic reignition model consisting of the hyperbolic model, the static model and the improved Mayr model is proposed to analyze the transient process during the on/off operation of open-type disconnectors. Meanwhile, the influence of arc resistance, line length and breakdown delay on the model were analyzed, and an experimental circuit was built to verify the simulation results through a comparison. It was found that the proposed model could reflect the high-frequency voltage and current during the on/off operation more accurately and thus provide an effective method for the precise modeling of the switching operation of the disconnector.

On the Issue of Calculating the Reverse Arc Breakdown Voltage of a High-Voltage Thermionic Diode and Its Maximum Specific Electrical Power

The issues of creating powerful power propulsion systems (PPS) based on a thermionic reactor-converter (TRC) and electric rocket propulsion systems (ERPS) are related to the development of compact high-temperature radiation–resistant current conversion systems (CCS) using plasma electric power devices - grid key elements (GKE) and high-voltage plasma thermionic diodes (HVPTD). The main problem of the development of GCE and HVPTD is the determination of their operating voltage (or reverse arc breakdown voltage in the locked state), which together with the current density in the conductive state characterizes the electric power density of the valve and is its main parameter. Within the framework of this work, the authors, based on the study of the locked state, numerically and analytically obtained new dependences for calculating the reverse arc breakdown voltage and determined the limiting values of the electrical power density of the HVPTD.

Uncovering microstructure and composition susceptibility of high permittivity ceramic granules to plasma‐induced arc breakdown

Uncovering microstructure and composition susceptibility of high permittivity ceramic granules to plasma‐induced arc breakdown

A method for determining arc breakdown in low-voltage electrical networks

In low voltage distribution networks, there is a high risk of fires caused by wiring faults that lead to short circuits. Arcing protection devices (ARCs) already exist, but experiments show that they also often do not disable such faults. The operation of most existing arc fault detection devices is based on the detection of high frequency current components and their comparison with load profiles. For the fast arc fault recognition low-frequency oscillations can be assessed, which serve as a marker of the arc fault presence in a LV distribution network. This method of arc fault recognition in LV networks is easier to implement practically. Using the windowed Fourier transform or Wavelet analysis, it is possible to determine the change in time of the harmonic components of the current, which will be a characteristic sign of the presence of an arc fault along with other signs.

Experimental study on the transition process from partial discharge to arc discharge of oil–paper insulation based on fibre‐optic sensors

Arc discharge in the power transformer can bring enormous economic losses and safety risks. The transformer protection system for arc discharge faults is still not ideal. The physical characteristics of the whole process from partial discharge defects transition to arc faults are not fully recognized, mainly because it is difficult to establish and sense the relevant characteristic parameters. This paper built a research platform for studying the transition process from partial discharge to early arc discharge based on fibre-optic ultrasonic, temperature, pressure sensors with traditional electrical voltage and current sensors. Five discharge models are designed and the changing pattern of multiple parameters in the transition process of different models is studied. The experiment results show that the amplitude and frequency of acoustic waves drop significantly after the arc breakdown. Ultrasonic and high-frequency current sensing in the early warning of arc fault each has its own limitations. The pressure caused by the arc is not only related to the arc energy but also related to the discharge types. The overall oil temperature change after the early arc discharge is small and hard to detect. This work highlights the promise of using fibre-optic sensors for physical process research within a harsh electromagnetic environment.

Effect of NC pins ESD test on the reliability of integrated circuits with high density BGA package

In this study, the failure phenomenon of high-pin-count BGA device ESD test by stressing NC pins was tested and analyzed since NC pin withstands HBM pulse as the signal pin during practical application and experiences new failure mode and mechanism. The effects of NC pins ESD test on the reliability of integrated circuits and the failure mechanism were subsequently investigated via experimental methods. Results show that ESD level identification tests with stressing NC pins exhibit abnormal failure mode compared with typical ESD failure. Meanwhile, a distributed capacitance method (DCM) is proposed to explain the phenomenon and failure mechanism, which is affected by the packaging materials and particular spacing distance between adjacent pins. When the HBM ESD pulse is applied on the NC pin, the signal pin adjacent to NC pin regularly fails due to the existence of distributed capacitance CM + CM(air) and air arc breakdown. The verification experimental tests of failure analysis reveal that the monitored huge and extremely fast current forms through the distributed capacitance coupling and air arc mode.

Experimental study of the effect of argon on the restrike characteristics of nitrogen arc

The arc restrike process is a typical mode of operation within a direct current arc plasma torch. By using a transfer arc device with a planar anode parallel to the gas flow direction, the effect of argon addition on the disappearance of downstream old arc roots, the overall arc downstream movement process and the generation of upstream new arc roots of the nitrogen arc restrike process is experimentally investigated. The experimental results show that for pure nitrogen arc, the restrike frequency is very high and the old arc root disappears very quickly. The addition of argon will significantly decrease the temperature of the arc root and prolong the coexistence time of the old and new arc roots. This phenomenon is caused by the rapid decay of charged particle density in the nitrogen arc, because the recombination process of charged particles in the nitrogen arc is faster than that in the argon arc. The breakdown field strength at the upstream location where the new arc root occurs is calculated by combining the measurements of arc voltage, arc grayscale image and temperature. The results show that as the percentage of argon increases, the boundary layer thickness becomes thinner and the critical electric field strength required for arc breakdown decreases, leading to the generation of new arc roots more likely to occur toward the upstream location. This study improves the understanding of the effect of argon on the nitrogen arc restrike process.

Enhancing mechanisms of arc-erosion resistance for copper tungsten electrical contact using reduced graphene oxides in situ modified by copper nanoparticles

To solve critical issues of premature failure for copper tungsten (CuW) based electrical contacts during arc erosion at the moment of arc breakdown, we proposed a new strategy of using metal doped reduced graphene oxides (rGOs) and in-situ formed tungsten carbides to inhibit movements of cathode spots during the arc ablation process. CuW composites were reinforced with Cu modified rGO nanopowders (i.e. Cu@rGO) using combined processes of chemical co-reduction, ball milling and spark plasms sintering (SPS). Effects of Cu@rGO addition on microstructure, arc erosion resistance and arc ablation resistance of the CuW composites were systematically investigated. Results showed that tungsten carbides with irregular shapes were formed through in-situ reactions of rGO and tungsten during the SPS process. Arc erosion resistance of CuW composites was significantly improved owing to introduction of nanostructured Cu@rGO. Compared with those of CuW composites, the ablation areas of Cu@rGO/CuW ones were much smaller and the ablation craters were shallower, and the average strengths of dielectric vacuum breakdowns of the CuW composites with 3 wt% Cu@rGO were increased by 28.9%. The arc breakdown mechanisms of Cu@rGO/CuW composites were identified as: (1) The nanostructured Cu@rGO increases the viscosity of molten metal Cu, thus inhibiting its fast flow and splashing; (2) Lower work functions of carbon (i.e. rGO) and tungsten carbide restrain the electron emissions during arc breakdown; and (3) The tungsten carbides with their good stability and high melting point shorten the solidification time of molten copper liquid and extend the service life time of the Cu@rGO/CuW composites.

Analysis of overload induced arc formation and beads characteristics in a residential electrical cable

The process and mechanism of breakdown induced cable insulation exposed to conductor heating caused by overload were investigated. The time from the beginning of the overload to the occurrence of an electrical arcing event was measured. A mathematical equation between the average time of the initial breakdown and current was established for 220 VAC distribution systems. The phenomena in these experiments were captured with a high-speed camera. The times and durations of arcing events occurring repeatedly were documented throughout the whole process, which could present some information associated with the possibility of this fault to ignite combustibles. The formation process of breakdown was evaluated theoretically. The established mathematical equation to calculate the average time of the initial breakdown could be employed to predict the interval between overload occurrence and breakdown arcing. The formation process of arc beads was affected by the hot environment created by breakdown and insulation combustion. Kinds of metallographic microstructure of arc beads might be found during a test, such as dendritic segregation structure, equiaxed recrystallized grains, and cylindrical crystals. This work could provide basic data for determining the breakdown occurrence attributed to overload.

Arc interruption performance of C 4 F 7 NCO 2 and dielectric recovery in disconnecting switch

SF6 gas is widely used in high voltage power switchgear. However, SF6 is a gas with strong greenhouse effect. Therefore, the study of new environment-friendly gases represented by perfluoronitrile (C4F7N) gas as a substitute gas for SF6 has become a hot issue in the field of high-voltage electrical appliances. In this paper, the magneto-hydro-dynamic (MHD) model of arc burning process was established for the structure of 126kV isolation switch. The results about the post arc breakdown voltage and electrical field distribution was calculated for the evaluation of the performance of arc interruption. The established model in this thesis is valid and can be widely used in arc simulation and the evaluation of dielectric recovery. The results of this paper are significant for the application of new environmental gases in isolating switchgear and optimization design.

Particle-in-cell simulation of vacuum arc breakdown process of tip-to-plate electrode configuration

The breakdown of a vacuum arc under high applied voltage conditions usually occurs on very short time and space scales, and a deep understanding of these processes is essential to extend the application of vacuum arc devices. To study the time and spatial evolution of plasma parameters during vacuum breakdown, a two-dimensional axial-symmetric particle-in-cell code with Monte Carlo collisions is used in the numerical simulation of tip-to-plate electrode configuration. In this simulation, in addition to considering the primary and secondary ionization of copper atoms, the excitation and de-excitation processes of copper atoms are also introduced so that the evolution of the light intensity of the vacuum arc in the different stages of breakdown processes can be obtained by tracking the de-excitation process of the atoms, which can be considered a virtual camera. In this way, the cathode radiance, anode light expansion, arc channel establishment, and arc quenching processes can be visually observed, and the trends are consistent with the images taken by Intensified Charge-Coupled Device (ICCD) and streak cameras reported in the literature. The analysis of the sputtering amount of the anode material due to the impact of the cathode plasma to the anode surface shows that the contribution of atoms, singly, and doubly ionized ions to the sputtering of the anode material varies at different stages of the discharge.

Analysis and Application of the Equivalent Circuit Model for Core Snubber

Core snubber is a surge suppression protection device installed between the high voltage power supply and the auxiliary heating load. When a breakdown occurs, the core snubber can limit the short-circuit current and consume fault energy, thus protecting the high-voltage power supply and auxiliary heating load. The existing snubber schemes have the problems of large volume, high price, complex integrated design, and large inductance affecting the normal working current of the power supply, so a new expression of equivalent magnetization inductance is established based on the saturated wave theory. The equivalent circuit model of core snubber is improved, and the surge suppression characteristics of core snubber and the attenuation process of breakdown arc current are studied. The circuit model consists of a magnetized inductor and an eddy current resistor in parallel. The expression can be expressed by the characteristic parameters of the alloy winding, the structural size of the core and the voltage integral at both ends of the snubber. In this article, a prototype of iron-based nanocrystalline snubber is made, and a dc high-voltage short-circuit experimental platform is built. By comparing the simulation and measured results of the prototype, the accuracy of the snubber equivalent parallel circuit model derived in this article and its practicability in core design are verified. There are other circuit components in the breakdown discharge circuit of the auxiliary heating system in addition to the distributed capacitance and snubber. In order to further analyze the surge suppression characteristics and breakdown arc current attenuation process of the core snubber including other circuit components, in this article, the extended discharge circuit with reverse bias diode and secondary winding is simulated and tested. The influence of the bridge arm in the reverse bias state on the arc current in the high voltage uncontrolled rectifier during breakdown is discussed. In view of the thickness limitation of core strip, the effectiveness of reasonable setting of secondary winding to avoid core saturation is demonstrated through simulation and measured analysis.