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A generator of high-power nanosecond pulses is described that contains a high-voltage unit, which is based on a magnetic-compression circuit and a diode current interrupter, and a high-voltage transistor unit, which provides high-efficiency energy switching to the high-voltage unit. The results of using this generator in an experimental plasma installation that was developed for studying the possibility of synthesizing silicon from a mixture of H2 and SiF4 are presented.

The time shift of mechanical watches is caused by individual differences (manufacturing error), environmental temperature, magnetism, posture, impact force and dynamic environment. The easiest and clearest method of measuring the accuracy of mechanical watches is to measure the time shift by comparing it with the reference time. The disadvantage of this method is that it can only measure accuracy at a certain time. Another method for measuring the accuracy of mechanical watches uses a watch timing machine that obtains the vibration sound of a watch using a microphone and calculates accuracy in the short term. This method can measure the change in watch accuracy over time. However, it cannot be used to measure accuracy in a dynamic environment because the watch timing machine is large and there is a sound noise. To clarify the accuracy of mechanical watches in dynamic environment, this study developed an accuracy measurement system which can be carried and measure in a dynamic environment. This study monitors the movement of a partly constituted mechanical watch using a photo interrupter and develops a method to calculate the rate and amplitude of a balance wheel from the output value of the photo interrupter. The validity of the developed system is verified by comparing the time shift of the system and radio clock time over the long term. The developed system, can be used in a dynamic environment because it consists of the photo interrupter in the watch case. Moreover, this study conducted measurements under forced vibration using vibration generator and during walking with the system.

The evolution processes of vacuum breakdowns in single- and double-break vacuum interrupters are reported in this paper, in order to reveal the formation mechanisms for the conductive channels in vacuum arcs. Breakdown experiments in two vacuum interrupters containing 10–30 mm gaps with single-break and double-break are studied. The light emission during breakdowns is observed by an intensified charge coupled device camera, with the current and voltage waveforms being recorded simultaneously. According to the results, there is no difference between the evolution processes of breakdowns in small gaps and large gaps. The establishment of the conductive channel and sustaining of the vacuum arc can be achieved by the effect of the cathode without any contribution from the anodic glow. In the double-break interrupter, the transition from insulation to conduction for the two serial connected gaps starts simultaneously but evolves independently.

The development of renewable sources of electrical energy represents the main goal of the most countries. This energy has to be transmitted for a long distance for the utilization in populated areas. The need of high-voltage direct current circuit breakers represents the key of the development of high-voltage direct current transmission systems. High and extra high-voltage six sulfur hexafluoride circuit breakers need more than one interrupter to be stable during arc extinguishes, so it can be used in high-voltage systems as cascaded interrupters. In this article, the multi-break high-voltage direct current HVDC gaseous circuit breaker characteristic is investigated by employing Mayr and Cassie arc models. The influences of the models parameters on the arc interruption time are studied using MATLAB/Simulink program. It is concluded that the simulated results by employing black box arc models achieve a success in multi-break HVDC gaseous circuit breakers simulation. Employing BBAMs black box arc models has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the multi-break high-voltage direct current gaseous circuit breaker HVDCGCB arcing time. That has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the arcing time. The main contributions of this article in points can be summarized as employing black box arc models achieves a success in multi-break HVDC gaseous circuit breakers simulation, investigation of the influence of commutation parameters on the cascaded HVDC gaseous circuit breaker interrupter performance, the controlled and uncontrolled parameters affecting the arcing time of HVDCGCB has been studied, the impact of the fault resistance value on arcing time and the damping resistance influence on the transient recovery voltage are investigated, and additionally, the initial transient interruption and the Metal Oxide Varistor voltages are analyzed. From the investigated forty cases done to check the Mayr’s model validity in the HVDC CD simulation, it is found that the values of P and τ which give acceptable outputs are at τ = 10−6 s, and P in range of 107 W to 1011 W. The output of the case τ = 10−6 s, P = 1010 W, which is introduced in the paper has proved that when τ reached to 10−7 s the MOV current rises and drops and thereafter rises and gradually decreases. This may leads to CB failure Com parameters influence on the interrupter performance are investigated and proved good simulation of the gaseous circuit breaker interrupter.

For interruption operations at higher voltage levels sulfur hexafluoride (SF6) is the dominating insulation and interruption medium. In medium to high voltage levels vacuum has advantages compared to SF6. In order to expand the operation voltage levels of vacuum circuit breakers (VCB), two approaches are possible. The first is the enlargement of the single contact gap and second is the series arrangement. In both cases the Time–Distance-Curve of the contact travel is one factor that influences the interruption performance of VCBs. The usage of a single gap for higher voltage levels requires an increased contact distance. In dependence of different interruption operations, like short circuit or capacitive interruption, a controlled Time–Distance-Curve could be useful. For experimental investigations a vacuum single break test setup using a brushless servo motor with a frequency converter is built. The electrical control of the drive enables parameter variations of the Time–Distance-Curve. The velocity, acceleration, deceleration, and final contact gap can be adjusted as required for testing and later in field application. For fine control a mechanical simulation considering the regulation loop between frequency converter and drive as well as the mechanical components is employed. Finally, tests of the setup for interruption operations are presented.

The article describes a measuring complex based on the 32-bit STM32F103VET6 microcontroller for studying the lux-ampere (light), frequency and inertial characteristics of a photoresistor with different laws of recombination of nonequilibrium charge carriers arising under the influence of light. The developed complex is connected to a personal computer (smartphone) and allows to analyze the rise and fall edges of the photoresistor current, as well as to determine the lifetime of excess charge carriers at different illumination levels. Unlike traditional methods for measuring the parameters of photoresistors operating in a dynamic mode, the proposed measuring complex does not use an oscilloscope and a separate modulator of the luminous flux (generator or light interrupter), this made it possible to significantly reduce the size and cost of the complex, as well as automate the measurement process. To determine the frequency response of the photoresistor, it is proposed to use a frequency synthesizer, which allows, together with a digital-to-analog converter of the microcontroller, to form an amplitude-modulated light flux of the required frequency and modulation depth. The complex described in the work can be connected to the Internet using a Wi-Fi module based on an ESP8266 microcontroller, which allows conducting research in a remote mode. It is also possible to determine the parameters of the photoresistor at different values of the load resistance.

This paper describes the design and testing of a low-cost dynamometer for milling force measurement. The monolithic design is based on constrained-motion/flexure-based kinematics, where force is inferred from displacement measured using a low-cost optical interrupter (i.e., a knife edge that partially interrupts the beam in an emitter-detector pair). The time-dependent displacement of the dynamometer’s moving platform caused by the milling force is converted to the frequency domain, multiplied by the inverse of the single degree of freedom frequency response, and converted back to the time domain to obtain the time dependent cutting force. Comparisons with commercially available, piezoelectric-based force measurement are provided.

The development of the renewable energy and the need of medium- and high-voltage direct current circuit breakers are the keys in the development of medium- and high-voltage transmission systems. It can be used in high-voltage systems as cascaded interrupters. In this paper, the cascaded interrupters of gaseous circuit breakers are simulated using black box arc models. The influences of the models parameters on the arc interruption time are studied. MATLAB/Simulink program is employed to carry out this study. It is concluded that the simulated results by employing black box arc models achieve a success in multi-break HVDC gaseous circuit breakers simulation. Employing BBAM models has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the multi-break HVDCGCB arcing time. That has proved more flexibility to study the effect of different controlled and uncontrolled parameters on the arcing time. From the investigated forty cases done to check the Mayr’s model validity in the HVDC CD simulation, it is found that the values of P and $$ \tau $$ which give acceptable outputs are at $$ \tau = 10^{ - 6} \;{\text{s}} $$ , and P in range of 107–1011 W. The output of the case $$ \tau = 10^{ - 6} \;{\text{s}} $$ , P = 1010 W, which is introduced in the paper has proved that when $$ \tau $$ reached to 10−7 s, the MOV current rises and drops and thereafter rises and gradually decreases. This may lead to CB failure; Com parameters influences on the interrupter performance are investigated and proved good simulation of the gaseous circuit breaker interrupter. The commutation parameters affecting the interrupter performance are investigated. Investigation of the change in the fault arc resistance and the fault location on the DC line on the arcing time is presented. Finally the impact of the changing of fault resistance value on arcing time and the damping resistance influence on the transient recovery voltage is also investigated. Additionally, the initial transient interruption and the metal oxide varistor voltages are analyzed.

When short current is interrupted in three-phase vacuum interrupter in switchgear, the “U”-type loop composed of external busbar, conductive rod, and vacuum interrupter, and its adjacent phases will generate external actual transverse magnetic field (EATMF) in the interrupter. The existence of EATMF will deflect the vacuum arc, which will affect the breaking performance of vacuum switch. In view of this situation, this article establishes two kinds of electrode system simulation models considering and not considering EATMF. The simulation results show that EATMF is not uniformly distributed in the interelectrode region, but is stronger in the contact cup edge area outside the “U”-type loop, weaker in the “U”-type loop, and mainly affects ${B} _{x}$ . In different short-circuit cases, EATMF is also different due to the difference of phase distance and short current. In the case of three-phase short circuit, the magnetic field in the interelectrode region of the middle phase is most significantly affected by EATMF. EATMF is closely related to the structure size of vacuum switch. By changing the structure size of vacuum switch (e.g., phase spacing ${d}$ , conductive rod length ${h} _{1}$ , ${h} _{2}$ ), EATMF can be weakened to some extent.

In this paper, the current limiting and the interrupting operations of the flux-lock type superconducting fault current limiting interrupter (SFCLI) using the mechanical switch (MS), which could be driven without additional driving power source, were analyzed. The operational principle of the suggested SFCLI is the same as one, except that the MS performs the fault current interrupting operation, driven by the electromagnetic repulsion force generated within the driving coil without the additional driving power source. Furthermore, the interrupting operation of the MS directly, after the current limiting operation of this SFCLI, can contribute to the improvement of the previous SFCL's performance. To verify the operational characteristics of the suggested SFCLI, the MS with the fixed plate (FP) and the moving plate (MP), which were located just above open round bobbin wound by the driving coil, was designed and manufactured. The short-circuit tests of the SFCLI using MS were carried out. Through the analysis on the results of the short-circuit tests, the current limiting and interrupting operations of the flux-lock type SFCLI using the MS could be confirmed to be effectively performed without the additional driving power source.

Nowadays, high voltage circuit breaker (CB) simulations are mostly based on Computational Fluid Dynamics (CFD) models. Such simulations require significant computer resources. An alternative approach is to use enthalpy flow models, which do not use space discretization of the interrupter unit chambers and valves. Gas flow is calculated based on state of gas in adjacent chambers and valve settings. However, the valve shape has significant influence on the effective flow cross section between chambers. Therefore, in order to ensure correct simulation results, it is necessary to determine the correct values of discharge coefficients for all valves in the interrupter unit of a circuit breaker. In this paper, the discharge coefficients were determined by combining a series of CFD and enthalpy flow simulations for each valve in the interrupter unit. After that, discharge coefficients are used as input for further simulations based on the enthalpy flow model. This way, benefits from both models are combined: more precise gas flow calculation and faster simulations. The proposed novel approach is validated in a high-power laboratory by pressure measurements on a 420 kV 63 kA self-blast circuit breaker.

The medium-voltage dc (MVDC) interruption technology has grown in recent years, driven by increased interest in using MVDC system for integrating distributed renewable energy and improving the efficiency of power supply. In this paper, two topologies of current injection MVDC breaker are focused on. The first topology is based on conventional precharged capacitor that utilizes a bridge-type commutation branch to realize the freewheeling for the interrupter and bidirectional breaking. With the help of simulation, the effect of stray inductances on the current commutation capability is analyzed in detail, and then, a prototype of the MVDC breaker is built to test the fault current breaking performance. The second topology is an improved MVDC breaker based on magnetic induction current commutation module (MICCM). With MICCM analyzed carefully in terms of circuit and structure parameters for determining their optimal values, the prototype of the improved 10-kV dc breaker is built and tested, which validates the feasibility and effectiveness of improved topology.

Current injection circuit breakers consist of a mechanical interrupter (MI) with a current injection and an energy dissipation branch in parallel. The performance of the complete device is largely determined by mechanical operation time and interruption performance of the MI. In the standard configuration, current injection is realised using a pre-charged inductor– capacitor circuit. A higher interruption performance of the MI makes it possible to scale down the resonant injection circuit, and thus have a more economical design. Additionally, the implementation of more complex injection circuits that quickly create zero crossings, while maintaining favourable conditions for interruption, can lead to economic benefits. In this study, the interruption performance of a model gas interrupter as part of a current injection topology is investigated. The results are used to verify a corresponding simulation model and two-dimensional upgrade circuits that influence the injection current to increase the range of interruptible fault currents. On the basis of experimental results, the simulation model is used to investigate the performance of upgrade circuits for the use in high-voltage direct current (HVDC) systems. The results indicate that using improved injection circuits can considerably increase the economic advantage of current injection circuit breakers compared with other topologies., High Voltage, 5 (3), ISSN:2397-7264

A force sensor design utilizing a photo-interrupter is presented for measuring the static coefficient of friction (COF). The measurement of ice friction on polymer surfaces, a process that requires detecting forces in the sub-Newton range, is chosen for the study. The photo-interrupter is coupled with a specially designed sensitive flexure, with structural parameters validated through finite element methods, to detect the small forces. The static properties of the sensor are characterized by calibration techniques. An accompanying rotary table is constructed to measure the COF of ice on polymethylmethacrylate (PMMA) and polyester specimens under refrigeration conditions. The experimental results indicate that the device can be utilized to predict the COF. The designed portable and miniature friction measurement setup can be a compact and cost-efficient alternative to bulky tribo-rheometer equipment.

This paper considers the output short-circuit protection of a Series-Parallel (S-P), switched capacitor converter for interfacing high-power PV farms and/or MV DC micro-grids. A so-called active interrupter can be used to isolate the converter from the fault; however, the inductor associated with this interrupter can used as the resonant inductor for the circuit, offering potential savings in inductor size/weight/cost and losses. A number of alternative S-P topologies were devised, which were compared against the existing circuit. Results from a scaled hardware prototype are presented, which highlights a number of practical issues related to circuit parasitcs.

Electric arcs caused by damages in wiring and electrical connections of an installation may result in fire. Conventional protection devices, such as circuit breakers, fuses and residual-current circuit breakers (RCCBs) are not capable of detecting this disturbance. New equipment, such as the Arc Fault Devices Interrupter (AFDI) have appeared in the last two decades with the purpose of meeting such demand. However, their application and efficiency are still restricted due, mainly, to the masking deriving from disturbances generated by some types of charges present in the power grid. Making such detection more robust and accurate is not a trivial task and, therefore, new methodologies have been developed in recent years. Considering such context, the purpose of this work is to assess the disturbances caused by serial arc faults through experimental tests and use of Wavelet Transform (WT) on the detection of the phenomenon. Based on the results, it was possible to develop a sorting model that produced very satisfactory outcomes. The model was developed through concepts of the support vector machine (SVM) and presented average accuracy around 90% even in critical detection situations.

We know that solar heat can be used as one of the natural resources that are still very abundant on earth and can be used as a new source of energy or better known as solar cells and power plants that use solar cells are generally still static. Therefore we need a mechanical system that can move the position of the solar panel so that it can move according to the position expected by the use of solar panels to get energy from the sun. Arduino Uno serves as the control center of all systems built and tools. in moving the solar panel using Askremote control to give orders to the L298 module as a controller of the dc motor so that the dc motor can move according to the design and construction of the system embedded into the Arduino and the Photo Interrupter functions as a barrier to the movement of the dc motor.

International audience; Circuit protection is a key enabler for future medium-voltage direct-current (MVDC) distribution systems. Hybrid dc circuit breaker (HCB) offers low conduction losses and reasonably fast response times, but suffers from large size. In this paper, a high power density power electronic interrupter design is introduced for the HCB. The device selection and tradeoff analysis of voltage clamping circuit are investigated. A small sized module with two parallel 1.7 kV discrete IGBTs are selected as main switches. The RC snubber and MOV are carefully designed to guarantee no tail current bump and sufficient turn-off voltage margin. Experimental results at 12 kV and 1 kA are provided to verify the operation of the prototype.

International audience; The power electronic interrupter (PEI) is a key component of the dc hybrid circuit breaker (HCB) as it facilitates the arc-less opening of the mechanical switch by taking over the fault current during the interruption process. A modular implementation of the PEI enables design scalability allowing the use of high peak current density discrete IGBTs in a seriesparallel configuration as needed for the maximum transient voltage and peak fault current levels seen by the system. In this paper, surge current turn-off experiments are conducted on discrete IGBTs to determine the limiting factors for fault current interruption. Experimental data are provided to show IGBT performance under two different PEI module configurations and identified failure modes are discussed along with main design tradeoffs.

This paper presents results of experimental studies the effect of changing operating temperature on the operating mode of thyratron-type gas-discharge current switches in a scheme with inductive energy storage. Analysis of the obtained results made it possible to establish that the average settling time in the continuous-frequency mode for such type of switches is 20–25 min. Based on the distributions of the surface temperature on the functional units of the devices over time, it can be seen that the degree of anode, grid and cathode nodes heating increases towards the anode node at U m ≥30 kV, at U m ≤30 kV heating degree increases towards the grid and cathode nodes, due to changes in the ratio of switching losses and conduction losses. In the new gas- discharge current interrupter, it was possible to reduce the heating of the grid node by an average of 15-20%, while a temperature change by 70°C leads to a 2-fold increase in a critical charge.

BACKGROUND Noninvasive respiratory support continues to have high failure rates in small preterm infants. We previously demonstrated significantly improved in vitro CO2 washout by applying oscillations to a high flow nasal cannula system. OBJECTIVE To develop a high frequency flow interrupter that could be applied to commonly used nasal continuous positive airway pressure (NCPAP) devices and to determine the effect of oscillations on end-tidal carbon dioxide (EtCO2 ) levels in an infant lung model. DESIGN/METHODS NCPAP was applied to a premature infant lung simulator using either bubble (BCPAP) or variable-flow (VCPAP) CPAP. Supply gas was interrupted with a solenoid pinch valve. EtCO2 was measured before and during oscillation and repeated at 4, 6, 8, 10, and 12 Hz oscillation and CPAP pressures of 4, 6, and 8 cm H 2 O. RESULTS BCPAP and VCPAP EtCO2 levels decreased with oscillation (P

Vacuum circuit breakers are well established in the distribution levels of the electrical power grids. To maximize the short-circuit interruption performance, an radial magnetic field (RMF)-contact design forces the arc from a fault current to rotate. The performance of the RMF-contact designs is usually evaluated in a model vacuum chamber with viewing ports that allows observing arc rotation with the help of high-speed cameras. These setups differ significantly from lifetime sealed vacuum bottles in geometry (and thus volume) and due to the fact that the main metallic vapor shield cannot be present. This, in turn, can affect the arc rotation behavior. In order to overcome these shortcomings, a new diagnostic tool has been developed to analyze the arcing behavior in standard lifetime sealed vacuum interrupters. Optical methods are not possible here, since the view is blocked by the opaque ceramics and the metallic vapor shield. For this reason, a Hall-sensor-based measuring system is applied, in which the variation in the magnetic field from the arc position is observed by multiple sensors. This paper presents the comparison of arc motion in lifetime sealed vacuum interrupters with different bottle geometries. For this purpose, investigations with identical spiral-shaped RMF contacts inside different vacuum bottle designs with differing vacuum volumes are performed. Also, for comparison, an interrupter with contrate cup contacts was investigated. Similarities and differences between the corresponding arc motion behaviors are discussed.

Mechanical circuit breakers (MCBs) are the limiting component for current injection HVDC circuit breakers. Improving their interruption performance reduces requirements for capacitance and inductance needed in the injection circuit and thus space use and costs. Higher performance can be achieved by creating a period of low current gradient before zero crossing in the MCB, e.g. by using a saturable inductor (SI). In this paper, the impact of duration and steepness during the low current-gradient phase is linked to arc parameters of the investigated model gas circuit breaker. It is shown in a scaled experimental setup that an optimum design of the SI can be derived from arc time constant and interruption limits for constant current gradients. This optimisation results in a considerable increase of interruption performance. The feasibility of implementing an SI in a full-scale HVDC circuit breaker is demonstrated using simulations. Using an improved injection scheme, the stresses for the MCB can be reduced significantly. Consequently, the injection circuit components can be scaled down, making the topology more economical. The reduced interruption requirements might also make it possible to use a single gas interrupter instead of a series connection of vacuum interrupters, reducing the complexity of the mechanical switch.

To reduce the operation power of the circuit breaker interrupter, here, the operation power is divided into two parts: the arc reaction force and kinetic energy of the moving parts, then the reaction force and the reactive force work calculation method are put forward. Based on the above method, the operating power of the original structure and the improved structure of the interrupter are obtained, and the comparison of the results shows that the improved structure can reduce the operating power.

The hybrid high-voltage direct current (HVDC) breaker combines mechanical and power electronics switching that enables it to interrupt power flows within a few milliseconds. Mechanical switch is a key component of hybrid HVDC breaker and has a number of serially connected interrupter units which ideally would divide the voltage equally. The static voltage distribution characteristics and voltage sharing design of a multi-break mechanical switch were discussed in this study. A finite-element model was developed to study the static voltage distribution characteristics and capacitance parameters of multi-break mechanical switch (which actually consists of resistance and capacitance parameters under direct current) as a preliminary study. Comparisons were made under the simulation of vertical and U-shaped arrangement forms. The results indicate that the static voltage distribution of the high-voltage terminal is at least more than 65%, whereas the severe non-uniform voltage distribution can be well improved by means of the method proposed in this study.

W artykule opisano autorski sposób pozwalający na określenie rzeczywistej wartości ciśnienia w próżniowej komorze rozłącznikowej SN podczas wysokonapięciowych badań laboratoryjnych. Konieczność opracowania metody tego typu wynikła z braku możliwości pomiaru ciśnienia bezpośrednio w komorze próżniowej w trakcie badań. Istniało bowiem ryzyko uszkodzenia próżniomierza w wyniku przeskoku elektrycznego. Proponowana metoda polega na pomiarze w warunkach beznapięciowych różnicy ciśnienia pomiędzy zestawem pomp próżniowych, a prototypem komory próżniowej wykonanym dla potrzeb realizacji tej metody. Dzięki temu znając wartość ciśnienia przy pompach oraz mając wyznaczone charakterystyki skalowania układu, w trakcie badań wysokonapięciowych możliwe będzie określenie rzeczywistego ciśnienia wewnątrz badanej rozłącznikowej komory gaszeniowej SN. Przeprowadzono pomiary spadku ciśnienia w kanale pompowym dla powietrza oraz trzech gazów elektroujemnych: helu, argonu oraz neonu, wykorzystywanych w badaniach przez autorów niniejszego artykułu.

In the community setting, assessing spirometry in school-aged children is often limited by the unavailability of respirology technicians at the point-of-care. We developed a new technique called the Rapid Expiratory Occlusion Method (REOM) that measures respiratory resistance during normal breathing, without specialized training. The aim was to examine the concordance between respiratory resistance measured with the REOM and respiratory resistance measured by oscillometry on the tremoflo. Children aged 6-17 yr, with or without asthma, received respiratory resistance testing on the tremoflo, then on the REOM. Three to five replicates with a coefficient of variation ≤15% were obtained on each instrument; the primary outcome was the concordance between the average respiratory resistance on the REOM and that measured at 5 Hz (R

This research paper presented a design that will address the challenges brought by remanence in ground-fault current interrupter devices (gfci). Remanence or residual magnetism is the magnetization left behind in a ferromagnetic material (such as iron) after an external magnetic field is removed. Remanence will make the gfci devices less accurate and less reliable in tripping the current above threshold in just five (5) years. It affects the performance of the device in terms of efficiency, accuracy, and response time. In this research, the problems caused by remanence were alleviated by using two identical transformers in detecting residual current both for hot and neutral wires. The difference of the current detected by the two transformers will be the basis of the signal threshold in tripping the device. By doing so, the problems caused by remanence phenomenon will be solved without compromising the response time of the circuit which is around 16 mS. The design will extend the life span of GFCI devices up to 15 years.

This paper describes aspects of switching capability of 126 kV SF6 puffer and auto-puffer interrupter types of circuit breakers during breaking of aperiodic current (DC component) resulting in such phenomena as missing current zero. It is shown that neither IEC/ANSI standards nor other technical brochures have requirements for circuit breakers in the condition of missing current zero. The review of 126 kV SF6 circuit breakers failures, operation problems and experimental data obtained during operation cycle on the substations in Russia are given. Experimental characteristics of pre-strike voltage for 126 kV SF6 circuit breaker at different filling pressures are shown. Current oscillograms of 126 kV SF6 circuit breakers failures related to missing current zero are presented. Simulation results of gas dynamic and thermal characteristics in condition of missing current zero are shown. The general countermeasures against prevention of circuit breakers failures related to missing current zero are given. This paper is the first part of the present research.

The DC circuit breaker is used to realize fault isolation and clearing of the DC system, and is an essential core equipment for the DC distribution network. The principle of the mechanical DC circuit breaker is to generate the medium frequency oscillating current by LC and reversely inject into the main circuit to form a current zero crossing point, and then complete the breaking by the AC circuit breaker. Since the design of the DC circuit breaker involves the design of the circuit topology, the design of the interrupter, the design of the operating mechanism, and the design of the final assembly. The process is very complicated and the workload is very large, and it is urgent to standardize, integrate and simplify the design process. This paper first analyzes the steps of mechanical DC circuit breaker design, and then plans the function of the virtual design platform according to the design steps. Finally, the method of contact design of the arc extinguishing chamber is described.

As a result of studies of a new gas-discharge current switch in a nanosecond voltage pulse generator, the megawatt power managed to achieve the following operating parameters. The pressure range when the device operated in the break current mode was 30 Pa - 45 Pa; the rise time range of the leading edge of the voltage pulse varied from 30 ns to 100 ns; the minimum recorded value of this parameter was 30 ns. The limit of the generator output voltage with the new device was 70 kV; the limit value of the switched current was 600A.

The Safety and Arming Device (SAD) is the essential component that prevents fuze arming until specific conditions have been achieved. The core principle of safe and arm mechanism is the interruption of energy transfer, usually explosion, laser, or high-speed flyer, with a movable interrupter. In the present research, we propose the design and characterization of two kinds of MEMS based on-chip SAD, the bidirectional SAD and the rotary SAD respectively. Part I, the bidirectional SAD is the initial mode of our SAD project, which reflects the design methodology of resettable disarming process, the large travel range of slider, 0 energy consumption of motion retention, and the foray into the programmability of SAD. In this part, the width of each tooth on the slider (interrupter) corresponds to the specific decoding voltage, 13.5V and 14.8V, respectively. And a firing test has been carried out to verify feasibility of the SAD for the application in microfuze. Part II presents the upgraded mode based on Part I, the bidirectional slider has transformed into a rotary gear, the control signal has decrease from 4 signals to 2 signals, and discrimination mechanism has been realized through the trap set in the teeth of gear. In addition, to verify the feasibility of application, the endurance of random vibration has been tested.

SF6 is widely used in the industrial field due to its stable structure and excellent properties. It is mainly used in electrical insulation equipment. Due to the boiling point of SF6, its use in extremely cold regions has been limited. It is harmful to the health of practitioners due to the toxicity of decomposition products. The gas has limited its wider use because of its strong greenhouse effect. As a result, researchers and electrical equipment manufacturing companies around the world are gradually searching for new environmentally friendly gases and have conducted research and exploration on theory and experiment. In this paper, the current status and existing problems of SF6 are summarized. The research contents and research methods of SF6 alternative gas direction are reviewed from the aspects of insulation performance, interrupter performance, and decomposition performance. The existing research results of the natural gas, SF6 mixed gas, perfluorocarbons, and CnFmX gas are summarized, and the future development trend of alternative gas for SF6 in the electrical industry is proposed.

Internet of Things (IoT) is a very relevant technology used by internet networks to send and receive sensed data via a sensor. The same relates to common data communication except that sensors and microcontrollers are commonly used in IoT. It is supposed to explore, and there will be developing interest in the IoT framework which gives frequent IoT system capabilities. It connects us to the Internet and also helps us to reveal and manage the actual world by using sharing its info. IoT systems make use of real-world data, so device-collected data may also be a tool for cyber attack. The attack surface also expands as IoT expands and all the vulnerabilities present in the digital world flow through our modern world. DDoS attacks built on compromised IoT systems emerge as a serious problem. There are many technological solutions, but technology has changed a lot, so software solution can be in risk as well. The proposed system will serve as a prevention tool for DDoS attack and send the admin an alert when an attempt is made to hack the IoT device. In this proposed system, intend to provide a highly secured platform that will clean out all the unnecessary data without disrupting IoT’s normal operation.

Here, we present a novel experiment on the yet unstudied phenomenon of ASC adults' responses to interruption, using a robot role-play clerical task. Using an IQ, gender, and task parameter matched NT control sample, we found that adults with ASC experience marginally less task disruption from a robot interrupter comparatively to a human. We surmise that robot-assisted therapy for adults with the condition is a potential research avenue worth further exploration.

В данной работе проведен анализ системы электроснабжения Санкт-Петербурга, целесообразность разработки элегазового выключателя на данных параметры. Проведен анализ конструкций элегазовых выключателей 330 кВ, 63 кА и их технических характеристик. Показаны недостатки рассмотренных выключателей. Рассматривается конструкция дугогасительного устройства с одним разрывом с использованием шунтирующего резистора и емкости. Разработана расчетная модель дугогасительного устройства. Расчетная модель подготовлена с использованием программного пакета PTC MathCad 15. Приведены результаты численного эксперимента характеристик выключателя. Проведен анализ влияния шунтирующего резистора и шунтирующей емкости на ПВН. Показана возможность применения их в выключателе. Была произведена координация изоляции дугогасительного устройства элегазового выключателя. Расчетная модель была построена в пакете comsol multiphysics. Построены эпюры распределения напряженности электрического поля, определены области с наибольшими значениями напряженности электрического поля. На основании полученных результатов, были приняты меры для успешного отключения емкостных токов., In this thesis, we analyze the power supply system of St. Petersburg, the feasibility of developing a gas-insulated circuit breaker for these parameters were analyzed. The analysis of the designs of gas-insulated switches 330 kV, 63 kA and their technical characteristics are carried out. The disadvantages of the considered switches are shown. The design of an arc control device with a single gap using a shunt resistor and capacitance is considered. A design model of the arc control device has been developed. The calculation model was prepared using the PTC MathCad 15 software package. The results of a numerical experiment of the circuit breaker characteristics are presented. The analysis of the effect of the shunt resistor and the shunt capacitance on the arc control device is performed. The possibility of using them in a switch is shown. The coordination of the insulation of the arc control device of the gas-insulated circuit breaker was made. The calculation model was built in the comsol multiphysics package. Plots of the distribution of the electric field strength are presented, the regions with the highest values of the electric field strength are determined. Based on the results, measures were taken to successfully disconnect capacitive currents.

The work presents experimental study results of gas discharge interrupter with a sector hole in the screen and a circular grid hole being asymmetrically placed regarding central axis as part of a high-voltage pulse generator with inductive energy storage. According to the results received the device under consideration managed to decrease minimum turn-off time by 6 times up to 30 ns compared to a switch with inverse hole pattern in a grid node. Limiting pulse voltage amplitude is fixed at the level of 50 kV, peak pulse power increase up to 13 MW is achieved.

Multi-interrupter in series is the only way for high voltage circuit breaker to develop Ultra high voltage levels. It is especially important for multi-interrupter in series to keep synchronization in breaking, but synchronous breaking of multi-interrupter is relative, and asynchronous breaking is absolute, so the conception of limited asynchronous breaking is brought up in this paper. Research on the compensation of dynamic dielectric recovery based on active asynchronous, and make each vacuum circuit breaker (VCB) has a different instantaneous gap length at current zero-crossing, to realize active compensation for dynamic dielectric recovery. In this paper, the model of post arc resistance will be established by ATP DRAW within the research of VCB with triple-interrupters as background, research the limited asynchronous breaking and the dynamic dielectric recovery characteristics of the various interrupter by adjusting the breaking time of the VCB, and the gain analysis of insulation breakdown voltage is analyzed. At last, the module of double-break VCB is established, and the correctness of simulation results is proved by tests.

The arc temperature profile in an interrupter, which determines the extinguishing characteristic of an SF6 circuit breaker (CB), is of interest to designers and developers. In this investigation, optical fibres and spectrograph were employed to measure the arc temperature profiles in a 252 kV SF6 CB during short current interrupting. The temperature profiles of the upstream, throat, and downstream of the nozzle have been measured. The optical fibres can transfer the arc light from the measuring points in the nozzle to the spectrograph. Moreover, the spectral line intensities of copper (Cu) 510.5, Cu 515.3, and Cu 521.8 nm were obtained by the spectrograph. The condition in CB can be treated as a local thermal equilibrium system, and the temperature profiles can be calculated by two-line method and Abel inverse method. The arc temperature profiles of the interrupter under 15–50 kA root mean square current have been analysed through the method established in this investigation.