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Further considerations are given to the use of an electromagnetic flux concentrator for arc plasma control in a rotary arc current interrupter. Such flux concentrators have been previously proposed for plasma fusion and other plasma applications. The possible extension of the proposed method for enhancing the interruption of direct currents with a rotary arc interrupter is discussed with the aid of theoretical modeling of the concentrator geometry and with its possible enhancement of ablation from the arc containing cylinders.

Functional and safety tests for lithium-ion batteries used in industrial applications are essential. Fig. 8.3 shows a diagram of such batteries. The battery consists of individual cells interconnected to form modules. Several modules are then also interconnected inside the battery itself. The battery also features a cooling circuit. A deaeration system evacuates gases during cell outgassing. The battery housing contains the battery management system (BMS) and the circuit interrupter.

In young children unable to perform reliable and reproducible spirometry, non-cooperative lung function techniques are necessary to measure bronchial hyperreactivity (BHR) during bronchial challenge [1]. Measuring the decrease in transcutaneous partial pressure of oxygen (PtcO2) is a robust technique that detects increased ventilation–perfusion mismatch during bronchial challenge [2] in preschool and school-aged children [3–5], and a 20% decrease in PtcO2 correlates to a 20% forced expiratory volume in 1 s (FEV1) decrease in children aged 6–14 years [3] and in adults (with correlation to arterial oxygen tension) [6]. When neither spirometry nor PtcO2 is available, other BHR outcomes can be measured such as wheezing that appears for mean±sd decreases of −44.7±14.5% in FEV1 and −6.3±2.7% in transcutaneous saturation of oxygen (SpO2) [7]. Respiratory resistances are easy to measure [8–10] but the relevant threshold for BHR is not yet defined and an at least 35% increase variably correlates with PtcO2 changes [8, 11]. First, we aimed to better study two alternative outcomes (i.e. interrupter resistance (Rint) and SpO2) and challenge the current recommendations [1] of measuring resistance during inspiration (as opposed to measuring during expiration for reversibility testing [12]), because the physiological expiratory glottis closure can be enhanced during bronchial challenge-induced bronchoconstriction and specific extrathoracic airway reactivity to bronchoconstrictor agents can occur. Second, we wished to evaluate the proposed thresholds for Rint and SpO2 (+35% and −5% baseline, respectively), as only a 3% decrease is considered to be significant in sleep studies and a mean±sd SpO2 decrease of −5.2±3.1% corresponds to a much larger than 20% decrease in FEV1 in 5–8-year-old asthmatic children (−33.3±7.4% decrease in FEV1) [13]., Inspiratory Rint better detects BHR than expiratory Rint and might better match PD20PtcO2 changes http://ow.ly/TrMvB

This paper employs the discrete wavelet transform (DWT) and an artificial neural network to identify the occurrence of serial arc faults on indoor low voltage power lines. Electric arc faults on power lines must be detected in order to turn off the electric power sources before fire events occur. However, since the characteristics of line current waveforms during serial arc faults are complicated, smart detection technology is required to have high accurate recognition. The DWT is utilized to obtain the time-domain characteristics of line current waveforms, and the signal energy of some sub-bands is useful information to reflect the serial arc fault patterns. And then, a radial basis function neural network (RBFNN) is trained by using the data of signal energy obtained from DWT. After the training process, the RBFNN has excellent ability to identify the serial arc-fault conditions. At last, the accumulative RBFNN outputs of 30 power cycle line current data are used to certify the occurring of a serial arc fault on the line. This study also compares the results of detecting serial arc faults with a commercial arc-fault circuit interrupter (AFCI) to reveal the goodness of the purposed method.

In order to avoid the electrical fire, AFCI(Arc Fault Cirruit Interrupter) has been obligated to be adopted in the United States of America since 2002. A study was carried out on how to detect Arc. In this paper, The propose is high-frequency signal detection methods and RSSI(Received Signal Strength Indication) signal processing algorithm for Arc detection. and the electrical characteristics were verifying.

In this article, large capacitor charging and discharging experimental system is utilized to generate 270V DC-current by pre-charging to the large capacitor and discharging. Interrupter switching experiments of 540A, 1800A are done in aviation environment, and results of arcing breakdown manner are analyzed and explained. The experiment results indicate that 270V DC-current and arc in aviation environment can be broken by the way of using IGBT in appropriate time; In aviation environment, the breaking capability can be improved, and arcing breaking manner can be used to estimate the arc time constant by several experiments.

Historically, Class A Ground-fault circuit interrupters (GFCIs) have been responsible for a substantial reduction in residential electrocutions. Yet they have not had much success in industrial applications because of the limitation on system voltage (maximum 240 V) and the 6-mA maximum allowed leakage current. As a result, industrial personnel protection has been lagging behind its residential counterpart. UL realized this gap and defined new GFCI classes to specifically address personnel protection in industrial applications. UL 943C defines the requirements of special-purpose GFCIs that can be used on systems up to 600 V and allows for a leakage current of 20 mA. This article describes the UL 943C requirements and the newly defined GFCI classes. The difference between equipment ground-fault protective devices (EGFPDs) and GFCIs is also addressed. Finally, the application of a Class C GFCI in a pulp and paper plant is described.

Research and development are currently being performed to transform the US's utility electric grid into a “smart grid [1], [2].” Smart meters are among the first intelligent metering devices used within the “smart grid” concept. They have been deployed in thousands of commercial and residential electrical installations around the US [3], [4]. While the wide-scale deployment of these devices has initially proven very successful, there is still much that is unknown about how they will impact the long-term operation of a large utility grid or the electrical devices sourced by them [5]. One such device, whose operation appears to be impacted by the smart meter, under specific conditions, is a ground-fault circuit interrupter (GFCI). It has been reported that the RF transmissions from smart meters can induce false tripping events on GFCI outlets installed on temporary construction poles. In an effort to understand why this may happen, a research study, which is presented here, has been performed to understand the correlation between RF transmissions and GFCI tripping events on construction poles.

A type of magnetic blow-out equipment is designed for air DC circuit breaker in this paper since it is difficult to break small currents. This equipment is composed of field coil and some magnetic plates which is made of iron to supply vertical and approximately uniform magnetic field for arc running zone in the interrupter without influencing performance of the main current circuit. The arc can be driven to the arc chute by the magnetic field and the arc stream can be cut and stretched which leads to the persistent rise of arc voltage. Finally the current of arc drops to zero and air DC circuit breaker breaks small current successfully. The magnitude and distribution of magnetic field result from the blow-out equipment is calculated in this paper by means of finite element analysis and the results has been proved by experimental investigation. To achieve the goal of breaking bidirectional small currents the equipment adopts system power supply of the contact fracture of air DC circuit breaker. There is a capacitor in parallel of the field coil and AC contactors in series. The design of control loop is beneficial to break out excitation circuit after the breaking of arc between the moving and fixed contacts and restrain transient overvoltage of high frequency to avoid burning of field coil. Lastly experimental investigations are done to prove the performance of the equipment. It can be concluded that magnetic equipment for arc driving is helpful for pulling-out of the arc and there exists a critical current which leads to a longest time of arcing. Beyond that, arcing time increases and breaking performance decreases when residual magnetism of magnetic material is considered when breaking bidirectional currents. This paper is meaningful for air DC circuit breaker to pass the testing item of “Search for critical currents and low current test duty” described in IEC standards.

In recent type tests, a 252kV SF6 self-blast circuit breaker re-ignites several times after interruption. In order to solve this problem, through CFD simulation of the gas flow field in the interrupter on load, the pressure, temperature and velocity after current zero are analyzed carefully. The conclusion is that, due to the upstream pressure decreased quickly after current zero and will lower than downstream pressure, the downstream hot gas returns to the upstream resulting in the re-ignition. Based on CFD simulation two optimal structure is proposed, and is verified by simulation.

In order to research the interruption process of vacuum circuit breaker in aviation intermediate-frequency (360Hz∼800Hz) power supply system, vacuum arc experiments are carried out in interrupter with the diameter being 41mm and with the contact material being CuCr50 alloy. It can be indicated from the results as follows: With the increase of frequency and peak value of the current, both the peak value and the rise rate of the intermediate-frequency vacuum arc voltage increase, and the interruption ability decreases. However, the erosion of contacts is weaker for a shorter arc time, comparing to the power frequency current in the same value. When the vacuum arc reignites0, metal droplets are emitted from the contacts. The drive force is from the center of the contact to edge. If the density of plasmas and metal vapors and the numbers of the metal droplets come to a certain level, the arc may be broken down, which cause the interruption failed.

In order to improve the breaking performance of the ultra-high voltage SF 6 circuit breaker, an optimal design scheme for increasing the straight line length of the nozzle throat is proposed. Based on the numerical simulation of the gas flow field in the optimized structure of the interrupter, the influence of the straight line length of the nozzle throat on the breaking performance of the circuit breaker is studied, and the breaking performance of the optimized structure of the interrupter is verified by breaking test. The results of simulation and experiment show that increasing the straight line length of the nozzle throat can improve the breaking performance of the circuit breaker effectively, which is of great significance for the research on the influencing factors of breaking performance of ultra-high voltage SF 6 circuit breaker.

Recently, the self-blast principle of extinguishing the arc by the blast pressure which is generated by the arc itself has been widely applied to the high voltage circuit breaker. In the self-blast principle, the pressure relief valve fitted on the piston is opened to release excessive pressure in the compression volume during high current interruption. The design of the pressure relief valve operation is important for the performance of self-blast interrupter. Practically, the pressure relief valve is actuated by spring force and designed to open when the overpressure becomes greater than the designated operating pressure difference. In this paper, the actual pressure measurement result of the compression volume to understand the movement of the pressure relief valve are presented. The analytic model which describes the movement of the pressure relief valve are proposed, and the effects of different pressure relief valve models are analyzed by gas flow simulation tools.

Aiming at the phenomenon that the arcing time is different when SF6 circuit breaker interrupts capacity current under the conditions of positive and negative polarity. So the capacity current breaking test by SF6 circuit breaker is used to study it, which can provide reference for the optimization of SF6 arc extinguishing chamber. In this paper, the interrupter structure of test prototype is introduced. Electrode reversal is analyzed when the static parts of SF6 circuit breaker is connected with capacitive loads. According to CB2 in GB 1984–2014, The back-to-back switching capacitor group test is completed in the 40.5kV SF6 self-circuit breaker prototype. Opening speed of test prototype is 3.85m/s. The main test parameters are as follow, closing surge peak is 26kA, inrush frequency is 4050Hz, the valid values of opening current is 826A. In the condition of positive and negative polarity, 83 times CO operations are completed in test prototype. The test result is that restrike did not occur. When the static part of breaker is connected with capacitive loads, the short arc time under the negative polarity condition is longer than that of the positive polarity. And the short arcing time is 0.9ms and 1.6ms, respectively. The results indicate that the 40.5kV self-energy SF6 circuit breaker can meet the requirements of power system to switch capacitor group. The polarity effect is existed in slightly uneven electric field inside of arc chamber. The short arcing time is longer when static arc contact is cathode during current-zero zone.

High voltage circuit-breakers switching shunt reactor is ascribed to small inductive current interruption. What's more, circuit-interaction between the breaker interrupter and the surrounding circuit can result in transient voltage with high amplitude and high-frequency, which is a great threat to the power grid. Particularly, the re-ignition overvoltage of Ultra-High voltage circuit-breaker will be very high on account of the large switching inductive current, therefore, it is very important to test and verify the inductive load switching capacity of the UHV circuit-breakers in the high power test station.

With the development of new energy, DC system is widely applied in urban rail, ships and other fields. H 2 -N 2 mixed gas switch has been one of the effective methods to interrupt direct circuit current for its large breaking capacity and small volume. In order to study the arc characteristics of H 2 -N 2 mixed gas switch, a detachable interrupter is designed. The arc voltampere characteristics of H 2 -N 2 mixed gas switch are obtained by experiments. Then DC arc characteristics and evolution are studied through arc appearances obtained by high-speed camera. Besides, the influence of electromagnetic drive on arc appearance and the arc motion are analyzed. It is indicated that the application of electromagnetic drive is beneficial to the arc movement of DC H 2 mixed gas arc and shorten the arcing time, which is favorable to arc extinguish during interruption.

The electric strength methods of insulating material are provided by the national standards but different methods may have different results. To solve the problems, the application conditions and the principles are researched by the standards, these electric strength methods for insulating material are compared and optimized through the simulation and the simulation results are verified through experiments. The test results show that the electrode shapes will affect the accuracy of the measurement value of breakdown voltage, and the results are reliable using spherical electrode and built-in electrode.

Arc faults are a fire-safety risk in both AC (alternating current) and DC wiring, but reliable detection of arc faults and determining the appropriate response is particularly difficult in DC plug-load circuits. This paper presents the development of AFCI lab setup to characterize DC arc current in DC circuits operating at 24-80 volts. The process to characterize the arc current utilizes the frequency spectrum of the arc current along with signal processing and a unique algorithm that allow us to develop an effective method to determine DC arcing occurrence. Once identified, an arc fault current interrupter circuit may then be designed to adequately eliminate the arc. Laboratory test setup and equipment for identifying DC arc will be described in this paper. Different scenarios for DC arcing occurrences in the development of the lab test setup will be explained. Several test results using the developed test setup to show the characteristic of arc current will also be presented.

Preinsertion resistors (PIR) are used in combination with circuit breakers to absorb switching transients and come into effect during the “closing” operation of the breaker. It is mainly used for rated voltages equal to or higher than 420 kV for line lengths above 200 km. Although it is an important component, power testing of complete PIR is very complicated and not well defined. Therefore, an attempt has been made in this paper to provide alternative test methods for power testing of PIR without compromising its important parameters. Due to high energy requirements and limitations of the test laboratory, a multipart testing of PIR is necessary to prove its thermal capability and dielectric behavior. Before proceeding with the complete PIR test, the critical parameters of PIR, such as mechanical insertion time, rate of decay of dielectric strength of the interrupter, and PIR switch, etc., should be verified with testing. These test procedures are also explained in detail along with a method to theoretically evaluate electrical insertion time for different network conditions. The series PIR configuration for the metal-enclosed ${\mathrm{SF}}_{6}$ system has been considered in this paper.

High voltage direct current circuit breakers (HVDC CBs) are necessary for reliable and safe operation of future multi-terminal meshed HVDC grids. So far no commercially mature products of such equipment exist. A few industrial concepts as a result of advances in power electronics have been proposed and prototypes have been built. However, performances of these concepts have never been demonstrated under realistic operation conditions. Since these tests require construction of high power DC sources incurring significant investment costs, alternative test circuits providing equivalent stresses must be considered. In this paper various test methods and circuits used for testing HVDC CBs are investigated and their performance is evaluated against the stresses in a conceptual future HVDC grid. A novel method of testing an HVDC CB using existing installations in a high power ac test laboratory is proposed and its prospective fault current and voltage is experimentally demonstrated. It is concluded that adequate test circuits need to maintain the supply voltage not only up to the current zero in the main interrupter unit of the HVDC CB, but also during the entire energy dissipation phase of the interruption process.

The controlled switch became a technical solution for reducing the switching stress. The controlled switching can be applied to any type of commutations. There are now dedicated controllers which are used more often for the switching of the transport and distribution lines, of the small inductive loads, of the capacitors batteries, or for energizing the no load power transformers. The paper deals with the simulation of the commutation of a transportation line by using the distributed parameters model. The controlled switch for fault interruption in transport and distribution lines is compared with the uncontrolled one, highlighting the major differences in what concerns the stress. The primary objective of controlled short-circuit interruption is to restrict the arcing time of the circuit-breaker and thereby seek to reduce the electrical stress and wear on the interrupter.

This paper presents finite element studies carried out on a porcelain insulator used in 420 kV SF6 live tank circuit breaker. For this purpose, porcelain interrupter insulator is modeled in axisymmetric domain as insulator is essentially rotationally axisymmetric. Electric potential and field distributions were studied in different environmental conditions along insulator leakage distance. Cases considered for this report include clean and dry insulator surface, wet insulator surface, sand covered insulator surface. All simulations were performed using the software Finite element method magnetics (FEMM) which uses finite element method (FEM) at its backend process. To get the electric field values at power frequency and lightning impulse voltages, results are extrapolated to specific voltage level and are specified wherever necessary.

In an increasing number of high-gradient linear accelerator applications, accelerating structures must operate with both high surface electric fields and low breakdown rates. Understanding the statistical properties of breakdown occurrence in such a regime is of practical importance for optimizing accelerator conditioning and operation algorithms, as well as of interest for efforts to understand the physical processes which underlie the breakdown phenomenon. Experimental data of breakdown has been collected in two distinct high-gradient experimental set-ups: A prototype linear accelerating structure operated in the Compact Linear Collider Xbox 12GHz test stands, and a parallel plate electrode system operated with pulsed DC in the kV range. Collected data is presented, analyzed and compared. The two systems show similar, distinctive, two-part distributions of number of pulses between breakdowns, with each part corresponding to a specific, constant event rate. The correlation between distance and number of pulses between breakdown indicates that the two parts of the distribution, and their corresponding event rates, represent independent primary and induced follow-up breakdowns. The similarity of results from pulsed DCto 12GHz rf indicates a similar vacuum arc triggering mechanism over the range of conditions covered by the experiments.

Future, large, multi-terminal HVDC networks are likely to require fast operating circuit breakers to allow stable operation. Several circuit breaker topologies have been developed for fill this purpose [1][2][3]. In this paper, a mechanical active resonant current zero topology DC breaker, capable of interrupting fault current within several milliseconds after tripping, is analysed. In this topology, it is critical that the mechanical interrupter unit is capable of withstanding both high di/dt prior to current zero and high dv/dt post current zero. The high frequency interruption capabilities of gas circuit breaker (GCB) and vacuum circuit breaker (VCB) are examined to assess their use for mechanical DC breaker applications. Comparison of the maximum di/dt capabilities demonstrated that vacuum interrupters are more appropriate for the task. The concept of residual plasma density at current zero was evaluated to explain the relationship between breaking current and di/dt capability.

With traditional circuit breakers, the interrupter capacity margin is insufficient. To increase interrupting capacity, the circuit breaker can be upgraded or a device can be installed to suppress the fault current, thereby correcting the small fault current margin. In this paper, the power dispatch method is used to suppress the fault current. Simulations are performed and summarized to show the best scheduling policy for increasing the breaker capacity margin to allow for safe operation of the system. Scheduling policies take advantage of existing equipment, so there is no need for any additional purchases for the system. The proposed method will be able to significantly reduce the fault current directly and effectively compared to traditional practices.

Dynamic elastic buckling behaviors of GFRP and Aluminum rods were experimentally investigated. In a gas circuit breaker of an electric power substation, an operating rod consisting of insulating materials is connected to an interrupter. The rod securely insulate between the interrupter and an operating mechanism. The rod is configured with a slender rod made of Glass Fiber Reinforced Plastics (GFRP). When the gas circuit breaker ends the opening operation, impulsive compression load acts on the GFRP rod. To develop a smaller and lighter GFRP rod, dynamic buckling loads of the rod must be studied. In this study, dynamic elastic buckling loads for slender GFRP and aluminum rods were investigated by an experimental method. The drop weight impact tests of the GFRP rods and aluminum rods were employed. In the testing device, a special load cell called the “Load Sensing Block” was used to measure the dynamic load of long time duration. Slender GFRP rods with various lengths were axially loaded at the impact velocities ranging from 0.75m/s to 4.5m/s. From the experimental results, an empirical criterion for the dynamic buckling load of the GFRP rod was proposed in terms of the impact velocity and the slenderness ratio. Furthermore, results showed the proposed criterion could successfully describe the buckling behavior of not only the GFRP rod but also the aluminum rod.

As the capacity of power facilities increases with the power demand, the fault current also increases in the case of a power system fault. Many studies are underway to limit the increasing fault current. They especially include superconducting fault current limiters (SFCLs). The existing SFCLs operate almost without loss because of their zero resistance characteristic in the normal condition, but limit the fault current by generating impedance in the event of a fault. However, this mechanism gives a significant burden on the SFCL. In this study, a high-speed interrupter and a normal conduction current-limiting unit were applied to the SFCL. In this structure, the current flows through the b-switch of a high-speed interrupter and the current-limiting element in the normal condition, but in the event of a fault, the current was bypassed to the current-limiting unit by the quench of superconducting units and interrupter switching operations. In this case, the magnitude of the fault current was covered by the SFCL, and after the switching operation, the current was limited by the normal conduction current-limiting unit. The results of this study showed that this structure reduced the power burden on the expensive superconducting element, and limited a high fault current that was initially generated from the fault.

A model of a disk-shaped explosive magnetic generator 400 mm in diameter with an initial energy storage capacity of about 40 MJ is considered. The generator is integrated with a cumulative current pulse shaper and is also equipped with a remote magnetodynamic interrupter. Calculations show that this generator is capable of forming current pulses with an amplitude of up to 20 MA and a rise time of about 130 ns in finiteinductance (∼10 nH) dynamic loads. This allows rapid (for about 60 ns) compression of light (20–30 mg) liners to generate intense beams of soft X rays. Results obtained using a computational model of the magnetodynamic interrupter, which is the key component of the generator, are verified experimentally.

The arcing processes of the short-circuit current with a significant dc component have been simulated under the long and short arcing time conditions, respectively, for an SF6 auto-expansion circuit breaker based on an MHD arc model. The influences of the dc component are investigated compared with cases where the dc component is negligible. The results show that the arc temperature, pressure, and radius as well as the pressurization in the expansion volume are increased significantly under the second current peak gone up by the dc component and long arcing time condition. However, the arc temperature at the final current zero becomes high in the current peak and is reduced by the dc component and short arcing time cases. Thus, the dc component would not be ignored in the interrupting investigation and in the design of the interrupter.

Sulphur hexafluoride (SF6) gas owns remarkable properties as insulation medium and current interrupter, which make it being widely used in gas-insulated equipment up to now. However, SF6 gas has a drawback that gives adverse effect to the environment since it is a strong greenhouse gas. As the effort to minimize the SF6 usage, this study was conducted to investigate the AC breakdown behavior of SF6/N2 gas mixtures with 10/90 ratio at low pressure levels (i.e. 0.11 MPa to 0.15 MPa) under non-uniform field (i.e. R0.5-plane and R6-plane electrodes configurations). The results of the study indicate that the breakdown voltage of SF6/N2 gas mixtures in non-uniform field increases linearly with the increase of gas pressure and electrodes gap distance. As a function of gap distance, a higher increasing rate of breakdown voltage values were achieved at lowest pressure of 0.11 MPa compared to other pressure levels. In addition, it is also found that a higher breakdown voltage values was obtained under R6-plane configuration. But, the difference in breakdown voltage values between R0.5-plane and R6-plane configuration is less significant as the gap distance is increased. It is also observed that the field efficiency factor of R6-plane is higher than R0.5-plane which indicates a more uniform field exists between the electrodes.

The transient pressure process in an interrupter, which determines the gas blasting characteristic of an SF6 circuit breaker (CB), is of interest to designers and developers. In this investigation, piezoresistive pressure transducers and thermally and electrically insulating tubes, which damped the reflection of the pressure waves, were employed to measure the transient gas pressure in a 252-kV puffer-type SF6 CB during no-load operation and fault current interrupting. The pressures of the puffer cylinder, throat, upstream, and downstream of the nozzle have been measured. The insulating tube can protect the pressure transducer from the high voltage and high temperature present during fault current interrupting. It is found that the reflection of the pressure wave inside the insulating tube will cause serious high-frequency oscillations, which superimpose upon the actual pressure waveforms during fault current interrupting. Filling the insulating tube completely with small polytetrafluorethylene (PTFE) particles can effectively damp the reflections and greatly suppress the oscillations. The pressure characteristics of the interrupter under 20-50 kA rms current have been analyzed through the method established in this investigation.

Hybrid circuit breaker (HCB) technology based on a vacuum interrupter and a SF6 interrupter in series has become a new research direction because of the low-carbon requirements for high voltage switches. The vacuum interrupter has an excellent ability to deal with the steep rising part of the transient recovery voltage (TRV), while the SF6 interrupter can withstand the peak part of the voltage easily. An HCB can take advantage of the interrupters in the current interruption process. In this study, an HCB model based on the vacuum ion diffusion equations, ion density equation, and modified Cassie-Mayr arc equation is explored. A simulation platform is constructed by using a set of software called the alternative transient program (ATP). An HCB prototype is also designed, and the short circuit current is interrupted by the HCB under different action sequences of contacts. The voltage distribution of the HCB is analyzed through simulations and tests. The results demonstrate that if the vacuum interrupter withstands the initial TRV and interrupts the post-arc current first, then the recovery speed of the dielectric strength of the SF6 interrupter will be fast. The voltage distribution between two interrupters is determined by their post-arc resistance, which happens after current-zero, and subsequently, it is determined by the capacitive impedance after the post-arc current decays to zero.

The paper answers the questions if it is possible to conclude in objective way on more (than one -Rint - in a classical IT) number of parameters from the time domain post-interrupter signals during the occlusional measurement of respiratory mechanics and also verifies what accuracy can be achieved in such attempt. To obtain reported results, the time-domain enhanced interrupter technique (TD-EIT) was developed in this paper using computer simulations. Three-stage scheme of work was assumed in the project. First, the quality of the model identification was assessed for various combinations of pressure and flow signals recorded during the interruption. Then, the correlation between the working characteristics of the interrupter valve and the precision of the parameter estimation were assessed for the TD-EIT algorithm. Finally, a verification experiment by forward-inverse modeling was organized, in which the mechanical characteristics of a complex model were mapped with reduced analogs and with the use of neural networks for three typical modes: 'Normal state', 'Airway constriction' and 'Cheeks supported'. Obtained results show that to became effective in time-domain post-interrupter data exploration, both pressure and flow signals should be used in assessment of respiratory mechanics, taken in a range of at least 100ms and when both slopes (valve closing and opening) of quasi-step excitation are included. What is more, the faster the valve the smaller error of parameter estimation in proposed TD-EIT was observed, and this uncertainty importantly falls down for the length of time window exceeding the limit of 100ms. The pioneering use of neural network for mapping the mechanical properties of lungs with the use of interrupter experiment methodology proves that it is possible to conclude about more (than one) number of parameters characterizing the complex system and that this insight is biased with the error not exceeding of 10%; only peripheral properties are estimated worse. Such observation has a potential to change the experimental protocol, which was used in interrupter measurements up to date and to make this technique more attractive in comparison to other method, i.e. forced oscillation technique or impulse oscillometry. As regards the practical meaning of reported results for engineers and end-users (physicians and patients), proposed solution can be applied in simple portable devices with a feature of easy operation (important for e-monitoring).

Outdoor air pollution has been associated with decrements in lung function and growth of lung function in school-age children. Lung function effects have not been examined in preschoolers, with the exception of one study on minute ventilation in newborns. Our goal was to assess the relationship between long- and short-term exposure to traffic-related air pollution and interrupter resistance in 4-year-old children.Lung function was measured using the interrupter resistance method in children participating in a Dutch birth cohort study. Long-term average air pollution concentrations of fine particulate matter, nitrogen dioxide and soot at the residential address at birth were assessed using land-use regression models. Daily average air pollution concentrations on the day of clinical examination were obtained from the Dutch National Air Quality Monitoring Network.Significant associations were found between long-term average air pollution concentrations and interrupter resistance. Interrupter resistance increased by 0.04 kPa.s.L-1 (95% CI 0.01-0.07) per interquartile range increase (3.3 mu g.m(-3)) in fine particle concentration. Short-term exposure was not associated with interrupter resistance.Long-term exposure to traffic-related air pollution was associated with increased interrupter resistance in 4-year-old children, supporting previous birth cohort studies reporting effects of air pollution on subjectively reported respiratory symptoms in preschool children.

The solenoid magnetic actuator has been widely used as an actuator for MS (magnetic switch). Thus, conventional MSs continuously consume electrical power to maintain a closed state. To address this problem, an innovative structure which uses a permanent magnet to generate holding force in the closed state without electrical power is suggested in this paper. Further, the permanent magnet is dedicated to the opening operation and the closing operation by means of its magnetic force. In other words, an eco-friendly MS is proposed in this research. However, this structure has a critical problem in that, if unexpected external force is applied to the MS when in the open state, the MS returns to the closed state by the force of the permanent magnet and remains in the closed state, causing an unintended operation of the load. To solve this problem, a novel inter-locking mechanism is proposed. Hence, we termed the proposed novel MS the MSPI (magnetic switch using a permanent magnet and an inter-locking system). In addition, analysis and design methods for the MSPI are proposed in this paper. The usefulness of the MSPI and the accuracy of the analysis and design methods are confirmed through an experiment.

In real life , arc fault circuit interrupter plays a very important role to prevent the arc fault from fire about protecting the circuit.This article mainly introduces the types of arc,and the main purpose of designing this new type interrupter.The paper tells that it knows about the basic principle of wavelet transformation and use the wavelet tested data to be analyzed.The paper uses the window moving method to summarizes how to judge the basis of arc fault.Some kinds of loads are suitable and some are not.The paper also designs arc detection flow chart.It applies for effective basis for further.

With the increasing power demands, size of the fault current in electrical grids is steadily increasing, and it exceeds the breaking capacity of circuit breakers. To effectively cope with these problems, a high-speed interrupter was suggested. The high-speed interrupter provides fault current with a bypass to a fault current limiter in case of accidents and consequently, fault current can be restricted. In this study, behavioral characteristics of high-speed interrupter were analyzed by accident types occurred in a distribution system. When accidents occurred, a and b contact of the high-speed interrupter were turned-off and then, turned-on. Accordingly, fault current flowed to the circuit connected to a current limiting element, and the fault current limiter restricted fault current to within a half-cycle. Nevertheless, the behavior of the high-speed interrupter was slowed down by a switching surge. As a result, fault current was confirmed to be restricted not to within the anticipated half-cycle, but to after a half-cycle. Moreover, the behavioral characteristics of the high-speed interrupter changed not only by accident types, but by behaviors of R, S, and T phases. This was due to the errors in stroke lengths of the high-speed interrupters, which resulted in a slight time discrepancy among three interrupters. In addition, the switching behaviors of the b and a contact were confirmed not to have coincided due to the switching surge; b contact behaved first and a contact followed. because of this, accuracy of stroke length and switching surges through the solenoid suction increases may be necessary to resolve.

When the fault occurs in power system, the fault-current exceeds breaking capacity of the circuit breaker. So, reliablity of the power system is decreased sharply. Superconducting fault-current limiter (SFCL) is operated without impedance in normal state. The fault-current is limited by its impedance during the fault condition. However, the SFCL has several weak points such as huge size, high-price, liquid-nitrogen operation for the real power system. In this paper, We suggested the high-speed interrupter to limit the fault-current in case of the single line-to-ground fault. In addition, we compared the high-speed interrupter with the SFCL to ensure the operation reliability. The proposed interrupter detected the fault-current through the CT, and the power was supplied by operation of the SCR control system. In this experiment, the power of high-speed interrupter was applied after the 4.8[msec] from fault instant. The on-off operation of the interrupter was started after half-cycle from the fault. The fault-current was flowed into the impedance element by the switching operation of the high-speed interrupter. So, the fault current was limited within one cycle, and then it didnt exceed the capacity of a circuit breaker. We confirmed that there was slight difference between the SFCL with high-speed interrupter in terms of limiting-time of the fault-current and switching speed of the SCR. The high-speed interrupter was considered to be more efficient than the SFCL in size, cost or reliability.

To resolve the problem of declination of Japanese agriculture, plant factories with automation, quality control, robotization and speaking plant approach are necessary. The multi operation system described in this paper has running unit with automatic position sensing. Growth environment measurement unit has transpiration, photosynthesis, distance and temperature sensors to obtain plant growth information. The pest control unit uses the antiseptic effect of ozone water. The harvesting unit is used for cucumbers that grow fast; recognition of cucumbers ready to be harvested is achieved through distance information gathered by an attached photo interrupter and distance sensors. The development of multi-operation robot is continued by developing controlling program that can change the operating pattern by sharing the contents by each controlling and operating unit.

In this study, a new concept is proposed on a combination device with functions of a commercial transformer and a superconducting fault current limiter (SFCL). This device serves as a transformer by stepping the voltage up or down in normal condition. When a transient phenomenon occurs in the power system, it serves as an SFCL to limit the fault current. The device quickly detects the line current using a current transformer (CT), and is based on the high-speed, silicon-controlled rectifier (SCR) interrupter operation. This is done by identifying the fault using an SCR switching control system. The test results showed that the fault current was limited by the impedance of the superconducting element a half cycle after a fault occurred. An SCR that initially had a normally open contact was turned on within a half cycle. However, an SCR with a normally close contact was turned off after a half cycle because the current dropped below the holding current after a half cycle. The voltage of the superconducting element was low in the step-down turn ratio condition of the transformer. This was because the secondary and tertiary windings were connected in series due to the SCR-1 turn-off condition, and the sum of voltages on each winding appeared on the superconducting element. By combining the existing power device technology and an SFCL technology, it is expected that the existing problems of an SFCL can be addressed to construct a smart power system.

The contact structure of the interrupter for the DC vacuum circuit breaker (VCB) is proposed in this paper. Based on the different structure, magnetic properties of the transverse magnetic field (TMF) and axial magnetic field (AMF) contacts, a hybrid AMF-TMF cup shape contact is presented. The steady magnetic field and the residual magnetic field has been analyzed using the finite element method (FEM). From the simulation results, it can be seen that: for the cognition of steady magnetic field, the middle region TMF of the hybrid AMF-TMF cup shape contact is enhanced, and the AMF in the central region is increased significantly. The RMF value for the novel hybrid cup is much smaller than that of the traditional cup, which is more favorable for the metal vapor diffusion and effective dissipation of the arc energy.

CO 2 gas is a possible substitute for SF 6 gas in circuit breaker with relatively superior arc interruption performance. To enhance the interruption capacity of the circuit breaker which employs CO 2 gas as its arc interruption dielectric, the interruption principle of the hybrid circuit breaker composed of vacuum interrupter and CO 2 gas interrupter is studied. Based on the black-box arc models of hybrid circuit breaker built in ATP-EMTP, the interactions characteristics of vacuum interrupter and CO 2 gas interrupter and the transient recovery voltage distribution between two interrupters during the interruption process are analyzed. The influence of voltage-dividing capacitors on transient recovery voltage distribution is discussed. The interruption capacity of hybrid circuit breaker and CO 2 gas circuit breaker are compared. The results of simulation demonstrate that preferable transient recovery voltage distribution can be obtained under suitable control strategy while interrupters paralleled with voltage-dividing capacitors. The vacuum interrupter series connected with CO 2 gas interrupter can assist in enhancing the high current interruption capacity of gas interrupter.

The vacuum pressure in Vacuum Interrupters (VI) is usually measured by inducing a magnetron discharge inside them. We have previously reported evidence that if this discharge is continued for long enough it causes the gases to be chemically bonded to solid surfaces in the interrupter, resulting in a permanent reduction of pressure. In a small proportion of interrupters however the pressure returns to a stable level similar to the pre-discharge pressure over a period of hours or days. We now report on measurements of this pressure recovery. It was found that with these VI the cycle of pumping and pressure return is repeatable. With this information it may be possible to adapt magnetron testing procedures to distinguish between pressure rise due to return of permanent gas, which will level off, and continuous pressure rise due to internal outgassing.

This paper illustrates the development, up to prototype stage, of an electromechanical actuation system for a medium-voltage vacuum contactor. Such development is carried out using a multi-domain simulation-based mechatronic approach, i.e. developing coordinated sub-models for the mechanism linking the actuator to the movable parts of the interrupter, the rotational electromagnetic actuator, and the power and control electronic circuit supplying the actuator and governing the system via a digital control unit. After a preliminary analysis, the modeling, design and check of the parts via coordinated simulations is presented. A prototype of the system, manufactured to validate the design procedure is finally presented.

The synchronization breaking technology which is leading in the vacuum circuit breaker has got general concern in electrical apparatus industry, and the dispersion of each single phase interrupter and operating mechanism parameters is one of the most important influencing factors. Based on this, a new structure with three-phase vacuum interrupter in the same chamber was proposed in this paper, and so as to make the research of the concrete structure design which has applied for a invention patent. In this paper, the entirety structure design of the new rotation disc vacuum interrupter has been studied based on the electric field numerical simulation of the three-dimensional entire field. Aiming at the problem that the structure of the conductor poles in the center of the vacuum interrupter is too compact, the researches on the distribution of electric field and the insulation structure rationality have been studied. Aiming at the contact structure of the new rotation breaking and the design feature of the new arc type shielding case, the researches on structure design of contact and new arc type shielding case have been studied based on electric field analysis. The researches show that the new breaker can reduce its volume while meeting the synchronization of breaking.

This paper covers work carried out on the electrical design for a 245kV Vacuum Circuit Breaker, specifically the design of the Vacuum Interrupters. The design is based on a “T” style transmission breaker, with two Vacuum Interrupters in series. The VCB uses a single permanent magnetic actuator with a toggle mechanism to provide the opening and closing forces required and the synchronization of the two Vacuum Interrupters. Vacuum Interrupters are not presently used at these high voltages, but the continuing search for a replacement for the present SF6 based technology for environmental reasons leads us to consider the use of Vacuum Interrupters at ever increasing system voltages. At present single interrupter VCB are in service up to 145kV, and have been for many years. This logically leads to the simple concept of a two break VCB for 245kV Multiple break circuit breakers using both SF 6 and Vacuum technology have been used for many years, and are well proven in service. Rather than taking existing 145kV Vacuum Interrupters and designing a VCB around them, we have taken the approach of designing special interrupters which are intended to work in pairs. Using Vacuum Interrupters in pairs gives significant advantages over single Vacuum Interrupters for these high voltages and this allows us to optimize the vacuum interrupter design for this application. The paper discusses the problems of achieving these high ratings and the methods of optimizing the performance, size, and cost to achieve these requirements. As part of the design process we have modelled the single Vacuum Interrupters and the pair of Vacuum Interrupters using 2D and 3D electrostatic finite element modelling to optimize the voltage design of the Vacuum Interrupters as well as modelling the arc control using 3D electromagnetic finite element modelling to give the required interruption performance. The electrostatic design of the Vacuum Interrupters is discussed in this paper, as well as the design of the VCB. The electromagnetic modelling will be discussed in a future paper.