Current Interruption Research Articles

Inexpensive short-circuit current limiter and switching device based on one commutation circuit for a three-phase system

The escalating levels of fault currents resulting from short circuits, particularly in the context of distribution generators, have presented a critical need for the widespread implementation of fault current limiters (FCLs) in power systems. Despite their evident advantages, the extensive adoption of FCLs has been hindered by the high production costs associated with these devices. To address this challenge, a comprehensive study was conducted to develop a cost-effective FCL tailored specifically for three-phase power systems. This paper proposes a novel approach based on a single commutation circuit for the FCL and offers detailed insights into the construction of the FCL circuit, with a particular focus on efficient current interruption. Additionally, the study comprehensively discusses the logic controller and measurement system employed in conjunction with the proposed FCL, ensuring precise fault detection and rapid response to disturbances within the power grid. The integration of an artificial zero-crossing circuit within the FCL design further enhances its capability to limit short-circuit currents proactively, even before the occurrence of the first peak, thereby bolstering overall system reliability and stability. The study's significant contribution lies in achieving cost-effectiveness through the simplicity of the FCL's design, eliminating the need for extensive upgrades to various network components.

Influence of state of charge inconsistency on electrical performance and thermal runaway characteristics in 2 serials 1 parallel lithium‐ion battery pack

AbstractLithium‐ion batteries (LIBs) are connected in series during use. State of charge (SOC) difference between two batteries will exist after charging/discharging owing to the capacity or resistance difference between them. This is also seen as SOC inconsistency. SOC inconsistency may cause battery electrical abuse. In this manuscript, a battery testing system, scanning electron microscope, heat furnace, and so on were employed to investigate the influence of SOC inconsistency on electrical performance and thermal runaway (TR) characteristics in 2 serials 1 parallel (2S1P) LIB pack after cycling. The results indicated that the cell with higher SOC in an inconsistent 2S1P pack was overcharged to 4.63 V during first charging, and the cell with lower SOC was over‐discharged to 1.90 V during first discharging. The cell with higher SOC became both overcharged and over‐discharged gradually with cycles. The cell with lower SOC became neither overcharged nor over‐discharged gradually. The electrical performance and TR characteristics of the cell with higher SOC became worse, while that of the cell with lower SOC did not change obviously. The state of health for cells with higher SOC decreased from 100% to 58% after 80 cycles. The time interval between current interrupt device activation and onset temperature of TR for cells with higher SOC was reduced by 183 s, and the maximum surface temperature increased by 34°C.

Nozzle Material Impact on Medium Voltage Load Current Interruption in Air and in a Fluoroketone Air Mixture

Nozzle Material Impact on Medium Voltage Load Current Interruption in Air and in a Fluoroketone Air Mixture

Revealing the Rate-Limiting Electrode of Lithium Batteries at High Rates and Mass Loadings

Lithium-ion batteries with superior capacities and rate performance are needed due to the soaring demands for even higher energy and power device requirements. [1-2] However, the main hurdle on achieving this predominately results from poor rate performance of the electrode, related to thermodynamic limitations and slow kinetics. To determine the rate-limiting electrochemical processes in a NMC622 vs graphite cell, a methodology based upon the galvanic intermittent titration technique, for investigating the diffusion coefficient and rate kinetics from the observed overpotential at each electrode has been developed. Variable current densities have been used to simultaneously extract the thermodynamic and kinetic properties of each electrode with increasing mass loading. Graphite is observed to reach its thermodynamic limits quicker than NMC, due to the flat plateaus and overpotentials observed from the charge transfer kinetics and mass transport. At high rates and high mass loadings, the graphite electrode is responsible for limiting both lithium-ion diffusion and reaction rates in the full cell. Slow diffusion kinetics are caused by the transport of the electrolyte in the porous electrode, which limits the availability of lithium for reaction at the surface of the graphite. This current interrupt testing methodology is proposed as a fast single technique for comprehensively parameterizing the rate limitations observed in a full cell configuration [3].

Investigation of the Effect of Safety Function Failure in Lithium-Ion Battery Systems at High Overvoltage

Balancing circuits in lithium-ion cell battery systems have the task of compensating for deviations in the capacity of the individual cells that arise due to manufacturing tolerances and ageing effects. It must be noted that a malfunction of this system can lead to great damage or even the destruction of the battery system. If cells are continued to be charged due to a fault in the BMS, the current interruption device (CID) will be the last protective function of a cell against overcharging. This irreversibly separates the positive and negative poles of the cell, and the cell’s resistance suddenly increases dramatically. The process of triggering the CID can also be triggered by the ageing process of the cell or other internal faults in the cell. If cells are interconnected to battery systems, a large voltage drop can be observed at the cell with a triggered CID, if a load is connected to the battery system. Under normal overcharge test conditions, cells are tests with twice the nominal cell voltage. In this case, the CID also functions correctly, and the charge current is interrupted. At significantly higher voltages, which occur in the cases described above, voltages close to maximum system voltage can be observed. At these voltage levels, the CID may not work properly. E.g., by overcharging and possible explosion of the cell may occur. For a more detailed investigation, a test series with 3 different chemistries was realized and the overcharge with 3 different voltage levels was investigated. It was found that on the investigated conditions, a more severe cell behavior was observed. Therefore updating abuse testing procedure are recommended or the usage of CIDs in cells battery systems should be avoided. Figure 1

Experimental Study of the Pressure Exerted in the Body of a High-Voltage Fuse and Metal Enclosed Switchgear

This article presents the importance of analyzing the breakdown behaviour of high voltage fuses and highlights the pressure values at the fuse ends. The theoretical basis, test scheme structure, design and sizing elements of fuse components, and numerical simulations performed in Matlab/Simulink are presented. The extinguishing environment is not modelled as it is considered to be a vacuum Starting with the oldest overcurrent protection device and continuing with the importance of high voltage fuses for operational safety, the study presents the behaviour of high voltage fuses during short-circuit current interruption. The key element is the value of the pressure on the contacts of fuses, which is often ignored in favour of the pressure of the middle element. When fuses change from solid to liquid state the inner parts are hotter than the outer parts and melt first, and the melting zone extends to the periphery. The study found that the pressure is much higher and is an important value for designers. Experiments showed that the maximum pressure is reached during the arcing period, a significant finding for the design process of the contacts of a high-voltage fuse. The research was then extrapolated to check the pressure in metal enclosed switchgear containing fuse combinations.

State of health estimation for lithium-ion batteries based on current interrupt method and genetic algorithm optimized back propagation neural network

Accurate state-of-health (SOH) estimation is an essential prerequisite for a battery management system (BMS) to improve battery utilization efficiency. The impedance information can be utilized to reflect the SOH. However, the traditional electrochemical impedance spectroscopy (EIS) method suffers from time-consuming measurements and specialized equipment. This study aims to establish a connection between EIS and the current interrupt method, which reduces the difficulty of obtaining impedance information through its utilization. This method can be applied in real time during charging, enabling it to be incorporated into a BMS. A genetic algorithm optimized back propagation neural network (GA-BPNN) is developed to estimate the SOH based on the impedance information obtained in the current interrupt method as inputs. The genetic algorithm improves the weights and thresholds of the neural network, which solves the parameter calibration problem. In this study, besides utilizing measurement data from different aging conditions as training set data, hybrid tests comparable to the actual usage environment are employed as validation set data. The experimental results show that a combination of the proposed current interrupt method and GA-BPNN can estimate SOH accurately with the root mean square error (RMSE) as low as 0.77 % in a complex hybrid test environment.

A fuse‐based DC circuit breaker with vacuum interrupter enhanced by an external transverse magnetic field

AbstractDue to the increasing power system capacity, the interruption of large fault currents has gradually become a major challenge in power systems. At the moment, such currents are interrupted mainly via circuit breakers based on the method of active current commutation. However, these types of circuit breakers tend to be costly and oversized. One possible alternative—a fuse‐based circuit breaker with current commutation process enhanced by an external transverse magnetic field (ETMF)—is proposed by the authors. Its main advantage lies in the fast current commutation achieved by an ETMF‐enhanced three‐stage increase of the vacuum arc voltage. The study of the current commutation process is mainly represented by the authors, and the influencing factors of the current commutation—contact opening speed and ETMF current—are discussed. At last, the proposed circuit breaker is verified by an experiment, whose results show that a short‐circuit current of 42 kA can be interrupted within just 2 ms.

Internal State of Fuse Arc Differentiating Interruption Success and Failure in Fuse‐SemiconductorDCCircuit Breaker

For the realization of sustainable society installing renewable energy sources, we have proposed a compact, low‐cost, versatile DC circuit breaker that combines a fuse and a power semiconductor. However, even under the same interruption conditions, there are cases where the interruption success and failure are observed probabilistically; the reason for this is still unknown. In the interruption failure, thermal reignition of an arc discharge occurs inside the fuse under transient recovery voltage. In this study, the spatiotemporal dynamics of the fuse arc was diagnosed for both interruption success and failure by a voltage–current waveform recording, high‐speed arc‐emission videography and borescope‐integrated optical emission spectroscopy, in order to identify the difference between the interruption success and failure. The waveform recording and videography demonstrated that at the arc initiation inside the fuse, the radial arc length for the interruption failure was longer than the interruption success. In the current interruption phase, the radial arc length was still longer, axial arc length was shorter, and arc column resistance was lower for the interruption failure. Further, the optical emission spectroscopy showed that localized regions with higher temperature and electrical conductivity existed for the failure in the current interruption phase. From these results, the dominant factors differentiating interruption success and failure were identified as the arc shape and electrical conductivity of the arc. To improve the interruption performance of the fuse and our DC circuit breaker, it is effective to increase the axial arc length, suppress the radial arc length, and reduce the electrical conductivity of the arc. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Characterization of Ultrahigh Pressure Nitrogen Arc Using Black Box Arc Model

In this paper, the effect of filling pressure on the black box arc parameters of nitrogen arc is reported using Mayr arc model. The arc current is approximately 130 A at 190 Hz. The filling pressure is varied at absolute pressure of 1, 20, and 40 bar. A phase transition from gas to supercritical state occurs when the pressure of nitrogen exceeds 33.5 bar at room temperature. To determine the effect of forced cooling, first, the free-burning arc is studied at different filling pressures. Afterwards, a self-blast arrangement is used where gas is blown into the arc near current zero. It has been observed that, without forced gas flow, both the time constant and the cooling power of the arc increase with the filling pressure. The forced cooling, however, reduces the time constant and further enhances the cooling power, thus facilitating the current interruption.

Thermal runaway-induced current interrupt device and vent activation behaviour in an 18650 lithium-ion battery cap using the Johnson-Cook criterion

Lithium-ion batteries (LIBs) thermal safety issues such as thermal runaway (TR) triggered by thermal or mechanical abuse have been one of the most important factors hindering its development at present. In order to effectively release the excessive pressure caused by TR, a safety vent is used as a reliable safety device in commercial LIBs. However, the current interrupt device (CID) and vent activation behaviour and mechanism are still unclear in the mesoscale. Herein, finite element simulations of metallic material deformation and failure during CID and vent activation at preset dynamic incremental pressure loads and various constant temperatures for a commercial 18650 LIB were carried out by introducing the Johnson-Cook (J-C) damage model in this study. The three-dimensional evolution, dynamical and mechanical analysis of the deformation to damage behaviour are quantitatively characterized. The CID- and vent-activation pressure based on the J-C damage criterion is significantly higher than the pressure value corresponding to the maximum von Mises stress. The results show fracture strain of the burst disk notch and plate will not exceed 0.93 % and 0.048 % respectively when the TR reaches the onset temperature. The temperature-dependent activation time reduction rate was developed to quantify the effect of temperature on the CID-and vent-activation times, indicating that TR temperature's effect on vent activation is significantly stronger than that of CID. These results may provide a reliable guide to LIB safety design.

Economic Implementation of 99.98% Efficiency in Natural-Cooling Modular MVDC SSCBs

This paper presents a modular medium voltage direct-current (MVDC) solid-state circuit breaker (SSCB) with high efficiency. The presented design method is modularity oriented, which includes thermal analysis of conduction cell, busbar design of conduction disk, and structure design of conduction tower. The implementation includes both continuous current conduction and fault current interruption. This paper includes three major contributions. First, it presents an economic analysis in terms of efficiency and cost as the design guideline for the main conduction configuration of SSCBs. Second, it provides a complete modular SSCB design procedure, showing both parallel and cascade scalability. Third, this paper investigates the effect of main conduction path stray resistances on SSCB efficiency and power loss. A medium-voltage SSCB prototype rated at 4kV/100A are experimentally implemented. The power density achieves 26.2 kW/L. The continuous conduction tests are conducted at 100A for 1hour, the steady-state efficiency achieves 99.98% with maximum temperature of 37°C. The fault interruption tests are successfully conducted at 4 kV/ 137A and 4 kV/ 1 kA with different system inertia.

Impact of Ablation Based Self Blast Nozzles on Load Break Switch Current Interruption Performance

In this contribution, SF6 free ablation assisted medium voltage load break switchgear, has been investigated. In these switches, gases generated by the arc polymer interactions are trapped in expansion chambers and are released back onto the arc at the current zero crossing. This increases the current interruption capability of the switch without the use of additional mechanical parts, as opposed to using a puffer to blow on the arc. Existing self-blast research, in medium voltage load break switchgear, has focused on blowing axially or tangentially onto the arc in a cylindrical arcing channel. More geometries are possible. In this paper, alternative self-blast blow-position and the presence of obstructions in the arcing channel have been investigated experimentally and with cold flow simulation. It has been determined that blowing right onto the arc centre is not optimal for cooling the arc, and that the presence of an obstruction in the arc channel is beneficial to arc interruptions.

Arc Voltage as an Indicator of Nozzle Ablation Degradation in High-voltage CO2 Gas Circuit Breakers

Energy released by electric arc during short-circuit current interruption is mostly absorbed by the surrounding cold gas and partly transferred to the arcing contacts and nozzle. The radiation is the main mode of thermal energy transfer between the electric arc and nozzle surface. Experimental research on the nozzle ablation has been carried out at a model circuit breaker, in which CO2 is filled in the chamber and poly-tetrafluoro-ethylene (PTFE) is used as the nozzle material. It is found that the arc voltage can be as an indicator of nozzle ablation degradation by comparing the voltage at current peak and arc voltage extinction peak. Under 20kA and 35kA peak current interrupting conditions, the voltage at current peak decreases with the number of operations. There are two factors that affect the arc voltage at current peak. One is the size of the arc cross section, and the other is the content of PTFE entering the arc zone, which affects its conductivity.

Thermal Current Interruption Performance of CO2 and CO2/C4F7N mixture

This contribution aims to compare the thermal interruption performance of pure CO2with a mixture of CO2/C4F7N. Measurements primarily show higher interrupting capability for amixture with C4F7N. Detailed analysis shows a distinct difference in the failure mechanism which forCO2/C4F7N is thermal failure and for CO2 mostly “hot dielectric” failure. The difference in the failuremechanism is relevant for the test duties with the most severe TRV. The influence of ablated nozzlematerial on the interruption process can be ruled out.

Transient Arc Characteristic of a Commutation Switch Utilizing High Velocity Contact Separation

Commutation circuits are commonly used for low on state resistance and high current interruption capability if this can not be achieved by a single device or single current switching path. In case of fault detection, a very fast commutation of the current from the low-impedance main current path into the parallel high-current interrupting path is necessary. For single usage applications a low-cost approach is the utilization of a pyrotechnical switch in the low-impedance path. Compared to other electromechanical switches, those switches provide very high velocity of contact separation and thus a fast arc voltage rise with short commutation times. Here, measurements of the contact movement of a pyrotechnical switch were carried out using optical high speed imaging and an arc elongation up to 100ms−1 was calculated. From this, transient arc characteristics were measured in a simplified commutation network during the period until current zero in the low-impedance main current path.

Direct current arc quenching performance of a model electric fuse equipped with SiO2 sand and additive silicone resin as an arc quenching medium: the effect of a vaporized silicone decomposition mixture on transient arc resistance

Most high-power electric fuses installed in DC distributions of automobiles employ silica sand (chemical formula SiO2) as arc quenching material to implement the limitation and subsequent interruption of high direct currents. This paper on arc quenching material describes the effects of the addition of silicone resin (chemical formula C2H6SiO) on SiO2 sand, based on the resistance of an arc discharge in SiO2 vapor mixed with silicone resin vapor. The measurement results obtained for the fuse operation of a model electric fuse show that the addition of silicone resin, e.g. an even coating of silicone resin on the surface of a Cu fuse element, attains a shorter arc quenching time. This phenomenon is subsequently explained based on the rise effect of an arc column resistance achieved by mixing with silicone vapor decomposition. The chemical compositions of high-temperature SiO2 vapor mixed with C2H6SiO vapor decomposition are evaluated to show the predominant chemical species at 30 000 K–5000 K for several C2H6SiO vapor concentrations, . The results obtained for of 10%–50% reveal that a H atom originating from C2H6SiO is present at high molar fractions above 0.1 over a wide temperature range of 12 000 K–5000 K. Further evaluations of the electrical resistivity for the high-temperature vapor show that mixing with C2H6SiO vapor contributes to a rise in at temperatures of 10 000 K–6000 K. A contribution analysis of the reveals that the rise effect of the is accomplished chiefly by the presence of a H atom that has dissociated from C2H6SiO.

ЗАКОНОМІРНОСТІ ЗМІНЕННЯ ЕНЕРГОЕФЕКТИВНОСТІ РОЗРЯДУ СУПЕРКОНДЕНСАТОРА НА ЛІНІЙНЕ АКТИВНЕ НАВАНТАЖЕННЯ ПРИ ЗМІНІ ТРИВАЛОСТІ РОЗРЯДУ

In the paper, the regularities of changes in electricity losses and the coefficient of its transfer to a linear active load during the discharge of a supercapacitor on the load under different conditions of interruption of discharge currents are determined. The influence of the conditions of interruption of discharge currents of the supercapacitor on the energy characteristics of the discharge circuit is determined, taking into account the fact that the capacity of the supercapacitor is a function of the voltage at its terminals. It was taken into account that this voltage can change its polarity. A mathematical model was developed that takes into account that the discharge process can be both aperiodic and oscillatory. The model was implemented in the Mat-lab/Simulink software package. A comparison of the energy characteristics during the discharge of a supercapacitor and a conventional linear capacitor on the same linear load at the same initial voltage on these capacitors was carried out. It has been established that the energy delivered to the load during the discharge of a supercapacitor is 1.8 times greater than dur-ing the discharge of a conventional linear capacitor charged to the same voltage, but the efficiency of energy transfer for these processes is almost the same. However, when the discharges of a supercapacitor and a conventional linear capacitor are forcibly interrupted, the efficiency of energy transfer to the load increases, and the efficiency during the discharge of the supercapacitor is always higher. Bibl. 14, fig. 3, tables 2. Key words: supercapacitor, capacitor, discharge, linear load, electricity losses, energy transfer efficiency.

СПОСОБИ ПІДВИЩЕННЯ ЕНЕРГОЕФЕКТИВНОСТІ СПЕЦІАЛІЗОВАНИХ ПЕРЕТВОРЮВАЧІВ ЕЛЕКТРОЕНЕРГІЇ ДЛЯ СУЧАСНИХ ІМПУЛЬСНИХ ТЕХНОЛОГІЙ

The article examines the proposed power electronics devices with an assessment of their basic quality indicators and functional purpose. The following of these devices have been identified, the use of which increases the e nergy efficiency of electrical networks the most. It is shown that these devices, due to their improved functional and parametric data, are also widely used in electrical consumer devices. Here are some of the mentioned devices. Combined and Controlled Latour-Gretz Rectifiers, Magnetic Semiconductor Pulse Regulators, DC/DC Pulse Converters, DC/AC Converters, DC/AC Converters, Full Thyristor Transistor Switch - VTS, Controlled Magneto-Semiconductor Generator pulses, an improved structural diagram of a magnetic semiconductor pulse generator. It was concluded that the following quality indicators of the above devices are the most acceptable for increasing the energy efficiency of electrical networks on the part of devices that are powered by them: high efficiency; improved electromagnetic compatibility; protection against short circuits and switching overvoltages; controllability according to load requirements; buffer resistance against interruption of the input current. Ref. 7, fig. 7. Keywords: energy efficiency of electrical networks, combined and controlled Latour-Gretz rectifiers, magnetic semi-conductor regulators and pulse generators, pulse converters DC/DC, DC/AC.

Safety Componentry for Mitigating Catastrophic Failure in Lithium-Ion Cylindrical Cells

The lithium-ion cylindrical cell is designed as a thin-walled pressure vessel, with various engineering controls to mitigate catastrophic failure. With an increase in pressure inside the cell, given suitable can wall thickness, the cell will fail through the header componentry. A tear down and inspection method has been developed to observe the header design and componentry of cells. A range of cylindrical cells were investigated - from 18650 to 46950 in size. This involved visual inspection, x-ray tomography, chemical analysis and microscopy. The presence of safety componentry, thickness and material type is discussed; factors which affect the propensity of the cell to fail at this location. Commonly observed was the Current Interrupt Device (CID) vent disc which is designed to mechanically deform in response to pressure increase within the cell. This in turn disconnects the cell circuitry and ruptures, initiating the venting process. Furthermore, cells typically contained a Positive Temperature Coefficient (PTC) device which protects the battery from external short circuits and electrical abuse conditions by limiting current flow when the cell reaches a particular temperature. This approach clearly outlines the safety componentry and their respective functions used within these cell sizes, allowing for a better understanding of battery safety. Additionally, we expect this work to disseminate new developments in larger format lithium-ion batteries as they are being sought for better system performance.