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An Algorithm for Short-Circuit Current Interval in Distribution Networks with Inverter Type Distributed Generation Based on Affine Arithmetic
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作者 Yan Zhang Bowen Du +3 位作者 Benren Pan GuannanWang Guoqiang Xie Tong Jiang 《Energy Engineering》 EI 2024年第7期1903-1920,共18页
During faults in a distribution network,the output power of a distributed generation(DG)may be uncertain.Moreover,the output currents of distributed power sources are also affected by the output power,resulting in unc... During faults in a distribution network,the output power of a distributed generation(DG)may be uncertain.Moreover,the output currents of distributed power sources are also affected by the output power,resulting in uncertainties in the calculation of the short-circuit current at the time of a fault.Additionally,the impacts of such uncertainties around short-circuit currents will increase with the increase of distributed power sources.Thus,it is very important to develop a method for calculating the short-circuit current while considering the uncertainties in a distribution network.In this study,an affine arithmetic algorithm for calculating short-circuit current intervals in distribution networks with distributed power sources while considering power fluctuations is presented.The proposed algorithm includes two stages.In the first stage,normal operations are considered to establish a conservative interval affine optimization model of injection currents in distributed power sources.Constrained by the fluctuation range of distributed generation power at the moment of fault occurrence,the model can then be used to solve for the fluctuation range of injected current amplitudes in distributed power sources.The second stage is implemented after a malfunction occurs.In this stage,an affine optimization model is first established.This model is developed to characterizes the short-circuit current interval of a transmission line,and is constrained by the fluctuation range of the injected current amplitude of DG during normal operations.Finally,the range of the short-circuit current amplitudes of distribution network lines after a short-circuit fault occurs is predicted.The algorithm proposed in this article obtains an interval range containing accurate results through interval operation.Compared with traditional point value calculation methods,interval calculation methods can provide more reliable analysis and calculation results.The range of short-circuit current amplitude obtained by this algorithm is slightly larger than those obtained using the Monte Carlo algorithm and the Latin hypercube sampling algorithm.Therefore,the proposed algorithm has good suitability and does not require iterative calculations,resulting in a significant improvement in computational speed compared to the Monte Carlo algorithm and the Latin hypercube sampling algorithm.Furthermore,the proposed algorithm can provide more reliable analysis and calculation results,improving the safety and stability of power systems. 展开更多
关键词 short circuit calculation inverter type distributed power supplies affine arithmetic distribution network
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Study on Effects of Short Circuit Between High and Common Ends of LVDT's Lead Wires on Sum Voltage
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作者 HE Zhiheng BAO Yan +3 位作者 SHANG Jie REN Zhengjia PI Ligang ZHAO Yiyue 《International Journal of Plant Engineering and Management》 2024年第3期142-153,共12页
The Linear variable differential transformer(LVDT)is widely used in the aircraft field and crucial to the safety of the aircraft.Based on the short-circuit failure mode between the high and common ends of the LVDT′s ... The Linear variable differential transformer(LVDT)is widely used in the aircraft field and crucial to the safety of the aircraft.Based on the short-circuit failure mode between the high and common ends of the LVDT′s lead wires,the theoretical formula of short-circuit sum voltage was deduced and verified via tests.Moreover,the effects of the core length and the winding resistance on the short-circuit sum voltage were analyzed and discussed through numerical methods.The present research put forward some references for LVDT′s design. 展开更多
关键词 LVDTs sum voltage short circuit
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Data-driven short circuit resistance estimation in battery safety issues 被引量:2
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作者 Yikai Jia Jun Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期37-44,共8页
Developing precise and fast methods for short circuit detection is crucial for preventing or mitigating the risk of safety issues of lithium-ion batteries(LIBs).In this paper,we developed a Convolutional Neural Networ... Developing precise and fast methods for short circuit detection is crucial for preventing or mitigating the risk of safety issues of lithium-ion batteries(LIBs).In this paper,we developed a Convolutional Neural Networks(CNN)based model that can quickly and precisely predict the short circuit resistance of LIB cells during various working conditions.Cycling tests of cells with an external short circuit(ESC)are produced to obtain the database and generate the training/testing samples.The samples are sequences of voltage,current,charging capacity,charging energy,total charging capacity,total charging energy with a length of 120 s and frequency of 1 Hz,and their corresponding short circuit resistances.A big database with~6×10^(5)samples are generated,covering various short circuit resistances(47~470Ω),current loading modes(Constant current-constant voltage(CC-CV)and drive cycle),and electrochemical states(cycle numbers from 1 to 300).Results show that the average relative absolute error of five random sample splits is 6.75%±2.8%.Further parametric analysis indicates the accuracy estimation benefits from the appropriate model setups:the optimized input sequence length(~120 s),feature selection(at least one total capacity-related variable),and rational model design,using multiple layers with different kernel sizes.This work highlights the capabilities of machine learning algorithms and data-driven methodologies in real-time safety risk prediction for batteries. 展开更多
关键词 Lithium-ion battery Safety risk Internal short circuit short circuit resistance Convolutional neural networks
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A Fault Feature Extraction Model in Synchronous Generator under Stator Inter-Turn Short Circuit Based on ACMD and DEO3S 被引量:1
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作者 Yuling He Shuai Li +1 位作者 Chao Zhang Xiaolong Wang 《Structural Durability & Health Monitoring》 EI 2023年第2期115-130,共16页
This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fa... This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fault,the sta-tor vibration signal analysis based on ACMD(adaptive chirp mode decomposition)and DEO3S(demodulation energy operator of symmetrical differencing)was adopted to extract the fault feature.Firstly,FT(Fourier trans-form)is applied to the vibration signal to obtain the instantaneous frequency,and PE(permutation entropy)is calculated to select the proper weighting coefficients.Then,the signal is decomposed by ACMD,with the instan-taneous frequency and weighting coefficient acquired in the former step to obtain the optimal mode.Finally,DEO3S is operated to get the envelope spectrum which is able to strengthen the characteristic frequencies of the stator inter-turn short circuit fault.The study on the simulating signal and the real experiment data indicates the effectiveness of the proposed method for the stator inter-turn short circuit fault in synchronous generators.In addition,the comparison with other methods shows the superiority of the proposed model. 展开更多
关键词 Synchronous generator stator inter-turn short circuit vibration signal processing adaptive chirp mode decomposition demodulation energy operator of symmetrical differencing
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Low switching loss and increased short-circuit capability split-gate SiC trench MOSFET with p-type pillar
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作者 沈培 王颖 +2 位作者 李兴冀 杨剑群 曹菲 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期682-689,共8页
A split-gate SiC trench gate MOSFET with stepped thick oxide, source-connected split-gate(SG), and p-type pillar(ppillar) surrounded thick oxide shielding region(GSDP-TMOS) is investigated by Silvaco TCAD simulations.... A split-gate SiC trench gate MOSFET with stepped thick oxide, source-connected split-gate(SG), and p-type pillar(ppillar) surrounded thick oxide shielding region(GSDP-TMOS) is investigated by Silvaco TCAD simulations. The sourceconnected SG region and p-pillar shielding region are introduced to form an effective two-level shielding, which reduces the specific gate–drain charge(Q_(gd,sp)) and the saturation current, thus reducing the switching loss and increasing the short-circuit capability. The thick oxide that surrounds a p-pillar shielding region efficiently protects gate oxide from being damaged by peaked electric field, thereby increasing the breakdown voltage(BV). Additionally, because of the high concentration in the n-type drift region, the electrons diffuse rapidly and the specific on-resistance(Ron,sp) becomes smaller.In the end, comparing with the bottom p~+ shielded trench MOSFET(GP-TMOS), the Baliga figure of merit(BFOM,BV~2/R_(on,sp)) is increased by 169.6%, and the high-frequency figure of merit(HF-FOM, R_(on,sp) × Q_(gd,sp)) is improved by310%, respectively. 展开更多
关键词 SiC gate trench MOSFET gate oxide reliability switching loss gate–drain charge(Q_(gd sp)) short circuit
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The Transformer Short-Circuit Test and the High Power Laboratory in China-the Past,Present,and Future
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作者 贺以燕 王茂松 《变压器》 北大核心 2005年第B08期32-37,共6页
We review the short-circuit testing of distribution and power transformers, and include a list of 110-220kV power transformers tested up to February 2002.
关键词 变压器 电路设计 高功率实验 能量转换
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Extreme Learning Machine-Based Thermal Model for Lithium-Ion Batteries of Electric Vehicles under External Short Circuit 被引量:15
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作者 Ruixin Yang Rui Xiong +1 位作者 Weixiang Shen Xinfan Lin 《Engineering》 SCIE EI 2021年第3期395-405,共11页
External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batte... External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batteries under ESC conditions.Experiments were systematically performed under different battery initial state of charge and ambient temperatures.Based on the experimental results,we employed an extreme learming machine(ELM)-based thermal(ELMT)model to depict battery temperature behavior under ESC,where a lumped-state thermal model was used to replace the activation function of conventional ELMs.To demonstrate the effectiveness of the proposed model,wecompared the ELMT model with a multi-lumped-state thermal(MLT)model parameterized by thegenetic algorithm using the experimental data from various sets of battery cells.It is shown that the ELMT model can achieve higher computa-tional efficiency than the MLT model and better fitting and prediction accuracy,where the average root mean squared error(RMSE)of the fitting is 0.65℃ for the ELMT model and 3.95℃ for the MLT model,and the RMES of the prediction under new data set is 3.97℃ for the ELMT model and 6.11℃ for the MLT model. 展开更多
关键词 Electric vehicles Battery safety External short circuit Temperature prediction Extreme learning machine
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Internal short circuit evaluation and corresponding failure mode analysis for lithium-ion batteries 被引量:8
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作者 Lishuo Liu Xuning Feng +5 位作者 Christiane Rahe Weihan Li Languang Lu Xiangming He Dirk Uwe Sauer Minggao Ouyang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第10期269-280,I0008,共13页
Internal short circuit(ISC)is the major failure problem for the safe application of lithium-ion batteries,especially for the batteries with high energy density.However,how to quantify the hazard aroused by the ISC,and... Internal short circuit(ISC)is the major failure problem for the safe application of lithium-ion batteries,especially for the batteries with high energy density.However,how to quantify the hazard aroused by the ISC,and what kinds of ISC will lead to thermal runaway are still unclear.This paper investigates the thermal-electrical coupled behaviors of ISC,using batteries with Li(Ni_(1/3)CO_(1/3)Mn_(1/3))O_(2) cathode and composite separator.The electrochemical impedance spectroscopy of customized battery that has no LiPF6 salt is utilized to standardize the resistance of ISC.Furthermore,this paper compares the thermal-electrical coupled behaviors of the above four types of ISC at different states-of-charge.There is an area expansion phenomenon for the aluminum-anode type of ISC.The expansion effect of the failure area directly links to the melting and collapse of separator,and plays an important role in further evolution of thermal runaway.This work provides guidance to the development of the ISC models,detection algorithms,and correlated countermeasures. 展开更多
关键词 Energy storage Lithium-ion battery Battery safety Internal short circuit Thermal runaway
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Effects of current waveform parameters during droplet transfer on spatter in high speed waveform controlled Short-circuiting GMAW 被引量:4
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作者 吕小青 曹彪 +1 位作者 曾敏 黄增好 《China Welding》 EI CAS 2005年第2期121-124,共4页
Aim at improving the stability of the Short-circuiting Gas Metal Arc Welding (GMAW-S) process for the enhanced speed usage, effects of current waveform parameters during short-term on the welding stability have been... Aim at improving the stability of the Short-circuiting Gas Metal Arc Welding (GMAW-S) process for the enhanced speed usage, effects of current waveform parameters during short-term on the welding stability have been investigated by experimental method. The welding power source used for the research is an inverter with a special current waveform control. It is shown that the spatter decreases at first then increases with each increase of the low current period, current increase rate and the maximum current limit. The test results are provided for welding of 1 mm and 3 mm mild steel at speed of 1.2 m/min. The stable GMA W-S process under high speed welding condition has been achieved by optimizing the parameters. 展开更多
关键词 gas metal arc welding short circuit arc current waveform control high speed welding SPATTER
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A fault warning for inter-turn short circuit of excitation winding of synchronous generator based on GRU-CNN 被引量:6
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作者 Junqing Li Jing Liu Yating Chen 《Global Energy Interconnection》 EI CAS CSCD 2022年第2期236-248,共13页
Synchronous generators are important components of power systems and are necessary to maintain its normal and stable operation.To perform the fault diagnosis of mild inter-turn short circuit in the excitation winding ... Synchronous generators are important components of power systems and are necessary to maintain its normal and stable operation.To perform the fault diagnosis of mild inter-turn short circuit in the excitation winding of a synchronous generator,a gate recurrent unit-convolutional neural network(GRU-CNN)model whose structural parameters were determined by improved particle swarm optimization(IPSO)is proposed.The outputs of the model are the excitation current and reactive power.The total offset distance,which is the fusion of the offset distance of the excitation current and offset distance of the reactive power,was selected as the fault judgment criterion.The fusion weights of the excitation current and reactive power were determined using the anti-entropy weighting method.The fault-warning threshold and fault-warning ratio were set according to the normal total offset distance,and the fault warning time was set according to the actual situation.The fault-warning time and fault-warning ratio were used to avoid misdiagnosis.The proposed method was verified experimentally. 展开更多
关键词 Synchronous generator Inter-turn short circuit Excitation winding Fault warning GRU-CNN IPSO
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DETECTION AND ANALYSIS OF WELD POOL SHAPE FOR CO_2 SHORT CIRCUITING ARC WELDING 被引量:3
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作者 Sun Zhenguo,Wang Junbo,Chen Qiang,Kong Wende (Department of Mechanical Engineering, Qinghua University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2001年第3期282-285,共4页
A general industrial CCD( ICCD) camera is redesigned to detect the weld pool without arc at the period of short circuiting, so that the interference of arc and spatter during CO2 short circuiting arc welding is elim... A general industrial CCD( ICCD) camera is redesigned to detect the weld pool without arc at the period of short circuiting, so that the interference of arc and spatter during CO2 short circuiting arc welding is eliminated. Through the analysis of weld pool image, both size parameters (such as weld pool area A, weld pool length L1, L2 and weld pool breadth b) and contour parameters (b, which describe the curves of weld pool boundany) ,which could indicate the shape features of weld pool, had been defined to express weld pool information quantitatively. The investigation of the relationships between weld pool shape parameters and welding process parameters may be beneficial to the quality control of CO2 welding. 展开更多
关键词 ICCD camera Pool image CO2 short circuiting arc welding
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Study on chaos in short circuit gas metal arc welding process 被引量:3
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作者 吕小青 曹彪 +2 位作者 曾敏 王振民 黄石生 《China Welding》 EI CAS 2007年第2期77-80,共4页
Based on the chaos theory, an idea is put forward to analyze the short circuit Gas Metal Arc Welding ( GMAW-S) process. The theory of phase space reconstruction and related algorithms such as mutual information and ... Based on the chaos theory, an idea is put forward to analyze the short circuit Gas Metal Arc Welding ( GMAW-S) process. The theory of phase space reconstruction and related algorithms such as mutual information and so on, are applied to analyze the chaos of the GMAW-S process. The largest Lyapunov exponents of some current time series are calculated, and the results indicate that chaos exists in the GMAW-S process. The research of the chaos in the GMAW-S process can be help to get new knowledge of the process. 展开更多
关键词 CHAOS Lyapunov exponents short circuit gas metal arc welding
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Influence of optical interference and carrier lifetime on the short circuit current density of organic bulk heterojunction solar cells 被引量:1
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作者 游海龙 张春福 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期349-356,共8页
Based on simple analytical equations, short circuit current density (Jsc) of the organic bulk heterojunction solar cells has been calculated. It is found that the optical interference effect plays a very important r... Based on simple analytical equations, short circuit current density (Jsc) of the organic bulk heterojunction solar cells has been calculated. It is found that the optical interference effect plays a very important role in the determination of Jsc; and obvious oscillatory behaviour of Jsc was observed as a function of thickness. At the same time, the influence of the carrier lifetime on Jsc also cannot be neglected. When the carrier lifetime is relatively short, Jsc only increases at the initial stage and then decreases rapidly with the increase of active layer thickness. However, for a relatively long carrier lifetime, the exciton dissociation probability must be considered, and Jsc behaves wave-like with the increase of active layer thickness. The validity of this model is confirmed by the experimental results. 展开更多
关键词 organic solar cells short circuit current density optical interference carrier lifetime
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Investigation on microprocessor based waveform control of short circuit transfer CO_2 welding 被引量:1
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作者 朱锦洪 石红信 +2 位作者 李兴霞 刘兆魁 涂益民 《China Welding》 EI CAS 2006年第4期26-29,共4页
A new kind of simple and flexible CO2 welding system was developed to carry out waveform control. The system consisted of IGBT inverter, PWM circuit and microprocessor unit ( MPU) , in which the output current of co... A new kind of simple and flexible CO2 welding system was developed to carry out waveform control. The system consisted of IGBT inverter, PWM circuit and microprocessor unit ( MPU) , in which the output current of constant current (CC) power supply could be changed according to transient physical state, and the variable down slope rate control could be used to ensure a stable welding process. The welding experiment results proved the effectiveness of this control approach. 展开更多
关键词 CO2 welding waveform control MICROPROCESSOR short circuit transfer
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Determining the feature values of parameters indicating the critical states of molten metal bridge in short circuit transfer 被引量:1
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作者 陈茂爱 蒋元宁 武传松 《China Welding》 EI CAS 2013年第1期47-52,共6页
Short circuit transfer involves bridging between the consumable electrode and the weld pool, associated with variations of electrical parameters which characterize the change of molten metal bridge state and are very ... Short circuit transfer involves bridging between the consumable electrode and the weld pool, associated with variations of electrical parameters which characterize the change of molten metal bridge state and are very important for the control of .spatter. In this paper, electrical process parameters and short circuit transfer images were simultaneously recorded with a LabView-based synchronous sensing and visualizing system. The arc^bridge resistance and derivatives of welding current, arc voltage and arc resistance at various instants were calculated by means of offline analysis of the welding current, arc voltage and droplet images. Parameters and their feature values indicating the onset of short circuit and the oncoming necking-down of molten metal bridge were determined. Using the calculated feature values, bridge-state-feedback control for .short circuit transfer was realized with a spatter rate less than 0. 25%. 展开更多
关键词 short circuit transfer molten metal bridge feature value
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A New Method of Early Short Circuit Detection 被引量:1
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作者 Feng Du Weigang Chen +1 位作者 Yue Zhuo Michael Anheuser 《Journal of Power and Energy Engineering》 2014年第4期432-427,共6页
To reduce the pressure on contacts and circuit breaker and realize the zone selective interlocking (ZSI) function above the instantaneous protection threshold (e.g., >10In), the short circuit current needs to be ea... To reduce the pressure on contacts and circuit breaker and realize the zone selective interlocking (ZSI) function above the instantaneous protection threshold (e.g., >10In), the short circuit current needs to be early detected. The state-of–art of early short circuit detection (ESCD) method is reviewed. Based on the equivalent model of the short circuit, a new method based on the current and its integration is proposed. The prospective current value can be detected in the early stage of the short circuit. According to the evaluation result, the short circuit current can be early forecasted with the proposed method. 展开更多
关键词 EARLY short circuit DETECTION ZONE Selective INTERLOCKING Instantaneous Protection
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Effect of welding speed and electrode extension on the approximate entropy of welding current in short-circuiting GMAW 被引量:2
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作者 向远鹏 曹彪 +1 位作者 曾敏 黄石生 《China Welding》 EI CAS 2007年第3期56-62,共7页
Based on the phase space reconstruction of welding current in short-circuiting transfer arc welding under carbon dioxide, the approximate entropy of welding current and its standard deviation have been calculated and ... Based on the phase space reconstruction of welding current in short-circuiting transfer arc welding under carbon dioxide, the approximate entropy of welding current and its standard deviation have been calculated and analyzed at different welding speeds and different electrode extensions respectively. The experimental and calculated results show that at a certain arc voltage, wire feeding rate and gas flow rate, welding speed and electrode extension have significant effects not only on the approximate entropy of welding current, but also on the stability of welding process. Further analysis proves that when the welding speed and electrode extension are in an appropriate range respectively, the welding current approximate entropy attains maximum and its standard deviation minimum. Just under such circumstances, the welding process is in the most stable state. 展开更多
关键词 gas metal arc welding short-circuiting transfer approximate entropy STABILITY
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Appearance and characteristics of non explosive short circuit transfer using basic electrodes
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作者 孟庆森 王宝 《China Welding》 EI CAS 1997年第1期77-81,共5页
By means of high-speed photograph and synchronous oscillograph, the appearance and technical features of non-explosive short circuiting transfer using basic electrodes are investigated, and the conditions to form this... By means of high-speed photograph and synchronous oscillograph, the appearance and technical features of non-explosive short circuiting transfer using basic electrodes are investigated, and the conditions to form this metal transfer mode are discussed. It is shown that the metal transfer mode has its high frequency of droplet, short period of arc extinguishing and long arc igniting period. This metal transfer mode is expected for basic electrodes for its less spatter and higher deposition efficiency. 展开更多
关键词 coated electrode short circuit transfer SPATTER deposition efficiency
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Short-circuit process model in underwater welding using rotating arc sensor
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作者 Li Zhigang Wang Yekai Ye Jianxiong 《China Welding》 EI CAS 2017年第3期12-20,共9页
In order to detecting and tracking along the weld seam with rotating arc sensor in underwater welding,the highpressure water environment rotating arc welding hardware platform is established and welding experiments us... In order to detecting and tracking along the weld seam with rotating arc sensor in underwater welding,the highpressure water environment rotating arc welding hardware platform is established and welding experiments using rotating arc sensor is done. Different radius of rotating arc sensor is used. And the corresponding welding current and voltage is obtained,which is compared with the results of rotating arc sensor short-circuit process simulation model under high-pressure water environment established in this article. The results show that under high-pressure water environment,rotating arc radius should be optimized,otherwise the short-circuit-arcing cycle will transit to a short-circuit-arcing-abruption cycle,making the welding quality poor. At last the critical radius between the short-circuit-arcing cycle and short-circuit-arcing-abruption cycle under high-pressure water environment is obtained. 展开更多
关键词 UNDERWATER welding high pressure water environment ROTATING ARC sensor short circuit process model optimization of ROTATING ARC RADIUS
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A new simulation model and its application in CO_2 short-circuiting transfer welding
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作者 胡连海 李桓 +1 位作者 李俊岳 杨立军 《China Welding》 EI CAS 2002年第2期171-176,共6页
A new simulation model of CO 2 short circuiting transfer welding may be employed to develop a new pattern of welding machine and to predict welding process parameters to obtain the optimum welding technology propert... A new simulation model of CO 2 short circuiting transfer welding may be employed to develop a new pattern of welding machine and to predict welding process parameters to obtain the optimum welding technology properties. In this paper, a new simulating model is developed according to the AWP (adapting welding physics process) waveform control method. Good agreement is shown between the predicted and experimentally determined results. The model will make an important promotion in the development of CO 2 arc welding technique. 展开更多
关键词 CO 2 arc welding simulation model short circuiting transfer welding parameters PREDICTION
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