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Effects of temperature on creepage discharge characteristics in oil-impregnated pressboard insulation under combined AC-DC voltage
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作者 金福宝 周远翔 +2 位作者 梁斌 周仲柳 张灵 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第5期14-22,共9页
Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the tr... Due to the complexity of the valve side winding voltage of the converter transformer,the insulation characteristics of the oil-impregnated pressboard(OIP)of the converter transformer are different from those of the traditional AC transformer.The study on effect of temperature on the creeping discharge characteristics of OIP under combined AC-DC voltage is seriously inadequate.Therefore,this paper investigates the characteristics of OIP creepage discharge under combined AC-DC voltage and discusses the influence of temperature on creepage discharge characteristics under different temperatures from 70℃to 110℃.The experimental results show that the partial discharge inception voltage and flashover voltage decrease with increasing temperature.The times of low amplitude discharge(LAD)decrease and amplitude of LAD increases.Simultaneously,the times of high amplitude discharge(HAD)gradually in crease at each stage of creepage discharge with higher temperature.The analysis indicates that the charge carriers easily accumulate and quickly migrate directional movement along the electric field ahead of discharging.The residual charge carriers are more easily dissipated after discharging.The'hump'region of LAD moves to the direction of higher discharge magnitude.The interval time between two continuous discharges is shortened obviously.The concentration of HAD accelerates the development of OIP insulation creepage discharge.The temperature had an accelerating effect on the development of discharge in the OIP under applying voltage. 展开更多
关键词 oil-impregnated PRESSBOARD INSULATION combined AC-DC VOLTAGE inception VOLTAGE CREEPAGE discharge temperature flashover VOLTAGE
Phase–amplitude model for doubly fed induction generators 预览
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作者 Hua HUANG Ping JU +3 位作者 Xueping PAN Yuqing JIN Xiaoming YUAN Yuan GAO 《现代电力系统与清洁能源学报(英文)》 CSCD 2019年第2期369-379,共11页
The doubly fed induction generator(DFIG) is major type of wind turbine generator used in grid-connected wind farms. Practical models of DFIG have been built to study the influence of wind power generation on power sys... The doubly fed induction generator(DFIG) is major type of wind turbine generator used in grid-connected wind farms. Practical models of DFIG have been built to study the influence of wind power generation on power system dynamics. However, most existing practical models of the DFIG are based on rectangular coordinates,in which frequency variation is neglected. In this paper, a phase-amplitude(P-A) model is proposed for a DFIG based on phase and amplitude of the internal voltage. The model structure is much like that of the synchronous generator, and the rotor voltage can manipulate both the amplitude and the phase of the internal voltage.Comparisons have been made between the new P-A model of the DFIG and the synchronous generator model,as well as the asynchronous motor model.The contributions of the new P-A model of the DFIG are discussed and it is demonstrated that the proposed model has better ability in describing power system dynamic phenomena such as voltage dynamics and structural dynamics. Simulation results and a field test validate these contributions. 展开更多
关键词 DOUBLY fed induction generator(DFIG) MODEL Internal VOLTAGE VOLTAGE DYNAMICS Frequency DYNAMICS
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Fault analysis method of integrated high voltage direct current transmission lines for onshore wind farm 预览
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作者 Shobha AGARWAL Aleena SWETAPADMA +1 位作者 Chinmoy PANIGRAHI Abhijit DASGUPTA 《现代电力系统与清洁能源学报(英文)》 CSCD 2019年第3期621-632,共12页
Voltage source converter(VSC) based high voltage direct current(HVDC) transmission is most suited for the wind farm as it allows flexibility for reactive power control in multi-terminal transmission lines and transmit... Voltage source converter(VSC) based high voltage direct current(HVDC) transmission is most suited for the wind farm as it allows flexibility for reactive power control in multi-terminal transmission lines and transmits low power over smaller distance. In this work, a new method has been proposed to detect the fault, identify the section of faults and classify the pole of the fault in DC transmission lines fed from onshore wind farm. In the proposed scheme, voltage signal from rectifier end terminal is extracted with sampling frequency of 1 k Hz given as the input to the detection, classification and section discrimi-nation module. In this work, severe AC faults are also considered for section discrimination. Proposed method uses fuzzy inference system(FIS) to carry out all relaying task. The reach setting of the relay is 99.9% of the transmission line. Besides, the protection covers and discriminates the grounding fault with fault resistance up to 300 Ω.Considering the results of the proposed method, it can beused effectively in real power network. 展开更多
关键词 VOLTAGE source converter based high VOLTAGE direct current(VSC-HVDC) transmission lines Wind FARM DOUBLY-FED induction generator(DFIG) Fuzzy INFERENCE system(FIS)
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Design and analysis of a NMOS triggered LIGBT structure for electrostatic discharge protection 预览
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作者 Li Tian Jianbing Cheng +2 位作者 Cairong Zhang Li Shen Lei Wang 《半导体学报:英文版》 EI CAS CSCD 2019年第5期47-50,共4页
A novel NMOS triggered LIGBT(NTLIGBT) structure is proposed for electrostatic discharge(ESD) protection in this paper. The structure utilizes internal NMOS to trigger SCR-like structure in LIGBT. The trigger voltage i... A novel NMOS triggered LIGBT(NTLIGBT) structure is proposed for electrostatic discharge(ESD) protection in this paper. The structure utilizes internal NMOS to trigger SCR-like structure in LIGBT. The trigger voltage is significantly reduced because the embedded NMOS causes N+-drain/P-body junction being apt to avalanche breakdown. At the same time, the new parasitic PNP transistor including the newly added P+-region as a collector forms another path to bleed ESD current and then the conductivity modulation in the LIGBT is weakened. As a result, the holding voltage is increased. So, the proposed NTLIGBT structure has a narrow ESD design window. The simulation results show an improvement of 71.5% in trigger voltage and over 50% in holding voltage comparing with the conventional LIGBT structure. 展开更多
关键词 ESD NMOS triggered LIGBT(NTLIGBT) TRIGGER VOLTAGE holding VOLTAGE ESD design window
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Improved virtual synchronous control for grid-connected VSCs under grid voltage unbalanced conditions 预览
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作者 Lei SHANG Jiabing HU +1 位作者 Xiaoming YUAN Yunhui HUANG 《现代电力系统与清洁能源学报(英文)》 CSCD 2019年第1期174-185,共12页
This paper presents an improved virtual synchronous control(VSynC) for the grid-connected voltage source converter(VSC) so as to continuously operate under the grid voltage with steady unbalance.The improved VSynC int... This paper presents an improved virtual synchronous control(VSynC) for the grid-connected voltage source converter(VSC) so as to continuously operate under the grid voltage with steady unbalance.The improved VSynC introduces the negative sequence power controls on basis of conventional VSynC.The improved VSynC is capable of regulating the negative sequence internal voltage to reduce the negative-sequence injected currents and oscillated powers of the VSC aroused by the negative-sequence grid voltage.Three alternative local control objectives for the VSC itself under steady state unbalanced grid conditions and their corresponding power references are deduced and computed.Simulated and experimental results are presented to validate the correctness and effectiveness of the proposed improved VSynC to enhance the continuous operation performance of VSynC-based VSCs during grid voltage steady-state unbalance. 展开更多
关键词 Grid VOLTAGE UNBALANCE VIRTUAL SYNCHRONOUS control(VSynC) GRID-CONNECTED VOLTAGE source converter(VSC)
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Influence of test procedure on dielectric breakdown strength of alumina
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作者 Bjoern MIELLER 《先进陶瓷(英文版)》 CSCD 2019年第2期247-255,共9页
Dielectric strength testing of ceramics can be performed with various setups and parameters. Comparisons of results from different sources are often not meaningful, because the results are strongly dependent on the ac... Dielectric strength testing of ceramics can be performed with various setups and parameters. Comparisons of results from different sources are often not meaningful, because the results are strongly dependent on the actual testing procedure. The aim of this study is to quantify the influence of voltage ramp rate, electrode size, electrode conditioning, and sample thickness on the measured AC dielectric strength of a commercial alumina. Mean values, Weibull moduli, and failure probabilities determined in standardized short time tests are evaluated and related to withstand voltage tests. Dielectric strength values in the range from 21.6 to 33.2 kV·mm–1 were obtained for the same material using different testing procedures. Short time tests resulted in small standard deviations(< 2 kV·mm–1) and high Weibull moduli around 30, while withstand tests at voltage levels with low and virtual zero failure probability in short time tests resulted in large scatter of withstand time and Weibull moduli < 1. The strong decrease in Weibull moduli is attributed to progressive damage from partial discharge and depolarization during AC testing. These findings emphasize the necessity of a thorough documentation of testing procedure and highlight the importance of withstand voltage tests for a comprehensive material characterization. 展开更多
关键词 DIELECTRIC STRENGTH DIELECTRIC BREAKDOWN withstand VOLTAGE test high AC VOLTAGE testing
Effect of UV radiation aging on creepage discharge characteristics of high temperature vulcanized silicon rubber at high altitude
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作者 金福宝 周远翔 +3 位作者 梁斌 梁曦东 周仲柳 张灵 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第5期23-33,共11页
The physicochemical properties and creepage discharge characteristics of aged high temperature Vulca nized(HTV)silicone rubber materials were investigated by ultraviolet radiati on(UV)aging method in this study.The ex... The physicochemical properties and creepage discharge characteristics of aged high temperature Vulca nized(HTV)silicone rubber materials were investigated by ultraviolet radiati on(UV)aging method in this study.The experimental results show that as the aging time increases,the creepage discharge flashover voltage increases first and then decreases.But the aging time has little effect on the creepage discharge inception voltage.With the aging time prolonged,the discharge endurance time of HTV silicone rubber is shortened,and the creepage discharge development velocity is accelerated.In the short time of applying voltage to aging material,the magnitude of discharge in creases rapidly.According to the partial discharge characteristic parameters of creepage discharge,the whole creepage discharge process is partitioned into four stages.Compared with unaged HTV silicone rubber,the aged HTV silicone rubber has less fluctuation in performance parameters and a clear trend.The study found that UV aging not only affects the physicochemical and hydrophobic properties of the HTV silicone rubber,but also accelerates the development of creepage discharge under AC voltage. 展开更多
关键词 HIGH temperature vulcanized silicone rubber CREEPAGE discharge UV AGING INCEPTION VOLTAGE FLASHOVER VOLTAGE HIGH altitude characteristic parameters
基于STM32的汽车喷油器动态响应特性检测系统 预览
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作者 李炎昊 刘斌 +1 位作者 李建文 雷威 《仪表技术与传感器》 CSCD 北大核心 2019年第11期83-86,共4页
为更加全面地检测汽车喷油器特性,开发了一种基于STM32的汽车喷油器动态响应特性检测系统。根据进气道式电压型喷油器的特点,设计并搭建了在线检测装置,研制了适用的喷油器的检测系统,能够有效采集喷油器的驱动电流曲线并精确测量其开... 为更加全面地检测汽车喷油器特性,开发了一种基于STM32的汽车喷油器动态响应特性检测系统。根据进气道式电压型喷油器的特点,设计并搭建了在线检测装置,研制了适用的喷油器的检测系统,能够有效采集喷油器的驱动电流曲线并精确测量其开启和关闭时间。在标准的测试环境下,通过对喷油器检测的实验表明,检测喷油器的动态响应相对误差小于2%,满足喷油器的检测要求,同时具有较高的稳定性。 展开更多
关键词 STM32 喷油器 动态响应 进气道式 电压型 稳定性
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Effects of V-pits covering layer position on the optoelectronic performance of InGaN green LEDs 预览
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作者 Chen Xu Changda Zheng +4 位作者 Xiaoming Wu Shuan Pan Xingan Jiang Junlin Liu Fengyi Jiang 《半导体学报:英文版》 EI CAS CSCD 2019年第5期61-65,共5页
The impact of the V-pits covering layer(VCL) position on the optoelectronic performance of InGaN-based green light-emitting diodes(LEDs) was investigated. It is found that earlier covering of V-pits will hinder the ho... The impact of the V-pits covering layer(VCL) position on the optoelectronic performance of InGaN-based green light-emitting diodes(LEDs) was investigated. It is found that earlier covering of V-pits will hinder the hole injection via the sidewall of V-pits, and then result in less quantum wells(QWs) participating in radioluminescence. The current-voltage characteristics show that the LEDs with earlier covering of V-pits have higher operating voltage at room temperature, and a more dramatic voltage rise with the reduction of temperature. Meanwhile, more manifested emission peaks for sidewall QWs and deeper QWs near to ntype layer was observed in the sample with earlier coveing of V-pits at cryogenic temperatures, for the reason that the holes being injected via V-pits sidewall have higher kinetic energy and could transport to deeper QWs. 展开更多
关键词 green LIGHT-EMITTING DIODES V-pits covering layer hole injection efficiency operating voltage
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Room-temperature continuous-wave operation of GaN-based blue-violet laser diodes with a lifetime longer than 1000h 预览
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作者 Feng Liang Jing Yang +9 位作者 Degang Zhao Zongshun Liu Jianjun Zhu Ping Chen Desheng Jiang Yongsheng Shi Hai Wang Lihong Duan Liqun Zhang Hui Yang 《半导体学报:英文版》 EI CAS CSCD 2019年第2期39-42,共4页
GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm~2 ri... GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm~2 ridge waveguide structure.The electrical and optical characteristics of a blue-violet LD are investigated under direct-current injection at room temperature(25 °C). The stimulated emission wavelength and peak optical power of the LD are around 413 nm and over 600 mW, respectively.In addition, the threshold current density and voltage are as small as 1.46 kA/cm~2 and 4.1 V, respectively. Moreover, the lifetime is longer than 1000 hours under room-temperature continuous-wave operation. 展开更多
关键词 GAN-BASED blue-violet laser DIODES long LIFETIME THRESHOLD voltage
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High open-circuit voltage organic solar cells enabled by a difluorobenzoxadiazole-based conjugated polymer donor
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作者 Ruiwen Zhang Junyi Wang +4 位作者 Xi Liu Shuting Pang Chunhui Duan Fei Huang Yong Cao 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第7期829-836,共8页
A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl... A new polymer donor based on 3,3′-difluoro-2,2′-bithiophene(2F2T) and difluorobenzoxadiazole(ffBX), named 2F2T-ffBX, is designed and synthesized. The organic solar cell(OSC) based on 2F2T-ffBX donor and [6,6]-phenyl-C60-butyl acid methyl ester([60]PCBM) acceptor exhibits a high efficiency of 7.3% with a high open-circuit voltage(Voc) of 1.03 V. When blended with perylenediimide-based acceptor(PDI6), the corresponding OSC shows a higher Voc of 1.19 V with a low energy loss of 0.50 e V but a much lower efficiency of 2.0%. The detailed analyses including charge generation, transport, recombination properties, and morphology were performed to understand the performance of corresponding devices. 展开更多
关键词 ORGANIC SOLAR cells CONJUGATED polymer difluorobenzoxadiazole open-circuit VOLTAGE energy LOSS
含石墨烯多层结构左手材料平面波导TM振荡模的传输特性
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作者 沈陆发 王子华 《半导体光电》 CAS 北大核心 2019年第3期338-342,346共6页
对含石墨烯多层结构左手材料的介质特性及其构成的平面波导TM振荡模的传输特性进行了研究。该波导的芯层为含石墨烯的多层结构,覆盖层和衬底为不同的普通材料。计算结果表明:随着归一化波导厚度的增加,TM振荡模的有效折射率同时具有增... 对含石墨烯多层结构左手材料的介质特性及其构成的平面波导TM振荡模的传输特性进行了研究。该波导的芯层为含石墨烯的多层结构,覆盖层和衬底为不同的普通材料。计算结果表明:随着归一化波导厚度的增加,TM振荡模的有效折射率同时具有增加和减小,且两者最终达到平衡的双模简并特性。上述特性可以通过调节石墨烯外加电压的方法实现;进一步研究发现,波导中传输的归一化功率流具有正值、负值和零三种情况。电压或者频率的变化对正功率流的影响较小,对负功率流和零功率流的影响较大。 展开更多
关键词 平面波导 各向异性左手材料 石墨烯 电压
Superconducting magnetic energy storage for stabilizing grid integrated with wind power generation systems 预览
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作者 Poulomi MUKHERJEE V.V.RAO 《现代电力系统与清洁能源学报(英文)》 CSCD 2019年第2期400-411,共12页
Due to the interconnection of various renewable energies and adaptive technologies, voltage quality and frequency stability of modern power systems are becoming erratic. Superconducting magnetic energy storage(SMES),f... Due to the interconnection of various renewable energies and adaptive technologies, voltage quality and frequency stability of modern power systems are becoming erratic. Superconducting magnetic energy storage(SMES),for its dynamic characteristic, is very efficient for rapid exchange of electrical power with grid during small and large disturbances to address those instabilities.In addition,SMES plays an important role in integrating renewable sources such as wind generators to power grid by controlling output power of wind plant and improving the stability of power system.Efficient application of SMES in various power system operations depends on the proper location in the power system, exact energy and power ratings and appropriate controllers. In this paper, an effort is given to explain SMES device and its controllability to mitigate the stability of power grid integrated with wind power generation systems. 展开更多
关键词 POWER FLUCTUATION POWER quality Low voltage RIDE through SUPERCONDUCTING magnetic ENERGY storage SUPERCONDUCTORS Wind ENERGY
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Thermal spallation in rock revealed by ultraviolet laser-induced voltage
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作者 Jing Zhu HongLei Zhan +3 位作者 Kun Zhao XinYang Miao Qiong Zhou WenZheng Yue 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2019年第7期123-126,共4页
In the petroleum industry, perforation plays an important role in the exploitation of oil and gas and a considerable number of studies have been conducted with the objective of improving the recovery rates of oil and ... In the petroleum industry, perforation plays an important role in the exploitation of oil and gas and a considerable number of studies have been conducted with the objective of improving the recovery rates of oil and gas (1,2)Lasers have been used to drill holes in a wide variety of rock types with the advantages of feasibility, cost, benefits, and environmental impact as determined by the Gas Technology Institute [1]. 展开更多
关键词 LIV THERMAL SPALLATION in ROCK REVEALED by ULTRAVIOLET LASER-INDUCED voltage
The influence of the metal microstructure on the breakdown mechanism of Schottky diodes 预览
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作者 Sh.G.Askerov M.G.Gasanov L.KAbdullayeva 《材料物理与化学》 2019年第1期57-62,共6页
In this paper, the influence of the microstructure of a metal on the breakdown mechanism of diodes with a Schott-ky barrier is studied. It is shown that in electronic processes occurring in the contact between a metal... In this paper, the influence of the microstructure of a metal on the breakdown mechanism of diodes with a Schott-ky barrier is studied. It is shown that in electronic processes occurring in the contact between a metal and a semicon- ductor, the metal plays a very active role and is a more important contact partner than a semiconductor. Unlike the known mechanisms of breakdown of diodes (avalanche, tunnel and thermal), another mechanism is proposed in this paper - the geometric mechanism of the reverse current flow of Schottky diodes made using a metal with a polycrystal- line structure. The polycrystallinity of a metal transforms a homogeneous contact into a complex system, which consists of parallel-connected multiple elementary contacts having different properties and parameters. 展开更多
关键词 SCHOTTKY DIODE Metal-semiconductor contact Interface BARRIER HEIGHT BREAKDOWN voltage
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一种电压回路N线全站一点接地回路可靠性检测改进方法 预览
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作者 苏晓 廖华 +1 位作者 柳明 苗树国 《自动化技术与应用》 2019年第2期104-109,共6页
接地回路可靠性在检测过程中存在抗干扰性差的问题,提出一种电压回路N线全站一点接地回路可靠性检测方法 ,通过分析N线全站一点接地回路可靠性检测过程现有缺陷,引入幅值对比变频检测技术,对现有方法存在的缺陷检测方法进行改进,将具有... 接地回路可靠性在检测过程中存在抗干扰性差的问题,提出一种电压回路N线全站一点接地回路可靠性检测方法 ,通过分析N线全站一点接地回路可靠性检测过程现有缺陷,引入幅值对比变频检测技术,对现有方法存在的缺陷检测方法进行改进,将具有一致幅值以及低频率的两个交流信号,不断输入母线,并对接地故障前后该信号发出的两个低频交流电流的幅值进行对比,明确接地支路,实现故障回路实施准确检测,进而分析其可靠性。实验结果说明,采用改进方法 ,其能满足电压N线全站一点接地回路检测规范,不受对地电容的干扰,有效处理接地回路形成的误动,准确分析电路可靠性。 展开更多
关键词 电压 N线 全站 一点接地 回路 可靠性 检测
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L型宽频压电能量收集装置仿真分析与优化设计 预览
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作者 余震 张斯阳 《磁性材料及器件》 CAS CSCD 2019年第1期31-34,共4页
在提出L型宽频压电能量收集装置的结构与原理的基础上,建立了L型压电振子有限元模型,并对其进行仿真分析。仿真分析出其一阶和三阶谐振频率所对应的电压分别为0.06V和0.183V,虽然比一般的压电振子产生的电压高,但其一阶模态与三阶模态... 在提出L型宽频压电能量收集装置的结构与原理的基础上,建立了L型压电振子有限元模型,并对其进行仿真分析。仿真分析出其一阶和三阶谐振频率所对应的电压分别为0.06V和0.183V,虽然比一般的压电振子产生的电压高,但其一阶模态与三阶模态不够接近,对拓宽带宽所起的作用不大。在此研究基础上,进一步建立多悬臂梁的L型压电振子的有限元模型,并对其结构尺寸进行优化得到其二阶、三阶谐振电压非常接近,其带宽可以达到12.5Hz,可以起到拓宽带宽的作用。该多悬臂梁L型压电振子可应用于各种对机械能进行收集的装置或器件中。 展开更多
关键词 压电智能结构 能量收集 L型压电振子 电压 仿真 设计
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探析农村电网配网的规划设计 预览
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作者 黄国强 《电力系统装备》 2019年第20期70-70,83,共2页
农村电网配网合理规划设计,可以有效提高电能的利用效率,保证电网运行安全,促进农村经济的发展,提升农村居民生活质量。农村电网配网规划设计时,需要综合多个因素进行分析,确保规划设计的科学性与合理性。尤其要对用电负荷的预测、经济... 农村电网配网合理规划设计,可以有效提高电能的利用效率,保证电网运行安全,促进农村经济的发展,提升农村居民生活质量。农村电网配网规划设计时,需要综合多个因素进行分析,确保规划设计的科学性与合理性。尤其要对用电负荷的预测、经济性分析、运行分析等方面给予足够的重视,才能保证农村电网配网规划设计的科学性,进一步提高电能分配效率。 展开更多
关键词 电网 配网 规划 设计 电压
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浅谈ISO11898汽车CAN总线电压测试 预览
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作者 马齐成 李销 《汽车实用技术》 2019年第17期72-74,共3页
随着电子技术在汽车上的广泛应用,汽车电子化程度越来越高。从发动机控制到传动系控制,从行驶、制动、转向系控制到安全保证系统以及仪表报警系统渐渐形成了一个复杂的大系统。整车厂大多时候将车载的电子控制单元(ECU)设计和生产外包... 随着电子技术在汽车上的广泛应用,汽车电子化程度越来越高。从发动机控制到传动系控制,从行驶、制动、转向系控制到安全保证系统以及仪表报警系统渐渐形成了一个复杂的大系统。整车厂大多时候将车载的电子控制单元(ECU)设计和生产外包给零部件生产商,整车集成期间电气系统被连成多个ECU、多节点的有机整体,使得其功能及性能更加完善。目前CAN总线作为国际上应用最为广泛的现场总线之一,以其优良的可靠性和稳定性获得用户的肯定,也被广泛应用于ECU间的通信连接。随着系统复杂度日益增加,其网络通信质量的可靠性要求变得日益突出。为了确保can总线的通信质量,CAN总线电压测试就排在首位。ISO11898标准中描述的CAN总线物理层一致性测试原理较为抽象,厂商在制定测试、执行测试过程中往往会遇到不少困难,这里主要是解读ISO 11898标准有关CAN物理层CAN总线电压测试项目。 展开更多
关键词 ISO 11898 CAN 电压 测试
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热电制冷器温度依赖的材料参数的提取 预览
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作者 聂山钧 王明富 +1 位作者 高晓东 廖靖宇 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2019年第11期68-74,共7页
为获取通常情况下大部分厂家保密但在计算过程中所必须的热电制冷器(TEC)的热电材料参数,对温度依赖的热电材料参数进行了提取.利用一款一级TEC性能的测试结果,基于热电基本公式,根据两种不同的材料参数取值方法分别建立了两个超定方程... 为获取通常情况下大部分厂家保密但在计算过程中所必须的热电制冷器(TEC)的热电材料参数,对温度依赖的热电材料参数进行了提取.利用一款一级TEC性能的测试结果,基于热电基本公式,根据两种不同的材料参数取值方法分别建立了两个超定方程组,通过对这两个方程组进行求解,分别提取了两组TEC的热电材料参数.并用所提取的两组热电材料参数对另一款相同材料的5级TEC性能进行了计算以验证所提取材料参数的有效性.结果表明:厂家性能曲线误差随级数增加而增大,对于5级TEC,制冷温度误差可达20 K以上,这在TEC选型中应予以重视;本文所提取的材料参数在计算另一款5级TEC制冷温度时,不同制冷量下误差最大为1.6 K~6.1 K.同时,电压的计算结果表明计算模型中接触电阻是不可忽略的,通过所提取的电阻误差对电压的计算进行修正后,在TEC适用工作电流区间内,两组参数计算的电压相对误差分别小于4.80%和7.00%.本文方法计算的制冷温度误差约为极值法误差的1/5~1/2,约为厂家参数误差的1/10~1/4,准确度与有限元法利用热电材料参数实测值计算的结果近似,可有效的用于相同材料TEC的性能评估. 展开更多
关键词 热电制冷器 热电材料参数 温度依赖 制冷温度 电压
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