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Analytical model for power dissipation in cell membranes in suspensions exposed to electric fields
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作者 覃玉荣 江悦华 赖声礼 《Journal of Southeast University(English Edition)》 EI CAS 2005年第2期145-148,共4页
Due to interaction among cells, it is too complex to build an exactanalytical model for the power dissipation within the cell membrane in suspensions exposed toexternal fields. An approximate equivalence method is pro... Due to interaction among cells, it is too complex to build an exactanalytical model for the power dissipation within the cell membrane in suspensions exposed toexternal fields. An approximate equivalence method is proposed to resolve this problem. Based on theeffective medium theory, the transmembrane voltage on cells in suspensions was investigated by theequivalence principle. Then the electric field in the cell membrane was determined. Finally,analytical solutions for the power dissipation within the cell membrane in suspensions exposed toexternal fields were derived according to the Joule principle. The equations show that theconductive power dissipation is predominant within the cell membrane in suspensions exposed todirect current or lower frequencies, and dielectric power dissipation prevails at high frequenciesexceeding the relaxation frequency of the exposed membrane. 展开更多
关键词 power dissipation analytical model cell suspension external electricfields
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Power dissipation characteristics of great power and super high speed semiconductor switch 被引量:2
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作者 梁琳 余岳辉 彭亚斌 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2627-2632,共6页
The power dissipation characteristics of pulsed power switch reversely switched dynistors (RSDs) are investigated in this paper. According to the expressions of voltage on RSD, derived from the plasma bipolar drift ... The power dissipation characteristics of pulsed power switch reversely switched dynistors (RSDs) are investigated in this paper. According to the expressions of voltage on RSD, derived from the plasma bipolar drift model and the RLC circuit equations of RSD main loop, the simulation waveforms of current and voltage on RSD are acquired through iterative calculation by using the fourth order Runge-Kutta method, then the curve of transient power on RSD versus time is obtained. The result shows that the total dissipation on RSD is trivial compared with the pulse discharge energy and the commutation dissipation can be nearly ignored compared with the quasi-static dissipation. These characteristics can make the repetitive frequency of RSD increase largely. The experimental results prove the validity of simulation calculations. The influence factors on power dissipation are discussed. The power dissipation increases with the increase of the peak current and the n-base width and with the decrease of n-base doping concentration. In order to keep a low power dissipation, it is suggested that the n-base width should be smaller than 320μm when doping concentration is 1.0×10^14cm^-3 while the doping concentration should be higher than 5.8×10^13cm^-3 when n-base width is 270μm. 展开更多
关键词 reversely switched dynistor (RSD) pulsed power SWITCH power dissipation
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Power dissipation in oxide-confined 980-nm vertical-cavity surface-emitting lasers 被引量:2
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作者 史国柱 关宝路 +2 位作者 李硕 王强 沈光地 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期257-262,共6页
We presented 980-nm oxide-confined vertical-cavity surface-emitting lasers (VCSELs) with a 16 -um oxide aperture. Optical power, voltage, and emission wavelength are measured in an ambient temperature range of 5 ℃-... We presented 980-nm oxide-confined vertical-cavity surface-emitting lasers (VCSELs) with a 16 -um oxide aperture. Optical power, voltage, and emission wavelength are measured in an ambient temperature range of 5 ℃-80 ℃. Measurements combined with an empirical model are used to analyse the power dissipation in the device and the physical mechanism contributing to the thermal rollover phenomenon in VCSEL. It is found that the carrier leakage induced selfheating in the active region and the Joule heating caused by the series resistance are the main sources of power dissipation. In addition, carrier leakage induced self-heating increases as the injection current increases, resulting in a rapid decrease of the internal quantum efficiency, which is a dominant contribution to the thermal rollover of the VCSEL at a larger current. Our study provides useful guidelines to design a 980-nm oxide-confined VCSEL for thermal performance enhancement. 展开更多
关键词 vertical-cavity surface-emitting lasers power dissipation thermal rollover
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Thermal stability improvement of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations using non-uniform finger spacing 被引量:1
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作者 陈亮 张万荣 +6 位作者 金冬月 沈珮 谢红云 丁春宝 肖盈 孙博韬 王任卿 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期667-671,共5页
A method of non-uniform finger spacing is proposed to enhance thermal stability of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations. Temperature distribution on the emi... A method of non-uniform finger spacing is proposed to enhance thermal stability of a multiple finger power SiGe heterojunction bipolar transistor under different power dissipations. Temperature distribution on the emitter fingers of a multi-finger SiGe heterojunction bipolar transistor is studied using a numerical electro-thermal model. The results show that the SiGe heterojunction bipolar transistor with non-uniform finger spacing has a small temperature difference between fingers compared with a traditional uniform finger spacing heterojunction bipolar transistor at the same power dissipation. What is most important is that the ability to improve temperature non-uniformity is not weakened as power dissipation increases. So the method of non-uniform finger spacing is very effective in enhancing the thermal stability and the power handing capability of power device. Experimental results verify our conclusions. 展开更多
关键词 heterojunction bipolar transistor thermal coupling power dissipation
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Unit stream power,minimum energy dissipation rate,and river engineering
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作者 Chih Ted Yang 《水道港口》 2010年第5期317-317,共1页
Unit stream power is the most important and dominant parameter for the determination of transport rate of sand,gravel,and hyper-concentrated sediment with wash load.Minimum energy dissipation rate theory,or its simpli... Unit stream power is the most important and dominant parameter for the determination of transport rate of sand,gravel,and hyper-concentrated sediment with wash load.Minimum energy dissipation rate theory,or its simplified minimum unit stream power and minimum stream power theories,can provide engineers the needed theoretical basis for river morphology and river engineering studies.The Generalized Sediment Transport model for Alluvial River Simulation computer mode series have been developed based on the above theories.The computer model series have been successfully applied in many countries.Examples will be used to illustrate the applications of the computer models to solving a wide range of river morphology and river engineering problems. 展开更多
关键词 computer model minimum energy dissipation rate river engineering river morphology sediment transport unit stream power
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Study on High-power LED Heat Dissipation Based on Printed Circuit Board 被引量:2
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作者 WANG Yiwei ZHANG Jianxin +1 位作者 NIU Pingjuan LI Jingyi 《Semiconductor Photonics and Technology》 CAS 2010年第2期121-125,共5页
In order to study the role of printed circuit board(PCB)in high-power LED heat dissipation,a simple model of high-power LED lamp was designed.According to this lamp model,some thermal performances such as thermal resi... In order to study the role of printed circuit board(PCB)in high-power LED heat dissipation,a simple model of high-power LED lamp was designed.According to this lamp model,some thermal performances such as thermal resistances of four types of PCB and the changes of LED junction temperature were tested under three different working currents.The obtained results indicate that LED junction temperature can not be lowered significantly with the decreasing thermal resistance of PCB.However,PCB with low thermal resistance can be matched with smaller volume heat sink,so it is hopeful to reduce the size,weight and cost of LED lamp. 展开更多
关键词 high-power LED printed circuit board(PCB) substrate of heat dissipation thermal resistance junction temperature
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Estimation of the sheath power dissipation induced by ion cyclotron resonance heating
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作者 Xin AN Jing OU Zongzheng MEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第6期81-90,共10页
During ion cyclotron resonance heating,the sheath power dissipation caused by ion acceleration in the radio frequency(RF)sheath is one of the main causes of RF power loss in the tokamak edge region.To estimate the pow... During ion cyclotron resonance heating,the sheath power dissipation caused by ion acceleration in the radio frequency(RF)sheath is one of the main causes of RF power loss in the tokamak edge region.To estimate the power dissipation of an RF sheath in the ion cyclotron range of frequency(ICRF),a 1 D fluid model for the multi-component plasma sheath driven by a sinusoidal disturbance current in the ICRF is presented.By investigation of the sheath potential and ion flux at the wall,it is shown that the larger frequency and lower amplitude of the disturbance current can cause smaller sheath power dissipation.The effect of the energetic ion on the sheath power dissipation depends on the disturbance current.For large amplitude of disturbance current,the increase in the concentration and energy of the energetic ion leads to a decrease in sheath power dissipation.While for a small disturbance current,the sheath power dissipation demonstrates non-monotonic variation with the concentration and energy of the energetic ion.In addition,the sheath power dissipation is found to have a small increase in the presence of light impurity ions with low valence. 展开更多
关键词 sheath power dissipation RF sheath energetic ion disturbance current
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GA-BASED MAXIMUM POWER DISSIPATION ESTIMATION OF VLSI SEQUENTIAL CIRCUITS OF ARBITRARY DELAY MODELS
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作者 Lu Junming Lin Zhcnghui (LSI Research Institute, Shanghai Jiaotong University, Shanghai 200030) 《Journal of Electronics(China)》 2002年第4期378-386,共9页
In this paper, the glitching activity and process variations in the maximum power dissipation estimation of CMOS circuits are introduced. Given a circuit and the gate library, a new Genetic Algorithm (GA)-based techni... In this paper, the glitching activity and process variations in the maximum power dissipation estimation of CMOS circuits are introduced. Given a circuit and the gate library, a new Genetic Algorithm (GA)-based technique is developed to determine the maximum power dissipation from a statistical point of view. The simulation on 1SCAS-89 benchmarks shows that the ratio of the maximum power dissipation with glitching activity over the maximum power under zero-delay model ranges from 1.18 to 4.02. Compared with the traditional Monte Carlo-based technique, the new approach presented in this paper is more effective. 展开更多
关键词 CMOS sequential circuits Maximum power dissipation estimation Genetic algorithm Logic simulation Monte-Carlo technique
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Modern Electrical Power Source on New System of Dissipation and Renewable Energies Sources
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作者 Zygmunt Szymanski 《Computer Technology and Application》 2014年第1期7-14,共8页
This paper presents some solutions of modem renewable energy system applied actually in dissipation energy source: wind turbine, solar panel battery charge, SSS (support set system), and standby diesel generator co... This paper presents some solutions of modem renewable energy system applied actually in dissipation energy source: wind turbine, solar panel battery charge, SSS (support set system), and standby diesel generator cooperated in series, parallel and hybrid system with main energy system. Its solution enable obtain independent individual energy source in different work exploitations. One of problems concerned with alternative energy source is changes of output voltages and output power dependence of climatic conditions. Possible solution is application of decoupled adjustable speed generation system in renewable energy generation. The decoupled generation system consists of: alternative energy source, internal combustion engine drives permanent magnet generator and DC/AC, or AC/AC converter. Performance of single decoupled generation set is discussed supported by results of laboratory tests. To provide high quality voltage is applied an additional energy storage, made from super capacitor and bidirectional DC/DC convert. Such system performs very stiff voltage in any load condition. Integration of solar battery panels or renewable wind energy system is provided via DC link of the variable speed decoupled autonomous generation system. Results of computer simulation and laboratory experiments are presented in the paper. 展开更多
关键词 power source renewable energy dissipation.
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Dynamic Power Dissipation Control Method for Real-Time Processors Based on Hardware Multithreading
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作者 罗新强 齐悦 +1 位作者 王磊 王沁 《China Communications》 SCIE CSCD 2013年第5期156-166,共11页
In order to eliminate the energy waste caused by the traditional static hardware multithreaded processor used in real-time embedded system working in the low workload situation, the energy efficiency of the hardware m... In order to eliminate the energy waste caused by the traditional static hardware multithreaded processor used in real-time embedded system working in the low workload situation, the energy efficiency of the hardware multithread is discussed and a novel dynamic multithreaded architecture is proposed. The proposed architecture saves the energy wasted by removing idle threads without manipulation on the original architecture, fulfills a seamless switching mechanism which protects active threads and avoids pipeline stall during power mode switching. The report of an implemented dynamic multithreaded processor with 45 nm process from synthesis tool indicates that the area of dynamic multithreaded architecture is only 2.27% higher than the static one in achieving dynamic power dissipation, and consumes 1.3% more power in the same peak performance. 展开更多
关键词 dynamic power dissipation control real-time processor hardware multithread low power design energy efficiency
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RESEARCH ON A REAL-TIME CONTROL SYSTEM OF LOW POWER DISSIPATION FOR CONTINUOUS CYCLIC PERITONEAL DIALYSIS(CCPD) CYCLER
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作者 Peng Yi Lu Songfang +1 位作者 Kong Hua Yang Zibin(Institute of Basic Medical Seiences,Chinese Academy of Medical SciencesSchool of Basic Medicine,Peking Union Medical College,Beijing 100005,China) 《Chinese Journal of Biomedical Engineering(English Edition)》 1998年第1期22-25,共4页
A low power dissipation control system for continuous cyclic peritoneal dialysis (CCPD) cycler and its characteristics are reported. Combined withhemodialysis and renal transplantation, peritoneal dialysis is used mai... A low power dissipation control system for continuous cyclic peritoneal dialysis (CCPD) cycler and its characteristics are reported. Combined withhemodialysis and renal transplantation, peritoneal dialysis is used mainly for thetreatment of renal failure. CCPD has been developed during 1980's. It provided automatic dialysis procedures during the night to avoid interruptions in patients'dailyroutine. Furthermore,there is a remarkable decrease in peritonitis occurance usingCCPD. The control system is a critical part for CCPD cycler. The system is approvedto be reliable and flexible in practical experiments. When AC power failure,the system can still ensure the completion of dialysis. 展开更多
关键词 CONTINUOUS CYCLIC PERITONEAL DIALYSIS (CCPD) control system SINGLE-CHIP MICROCOMPUTER low power dissipation
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A cladding-pumping based power-scaled noise-like and dissipative soliton pulse fiber laser
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作者 吕志国 滕浩 魏志义 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期298-302,共5页
We report a high-average-power noise-like pulse(NLP) and dissipative soliton(DS) pulse fiber laser. Average power as high as 4.8 W could be obtained at the fundamental mode-locked repetition rate. The NLP can also be ... We report a high-average-power noise-like pulse(NLP) and dissipative soliton(DS) pulse fiber laser. Average power as high as 4.8 W could be obtained at the fundamental mode-locked repetition rate. The NLP can also be transformed into a more powerful DS mode-locking state by optimizing the polarization and losses of intra-cavity pulses in the nonlinear polarization evolution regime. The operation mode between the NLP and DS can be switched, and the laser output performance in both modes has been studied. The main advantage of this work is switchable high-power operation between the NLP and DS. In comparison with conventional single-mode NLP fiber lasers, the multi-function high-power optical source will greatly push its application in supercontinuum generation, coherence tomography, and industrial processing. 展开更多
关键词 cladding pumping high power noise-like pulse dissipative soliton
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Advanced Burst Mode Control to Reduce the Standby Power of Flyback Converter
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作者 Min-Sung Kim Hyoung-Woo Kim +1 位作者 Ji-Hye Jang Ki-Hyun Kim 《Engineering(科研)》 2013年第1期137-141,共5页
This paper we proposed advanced burst mode control technique to reduce the standby power consumption of the switch mode power supply (SMPS). To reduce the standby power consumption, most of the converter use burst mod... This paper we proposed advanced burst mode control technique to reduce the standby power consumption of the switch mode power supply (SMPS). To reduce the standby power consumption, most of the converter use burst mode or skip mode control technique. However Conventional standby mode control techniques have some problems such as audible noise and poor regulation. In proposed techniques, basically, the burst mode control technique is employed to reduce the fundamental switching frequency while limiting the peak drain current. But, in proposed technique, to improve the regulation characteristic, burst period of the proposed technique is shorter than that of the conventional burst mode technique. And also, to reduce the switching loss increase due to the short burst period, burst switching signal of the proposed technique is partially skipped. By using proposed advanced burst mode control technique, calculated standby power is 0.695W while standby power of the conventional burst mode control is 1.014W. 展开更多
关键词 STANDBY power flyback CONVERTER PWM IC SMPS
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单开关Buck-Flyback功率因数校正变换器 被引量:21
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作者 王楠 许建平 刘雪山 《中国电机工程学报》 EI CSCD 北大核心 2015年第3期679-687,共9页
针对传统Buck功率因数校正(power factor correction,PFC)变换器输入电流谐波分量高的问题,提出一种单开关Buck-Flyback PFC变换器。它由Buck PFC变换器与Flyback PFC变换器的输入和输出分别并联并合并主开关管而构成。当输入电压低于... 针对传统Buck功率因数校正(power factor correction,PFC)变换器输入电流谐波分量高的问题,提出一种单开关Buck-Flyback PFC变换器。它由Buck PFC变换器与Flyback PFC变换器的输入和输出分别并联并合并主开关管而构成。当输入电压低于输出电压时,变换器工作于Flyback模式,消除了传统Buck PFC变换器的输入电流死区,进而降低了输入电流谐波。分析工作在断续模式的单开关Buck-Flyback PFC变换器的输入电流特性,理论分析表明,该变换器可在全电压输入范围内获得高功率因数与低总谐波失真率,满足IEC 61000-3-2 C类法规对输入电流各次谐波的要求。最后,通过一台96 W实验样机验证理论分析的正确性。 展开更多
关键词 Buck-flyback变换器 功率因数校正 单开关 低总谐波失真率 电流谐波
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一种同步整流Buck-flyback拓扑的研究 被引量:3
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作者 周岩 王柏林 王梦婷 《电力电子技术》 CSCD 北大核心 2010年第1期39-40,54,共3页
随着数字控制芯片DSP/FPGA在模块电源中的广泛应用,其待机静态工作电流大、功耗高的问题也日益突出。采用传统的辅助电源方式难以满足设计要求。提出了一种同步整流Buck-flyback拓扑,分析了其工作原理,并推导了其稳态工作基本关系。通... 随着数字控制芯片DSP/FPGA在模块电源中的广泛应用,其待机静态工作电流大、功耗高的问题也日益突出。采用传统的辅助电源方式难以满足设计要求。提出了一种同步整流Buck-flyback拓扑,分析了其工作原理,并推导了其稳态工作基本关系。通过构建实验样机平台,证明了理论分析的正确性。 展开更多
关键词 同步整流器 数字控制 模块电源 反馈
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一种带功率解耦的Flyback微型逆变器研究 被引量:7
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作者 王晓 张立伟 +1 位作者 李艳 游小杰 《电工电能新技术》 CSCD 北大核心 2015年第2期44-49,共6页
单相光伏并网逆变器中由于输入输出瞬时功率存在差异,通常需要并联很大的电解电容来平衡这部分功率,由于电解电容寿命短,严重限制了逆变器的寿命,所以在电路中加入功率解耦单元,用长寿命的薄膜电容代替电解电容。本文研究一种带功率解耦... 单相光伏并网逆变器中由于输入输出瞬时功率存在差异,通常需要并联很大的电解电容来平衡这部分功率,由于电解电容寿命短,严重限制了逆变器的寿命,所以在电路中加入功率解耦单元,用长寿命的薄膜电容代替电解电容。本文研究一种带功率解耦的Flyback微型逆变器,并对其进行参数计算和损耗分析,推导出了通用的计算公式,最后通过仿真和实验验证了该拓扑的可行性。 展开更多
关键词 flyback微型逆变器 光伏发电 功率解耦 损耗分析
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DCM-CRM Boost-Flyback单级PFC变换器 被引量:4
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作者 阎铁生 李明洪 +3 位作者 陶权保 周国华 曹太强 王军 《电力自动化设备》 EI CSCD 北大核心 2019年第11期152-158,共7页
为了实现功率因数校正(PFC)功能,单级Boost-Flyback变换器的前级Boost变换器通常工作在断续导电模式(DCM),为了实现高效率,通过控制使后级Flyback变换器工作在临界连续导电模式(CRM)。详细分析了变换器的工作原理和功率因数、中间储能... 为了实现功率因数校正(PFC)功能,单级Boost-Flyback变换器的前级Boost变换器通常工作在断续导电模式(DCM),为了实现高效率,通过控制使后级Flyback变换器工作在临界连续导电模式(CRM)。详细分析了变换器的工作原理和功率因数、中间储能电容电压、开关频率等相关工作特性,并搭建了60 W的实验样机,验证了此变换器能够仅使用1个开关管和1个峰值电流模控制器,同时实现PFC功能和恒定输出电压,且相比DCM-DCM,DCM-CRM Boost-Flyback单级PFC变换器在保持相同功率因数的前提下,提高了变换器的效率。 展开更多
关键词 Boost-flyback 功率因数校正 单级 断续导电模式 临界连续导电模式 峰值电流模式
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一种一次侧控制的Buck-Flyback单级功率因数校正变换器LED驱动电路 被引量:23
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作者 阎铁生 李明洪 +2 位作者 周国华 陶权保 曹太强 《电工技术学报》 EI CSCD 北大核心 2019年第16期3355-3365,共11页
本文提出一种一次侧控制的Buck-Flyback单级功率因数校正(FCP)变换器LED驱动电路,分析其主电路的工作原理和一次侧恒流控制策略的原理。它由共用一个开关管的前级Buck变换器和后级Flyback变换器级联而成,前级Buck变换器实现PFC功能,后级... 本文提出一种一次侧控制的Buck-Flyback单级功率因数校正(FCP)变换器LED驱动电路,分析其主电路的工作原理和一次侧恒流控制策略的原理。它由共用一个开关管的前级Buck变换器和后级Flyback变换器级联而成,前级Buck变换器实现PFC功能,后级Flyback变换器实现DC-DC恒流输出。该LED驱动电路无需使用光耦和二次电流采样电路,仅使用一个开关管和一个控制器,就能够实现高功率因数、高效率、低成本和无频闪。最后设计了一台36W的实验样机验证了理论分析的正确性。 展开更多
关键词 LED驱动电路 功率因数校正 一次侧控制 Buck-flyback 无频闪
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基于Saber的单级Flyback电路的仿真研究 被引量:1
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作者 张国平 王维俊 +1 位作者 王海龙 刘华 《微型机与应用》 2012年第18期23-26,共4页
反激式变换电路是小功率LED照明中使用最为广泛的一种拓扑结构,为了使LED驱动器能够满足高效率、高可靠性和低成本的要求,给出了一种单级反激式变换电路,详细分析了电路的工作原理,并对主要元器件的参数进行了设计。最后,使用Saber仿真... 反激式变换电路是小功率LED照明中使用最为广泛的一种拓扑结构,为了使LED驱动器能够满足高效率、高可靠性和低成本的要求,给出了一种单级反激式变换电路,详细分析了电路的工作原理,并对主要元器件的参数进行了设计。最后,使用Saber仿真软件在不同的输入条件下进行了仿真分析,仿真结果表明电路具备较高功率因数和效率。 展开更多
关键词 LED 反激式 功率因数 SABER
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Study on 10 kVDC Powered Junction Box for A Cabled Ocean Observatory System 被引量:10
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作者 陈燕虎 杨灿军 +2 位作者 李德骏 金波 陈鹰 《China Ocean Engineering》 SCIE EI CSCD 2013年第2期265-275,共11页
A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current (kVDC) with up to 10 kW power, along with l Gigabit/s... A cabled ocean observatory system that can provide abundant power and broad bandwidth communication for undersea instruments is developed. A 10 kV direct current (kVDC) with up to 10 kW power, along with l Gigabit/sec Ethemet communication, can be transmitted from the shore to the seafloor through an umbilical armored cable. A subsea junction box is fixed at a cable terminal, enabling the extension of up to nine connections. The box consists of three main pressure vessels that perform power conversion, power distribution, and real-time communication functions. A method of stacking modules is used to design the power conversion system in order to reduce the 10 kV voltage to levels that can power the attached instruments. A power distribution system and an Ethemet communication system are introduced to control the power supply and transmit data or commands between the terminals and the shore station, respectively. Specific validations of all sections were qualified in a laboratory environment prior to the sea trial. The ocean observatory system was then deployed at the coast of the East China Sea along with three in situ instruments for a 14-day test. The results show that this high voltage-powered observatory system is effective for subsea long-term and real-time observations. 展开更多
关键词 cabled ocean observatory high voltage REAL-TIME power delivery heat dissipation
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