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有杆泵抽油系统气体膨胀能研究 被引量:1
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作者 张喜顺 张祖国 +2 位作者 吴晓东 胡燕 汪友平 《科学技术与工程》 北大核心 2014年第15期39-42,共4页
目前抽油机井系统效率仿真方法只考虑地层产出气对泵效的影响,忽略了其在举升过程中释放的能量,导致高气油比井系统效率仿真结果精度偏低。针对这种现象,提出了地层中的气体在举升过程中释放的能量,包括溶解气膨胀能和自由气膨胀能两部... 目前抽油机井系统效率仿真方法只考虑地层产出气对泵效的影响,忽略了其在举升过程中释放的能量,导致高气油比井系统效率仿真结果精度偏低。针对这种现象,提出了地层中的气体在举升过程中释放的能量,包括溶解气膨胀能和自由气膨胀能两部分的理论。将有杆抽油系统输入功率划分为有效功率、气体膨胀功率、地面损失功率、地下损失功率4部分。应用能量守恒的理论,建立了自由气膨胀功率计算仿真模型,完善了以能量法为基础的系统输入功率计算模型,提高了系统效率计算仿真精度。仿真实例表明,在计算系统输入功率时,自由气膨胀功率不可忽略,其系统效率计算模型仿真精度更高。 展开更多
关键词 气体膨胀功率 自由气膨胀能 系统输入功率 系统效率 能量法
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抽油机井节能参数优化设计方法 被引量:4
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作者 张喜顺 吴晓东 《价值工程》 2011年第34期46-47,共2页
应用抽油机井动态参数仿真方法,建立了悬点示功图、曲柄轴扭矩、电机输出功率、系统输入功率等动态参数模型,以此为基础完善了系统效率仿真模型。基于定流压生产,以系统输入功率最低为优化设计的目标函数,考虑约束条件,建立了抽油机井... 应用抽油机井动态参数仿真方法,建立了悬点示功图、曲柄轴扭矩、电机输出功率、系统输入功率等动态参数模型,以此为基础完善了系统效率仿真模型。基于定流压生产,以系统输入功率最低为优化设计的目标函数,考虑约束条件,建立了抽油机井节能参数优化设计模型。通过应用实例,说明通过优化抽汲参数可以提高系统效率,降低系统输入功率。 展开更多
关键词 抽油机井 系统输入功率 节能 抽汲参数 优化设计
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基于比例复数积分的风力发电并网逆变器控制方法 被引量:7
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作者 冯奕 颜建虎 《农业工程学报》 EI CAS CSCD 北大核心 2016年第13期177-182,共6页
针对现有新能源并网逆变系统存在控制算法复杂和硬件锁相环带来的成本增加等问题,该文提出了一种基于比例复数积分控制的双闭环控制新方法。该控制方法以比例复数积分控制作为电流内环,以功率源形式直流母线电压控制作为系统外环。前者... 针对现有新能源并网逆变系统存在控制算法复杂和硬件锁相环带来的成本增加等问题,该文提出了一种基于比例复数积分控制的双闭环控制新方法。该控制方法以比例复数积分控制作为电流内环,以功率源形式直流母线电压控制作为系统外环。前者解决了传统PI控制无法消除并网电流稳态误差的问题,后者实现了功率源直流母线电压的稳定,以保障并网系统正常可靠运行。该文对功率源输入并网逆变器的电流内环与电压外环的参数和性能进行了详细地分析,并搭建了基于Matlab/Simulink的仿真系统,验证了控制算法的正确性。在理论分析与系统仿真的基础上,采用TMS320F2812 DSP实现了系统数字化控制,并基于风力发电系统平台试验验证了所提出控制方法的可行性与有效性,结果表明网侧的功率因数保持在0.97以上,电网电流最大谐波约为2.13%,满足电网要求。 展开更多
关键词 逆变器 风力 控制装置 发电 比例复数积分控制 功率输入系统
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Robust MSE precoder for imperfectly known MIMO wireless correlated channel 被引量:1
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作者 马鹏飞 赵慧 王文博 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期36-40,共5页
Aimed at that only one form of channel statistic information is utilized in traditional robust precoder schemes: either the channel mean or the transmit antenna correlation in multiple-input multiple-output (MIMO) wir... Aimed at that only one form of channel statistic information is utilized in traditional robust precoder schemes: either the channel mean or the transmit antenna correlation in multiple-input multiple-output (MIMO) wireless system, this paper proposes robust precoder designs which exploit both of statistic information to minimize the equalization mean-square error (MSE) with power constraint. Two different power constraints are studied. Besides the usual sum power constraint over all antennas, the per-antenna power constraint is imposed at transmitter in this paper. Since each antenna has its own amplifier, individual power constraint on each antenna is more realistic. Especially in MIMO-OFDM systems, the Peak-to-Average Ratio (PAR) is one of main practical problems. Simulations show that the proposed schemes have better performance than traditional normalized zero forcing schemes for imperfectly known correlated channel. Moreover, per-antenna power constraint can efficiently decrease the demand of dynamic range of power amplifier on each transmit antenna, especially in MIMO-OFDM systems. 展开更多
关键词 preeoder convex optimization imperfect channel knowledge multiple-input multiple-output MIMO) systems
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The New Architecture with Time-Spatial Consistency for 5G Networks 被引量:3
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作者 SUN Zhennian XU Xu +3 位作者 CHAI Xiaomeng ZHANG Tianyu TIAN Lin ZHANG Zhongshan 《China Communications》 SCIE CSCD 2016年第1期68-79,共12页
While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drasti... While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract) 展开更多
关键词 wireless access network spectral efficiency energy efficiency super base station heterogeneous network
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Experimental study on high-power LEDs integrated with micro heat pipe 被引量:3
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作者 李聪明 周传鹏 +3 位作者 罗怡 Mohammad Hamidnia 王晓东 由博 《Optoelectronics Letters》 EI 2016年第1期31-34,共4页
Micro heat pipe(MHP) is applied to implement the efficient heat transfer of light emitting diode(LED) device.The fabrication of MHP is based on micro-electro-mechanical-system(MEMS) technique,15 micro grooves were etc... Micro heat pipe(MHP) is applied to implement the efficient heat transfer of light emitting diode(LED) device.The fabrication of MHP is based on micro-electro-mechanical-system(MEMS) technique,15 micro grooves were etched on one side of silicon(Si) substrate,which was then packaged with aluminum heat sink to form an MHP.On the other side of Si substrate,three LED chips were fixed by die bonding.Then experiments were performed to study the thermal performance of this LED device.The results show that the LED device with higher filling ratio is better when the input power is 1.0 W; with the increase of input power,the optimum filling ratio changes from 30% to 48%,and the time reaching stable state is reduced; when the input power is equal to 2.5 W,only the LED device with filling ratio of 48% can work normally.So integrating MHP into high-power LED device can implement the effective control of junction temperature. 展开更多
关键词 Capillary flow FILLING Heat pipes Heat transfer MEMS
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