共查询到18条相似文献，搜索用时 218 毫秒
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提出了采用最大功率点跟踪技术提高太阳电池的输出功率．跟踪器实时调整太阳电池的输出,电压和电流,使其工作在最大功率点上．建立了最大功率跟踪的测量装置,并可直接对比有、无跟踪条件下的输出功率．本实验条件下,采用最大功率跟踪后,其平均功率增益可达10．61％． 相似文献
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崔淑芳 《中学生数理化(高中版)》2011,(4):15-15
在恒定电流中，讨论电源最大输出功率、用电器获得的最大输出功率这类题目较多，处理此类问题常采用等效电源法，解题时根据需要选用不同的等效方式，将用电器获得的最大功率的问题转化为电源最大输出功率的问题解决．本文就等效法分析电源最大输出功率做一简单讨论． 相似文献
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风速的随机性、间歇性及不确定性,必将导致风电场的输出功率也具有随机波动性和间歇性,风电系统的输出功率影响电网的安全稳定运行和电能质量．通过构建了以鼠笼式感应电机为发电系统的定速变桨距风力发电系统,展开功率跟踪控制系统分析．给出了风力机空气动力学特性和建模方法,建立了传动链数学模型和感应发电机的数学模型．设计了转矩控制环、速度控制环,给出了实现功率跟踪的功率控制环设计思路,仿真结果表明,该系统能实现风电系统的最优功率跟踪控制． 相似文献
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本文提出一种实现太阳电池输出最大功率的跟踪控制方法,给出实验结果,证实这一控制方法的可行性和有效性。文中还讨论了太阳电池发电系统最佳功率流控制的实现方法以及补偿无功功率和谐波失真等问题. 相似文献
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设计和建立一个基于PLC的全功率风力发电实验模拟平台。PLC作为主控制器,通过两台变频器分别控制一台3 kW的全功率风力发电机和一台4 kW的风力机;ATV71变频器带动风力机模拟实际环境风力变化,外界输入的风能功率通过ATV71的转矩控制反映;四象限变频器ACS800通过磁通矢量控制给定全功率风力发电机的速度,发电机在电动机带动下工作在回馈制动状态,回馈的电能通过四象限变频器ACS800传递给电网。转矩控制使用一个简单的风机模型用于计算给定转矩。长时间运行验证其稳定性,同时得到静态特性下系统的最大功率点。系统运行结果:运行曲线与理论期望相符,最大功率点在500 r/min左右,可以承担后续研究任务。四象限变频器大大减少了系统的复杂度。 相似文献
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光伏阵列是光伏系统的发电设备,光伏阵列中的最大功率点追踪影响光伏系统的发电效率。对光伏阵列输出特性曲线进行分析,在此基础上分析了几种传统最大功率点追踪算法的适用范围和各自的优缺点,提出一种将变步长电导增量法与牛顿插值法相结合的算法。仿真结果表明,与传统扰动观测法及电导增量法相比,改进型最大功率点追踪算法可对最大功率跟踪点输出的功率波形振动幅度高效控制,具有追踪速度快、环境适应性好等优点。 相似文献
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目的：旨在观察运动前补服支链氨基酸对人体无氧功率的影响．方法：随机抽取忻州师范学院健康男生6名作为实验对象．分为实验组与对照组,两组分别在运动前半小时补服不同补剂后在无氧功率自行车上做3组持续10s的全力蹬踏运动,组间休息2min,运动结束后,系统将自动测出其最大无氧功率值、每千克体重无氧功率值．采用SPSS 11．5 for Windows统计软件处理．结果表明：无氧功率测试后,采用自身对照法,氨基酸组与安慰剂组相比,氨基酸组有4人无氧功率值略大于安慰剂组,但无显著性差异（P〉0．05）．结论：补服3克支链氨基酸后,受试者无氧功率并无显著提高． 相似文献
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有关求电阻消耗的功率，以及在什么条件下消耗的功率最大等问题，在解题中容易出错，而且运算比较繁杂．本文就上述问题进行探讨，并举例说明如何求电阻的最大功窒． 相似文献
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On maximum power point tracking control strategy for variable speed constant frequency wind power generation 总被引：1，自引：0，他引：1
WU Guo-qing NI Hong-jun WU Guo-xiang ZHOU Jing-ling Zhu Wei-nan MAO Jing-feng CAO Yang 《重庆大学学报(英文版)》2010,9(1):21-28
Based on the characteristic of AC-excited variable speed constant frequency （VSCF） wind power generation, the vector control technique was applied in a doubly fed induction generator （DFIG）. Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power. The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most. We presented a novel maximum power point tracking （MPPT） control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid. The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve, which had excellent dynamic and static performances and robustness. Simulation and experimental results testify the accuracy and validity of the control strategy. 相似文献
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文章从活跃发电市场、实现社会总体福利最大化角度出发,考虑电力环境管控、税收调节等手段,建立发电商目标利润模型和以政府为代言人的社会福利模型,通过社会福利最大化市场均衡解的求出,得出改变当前电商寡头垄断发电格局、推进发电侧市场竞争的结论． 相似文献
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A maximum power point tracker for photovoltaic energy systems based on fuzzy neural networks 总被引：1，自引：0，他引：1
Chun-hua Li Xin-jian Zhu Guang-yi Cao Wan-qi Hu Sheng Sui Ming-ruo Hu 《浙江大学学报(A卷英文版)》2009,10(2):263-270
To extract the maximum power from a photovoltaic （PV） energy system, the real-time maximum power point （MPP） of the PV array must be tracked closely. The non-linear and time-variant characteristics of the PV array and the non-linear and non-minimum phase characteristics of a boost converter make it difficult to track the MPP for traditional control strategies. We propose a fuzzy neural network controller （FNNC）, which combines the reasoning capability of fuzzy logical systems and the learning capability of neural networks, to track the MPP. With a derived learning algorithm, the parameters of the FNNC are updated adaptively. A gradient estimator based on a radial basis function neural network is developed to provide the reference information to the FNNC. Simulation results show that the proposed control algorithm provides much better tracking performance compared with the filzzy logic control algorithm. 相似文献
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A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine (HESM) is introduced
in this paper. The generator is connected to an uncontrollable rectifier, and a fully controlled voltage-source inverter is
used to connect the system to utility grid. An intermediate DC bus exists between the rectifier and inverter. A new control
strategy is proposed which achieves the maximum power point tracking (MPPT) with the control of excitation current of HESM
and stabilizes the DC link voltage with the control of inverter output current simultaneously. Specially-designed buck circuit
is used to control the excitation current of HESM, and grid voltage-oriented vector control strategy is employed to realize
the decoupling of the inverter output power. Simulation results and experiment in 3 kW lab prototype show an excellent static
and dynamic performance of the proposed system. 相似文献
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This paper presents a multi-mode control scheme for a soft-switched flyback converter to achieve high efficiency and excellent load regulation over the entire load range. At heavy load, critical conduction mode with valley switching （CCMVS） is employed to realize soft switching so as to reduce turn-on loss of power switch as well as conducted electromagnetic interference （EMI）. At light load, the converter operates in discontinuous conduction mode （DCM） with valley switching and adaptive off-time control （AOT） to limit the switching frequency range and maintain load regulation. At extremely light load or in standby mode, burst mode operation is adopted to provide low power consumption through reducing both switching frequency and static power dissipation of the controller. The multi-mode control is implemented by an oscillator whose pulse duration is adjusted by output feedback. An accurate valley switching control circuit guarantees the minimum turn-on voltage drop of power switch. The prototype of the controller IC was fabricated in a 1.5-μm BiCMOS process and applied to a 310 V/20 V, 90 W flyback DC/DC converter circuitry. Experimental results showed that all expected functions were realized successfully. The flyback converter achieved a high efficiency of over 80% from full load down to 2.5 W, with the maximum reaching 88.8%, while the total power consumption in standby mode was about 300 mW. 相似文献
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微逆变器可实现独立的光伏模组最大功率点追踪控制,极大优化并网光伏发电系统的光伏能量转换,提供即插即用概念。光伏微逆变器在功率变换中,常采用高频变压器升压产生期望的输出交流电压,根据直流链配置可以分为直流链、伪直流链和无直流链3种微逆变器拓扑结构。微逆变器控制技术包括最大功率点追踪控制技术、输出电流控制技术、孤岛效应侦测与保证技术等,且功率开关对于改善微逆变器的转换效率至关重要。 相似文献
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太阳能驱动多单元半导体温差发电器的性能分析 总被引：1，自引：1，他引：1
应用非平衡态热力学和有限时间热力学理论，研究了多单元太阳能驱动的半导体温差发电器的性能特性，导出多单元发电器的输出功率一般表示式，探讨最大输出功率及其有关的优化条件，得到一些有意义的新结论。 相似文献