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针对实际波浪的不规则性、扰动性以及滑模变结构控制中存在明显抖振和开关动作产生高频纹波问题,采用快速傅里叶变换对波浪激励力进行频谱分析。通过矢量叠加原理构造最大波浪能捕获策略,建立直驱式波浪发电系统模型。采用自适应快速终端滑模变结构控制方法实现最优功率状态跟踪控制,提高抗干扰性和实现限时收敛,同时利用卡尔曼滤波滤除纹波和减少抖振,结合Lyapunov函数分析系统稳定性。仿真结果表明,快速傅里叶变换(FFT)可满足未知不规则波浪的功率最优跟踪要求,所提滑模控制方法可实现快速跟踪,准确跟随,鲁棒性强。 相似文献
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为提高不规则海况下直驱式波浪发电系统的功率捕获能力,通过建立水动力模型及直线电机模型,分析等效模拟电路共振状态,构造最优功率捕获条件;针对波浪工作环境强噪声干扰问题,采用Rife法获取波浪主导激励分量,设置等效阻尼系数,计算q轴最优期望电流跟踪值;通过设计径向基函数(RBF)神经网络PI控制,提高等效控制电流信号的跟踪精度,改善系统动态性能。仿真结果表明,所提策略对含强噪声干扰的波浪信号主频段幅值和频率预估精度高,跟踪期望电流效果好,鲁棒性强,系统输出功率优化效果显著。 相似文献
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研究一种单相光伏并网发电控制仿真系统。利用Matlab2008b/Simulink,采用boost电路和逆变电路两级式结构,其中采用电导增量法的最大功率跟踪功能在boost电路中实现,并网控制通过采集电网电压参数和逆变输出电流电压参数在逆变电路中通过PI调节实现。通过光伏阵列通用模型验证最大功率跟踪模块的正确性,通过并网实验验证并网跟踪性能。基本实现了光伏阵列最大功率点的快速、准确跟踪功能和逆变输出电流电压与电网电压的同频同相,保证了输出电流为正弦波形且纹波较少,能够快速跟踪电网电压的变化。证明此系统在实际中是可行的。 相似文献
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常规变速控制系统的精度不高,变换器晶闸管开关动作产生的高频纹波较大,为此提出一种基于卡尔曼滤波的反步控制方法。文章通过分析波浪能提取装置的受力及幅频特性,获取了波浪能转化效率最大化的控制条件,并搭建了一套基于卡尔曼滤波的波浪发电反步最优功率控制系统。通过仿真研究了3种控制方法的控制精度和有效性,仿真结果表明:低通滤波反步法存在相位延迟,不能满足最大功率捕获策略的相位条件,影响系统的最终有功功率输出;反步法的跟踪误差较大,导致系统输出的有功功率较低;卡尔曼滤波反步法的动态性能较好,跟踪电流的波形振幅较小,能保证系统全局收敛,在电机速度方向、幅值和频率突变的情况下,仍能快速准确跟踪给定信号,鲁棒性和抗干扰能力更好。 相似文献
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针对目前光伏系统最大功率点跟踪方法普遍须要同时采集光伏电池输出电压信号和输出电流信号这一情况,文章提出了一种只须要检测光伏电池输出电压的控制方法,该方法采用占空比扰动法的工作模式,去掉了电流采样电路,简化了系统结构,并在saber环境下进行了仿真试验。最后通过对仿真结果的分析,证明了提出的光伏系统最大功率点跟踪方法的可行性和准确性。 相似文献
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论述了风电容量在占局部电网相当比例时,风电机组的无功功率调整与电网电压之间的关系,对于定速和变速风电机组的运行特性做了分析,提出了在需要做无功功率调整时风电机组应能满足的特殊要求。 相似文献
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HAN Chen-xi ZHANG Si-han 《能源与动力工程:英文版》2009,(9):45-48
This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field(VSCF), program implementation included Alternating Current (AC)-Direct Current (DC)-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale. 相似文献
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Tomonobu Senjyu Toshiaki Kaneko Akie Uehara Atsushi Yona Hideomi Sekine Chul-Hwan Kim 《Renewable Energy》2009,34(11):2334-2343
Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives of output power leveling and acquisition power increase are achieved. In this control approach, WTG is given output power command by fuzzy reasoning which has three inputs for average wind speed, variance of wind speed, and absolute average of frequency deviation. Since fuzzy reasoning is used, it is possible to define output power command corresponding to wind speed condition and changing capacity of power system momentarily. Moreover, high performance pitch angle control based on output power command is achieved by generalized predictive control (GPC). The simulation results by using actual detailed model for wind power system show the effectiveness of the proposed method. 相似文献
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R.J. Gutmann 《Solar Energy》1978,21(4):323-330
The first comprehensive evaluation of output power variations expected from Solar Power Satellites is presented. The various factors are classified in a two tier manner as: deterministic (either periodic or non-periodic) and statistical (either constant with system life or changing with life). The largest variations are due to seasonal periodic factors, namely variations in the solar constant (± 3.3 per cent) and a solar illumination variation with the photovoltaic array held perpendicular to the orbit plane (± 4.2 per cent). Other key factors delineated which are being quantified presently include power reductions due to microwave power tube failure and silicon solar cell radiation damage, while multiple shadowing of adjacent power stations in geosynchronous orbit and rectenna structural factors and combining efficiency variations are representative of areas that need further study. 相似文献
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A promising energy source for portable MEMS devices, microthermophotovoltaic (micro-TPV) power generator, is described in this paper. The system mainly consists of a micro SiC combustor, and a GaSb photovoltaic (PV) cell array and a simple nine-layer dielectric filter, with a volume of about 3.1 cm3. When the flow rate of H2 is 4.2 g/h, and H2/O2 ratio is 0.7, the system is able to deliver 3.06 W electrical power, the open-circuit voltage and short-circuit current are 2.31 V and 1.74 A, respectively, the result is a power density of about 1.0 W/cm3 (1 MW/m3). The effect of all kinds of factors on the performance of the micro-TPV system is also discussed in this paper. 相似文献
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Average market prices for intermittent generation technologies are lower than for conventional generation. This has a technical reason but can be exaggerated in the presence of market power. When there is much wind smaller amounts of conventional generation technologies are required, and prices are lower, while at times of little wind prices are higher. This effect reflects the value of different generation technologies to the system. But under conditions of market power, conventional generators with market power can further depress the prices if they have to buy back energy at times of large wind output and can increase prices if they have to sell additional power at times of little wind output. This greatly exaggerates the effect. Forward contracting does not reduce the effect. An important consequence is that allowing market power profit margins as a support mechanism for generation capacity investment is not a technologically neutral policy. 相似文献
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A hybrid power source for pulse power applications 总被引:2,自引:0,他引:2
Peter B. Jones J. Barry Lakeman Gary O. Mepsted Jon M. Moore 《Journal of power sources》1999,80(1-2):242-247
Portable 12 V power supplies are used extensively for communications and power tool applications. These devices demand fast response times of the power supply. Fuel cells are generally best suited to continuous power applications and require an initial warm-up period, although they offer the prospect of increased operational duration over a battery for a given weight of portable system. This paper investigates the combination of specific energy performance from the fuel cell system with the specific power and response time of the battery. Two separate hybrid systems have been developed and tested; a planar, 20-cell, polymer electrolyte membrane fuel cell (PEMFC) stack together with either a lead–acid or nickel/cadmium battery; and a conventional 20-cell, bipolar, PEMFC stack. Both systems have been tested under pulse-load conditions at temperatures between −20°C and +40°C, and for comparison, the individual components have undergone similar tests. The hybrid systems have successfully operated continuously for several weeks under load profiles that the fuel cell alone could not sustain. 相似文献
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Economic environmental dispatch (EED) is a significant optimization problem in electric power system. With more wide spread use of wind power, it is necessary to include wind energy conversion system (WECS) in the EED problem. This paper presents a model to solve the EED problem incorporating wind power. In addition to the classic EED factors, the factors accounting for overestimation and underestimation of available wind power in both economic and environmental aspects are also considered. In order to obtain some quantitative results, the uncertain characteristic of available wind power and the performance of WECS are determined on the basis of the statistical characteristic of wind speed. The optimization problem is numerically solved by a scenario involving two conventional generators and two wind-powered generators. The results demonstrate that the allocation of system generation capacity may be influenced by multipliers related to the cost for overestimation and underestimation of available wind power, and by the multiplier related to the emissions for underestimation of available wind power. Nevertheless, the multiplier related to the emissions for overestimation of available wind power has little impact on the allocation. Taking account of economic factors, environmental factors and impacts of wind power penetration, the proposed EED model is beneficial to finding the right balance between radical and conservative strategy for wind power development. 相似文献