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根据多年的设计实践经验,对于多层民用建筑常用形式——单管上供下回式(不分户循环,计量的系统)系统提出了不同的见解;同时提出了水平串联、单户控制、单户循环、单户计量(以下简称水平串联、单独控制)系统在管理、节能、实用方面的可行性,以及水平串联、单独控制系统在实际应用中应注意的问题。 相似文献
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太阳电池效率与串联电阻的近似指数关系 总被引:2,自引:0,他引:2
太阳电池的串联电阻对其效率有显著的影响。呈近似指数关系。串联电阻对填充因子有重要的影响。串联电阻。对太阳电池的卜一v特性进行数值分析,证明效率和串联电阻由实测的开路电压、短路电流和效率可以简便地数值计算确定 相似文献
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研究太阳能联合城市燃气锅炉供暖系统的节能设计优化方案。设计集太阳能集热器、蓄热水箱、换热器、水泵、燃气锅炉等重要设备于一体的联合供暖系统,分析串联供暖与并联供暖组合方式,以及适用于联合供暖组合的太阳能单独供暖、同时供暖、燃气锅炉单独供暖三种供暖模式,采用TRNSYS构建串联供暖系统与并联供暖系统模型,对串联供暖系统与并联供暖系统节能设计进行比选,并从运行经济性角度出发优化联合供暖系统容量匹配节能设计。串联供暖系统节能设计比并联供暖系统节能设计的太阳能保证率高、系统性能好、系统能耗低。 相似文献
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对柴油机两级涡轮增压系统不稳定流动过程,采用一维不稳定流动的特征线方法进行模拟计算,主要对串联涡轮所遇到的压气机变入口压力边界条件和串联压气机所遇到的压气机变入口压力边界条件的确定进行了讨论;并完成了柴油机两级涡轮增压不稳定流动过程模拟计算程序的编制,实现了对过程的模拟计算。 相似文献
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为解决上游串联双调压室系统中调压室稳定断面面积设计的问题,基于托马假定,推导了串联双调压室系统的特征方程,根据霍尔维茨稳定判据得出了上游串联双调压室系统调压室临界断面面积的稳定域,并分析了串联双调压室系统稳定域的变化规律。结果表明,串联双调压室系统稳定域边界线由两条交于一个拐点的曲线组成,在拐点处靠近机组的调压室有最小临界稳定断面面积。最后,推导得出了串联双调压室系统稳定域边界线拐点的解析计算公式,提出了串联双调压室系统调压室临界断面面积的设计原则,为串联双调压室系统调压室临界断面面积的计算提供了理论依据。 相似文献
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该文介绍一种卫星太阳翼在轨功率输出预测方法,由单体太阳电池根据固体物理理论推导出来直流理论分析模型获得其等效电路,通过对单体太阳电池串、并联后组成的太阳翼电气电路,获得太阳翼等效电路,并根据该等效电路推导出太阳翼的直流分析模型。将太阳翼的直流分析模型转化为由单片太阳电池片开路电压V oc 、短路电流I sc 、最大功率点电压V mp 、最大功率点电流I mp 这4个参数决定的太阳翼工程应用方程。同时,通过地面试验获得单体太阳电池的电压和电流衰降系数,获取太阳翼实际在轨不同时刻的开路电压V Aoc 、短路电流I Asc 、最大功率点电压V Amp 、最大功率点电流I Amp ,并通过计算获取太阳翼工作点电压、电流,得到太阳翼的在轨预测工作输出功率。通过将该文模型预测值与太阳翼实际在轨输出电流、电压遥测值进行比较,验证该预测模型的有效性。该预测模型可通过单体太阳电池的4个工程参数,获得整个太阳翼的直流分析模型,便于太阳翼设计阶段建模分析的工程化应用。 相似文献
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A hybrid and adaptive control approach for solar photovoltaic system and fuel cell fed voltage source converter (VSC) is presented in this work. Further maximum power from solar photovoltaic array is extracted by using incremental conductance (INC) based maximum power point tracking approach. This hybrid approach combines I cos ? technique and gradient descent back propagation learning (GDBP) neural network (NN) to extract fundamental components from load current for efficient harmonics compensation and provides power quality improvement and support the three-phase AC grid by supplying power to the grid and as well as connected loads. The proposed system includes photovoltaic (PV) array, a voltage source converter (VSC), ripple filter and combination of linear and non-linear loads. The proposed control approach provides a fast response during dynamic conditions as well. Results of the proposed control technique also compared with the other available control techniques for its superiority analysis. The developed control technique is demonstrated by using MATLAB/SIMULINK platform. 相似文献
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Employing the theorem that matching impedance produces maximum power transfer, the current study develops a low-cost and highly efficient “maximum power point tracker for a solar cell unit,” for the purpose of allowing a solar cell to achieve optimal power transfer under different solar intensities and temperatures. Circuit control takes a single-chip microprocessor as the core and the booster circuit design undergoes the solar cell charging operation even though the solar cell output voltage is lower than the rated storage battery voltage. Experiments conducted in this study prove that the tracker this study develops effectively enhances the utilization efficiency of a solar cell. When a solar cell is at an output voltage above 30% of the rated voltage, it can charge a storage battery. When it reaches above 80% of the rated voltage, its power conversion efficiency can reach above 85%. The charge and discharge management mechanism of the device also avoids excessive charge and discharge of the storage battery, and extends storage battery longevity. 相似文献
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针对复杂工况对光伏制氢系统性能产生不确定性的影响,提出考虑多变量因素影响的光伏制氢系统模型,探索辐照度、温度、膜厚、压力等因素对光伏质子交换膜(PEM)制氢系统的影响。系统首先建立考虑辐照度、温度、膜厚、压力等因素影响的光伏-质子交换膜电解槽-氢储罐的光伏制氢模型,之后对系统进行定量计算和定性分析,并依据实际光伏数据进行实验验证。结果表明,在额定功率范围内,太阳电池输出电流和功率随辐照度的增加而增大,随温度的升高而降低。质子交换膜电解槽电压随辐照度、膜厚、压力的增加而增大,随温度的升高而减小。太阳电池输出功率、质子交换膜电解槽电压的变化趋势与辐照度变化趋势具有一致性。最终计算得到太阳电池系统、质子交换膜电解槽系统和总系统效率分别为16.8%、72.2%和12.1%。 相似文献
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Harmonic control using matrix converter of unbalanced input voltage supplied from solar power system
Most of the renewable energy sources are not distributed directly to consumer. It gone through several section to get optimum output voltage and current with the almost zero distortion. Direct Matrix converters are well known of its better power quality and low power distortion to the reactive loads. Conversely, multilevel H bridge inverters are broadly used to attain a sinusoidal output voltage in solar photovoltaic application. Reactive power is subject to high importance for the operation of alternating current (AC) power systems. Moreover there is always a challenge to obtain the balance current control from an unbalanced supply voltage with minimum harmonic distortion for reactive load application from solar power system. The main objective of the proposed system is to maximize the power usage by maintaining the current and power factor nearby unity. There are many different optimization techniques are used so far in matrix converter, a novel method of optimization BAT algorithm is proposed for the power quality to get the best result. This work mainly deals with the compensation of reactive power used in Solar Photovoltaic Power System. Bidirectional energy flow is possible with matrix converter for battery charging. Simulation results are presented to confirm the appropriate operation of the system under different of operating conditions. Also, in the proposed method the percentage of the higher order harmonics can reduced less than 9% of matrix converter for solar photovoltaic application. 相似文献