单轴菲涅尔反射聚光CPV/T系统的分析与研究

基于TracePro光路分析软件,对菲涅尔反射聚光系统进行了模拟,发现反射聚光后在光伏电池上的光强分布均匀。在不同追踪精度的情况下,接收器上接收的能量分析表明追踪精度在±3°以内时,可以将辐射能量的70%聚集到接收器上。采用主动追踪算法定位太阳位置,考虑赤经因素对追踪精度的影响,修正算法后追踪误差小于1°。太阳能电-热综合利用CPV/T系统有效解决了聚光后电池升温的问题,验证了菲涅尔反射聚光电-热综合利用的可行性。     

基于秩-1矩阵摄动的递归主元分析算法

针对传统主元分析（PCA）算法仅适用于定常系统监测的不足,提出了一种基于秩-1矩阵摄动的递归主元分析（RPCA）算法以适应实际工业过程的时变特性.RPCA算法首先对初始化样本协方差矩阵进行特征值分解,得到特征向量矩阵与特征值矩阵;然后在各时刻采用秩-1矩阵摄动算法对这两个矩阵递归更新并对其各向量与各元素排序,同时以累计方差百分比（CPV）为标准选取主元数目,从而显著降低了运算复杂度,节省了存储量.青霉素间歇发酵过程在线监测的仿真结果表明,RPCA算法大大降低了系统的误警率,并及时监测出过程中存在的故障.     

Monolithically interconnected lamellar Cu(In,Ga)Se2 micro solar cells under full white light concentration

Thin film solar cells already benefit from significant material and energy savings. By using photon management, the conversion efficiency and the power density can be enhanced further, including a reduction of material costs. In this work, micrometer‐sized Cu(In,Ga)Se₂ (CIGS) thin film solar cells were investigated under concentrated white light illumination (1–50×). The cell design is based on industrially standardized, lamellar shaped solar cells with monolithic interconnects (P‐scribe). In order to characterize the shunt and serial resistance profiles and their impact on the device performance the cell width was reduced stepwise from 1900 to 200 µm and the P1‐scribe thickness was varied between 45 and 320 µm. The results are compared to macroscopic solar cells in standard geometry and dot‐shaped microcells with ring contacts. Under concentrated white light, the maximal conversion efficiency could be increased by more than 3.8% absolute for the lamellar microcells and more than 4.8% absolute in case of dot‐shaped microcells compared to their initial values at 1 sun illumination. The power density could be raised by a factor of 51 and 70, respectively. But apparently, the optimum concentration level and the improvement in performance strongly depend on the chosen cell geometry, the used contact method and the electrical material properties. It turns out, that the widely used industrial thin film solar cell design pattern cannot simply be adapted to prepare micro‐concentrator CIGS solar modules, without significant optimization. Based on the experimental and simulated results, modifications for the cell design are proposed. Copyright © 2015 John Wiley & Sons, Ltd.     

Experimental performance of a Fresnel-transmission PVT concentrator for building-façade integration

A building-façade integrated concentrating photovoltaic-thermal system has been designed, constructed and experimentally characterised. Comparative performances with a non-concentration reference unit have been conducted to analyse the differential outputs. The concentrating system consists of double-side reflective strips which concentrate the incident beam towards a static photovoltaic-thermal receiver. The reflectors are placed vertically at the façade and track the sun by rotating axially. The concentrating reflector outperforms the reference one in both, thermal and electrical power. The thermal output of the concentration module almost doubles the reference one and the electrical power registered is more than 4.5 times in the case of the concentrating configuration.     

Extended description of tunnel junctions for distributed modeling of concentrator multi-junction solar cells

One of the key components of highly efficient multi-junction concentrator solar cells is the tunnel junction interconnection. In this paper, an improved 3D distributed model is presented that considers real operation regimes in a tunnel junction. This advanced model is able to accurately simulate the operation of the solar cell at high concentrations at which the photogenerated current surpasses the peak current of the tunnel junction. Simulations of dual-junction solar cells were carried out with the improved model to illustrate its capabilities and the results have been correlated with experimental data reported in the literature. These simulations show that, under certain circumstances, the solar cell's short circuit current may be slightly higher than the tunnel junction peak current without showing the characteristic dip in the J-V curve. This behavior is caused by the lateral current spreading toward dark regions, which occurs through the anode/p-barrier of the tunnel junction.     

Water desalination with concentrating photovoltaic/thermal (CPVT) systems

A coupled system is proposed, comprised of a concentrating photovoltaic/thermal collector field and a multi-effect evaporation desalination plant. The combined system produces solar electricity and simultaneously exploits the waste heat of the photovoltaic cells to desalinate water. A detailed simulation was performed to compute the annual production of electricity and water. The cost of desalinated water was estimated and compared to that of alternative conventional and solar desalination plants. Several economic scenarios were analyzed. The results indicate that the proposed coupled plant can have a significant advantage relative to other solar desalination approaches. In some cases, CPVT desalination is even more cost-effective than conventional desalination.     

A theorem on the generalized canonical projective vectors

This paper proposes a kind of generalized canonical projective vectors (GCPV), based on the framework of canonical correlation analysis (CCA) applying image recognition. Apart from canonical projective vectors (CPV), the process of obtaining GCPV contains the class information of samples, such that the combined features extracted according to the basis of GCPV can give a better classification performance. The experimental result based on the Concordia University CENPARMI handwritten Arabian numeral database has proved that our method is superior to the method based on CPV.