局部阴影下光伏阵列非机理建模

现有的阴影条件下的光伏阵列机理模型多为分段函数形式,较为复杂。提出采用傅里叶函数并使用曲线拟合的方法对阴影条件下光伏阵列进行非机理建模。改进了局部阴影条件下的光伏阵列的机理模型,获取光伏阵列的输出数据并进行线性插值。选取不同阶数的傅里叶函数对单阴影和多阴影条件下的光伏阵列的输出进行曲线拟合。该非机理模型具有统一的数学表达式,不需要分段描述,能对不同功率等级、不同精度要求的光伏阵列进行建模,简化了模型。     

Effect of partial shading conditions on off-grid solar PV/Hydrogen production in high solar energy index regions

In present work, the effect of partial shading on off-grid solar PV/hydrogen production in solar energy has been studied. The study was designed to stimulate future work in this area and to help demonstrate PV/hydrogen production. Four different electrodes in the study were coated and used in PV/Hydrogen Production. Pt anode and four different cathode materials which were Cu, Cu/Ni, Cu/NiBi and Cu/NiMo were used in the study. Data obtained from 105 W PV panel via automation system installed at ATU University, Adana, in Turkey were used for data of days representing different seasons by electrolysis experiment. The experiments were carried out between 08:00 and 16:00. The main contribution of this study is to produce hydrogen by using a part of the electrical energy gained from the solar panels, and at the same time to reveal the effect of the electrical energy produced by the partial shading of the panels on the hydrogen production. Furthermore, the effect of cathode material type was investigated for the impact of partial shading on hydrogen production. Results showed that Cu/NiMo has better hydrogen production efficiency than Cu/Ni, Cu/NiBi. The lowest efficiency was observed in the bare Cu electrode.     

探索建筑采光的优化设计之道

文章阐述了一种建筑采光设计方法，重点强调了在地域性光气候条件下的采光分析以及利用参数化模型进行采光方案的比对，以上过程保证了优化方案的获得。文中以位于广州市的某给定的建筑项目为例探讨了建筑侧窗遮阳构件可能给室内采光带来的改善，设计过程可概括为：以优化的自然光环境的优化为目标，利用参数化模型技术对于方案进行了高效的择优，最终得出了兼顾遮阳效果的采光设计方案。基于课题组前提的研究成果，文章涉及的采光模拟工作均在可反映广州地区地域性光气候特征的典型天空亮度模型（CSRS）的基础上进行。     

Adaptive Compression of Texture Pyramids

High‐quality texture minification techniques, including trilinear and anisotropic filtering, require texture data to be arranged into a collection of pre‐filtered texture maps called mipmaps. In this paper, we present a compression scheme for mipmapped textures which achieves much higher quality than current native schemes by exploiting image coherence across mipmap levels. The basic idea is to use a high‐quality native compressed format for the upper levels of the mipmap pyramid (to retain efficient minification filtering) together with a novel compact representation of the detail provided by the highest‐resolution mipmap. Key elements of our approach include delta‐encoding of the luminance signal, efficient encoding of coherent regions through texel runs following a Hilbert scan, a scheme for run encoding supporting fast random‐access, and a predictive approach for encoding indices of variable‐length blocks. We show that our scheme clearly outperforms native 6:1 compressed texture formats in terms of image quality while still providing real‐time rendering of trilinearly filtered textures.     

德国对建筑遮阳产品的政策支持与经济资助措施

文章分析了德国政府对节能技术包括建筑遮阳产品在政策扶持和经济资助方面的具体措施，包括宏观政策导向与原则，经济资助与税收优惠措施，建筑节能技术研发资助思路，实施组织结构等情况，并介绍了欧洲遮阳协会建筑遮阳节能减排报告的主要成果。     

Implicit Decals: Interactive Editing of Repetitive Patterns on Surfaces

Texture mapping is an essential component for creating 3D models and is widely used in both the game and the movie industries. Creating texture maps has always been a complex task and existing methods carefully balance flexibility with ease of use. One difficulty in using texturing is the repeated placement of individual textures over larger areas. In this paper, we propose a method which uses decals to place images onto a model. Our method allows the decals to compete for space and to deform as they are being pushed by other decals. A spherical field function is used to determine the position and the size of each decal and the deformation applied to fit the decals. The decals may span multiple objects with heterogeneous representations. Our method does not require an explicit parametrization of the model. As such, varieties of patterns, including repeated patterns like rocks, tiles and scales can be mapped. We have implemented the method using the GPU where placement, size and orientation of thousands of decals are manipulated in real time.     

A new MPPT controller based on the Ant colony optimization algorithm for Photovoltaic systems under partial shading conditions

The Maximum Power Point Tracking controller (MPPT) is a key element in Photovoltaic systems (PV). It is used to maintain the PV operating point at its maximum under different temperatures and sunlight irradiations. The goal of a MPPT controller is to satisfy the following performances criteria: accuracy, precision, speed, robustness and handling the partial shading problem when climatic changes variations occur. To achieve this goal, several techniques have been proposed ranging from conventional methods to artificial intelligence and bio-inspired methods. Each technique has its own advantage and disadvantage. In this context, we propose in this paper, a new Bio- inspired MPPT controller based on the Ant colony Optimization algorithm with a New Pheromone Updating strategy (ACO_NPU MPPT) that saves the computation time and performs an excellent tracking capability with high accuracy, zero oscillations and high robustness. First, the different steps of the design of the proposed ACO_NPU MPPT controller are developed. Then, several tests are performed under standard conditions for the selection of the appropriate ACO_NPU parameters (number of ants, coefficients of evaporation, archive size, etc.). To evaluate the performances of the obtained ACO_NPU MPPT, in terms of its tracking speed, accuracy, stability and robustness, tests are carried out under slow and rapid variations of weather conditions (Irradiance and Temperature) and under different partial shading patterns. Moreover, to demonstrate the superiority and robustness of the proposed ACO_NPU_MPPT controller, the obtained results are analyzed and compared with others obtained from the Conventional Methods (P&O_MPPT) and the Soft Computing Methods with Artificial intelligence (ANN_MPPT, FLC_MPPT, ANFIS_MPPT, FL_GA_MPPT) and with the Bio Inspired methods (PSO) and (ACO) from the literature. The obtained results show that the proposed ACO_NPU MPPT controller gives the best performances under variables atmospheric conditions. In addition, it can easily track the global maximum power point (GMPP) under partial shading conditions.     

Geometrical design of thin film photovoltaic modules for improved shade tolerance and performance

Partial shading in photovoltaic modules is an important reliability and performance concern for all photovoltaic technologies. In this paper, we show how cell geometry can be used as a design variable for improved shade tolerance and performance in monolithic thin film photovoltaic modules (TFPV). We use circuit simulations to illustrate the geometrical aspects of partial shading in typical monolithic TFPV modules with rectangular cells, and formulate rules for shade tolerant design. We show that the problem of partial shading can be overcome by modifying the cell shape and orientation, while preserving the module shape and output characteristics. We discuss two geometrical designs with cells arranged in radial and spiral patterns, which (i) prevent the reverse breakdown of partially shaded cells, (ii) improve the overall power output under partial shading, and (iii) in case of spiral design, may additionally improve the module efficiency by reducing sheet resistance losses. We compare these designs quantitatively using realistic parameters and discuss the practical aspects for their implementation. Copyright © 2013 John Wiley & Sons, Ltd.     

建筑遮阳条件下的自然采光设计策略

建筑遮阳装置的普遍应用会使采光口的采光效率大为降低,甚至会阻断使用者与自然景观的联系。文章通过绘制图示和实例阐述了在满足建筑遮阳的条件下,能够提高自然采光效果的设计策略：一方面是通过附着于建筑界面上的水平外遮阳装置阻挡阳光入射或对光线进行调节;一方面是通过对建筑采光口自身的设计改变采光方向和减少阳光直射。以此来平衡建筑遮阳和自然采光之间的矛盾,恢复采光口的多重功能。