Applied Mechanics and Materials Vols. 448-453

Abstract: This paper introduces the single unit model of photovoltaic (PV) system as the basic component for the modeling of the large-scale PV power plant. Based on the single unit model, the equivalent models of the large-scale PV power plant are presented in two different situations. As the general situation of the two in which the parameters of the inverter controllers are different, a clustering and equivalent modeling method based on the characteristic distance of parameter sensitivity is proposed. Finally, the simulation cases are provided to verify the effectiveness of the equivalent models.

Abstract: Subspace identification method was adopted to build a state-space model of the battery pack by directly using the acquisition data of current and voltage. The terminal voltage was split into four parts according to the relationship between the current and each element of the models output voltage. Then an equivalent circuit model composed of resistances and capacities was set up to simulate the relationship. Based on the battery model, a state space model with SOC as the state variable and voltage U_Cb as the output was set up. By applying a designed adaptive Kalman filter method to the model and adopting the voltage U_T1 from the subspace method as the measured output, the optimum estimation of SOC can be acquired with only calculations of one dimension.

Abstract: For increasing energy conversion efficiency of PV module, this study was divided to two experiments. The first experiment was to investigate optimal tilt angle of PV module from 0-35° from horizontal plane in facing south for using in Udon thani Province and neighbouring in Thailand. The second experiment was to decrease PV module temperature and to determine appropriate cooling system by using water and small spray nozzles between front and back PV module. The results found, conversion efficiency was high during 15°-25° from horizontal plane for tilt angle in facing south, especially at 25° in whole year. Using thin film by spray nozzles at the front side was higher open circuit voltage and energy conversion efficiency than back side, with 6.06% of increasing open circuit voltage and 1.93% of increasing energy conversion efficiency when compared with no cooling system, due to can thoroughly distribute water on surface area and easily install.

Abstract: In this study, the three dimensional ZnO (3D-ZnO) nanorods were synthesized by a simple chemical solution method, which were used as photoelectrodes, and CdS QDs were deposited on the surface of the 3D-ZnO nanorods to act a light absorber by using the successive ionic layer adsorption and reaction (SILAR) method. The photovoltaic performances of the semiconductor quantum dots sensitized solar cells based on CdS QDs/3D-ZnO photoelectrodes were investigated. A maximum 5.06 mA/cm² short circuit current density and 1.03% conversion efficiency under one sun illumination has been achieved. These results demonstrate that the CdS QDs-sensitized 3D-ZnO nanorods photoelectrode has a potential application in solar cells.

Abstract: There have been recent research interests in obtaining an optimum efficient design for the solar tracking system in published papers over the past three decades. This paper presents an in-depth overview of the assessment parameters and characteristics of various sensor devices employed to provide precise feedback control mechanism used in dynamic solar tracking systems. We found that the webcam sensor device has superior capability compared to other solar sensors devices. In conclusion, we propose a future research direction for a better efficiency and effective dynamic solar tracking system. Keywords: Solar tracking; Solar sensors; Solar panels; Overall output generated energy; Webcam; Photoresistors; Photodiodes; Feedback Control mechanism

Abstract: A single layer of organic solar cells with the Al/P3HT/PEDOT: PSS/ITO structure on glass substrate was investigated in this paper, and examined the performance of the polymer solar cells by changing 60, 70 and 80 nm thickness of the P3HT active layer. These devices had better absorption in the active layer and poor charges collect in the electrode with increase thickness of active layer were observed. It is found that the best properties that the single layer organic solar cell with open-circuit voltage 0.457 V, short-circuit current 1.05E-4 mA and power conversion efficiency of 3.3E-5% was achieved under illumination 100 mW/cm² when the thickness of P3HT active layer is about 80 nm.

Abstract: Diatomite/TiO₂ composite films were prepared with diatomite and P25 TiO₂ nanoparticles on conductive glass substrates. The surface morphology and phase composition of the film were characterized with scanning electron microscopy (SEM) and X ray diffraction (XRD). It is concluded that diatomite doped into the film will form granular cores. Dye sensitized solar cells (DSSC) were fabricated with the diatomite/TiO₂ composite film as anode, and the photoelectric properties of the cells were tested. Results show that the doping of diatomite can significantly increase the open circuit voltage and short circuit current of DSSC. Optimized photoelectric properties can be acquired as 1.3 percent diatomite doped in TiO₂ film.

Abstract: The application system of solar energy comprises: solar water heating system, solar heating system and solar photovoltaic system, etc. The data monitoring system used in the solar water heating system consists of measuring and monitoring equipment, data acquisition appliances and data-center softwares. The measuring and monitoring equipment includes outdoor temperature sensor, total solar irradiance sensor, water inlet and outlet temperature sensor of heat collecting system, circulating flow sensor of heat collecting system and the electric meter for supplementary heat source, etc.. The data monitoring system used in the solar photovoltaic system consists of measuring and monitoring equipment, data acquisition appliances and data-center softwares. The measuring and monitoring system is composed of outdoor temperature sensor, total solar irradiance sensor, the sensor for the surface temperature of back panel of solar photovoltaic modules and electric meter for the monitoring of power generation of solar photovoltaic system, etc.

Abstract: This paper evaluated the solar energy resource of Baicheng district in western Jilin province with HOMER simulation software. The results show that the solar energy resource of Baicheng district is quite abundant and relatively stable. This paper analyzed the current situation of PV generation in Baicheng district, considered that Baicheng district is suitable for large-scale PV generation projects and put forward some reasonable advice.

Abstract: The maximum power tracking and Grid-connected is the urgent need to solve the problem which exists in the grid-connected PV system. This article expounds on the maximum power point tracking and grid inverter control strategy. It puts forward the control strategy of researching maximum power point tracking, which is effective in improving solar panels convert solar energy into energy. With the development of photovoltaic technology, requirements of photovoltaic grid control strategy are getting higher and higher. This article examines adaptive disturbance observed method integrated control combined BOOST boosted circuit, in order to achieve the maximum power point tracking for photovoltaic panels .The photovoltaic inverter control structure is to meet the photovoltaic conversion efficiency and power quality of the main technical indicators. It put to use double topology and feed forward decoupling control strategy, which provides protection for the flexible grid.