Advanced Materials Research Vols. 608-609

Abstract: Based on China's Photo Voltaic Energy Application Status Analysis, the paper forecast and analyzed photo voltaic applications installed capacity by combining the grey GM (1, 1) model with the second-order weakening buffer operator. The results of the forecast showed that the annual growth rate of total installed capacity of PV applications is 17.4% during "The 12th Five-Year Plan", to reach 14829.55 MW which can achieve the basic planning objectives by 2015. The future of renewable energy accounting for the proportion of energy consumption will become increasingly large. Judging from the forecast results, due to the PV Application market uncertainties highlight, the Government should continue to promote technical progress, improve energy efficiency, in order to better promote the development of PV Application market.

Abstract: In photovoltaic power systems, both photovoltaic modules and switching-mode converters present nonlinear and time-variant characteristics, which result in a difficult control problem. This paper presents an in-depth analysis and modeling to discover the inherent features of a photovoltaic (PV) power system and proposes a control method for PV power system based on small-signal model. This paper also presents a state equation and transfer function of PV power system and a stable control system for regulating the photovoltaic voltage. Simulation and experiment results demonstrate the effectiveness of the presented analysis, design, and implementation.

Abstract: As the development trend of solar energy, which is a green way of energy utilization, photovoltaic power generation has been a research hotspot of solar energy utilization technologies. Using the concentrating and tracking technology to increase the illumination intensity, and obtain more electrical energy, that will reduce the cost of the photovoltaic power generation system sharply. A kind of steric and multilevel concentrator for photovoltaic generation is introduced in this paper, whose concentration ratio is 3. The operating factor of plane mirrors and performance price ratio of the system is increased for optimizing the condensation parameters and structure of the concentrator.

Abstract: In order to improve the solar energy utilization, in the respect of technology, we should perfect solar tracking devices, realization of the sunlight is always vertical to the solar panels. This paper is to design a kind of solar automatic tracking system. Design adopts the traditional photoelectric tracking method, with the FPGA as the core, and by using the methods of scheduled monitoring, achieve precise control of stepping motor, thereby promoting the solar panels rotate remains vertical to the sun, which can effectively improve the efficiency of solar power systems.

Abstract: Based on the thermal equilibrium between the PV panels and the glazing cover of PV/T system, the influence of the spacing between PV panels and glazing cover on the solar-thermal efficiency is discussed. The heat release and solar-heat conversion efficiency of the photovoltaic panels, under different plate spacing, in the PV/T systems in summer are calculated, according to the typical annual meteorological parameters of Tianjin area. The results show that the photo-thermal efficiency of the PV/T system can be improved by appropriate setup of the plate spacing, and the optimal plate spacing is affected by the temperature of photovoltaic panels.

Abstract: This paper first compares with international incentive policies, reviews some relevant incentive measures in China. Meanwhile, introduce the content of the critical subsidy policies in detail, summarize its positive impact on PV industrial development, and analyze a few of representative unreasonable problem in the process of policy application. Finally, gains some inspirations for the worldwide application of PV industry in China as follow: promotes the on-grid of building integrated PV (BIPV) projects, formulates rational feed-in tariff linking to the distinction of solar energy resources of different areas, which can ensure the profitability of PV industry in its operation period.

Abstract: The MPPT techniques of Incremental Conduction Method (ICM) and Perturbation and Observation (P&O) cannot track the maximum power point (MPP) of solar cell quickly without oscillation around MPP. This is happens because of the working point’s movement given by MPPT always has a same distance. This paper proposes a MPPT technique based on PI controller which able to reach the MPP quickly and the oscillation is near to zero. PI controller with error feedback is the gradient of solar cell’s power characteristic curve, is used as power optimizer replacing the step-size optimizer. Performance of the proposed technique is compared against the ICM one through simulations. The results show the proposed technique has much faster tracking time than the ICM has and the oscillation can be set to near zero.

Abstract: All photovoltaic panel heats up when exposed to sunlight and this heating reduces the electrical power output of the same. This work presents the use of this unwanted waste heat, converting it into thermal energy directly by means of the Seebeck effect, which is the direct conversion of thermal energy into electrical energy by means of an arrangement of semiconductor materials that when exposed to temperature gradients generate electric current. In this work emphasis was placed on the influence of temperature on generation processes involved. Thus, the theoretical evaluation, it presents the mathematical models of thermoelectric and photovoltaic systems by raising the curves of voltage, current and electric power generated, and analyses the influence of temperature in each model. To obtain the simulation curves it uses MATLAB ® 5.3, taking into account the parameters of thermoelectric modules and real photovoltaic cells. In practical evaluation, a prototype was assembled containing thermoelectric module attached to the bottom of a photovoltaic panel in order to use the heat energy absorbed by the panel. The data were stored and analyzed, where we observed the influence of temperature in both systems, validating the mathematical modeling. It is the applicability of the mathematical model given the results obtained with the prototype system.

Abstract: Parameter identification is the core of PV power generation modeling. In this paper, A model of PV power generation is established. It is based on the PV power generation control mechanism and suitable for electromechanical transient simulation of power system. The identifiability of model parameters is also analyzed. The study results show that: the model has a simple structure, when the input-output dynamic data is known, The model parameter can be identified.

Abstract: This paper gives an overview of energy status around the world, and shows the importance and prospects of photovoltaic system. It introduces the classification and characteristics of solar of different generation battery in detailed as well as summary of inverter. Finally, some key technology Of connecting grid will be discussed which means great significance to popularizing and spreading of application of Photovoltaic generation.