Advanced Materials Research Vols. 724-725

Abstract: As the installed capacity of photovoltaic power station is growing, the power prediction techonology is of great important to reduce the random damage to the power system. A prediction model using neural network is proposed in the paper, the solar radiation model is adopt to ensure the accuracy of the prediction results in clear sky contions.Through the analysis of photovoltaic power station output power influence factors, the the solar radiation intensity, humidity and temperature are chosen as the input of the neural network prediction model.At the same time, in order to improve accuracy the photovoltaic power station power prediction model, the power adopt numerical weather forecast information. And the prediction model is tested by the photovoltaic power station historical operation data, and the short-term power prediction has a good performance.

Abstract: This paper proposes a modified equation-based model for a PV cell to get the best I-V characteristic comparing with the points taken directly from the manufacturer’s published curves. Based on the model discussed in [1, 3], a modified mathematical equation is put forward taking the changes of environmental parameter into account. Moreover, on the basis of Boost-circuit, an optimized initial Duty Circle is proposed. The initial data varies with the different temperature and irradiance. This method can result in a high speed MPPT. To validate the model accuracy and the MPPT efficiency, the elements library about PV system has been developed in PSCAD software. A particular typical 200W photovoltaic panel (KC200GT) is used in simulation. By comparing with the general model and manufacturer’s datasheet, the simulation results show excellent correspondence to the modified model. The improved MPPT module in PSCAD can track the maximum power point quickly and exactly.

Abstract: A numerical method for determining the five-parameter model of photovoltaic cells is presented in the paper. Explicit equations are applied to analyze the relations between parameters and determine their values by optimization algorithm. Unlike previous works, the application of explicit equations and the simple algorithm make the proposed method very simple. The proposed method is validated by Shell S65 .It is found that the proposed method gives superior results not only on standard but also on operating conditions of photovoltaic cells. Considering its simplicity and accuracy the method can be applied in practice widely.

Abstract: For the uncertain characteristics of output power of distributed Photovoltaic (PV), the energy storage device is used to make up the error, between the predicted output and the actual output, to achieve the volatility control of PV power system. This paper presents that the application of support vector machine (SVM) in the power output forecasting of PV volatility control. Based on the complex and non-linear of the factor affecting the PV output, it points the non-linear relationship between the influencing factors and predicted values, and it establishes the SVM regression model of the PV system. Meanwhile, combined with the historical data of the PV operation, it gives the predictive values. Both theoretical analyses and calculation examples show that this method is simple, with high precision, and it is more suitable to the PV output volatility control.

Abstract: With energy saving and comfort as top priorities, a hot water supply system is designed with solar energy and gas as compound heat sources. In the design, mathematical models are set up for the solar energy and gas compound hot water system and for its economic evaluation. Taking a three-bedroom flat building in Guangzhou City for example, a whole years energy consumption for domestic hot water is simulated; the gas consumption is calculated; comparisons are made between the new system and the gas hot water supply system in terms of their technique, economy and energy efficiency. Results show that the solar energy and gas compound hot water supply system effectively saves energy and has good economic benefits.

Abstract: Solar energy has the resource characteristics of cleanlinessno pollutiondispersion and intermittence. The research results and progress of solar energy integration technology application in the photothermal iron-making, photothermal concentrate titanium white waste acid, photovoltaic steel-making and preparation of pure iron by photovoltaic electricity both at home and abroad are summarized. As an effective clean energy, solar energy is regarded having a great application prospect in the metallurgical field.

Abstract: Starting from the present situation of energy in China, we discuss how to improve building energy efficiency through comprehensive utilization of solar-energy (SE). Moreover, we study how to adapt the multi-function system for SE, which not only can be used for solar refrigeration but also for solar heating and hot water supply.

Abstract: This paper presents a smart dual-axis solar tracking system, its architecture includes sensors, embedded controllers, AC motors, Integrated electric putter design biaxial institutions, and the GSM automatic report of fault notification, to achieve autonomous tracking solar track system and adjust the solar panels to reach the maximum smooth by tracking the solar azimuth angle and elevation angle, and ensure that the solar panels with the sun to maintain the vertical in any time and any place, thus achieving the best power efficiency. This system proposed a dual-axis design, and an embedded controller used as the main system controller to detect voltage difference and determine the solar azimuth angle with four groups of CDS as a sensing element. To lock the sun, the solar panels be perpendicular via the moving of AC motor (EW) and motorized faders (north-south). The control system software using C language can be extremely fast and accurate tracking of the solar angle, and dual-axis operation with recovery mode to save the power loss. Finally, we have the actual analysis and verification of benefit of power generation in this paper, from this experimental results, we can verify the integration of build dual-axis solar tracking system and solar power system have promoted 30% generating power capacity more than fixed solar power system and has low failure rate. It can improve the problem of traditional tracking system reliability and greatly enhance the usefulness of this system.

Abstract: Recently, Solar energy and wind energy composite wind turbine by a number of studies have been carried out to examine the fault-ride through capability of the DFIG system during network disturbance. Whereas for all the work reported, the network voltage was assumed to be symmetrical. However, in practice, asymmetric faults occur more frequently than symmetric ones. For a DFIG system, if the voltage unbalance is not considered in the control system, the stator current could be highly unbalanced even with a small unbalanced stator voltage. The unbalanced currents create unequal heating among stator windings and torque pulsation in the generator. A wind-turbine driven DFIG without unbalancing voltage control considered might have to be disconnected from the network during network voltage unbalance.