Advanced Materials Research Vols. 608-609

Abstract: Due to gearbox is one of the high failure rate component in the wind turbine, the research of it has been paid wide attention in recent years. This paper reviewed the two aspects about the wind turbine gearbox. First, some signal process methods including how to determine the threshold were summarized. Then, the condition monitoring and fault diagnosis of gearbox were reviewed using the measured signals. These researches are benefited for reducing economic losses which is caused by the gearbox failure. Based on the above reviews, this paper gives some developmental direction.

Abstract: Wind speed prediction is critical for wind energy conversion system since it not only can relieve or avoid the disadvantageous impact on power system, but also can enhance the competitive ability of wind power plants against others in electricity markets. The model presented in this paper was based on artificial neural network (ANN) and the selection of the model parameters was presented in detail. The autocorrelation function (ACF) of wind speed time series was used to determine the input variables of the neural network. The simulation was carried out with the proposed ANN model.The conclusion that the optimal network structure may be different corresponding to different error evaluation was drawn through a large number of simulation experiments. And the simulaiton results showed that the ANN model is less than 10.77% in terms of root mean square error and 5.86% in terms of mean absolute error compared with the persistence model.

Abstract: Electricity is the basic industry in China, which has the important strategic significance to maintain the social stability, ensure the national security and promote the economic development. With the rapid development of power market reform and the establishment of bidding for access mechanism, the competition among the power generation enterprises becomes much drastic. To evaluate the development ability of wind power enterprises in the power new energy, the authors proposed a novel particle swarm optimization (PSO) algorithm, which used the randomness, the rapidity and the global characteristics to obtain the pheromone distribution, and had the faster convergence velocity. The development ability evaluation of 12 wind power enterprises showed that the results given by this model were reliable, and it is feasible to evaluate the development ability using this method.

Abstract: According to the provisions of low voltage ride through capability of wind turbines in the “large-scale design and technical specifications for wind farm to grid” of china, proposed a method to simulate this low voltage ride through grid voltage by computer simulation software. The simulation method is mainly used to simulate whether the wind turbines grid can meet the low voltage ride through requirements. In order to obtain the required grid voltage, the fault simulation circuit is divided into voltage dip part and voltage recovery part, which were used to simulated 20% & 90% voltage dip and the 20% grid voltage gradually recovered to 90% grid voltage. Three-phase fault modules for the voltage dip part, Three-phase programmable voltage source module for the voltage recovery part. The simulation results show that simulation system we build can simulate the required grid voltage.

Abstract: With the large-scale and rapid development of wind power in China, the accuracy of wind power prediction is asked for higher. So how to improve the accuracy of numerical weather prediction models which forecast wind has become an important and critical issue. That the accuracy of numerical prediction models as well as the bias of background data is main cause why generate simulated error. This paper attempted to employ the advanced WRF model to simulate the low-level wind in arid region of northwest China, and then evaluated the impact size that using FNL and GFS background data. The results show that using FNL and GFS data simulated wind is very close. It is found that simulation results driven by the FNL assimilated data are worse sometimes. Consequently, we can conclude that FNL assimilated data as well as GFS forecast data are close and the assimilation of FNL data is still need to improvement in northwest China.

Abstract: Both rotor aerodynamic characteristics and structural performance of the blade are critical to the wind turbine system service life; an accurate loading model of the blade is extraordinary complex due to the complexity of the geometry shape and variety of blade thickness. In this paper, a 10KW fixed-pitch variable-speed wind turbine blade with five different thickness of aerofoil shape along the span of the blade is presented as a case study, main parameters of the wind turbine rotor and the blade aerodynamic geometry shape are determined based on the principles of the blade element momentum (BEM) theory, a specific blade internal structure and layup schedule are designed. Based on the FE method, deflections and strain distributions of the designed blade under extreme wind conditions are numerically predicted. Theoretical and numerical results indicate that aerodynamic characteristics of the designed blade meet the requirement, the tip clearance is sufficient to prevent collision with the tower, and the blade material is linear and safe.

Abstract: The blade is the most important and the most basic component in a wind turbine. Testing its river basin through the physical experiment is difficult, because this test system is complex and workload is heavy, and through the macroscopic observation result far from the actual value.According to this problem, this study employs UG 3d entity software modeling, using computational fluid dynamics software FLUENT to simulate the speed changes of fan blade rotating basin and the pressure distribution.The simulation results show that the airflow velocity in the impeller increases with impeller radius increasing,static pressure with air from entry to export flow decreases gradually.

Abstract: This document explains the development of wind power; especially the wind power energy in Xinjiang. At the same time the paper demonstrates the difficulties, wind power technology, Wind power is a fixed tariff and tariff subsidies lag, the grid company lack of acquisition of wind power and the trading system is incomplete and hampered a wide range of consumer satisfaction, which faced in the further development of Wind power industry and finds some factors. The good news is National policy began to tilt to the solar, wind and other clean energy, which is a good opportunity for the wind power industry in Xinjiang.

Abstract: The current worldwide energy consumption is largely dominated by non-renewable energies such as coal, oil and gas. For well-known reasons, this concept should be changed to a more sustainable one based on renewable. Wind power, the most developed and commercialized renewable energy technology, has considerable potential. The relationship between economic growth, energy exhaustion and green house gas (GHG) emissions becomes the major recent years. Considering economic development, demand for energy, emissions abatement and wind energy substitution rate, a dynamic growth model with substitution of wind energy is presented. Based on the model, it describes how the activity of substitution impacts other elements in the economic system in the future. China is the selected study region and the optimal systemic project of wind power industry has been obtained by using the theory of cybernetics.

Abstract: Low voltage ride through (LVRT) behavior is one of the key indices of wind turbine grid-integration evaluation. The key electric components of wind turbine, such as converter, control system had been researched. While other components of wind turbine, such as the rotor arrester, are also non-ignorable. Firstly, overvoltage of rotor during the LVRT is analyzed and one failure test has been presented because of rotor arrester performance. Finally, the rotor arrester has impact not only on the LVRT ability of wind turbine, but also damage to other hardware by on-site testing.