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Grid connection of small permanent magnet generator (PMG) based wind turbines requires a power conditioning system comprising a bridge rectifier, a dc–dc converter and a grid-tie inverter. This work presents a reliability analysis and an identification of the least reliable component of the power conditioning system of such grid connection arrangements. Reliability of the configuration is analyzed for the worst case scenario of maximum conversion losses at a particular wind speed. The analysis reveals that the reliability of the power conditioning system of such PMG based wind turbines is fairly low and it reduces to 84% of initial value within one year. The investigation is further enhanced by identifying the least reliable component within the power conditioning system and found that the inverter has the dominant effect on the system reliability, while the dc–dc converter has the least significant effect. The reliability analysis demonstrates that a permanent magnet generator based wind energy conversion system is not the best option from the point of view of power conditioning system reliability. The analysis also reveals that new research is required to determine a robust power electronics configuration for small wind turbine conversion systems. 相似文献
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为了最大限度地减少风机停机时间和提高风机发电量,基于风机功率曲线特性,结合多元统计Hotelling T~2控制图,提出了一种风力发电机性能及故障监测方法。首先,根据SCADA系统历史数据集,应用粒子群算法(PSO)寻优最小二乘支持向量机的模型,构造风电机组参考功率曲线。然后,计算风场各风机功率特性的多元峰度、多元偏度,将其偏离参考曲线的程度作为评估风力发电机性能的指标。最后,监测风机发生故障的时刻,引入用于监测风机的Hotelling T~2多变量质量控制图。将该方法用于某风场1.5 MW级风力发电机,实例表明,该算法可以有效地对风电机组状态及故障进行监测,为风电机组的故障识别及分析提供了一种新的方法。 相似文献
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世界风电机组技术发展的趋势是兆瓦级大功率,作为兆瓦级风力机核心部件的叶片是如何制造的?又有些什么特性呢?其发展趋势是什么?等等,本文就此做一概括介绍,供读者参考. 相似文献
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If there is an ideal wind turbine, its performances will be the pursuit goals for designing the actual wind turbine. In this paper, the wind turbine that has the maximum efficiency is defined as ideal wind turbine, which has three main features: lift-drag ratio is infinite, it has enough number blades so that the blade tip and root losses can be ignored, and its blades are limited in width. Using blade element theory, the differential equations of power, torque, lift and thrust of blade element were derived, and the expressions of power, torque, lift and thrust coefficients of the ideal wind turbine were gained by integrating along the blade span. Research shows that the power, torque and lift coefficients of the ideal wind turbine are functions of tip-speed ratio. When the lift-drag ratio and the tip-speed ratio is approaching infinity, power coefficient of the ideal wind turbine is close to the Betz limit; The torque limit is 0.401 when the tip-speed ratio equals about 0.635; The Lift limit is 0.578 when the tip-speed ratio equals about 0.714; The thrust coefficient is 8/9, which is unrelated with tip-speed ratio. For any wind turbine which tip-speed ratio is less than 10, the power coefficient is unlikely to exceed 0.585, for any high-speed wind turbine which tip-speed ratio is greater than 6, the torque coefficient in steady state is unlikely to exceed 0.1, and the lift coefficient is unlikely to exceed 0.2. 相似文献
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浓缩风能型风力发电机 总被引:4,自引:0,他引:4
一产品特点浓缩风能型风力发电机是内蒙古农业大学新能源技术研究所研制开发的实用新型专利(专利号:ZL94244155.9)产品。该机将稀薄的风能经浓缩风能装置加速、整流和均匀化后驱动叶轮旋转发电,从而提高了风能的能流密度,改善了风能的不稳定性,提高了风能品位。与普通型风力发电机相比,本专利产品具有以下特点: 相似文献
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The Composite Bearingless Rotor (CBR) concept has been shown to have characteristics ideally suited for wind turbine applications. Originally developed for helicopters to reduce weight, costs and complexity, the CBR eliminates blade bearings and hinges through the utilization of the unique structural characteristics of uniaxial composite materials. This rotor concept was further developed under an ERDA contract to provide a fully self-regulating and self-aligning wind turbine. Such a system was achieved without the need for auxiliary controls or sensors. These features allow self-starting for wind initiating from any direction and automatic pitch and yaw variations to optimize performance under all normal wind conditions. The work described in this report consists of the design and fabrication of a 4.5 ft dynamically scaled wind turbine model and the successful testing of this model in the United Technologies Research Center low speed wind tunnel. 相似文献
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Optimum siting of wind turbine generators 总被引:3,自引:0,他引:3
This paper investigates optimum siting of wind turbine generators from the viewpoint of site and wind turbine generator selection. The methodology of analysis is based on the accurate assessment of wind power potential of various sites. The analytical computations of annual and monthly capacity factors are done using the Weibull statistical model using cubic mean cube root of wind speeds. As many as fifty-four potential wind sites, with and without wind turbine installations, geographically distributed in different states of India are used for the siting analysis. As an outcome of this analysis several definitive conclusions of archival nature have been arrived at and are presented in the paper. If this analysis is done at the planning and development stages of installation of wind power stations, it will enable the wind power developer or the power utilities to make a judicious choice of potential site and wind turbine generator system from the available potential sites and wind turbine generators respectively 相似文献