Permanent-Magnet Synchronous Generators (PMSGs) exhibit high efficiency and power density, and have already been employed in gearless wind turbines. In the gearless wind turbines, due to the removal of the gearbox, the cogging torque is an important issue. Therefore, in this paper, at first, design of a Permanent-Magnet Synchronous Generator for a 2MW gearless horizontal-axis wind turbine, acco...

Synthetic Aperture Radar (SAR) is a useful and efficient tool for providing high-resolution images from sea surface wind fields. Wind field analysis based on SAR image descriptors makes the estimation of wind direction and speed possible. This is very useful for applications and Studies such as oil spills, waves, ocean circulation, marine meteorology and the coupling of oceanic and atmospheric ...

a wind farm is a collection of wind turbines built in an area to provide electricity. wind power is a renewable energy resource and an alternative to non-renewable fossil fuels. in this paper impact of wind farms in power system reliability is investigate and a new procedure for reliability assessment of wind farms in hl1 level is proposed. in proposed procedure, application of fuzzy – markov f...

Previous studies indicated that surface wind speed over China declined during past decades, and several explanations exist in the literature. This study presents long-term (1960–2009) changes of both surface and upper-air wind speeds over China and addresses observed evidence to interpret these changes. It is found that surface wind over China underwent a three-phase change over the past 50 yr:...

Line type heat detectors (LTHD) are used since many years in road tunnels for reliable fire detection. Today various systems as semiconductor sensor cables, fiber-optic sensor cables, and pneumatic copper tube systems are in use. In addition, after first pilot installations done in the last years, the demand for applications of LTHD in railroad and metro tunnels as well as in underground statio...

Because of their high wind gradient structures, tropical cyclones (TC’s) present a major challenge to space-borne scatterometer measurements of ocean surface wind vectors. Frequently spiral bands of strong rains accompany the high winds, and this precipitation attenuates the ocean backscatter due to wind. Also scattering by the rain volume increases the backscatter measured by the scatterometer...

To study the aerodynamic effects and load spectra caused by high-speed trains passing through double-track tunnels, this paper uses unsteady, viscous, compressible Navier-Stokes equations Re-Normalization Group k-? turbulence model with sliding grid technology for simulation. A dynamic test is carried out to verify calculation method grid. This considers impact of three main factors tunnel effe...