In this work, a second-order sliding mode control algorithm is proposed for variable speed laboratory size DC generator wind turbine experiment system in order to track a speed profile and operate the wind turbine at maximum power extraction. The turbine torque, which varies with the wind speed, is considered as an unknown disturbance and rejected by the sliding mode strategy. The sliding mode ...

This paper presents the results of simulations of the complete three-dimensional fluid flow through the Spiral Casing, Stay Vane, Guide Vane, and then through the Francis turbine runner of the Derbendikan power station. To investigate the flow in the Francis turbine and also to identify the loads acting on the turbine blades, a three-dimensional model was prepared according to specifications pr...

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these publi...

The mechanisms underlying chromosome organization in bacteria are still shrouded in mystery. Sullivan et al. (2009) and Gruber and Errington (2009) now report that the DNA-binding protein ParB ensures proper arrangement and partitioning of chromosomal DNA in Bacillus subtilis by recruiting the condensin SMC to the replication origin region.

flow in the first two-stage of v 94.2 gas turbine is simulated numerically. in this turbine, the second stator is clocked relative to the first stator to different positions. steady-state analysis was carried out by varying the circumferential relative position of the consecutive stator vanes to study the effects of the clocking on turbine performance. a density based compressible inviscid flow...

determination of the starter torque-speed diagram is a major task in the design or selection of a proper gas turbine starter. in this paper, the maximum power of the mgt-40 gas turbine starter was calculated based on the dynamics of the rotor, start-up logic, and compressor map. in a recent research, the pressure ratio was assumed as a linear function of the rotor speed and the required starter...

This paper is based on a recent paper presented in the 2007 IEEE SMC conference by the same authors [1], discussing an approach to predicting energy output from an instream tidal turbine farm. An in-stream tidal turbine is a device for harnessing energy from tidal currents in channels, and functions in a manner similar to a wind turbine. A group of such turbines distributed in a site is called ...

A new composite turbine control architecture that consists of feedforward and feedback parts based on the upwind speed measurements and wind speed measurements at the turbine site, respectively, is described. The algorithm starts with preprocessing of a low-rate sampled upwind speed via the spline interpolation method. A run-ahead model driven by the signals from a preprocessing block models th...

Pregnancy in women aged 40 and above is frequently unplanned and the legal abortion rate is high in this age group. Contraception and fertility are shrouded in popular mythology and many women do not appreciate either their risk of conception or the range of methods available to prevent conception. Either hormonal or non-hormonal methods of contraception may be appropriate.

Based on the recent QSO surveys it is shown that, contrary to the widespread notion, high-luminousity QSOs are at least as numerous in the nearby universe as the ultraluminous far-infrared galaxies (ULIGs). Therefore, the fraction of ULIGs that have got a hidden quasar at the nucleus, for example in the dust shrouded phase, cannot be overwhelmingly large.