Variable-speed wind power generation using doubly fed wound rotor induction machine-a comparison with alternative schemes

A brief status on condition monitoring and fault diagnosis in wind energy conversion systems

“…One of the preferred options at present, for large turbines in excess of 2-MW rating, is the variable speed DFIG with the rotor converter connected to the rotor via slip rings [7], [27]. However, in contrast to squirrel cage generators there are additional wear parts, e.g.…”

Silver Doped TiO2 Photocatalyst for Methyl Orange Degradation

“…Due to the stability of modern dyes, conventional biological treatment methods for industrial waste water are ineffective, resulting often in an intensively colored discharge from the treatment facilities. Recently, a number of researches have dealt with heterogeneous photocatalytic decomposition of many kinds of azo-dyes [5,6] by UV, visible light and solar irradiation [7]. Methyl orange (MeO) is comparatively stable without photocatalyst under UV and outdoor irradiation.…”

“…Methyl orange (MeO) is comparatively stable without photocatalyst under UV and outdoor irradiation. Titanium dioxide has been widely used as a photocatalyst for the degradation of МeО [6,8,9]. Photocatalytic efficiency of the nanocrystalline TiO2 system is strongly influenced by light sources and recombination of photoinduced electrons and holes.…”

Robust Speed Sensorless Control of Doubly-Fed Induction Machine Based on Input-Output Feedback Linearization Control Using a Sliding-Mode Observer

“…This arrangement provides flexibility of operation in sub-synchronous and super-synchronous speeds in both generating and motoring modes. The power inverter needs only be rated for a fraction of the total output power, the fraction depending on the permissible sub-and supersynchronous speed range [4]. Therefore, it is possible to use a high-frequency switching PWM converter to achieve high performance, such as fast dynamic response, low harmonic distortion, high efficiency, etc., without cost penalty.…”

“…The last problem is particularly crucial in applications such as wind power generation because there is a large physical separation between the generator (which is coupled to the turbine shaft through gears) and the power electronic equipment (which is at ground level) [4].…”