This research deals with investigations on the “Active Generator” under rotor speed variations and output frequency control. It runs at turbine speed and it is connected to a three phase electrical power grid which has its own frequency different from turbine frequency. In this regard the set composed of a four phase synchronous generator and a natural commutated matrix converter (NCMC) made wi...

The work presented in this paper has two major aspects: (i) investigation of a simple, yet efficient model of the NREL (National Renewable Energy Laboratory) 5-MW reference wind turbine; (ii) nonlinear control system development through a real-time nonlinear receding horizon control methodology with application to wind turbine control dynamics. In this paper, the results of our simple wind turb...

A circuit model is proposed in this paper for calculating the transient potential rise on the wind turbine struck by lightning. The model integrates the blade, sliding contact site, and tower and grounding system of the wind turbine into an equivalent circuit. The lightning current path from the attachment point to the ground can be fully described by the equivalent circuit. The transient poten...

Turbine oil plays an important role in supporting optimal steam turbine performance. Some additives in turbine oil can cause emulsification when the oil is contaminated by water, so demulsibility is a very important property of the steam turbine oil. In order to improve the demulsibility of steam turbine oil, two kinds of polyether-silicone comb copolymers are synthesized and used as steam turb...

Surveys have shown that noise from wind turbines is perceived as annoying by a proportion of residents living in their vicinity, apparently at much lower noise levels than those inducing annoyance due to other environmental sources. The aim of the present study was to derive the exposure-response relationship between wind turbine noise exposure in L(den) and the expected percentage annoyed resi...

OBJECTIVES The aim of this study was to analyze the effect of the International Nosocomial Infection Control Consortium's multidimensional approach on the reduction of ventilator-associated pneumonia in patients hospitalized in intensive care units. DESIGN A prospective active surveillance before-after study. The study was divided into two phases. During phase 1, the infection control team at...

Abstract One of the food diversification strategies coconut commodity is to process it into Pliek U. U a typical Province Aceh, Indonesia, which in its processing stage requires drying process. So far, often conducted conventionally through direct (sun drying), so that produced susceptible dust and other dirt contamination. This research aimed design dryer using Dafa type solar energy. The ener...

A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles fo...