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Individual pitch control is seen as a promising control technique for load reduction of the rotor blades in megawatt wind turbines. As the rotor blades are getting bigger and bigger, the asymmetric loads due to wind speed variations across the rotor area are increasing, too. Modern wind turbines include individual pitch actuators for every blade and the control effort is also reasonable. This is why...
This paper presents optimum power output from vertical axis wind turbine (VAWT's) by changing variable swept area. We used the H-Darrieus type of VAWT's, it has developed extendable blade and radius of VAWT's. These turbines response to the wind speed by changing swept area automatically extend outward at low wind speed and retract at excessive wind speed. This action increases the efficiency and...
This paper proposes the use of an active yaw system to protect small and medium wind turbines in the high wind zone from overloading. The active yaw system turns the rotor partially out of the wind to decrease the turbine power. The dependency of the power on the yaw angle is modeled by the third power of the cosine of the yaw angle. A proper controller is configured based on on-off control of the...
Nowadays, in the context of the demand for energy is growing by the day, the fossil energy sources are being depleted and environmental pollution problems caused by the exploitation and use of this energy resources is causing severe consequences for life on Earth, the development of renewable energy has become a strong trend throughout the world. In types of renewable energy sources, solar and wind...
More accurate dynamic models of wind turbines are of great importance in validating simulation results of their interaction with the network (micro-grid), and thus the reliability of the network (micro-grid) is improved. The first of this paper is an overview of wind power and wind energy conversion system structures. In addition, network requirements in the presence of wind energy conversion systems...
Modern wind turbines are mainly horizontal axis and operate in bottom atmospheric boundary layer driven by wind shear flow, therefore as the blades rotating the aerodynamic load vary cyclically, with horizontal axis wind turbine (HAWT) large-scaling the cyclical characteristic becomes more obvious, shortening blade life and increasing cost of wind turbine. As the development of wind turbine large-scaling...
Various components of Wind energy system included in pitch control where explained in this paper. Pitch angle control design was described and wind velocity variation of pitch controller response is discussed. Large output power and settling time are the results of the pitch control system. The control over the mechanical power is obtained by pitch function and it is the most common method applicable...
Icreasing demands of electricity, to reduce reliance on fossil fuels, reduction in greenhouse gases, increasing oil prices and climate changes are the main factors which motivate utilization of renewable energy technologies in the world. Wind Energy has made a significant progress over the last two decades and evolved as one of the mature and fastest growing renewable energy technology due to its...
Wind energy technology has seen steady growth in the energy market as a clean, renewable source of energy. This has brought attention to areas with moderate wind energy potentials. Darrieus type Vertical Axis Wind Turbines (VAWTs) allows capturing of this potential for energy production at a cost-effective scale. To improve the performance of these turbines their design needs to be modified. With...
Traditional Savonius wind turbine has advantages such as simple structure, fast start-up, etc., however, it also has significant disadvantages of low wind energy utilization efficiency. A novel wind turbine is proposed by improving structure of Savonius wind turbine in order to increase the low wind energy utilization efficiency. To compare performance of the novel wind turbine and the Savonius wind...
This paper presents a simulation of an onshore energy conversion system connected to the electric grid and under a strategy of a supervisor control based on deterministic version of a finite state machine. The simulation is planned to address an analysis on performance due to the action of the supervisor. The supervisor is included at the higher level, having the objective of analyzing the operational...
The principle of autorotation could potentially be utilized for harvesting energy from strong wind fields. Autorotation is a well-known phenomenon where a rotor in a strong wind field experiences significant lift force and aerodynamic torque. With recent works indicating immense, persistent availability of wind energy at high altitudes, autorotation could be used for harvesting wind energy from such...
This paper investigates a drive system control strategy for grid-connected wind energy conversion systems with doubly-fed induction generator and its behavior under grid fault operation. During grid faults there is a possibility for undefined load situations in the mechanical drive system. These loads are able to start oscillations in the drive system not only in the shaft but in the blades as well...
In recent years, concern has grown towards renewable energy sources particularly wind energy for the production of electricity. The scientist and researchers have gone through rigorous study and experimentation to search the solution for fruitful utilization of wind energy. Our day to day activity is heavily based on energy, hence the work towards energy research is highly important and sensitive...
Energy demand and supply has always been a core issue in the world for decades. These days all the countries are trying to cope up with the rapidly growing energy demands due to high energy appliances and industrial machines. The renewable energy resources are a preferred area of interest for researchers as these resources are harmless to the environment. The aim is to contribute towards wind energy...
In this study, we developed a dynamic equivalent model for large-scale wind power plants based on an aggregation technique. The model is obtained in steps that include wind turbine clustering, development of slow dynamic models for the clusters, and aggregating of the models with the rest of wind power plant network. To confirm the effectiveness of the proposed method, the developed model is tested...
Fossil fuels have been a means of energy source since a long time, and have tended to the needs of the large global population. These conventional sources are bound to deplete in the near future and hence there is a need for producing energy from renewable energy sources like solar, wind, geothermal, tidal etc. Technologies involving renewable energy are a growing subject of concern. The problem is...
This paper presents a control strategy based on two distinct controllers for different operating regions applied to a wind turbine benchmark. In previous works, we proposed the control of a wind turbine using two distinct controllers for all operating regions. The contribution of this work focus on the use of two distinct controllers for two different operation regions, the fuzzy proportional integral...
This paper investigates a drive system control strategy for grid-connected wind energy conversion systems with doubly-fed induction generator and its behavior under grid fault operation. During grid faults there is a possibility for undefined load situations in the mechanical drive system. These loads are able to start oscillations in the drive system not only in the shaft but in the blades as well...
To reduce the blades asymmetric loads of large wind turbines operated in the above-rated wind speed region, this work proposes a model predictive individual pitch controller with the linear interpolation model. Results show a significant reduction of 1P (once-per-revolution), 2P, 4P blade asymmetric loads within the limits of pitch rate. The proposed model of wind turbine can describe the characteristic...
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