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Showing 3 results for Pitch Control
Volume 16, Issue 4 (7-2017)
Abstract
In the recent years, wind energy improves to one of the most important sources of electricity production. For instance it is predicted that the installed wind capacity in China will be about 40 GW till 2020. The permanent magnet synchronous generators (PMSG) which contains a permanent magnet that causes DC excitation current in the stator windings, are widely used in variety of wind turbines. The advantages of this type of generators in comparison to the others, are higher efficiency, controllable terminal voltage and reactive power. It is also remarkable that the PMSG speed can be controlled by the converter leads to MPPT implementation. The MPPT is always implemented to control the generator speed and output power between the cut-in and nominal wind speed. It is necessary to control the generator speed by pitch or stall control for upper rated wind speeds. In this paper after explaining the structure and components of a typical wind turbine with permanent magnet synchronous generator, designing of an offline DMC (Dynamic Matrix Control) and a gain scheduled PI pitch controller are presented. Both of these controllers have been tested on the practical simulator of 100 KW wind turbine with PMSG generator and the results are presented and compared.
Amir Hossein Asgharnia, Reza Shahnazi, Ali Jamali,
Volume 17, Issue 3 (5-2017)
Abstract
In this paper, an optimal Fractional-order Proportional-Integral-Derivative (FOPID) controller is proposed to control an offshore 5MW wind turbine’s pitch angle in above rated speed. The proposed pitch controller regulates the generator angular speed and consequently the generator power to its nominal value without any knowledge of the model. In order to find the parameters of the controller, a hybrid cost function is proposed, which consists of sum of absolute error signal and absolute rate of control signal in three different wind speeds. The wind speeds are chosen in the beginning, middle and at the end of the interval, thus, the optimized controller is able to show an acceptable performance in whole range of wind speeds, without any demand to nonlinear and complex controllers. To this end, the proposed cost function is minimized using three optimization algorithms: Differential Evolution (DE), Firefly algorithm and Particle Swarm Optimization (PSO). In order to evaluate the robustness of proposed FOPID, numerous wind profiles with different speeds and fluctuations are applied and the results are compared with the optimal integer order PID controller. The comparison demonstrates that the proposed FOPID has more effective performance and robustness than optimal integer order PID.
M. Mazare, M. Taghizadeh , S.m. Aghaeinezhad ,
Volume 19, Issue 4 (4-2019)
Abstract
Conspicuously, pitch angle control strategy has been applied to mitigate the influence of mechanical load and also output power control at above-rated wind speeds. In this paper, a wind turbine is modeled based on simplified two-mass model and an adaptive sliding mode controller (ASMC) is designed based on individual pitch control (IPC) strategy. To do this, the single-blade approach is used and the wind turbine was divided into aerodynamics and mechanical subsystems and governing equations of each subsystem were derived. By designing and applying the ASMC to two-mass model, system behavior is observed and simulated in terms of step and turbulent wind speed inputs. In addition, to verify the validity of the ASMC, the proposed controller is implemented in the FAST environment and the wind speed profiles are generated using TurbSim. In order to analyze the environmental effects on the dynamic behavior of the system, the controller performance is explored in presence of parametric uncertainties. It should be noted that rotor speed tracking error is evaluated and demonstrated through different criteria.
