Operating Characteristics Of Wind Turbine Research Articles

Rotor equivalent wind speed calculation method based on equivalent power considering wind shear and tower shadow

Wind speed spatial variation in the whole wind wheel rotation plane caused by wind shear and tower shadow effect becomes more obvious with the increase of rotor diameter and tower height, thus the hub height wind speed is not sufficient to represent the actual wind speed effect and the rotor equivalent wind speed should be used. However, the existing rotor equivalent wind speed calculation models do not consider wind turbine operation characteristics, which cannot match the actual power control effect, thus ignoring the power loss caused by actual power control deviation. To address this problem, a rotor equivalent wind speed calculation method based on equivalent power is proposed in this paper, which comprehensively considers wind shear, tower shadow and wind turbine operation characteristics. The rationality of the proposed model was qualitatively evaluated from different power control stages of wind turbine and the validity was quantitatively verified from the aspect of theoretical power calculation. The results demonstrated that the proposed model can effectively reflect the variation law of rotor equivalent wind speed under the actual control effect of different power control stages, which contains the power loss caused by actual power control deviation, thus improving the theoretical power calculation accuracy.

Double‐Fed Wind Power System Adaptive Sensing Control and Condition Monitoring

This paper presents an in‐depth study and analysis of improving the performance of doubly fed wind power systems using adaptive sensing control technology. The maximum wind energy tracking principle is analyzed in this paper with the wind turbine operation characteristics. Considering that the operation state and control strategy of a doubly fed wind power generation system is different before and after grid connection, the no‐load simulation model and power generation simulation model are established based on the idea of separate modeling and time‐sharing work. Combined with the respective control strategies and enabling modules, the overall simulation system is constituted for the continuous process from no‐load operation to power generation operation. To analyze the chaotic mechanism of ferromagnetic resonance of wind farm power system and suppress the problem, based on the ferromagnetic resonance model of wind farm power system, analyze the basic conditions of the system into the chaotic state, consider the resonance phenomenon when external excitation acts, adopt the multiscale method to calculate the approximate solution at the resonance of main parameters and determine the steady‐state solution and stability conditions, and explore the influence of external excitation on the dynamic characteristics of ferromagnetic resonance. In this paper, the inverse system approach, applied to the linearized decoupling of doubly fed wind power, a nonlinear, strongly coupled multivariable system, is derived for the no‐load inverse system model and the inverse system model for the power control scheme and the speed control scheme to achieve maximum wind energy tracking for grid‐connected power generation, respectively. The model further extended to fractional order to study the complex dynamical behavior of the system of different orders and flux chain subsquares. To suppress the system chaotic oscillation phenomenon, a fractional‐order finite‐time terminal sliding mode controller is proposed based on the frequency distribution model with time‐frequency domain conversion, which achieves the suppression of chaotic phenomena in resonant overvoltage infinite time and is compared with the conventional sliding mode to confirm the effectiveness and superiority of the proposed controller. This paper explores and discusses the impact of adaptive sensing control technology on the practice of doubly fed wind power systems, to provide theoretical possibilities for the adaptive sensing control technology to be more effective for the practice of doubly fed wind power systems.

Horizontal Axis Wind Turbine Numerical Simulation of Two Dimensional Angle of Attack

wind power is the most effective form of wind energy utilization, modern large-scale wind turbine with horizontal axis wind mainly. Horizontal axis wind turbine aerodynamic performance calculation of the wind turbine aerodynamics research hot spot, is a wind turbine aerodynamic optimization design and calculation of critical load. Horizontal axis wind turbine airfoil aerodynamic performance of the wind turbine operation characteristics and life plays a decisive role". Using Fluent software on the horizontal axis wind turbine numerical simulation, analysis of the United States of America S809NREL airfoil aerodynamic characteristics of different angles of attack numerical simulation, analyzes the different angles of attack in the vicinity of the pressure, velocity distribution. By solving the two-dimensional unsteady, compressible N-S equations for the calculation of wind turbine airfoil S809used the characteristics of flow around. N-S equation in body-fitted coordinate system is given, with the Poisson equation method to generate the C grid.

Study on the Power Control Method of a Stand-Alone Wind Energy System Based on DSEG

The Stand-Alone wind energy supply system equipped with a doubly Salient Electro-Magnetic Generator (DSEG) is presented in this paper. First, the analysis of the operating characteristics of wind turbine and DSEG is introduced. Based on the strategy of power signal feedback (PSF), the excitation current of DSEG is regulated, as a result, Electro-Magnetic torque of the DSEG is controlled and the maximum wind energy tracking is achieved. Battery is employed as an energy storage device and interfaced to the wind energy system through bidirectional DC/DC converter. The control strategies of the bidirectional DC/DC are proposed to balance the power differences between the generator and the power the load, so that voltage of the DC bus could be constant under varying wind speed and load. The simulation results show the effectiveness of the control methods.