Axial Low Cyclic Loading Control Method for Ocean Wind Turbine

2019 ◽  
Vol 83 (sp1) ◽  
pp. 941
Author(s):  
Cong Cong
2021 ◽  
Vol 80 ◽  
pp. 103079
Author(s):  
Hongwang Ma ◽  
Zhiyue Lu ◽  
Yutao Li ◽  
Chen Chen ◽  
Jun Yang

Inventions ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 3
Author(s):  
Wenping Cao ◽  
Ning Xing ◽  
Yan Wen ◽  
Xiangping Chen ◽  
Dong Wang

Wind energy conversion systems have become a key technology to harvest wind energy worldwide. In permanent magnet synchronous generator-based wind turbine systems, the rotor position is needed for variable speed control and it uses an encoder or a speed sensor. However, these sensors lead to some obstacles, such as additional weight and cost, increased noise, complexity and reliability issues. For these reasons, the development of new sensorless control methods has become critically important for wind turbine generators. This paper aims to develop a new sensorless and adaptive control method for a surface-mounted permanent magnet synchronous generator. The proposed method includes a new model reference adaptive system, which is used to estimate the rotor position and speed as an observer. Adaptive control is implemented in the pulse-width modulated current source converter. In the conventional model reference adaptive system, the proportional-integral controller is used in the adaptation mechanism. Moreover, the proportional-integral controller is generally tuned by the trial and error method, which is tedious and inaccurate. In contrast, the proposed method is based on model predictive control which eliminates the use of speed and position sensors and also improves the performance of model reference adaptive control systems. In this paper, the proposed predictive controller is modelled in MATLAB/SIMULINK and validated experimentally on a 6-kW wind turbine generator. Test results prove the effectiveness of the control strategy in terms of energy efficiency and dynamical adaptation to the wind turbine operational conditions. The experimental results also show that the control method has good dynamic response to parameter variations and external disturbances. Therefore, the developed technique will help increase the uptake of permanent magnet synchronous generators and model predictive control methods in the wind power industry.


2020 ◽  
Vol 190 ◽  
pp. 00019
Author(s):  
Katherin Indriawati ◽  
Choirul Mufit ◽  
Andi Rahmadiansah

The variation of wind speed causes the electric power generated by the turbine also varies. To obtain maximum power, the rotor speed of wind turbines must be optimally rated. The rotor speed can be controlled by manipulating the torque from the generator; this method is called Torque Control. In that case, a DC-DC converter is needed as the control actuator. In this study, a buck converter-based supervisory control design was performed on the Horizontal-axis wind turbines (HAWT). Supervisory control is composed of two control loops arranged in cascade, and there is a formula algorithm as the supervisory level. The primary loop uses proportional control mode with a proportional gain of 0.3, whereas in the secondary loop using proportional-integral control mode with a proportional gain of 5.2 and an integral gain of 0.1. The Supervisory control has been implemented successfully and resulted in an average increase in turbine power of 4.1 % at 5 m s–1 and 10.58 % at 6 m s–1 and 11.65 % at 7 m s–1, compared to wind turbine systems without speed control.


2015 ◽  
Vol 64 (2) ◽  
pp. 291-314 ◽  
Author(s):  
Maziar Izadbakhsh ◽  
Alireza Rezvani ◽  
Majid Gandomkar

Abstract In this paper, dynamic response improvement of the grid connected hybrid system comprising of the wind power generation system (WPGS) and the photovoltaic (PV) are investigated under some critical circumstances. In order to maximize the output of solar arrays, a maximum power point tracking (MPPT) technique is presented. In this paper, an intelligent control technique using the artificial neural network (ANN) and the genetic algorithm (GA) are proposed to control the MPPT for a PV system under varying irradiation and temperature conditions. The ANN-GA control method is compared with the perturb and observe (P&O), the incremental conductance (IC) and the fuzzy logic methods. In other words, the data is optimized by GA and then, these optimum values are used in ANN. The results are indicated the ANN-GA is better and more reliable method in comparison with the conventional algorithms. The allocation of a pitch angle strategy based on the fuzzy logic controller (FLC) and comparison with conventional PI controller in high rated wind speed areas are carried out. Moreover, the pitch angle based on FLC with the wind speed and active power as the inputs can have faster response that lead to smoother power curves, improving the dynamic performance of the wind turbine and prevent the mechanical fatigues of the generator


Author(s):  
Pengyin Liu ◽  
Jinge Chen ◽  
Shen Xin ◽  
Xiaocheng Zhu ◽  
Zhaohui Du

In this paper, a slotted tip structure is experimentally analyzed. A wind turbine with three blades, of which the radius is 301.74mm, is investigated by the PIV method. Each wind turbine blade is formed with a slots system comprising four internal tube members embedded in the blade. The inlets of the internal tube member are located at the leading edge of the blade and form an inlet array. The outlets are located at the blade tip face and form an outlet array. The near wake flow field of the wind turbine with slotted tip and without slotted tip are both measured. Velocity field of near wake region and clear images of the tip vortex are captured under different wake ages. The experimental results show that the radius of the tip vortex core is enlarged by the slotted tip at any wake age compared with that of original wind turbine. Moreover, the diffusion process of the tip vortex is accelerated by the slotted tip which lead to the disappearance of the tip vortex occurs at smaller wake age. The strength of the tip vortex is also reduced indicating that the flow field in the near wake of wind turbine is improved. The experimental data are further analyzed with the vortex core model to reveal the flow mechanism of this kind of flow control method. The turbulence coefficient of the vortex core model for wind turbine is obtained from the experimental data of the wind turbine with and without slotted tip. It shows that the slotted tip increases the turbulence strength in the tip vortex core by importing airflow into the tip vortex core during its initial generation stage, which leads to the reduction of the tip vortex strength. Therefore, it is promising that the slotted tip can be used to weaken the vorticity and accelerate the diffusion of the tip vortex which would improve the problem caused by the tip vortex.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Qingguang He ◽  
Yanxia Bai ◽  
Weike Wu ◽  
Yongfeng Du

A novel assembled self-centering variable friction (SCVF) brace is proposed which is composed of an energy dissipation system, a self-centering system, and a set of force transmission devices. The hysteretic characteristics and energy dissipation of the SCVF brace with various parameters from low-cyclic loading tests are presented. A finite element model was constructed and tested under simulated examination for comparative analysis. The results indicate that the brace shows an atypical flag-type hysteresis curve. The SCVF brace showed its stable self-centering ability and dissipation energy capacity within the permitted axial deformation under different spring and friction plates. A larger deflection of the friction plate will make the variable friction of this SCVF brace more obvious. A higher friction coefficient will make the energy dissipation capacity of the SCVF brace stronger, but the actual friction coefficient will be lower than the design value after repeated cycles. The results of the fatigue tests showed that the energy dissipation system formed by the ceramic fiber friction blocks and the friction steel plates in the SCVF brace has a certain stability. The finite element simulation results are essentially consistent with the obtained test results, which is conducive to the use of finite element software for calculation and structural analysis in actual engineering design.


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