scholarly journals Variable-Gain Higher-Order Sliding Mode Pitch Control of Floating Offshore Wind Turbine

2021 ◽  
Vol 9 (11) ◽  
pp. 1172
Author(s):  
Shuzhen Li ◽  
Yaozhen Han ◽  
Weigang Pan ◽  
Shuang Liu ◽  
Mingdong Hou
Keyword(s):  
Wind Speed ◽  
Control Strategy ◽  
Sliding Mode ◽  
Higher Order ◽  
Offshore Wind ◽  
Adaptive Sliding Mode Control ◽  
Fatigue Load ◽  
Pitch Control ◽  
Variable Gain ◽  
Power Fluctuations

A variable-gain higher-order sliding mode pitch control strategy is proposed for a strongly nonlinear and coupled floating offshore wind power system. The main goal of the proposed strategy is to suppress platform motion caused by random disturbances such as waves and wind speed and to reduce fatigue loads and power fluctuations. Feedback control and super-twisting second-order sliding mode algorithm were adopted to carry out collective pitch control and track the rated rotor speed, which involves the factor of platform pitch. To adaptively adjust the collective pitch control parameters according to random wave and wind speed disturbances, the barrier function method was used to conceive adaptive sliding mode control gains. For comparison purposes, the proposed control strategy and PI control were executed under different wind and wave conditions on a FAST and MATLAB/Simulink platform. Furthermore, the fatigue load was calculated by Mlife. The results demonstrate that the proposed scheme is effective and robust. Moreover, it has advantages in resisting external disturbances, especially in suppressing the platform pitch and roll, as well as reducing the power fluctuations and the fatigue load on the blade root.

Integrated Dynamic Analysis of Floating Offshore Wind Turbines

2006 ◽  
Author(s):  
Finn Gunnar Nielsen ◽  
Tor David Hanson ◽  
Bjo̸rn Skaare
Keyword(s):  
Wind Speed ◽  
Dynamic Analysis ◽  
Wind Turbines ◽  
Control Strategy ◽  
Rotor Blade ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Pitch Control ◽  
Floating Offshore Wind Turbines ◽  
Wind Velocities

Two different simulation models for integrated dynamic analysis of floating offshore wind turbines are described and compared with model scale experiments for the Hywind concept for floating offshore wind turbines. A variety of both environmental conditions and wind turbine control schemes are tested. A maximum power control strategy is applied for wind velocities below the rated wind speed for the wind turbine, while a constant power control strategy is achieved by controlling the rotor blade pitch for wind velocities above rated wind speed. Conventional rotor blade pitch control for wind velocities above rated wind speed introduces negative damping of the tower motion. This results in excitation of the natural frequency in pitch for the tower and may lead to unacceptable tower motions. Active damping of the undesirable tower motions is obtained by an additional pitch control algorithm based on measurement of the tower velocity.

scholarly journals Emerging trends in vibration control of wind turbines: a focus on a dual control strategy

2015 ◽  
Vol 373 (2035) ◽  
pp. 20140069 ◽  
Author(s):  
Andrea Staino ◽  
Biswajit Basu
Keyword(s):  
Vibration Control ◽  
Wind Turbines ◽  
Control Strategy ◽  
Offshore Wind ◽  
Structural Vibration ◽  
Offshore Wind Turbine ◽  
Dual Control ◽  
Pitch Control ◽  
Emerging Trends ◽  
Control Schemes

The paper discusses some of the recent developments in vibration control strategies for wind turbines, and in this context proposes a new dual control strategy based on the combination and modification of two recently proposed control schemes. Emerging trends in the vibration control of both onshore and offshore wind turbines are presented. Passive, active and semi-active structural vibration control algorithms have been reviewed. Of the existing controllers, two control schemes, active pitch control and active tendon control, have been discussed in detail. The proposed new control scheme is a merger of active tendon control with passive pitch control, and is designed using a Pareto-optimal problem formulation. This combination of controllers is the cornerstone of a dual strategy with the feature of decoupling vibration control from optimal power control as one of its main advantages, in addition to reducing the burden on the pitch demand. This dual control strategy will bring in major benefits to the design of modern wind turbines and is expected to play a significant role in the advancement of offshore wind turbine technologies.

scholarly journals Overall Adaptive Controller Design of PMSG Under Whole Wind Speed Range: A Perturbation Compensation Based Approach

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 732 ◽  
Author(s):  
Jian Chen ◽  
Wenyong Duan ◽  
Xiaodong Yang ◽  
Lanhong Zhang ◽  
Yi Shan ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Wind Speed ◽  
Control Strategy ◽  
Controller Design ◽  
Current Control ◽  
Parameter Uncertainties ◽  
Pitch Control ◽  
Grid Current ◽  
Wind Speeds ◽  
Speed Range

This paper proposes an adaptive overall control strategy of the permanent magnet synchronous generator-based wind energy conversion system (WECS) in the whole wind speed range. For the machine side, the maximum power point tracking (MPPT) operation is realized by stator current and mechanical rotation speed control under below-rated wind speeds. Under above-rated wind speeds, the extracted wind power is limited via pitch control. For the grid side, the reactive and active power injected into grid is regulated by DC-Link voltage and grid current control loop. In addition, under grid voltage dips, the pitch control is employed for limiting grid current and maintaining the DC-Link voltage around its rated value. The fault ride-through capability (FRTC) can be enhanced. The overall control strategy is based on perturbation estimation technique. A designed observer is used for estimating the perturbation term including all system nonlinearities, uncertainties and disturbances, so as to compensate the real perturbation. Then, an adaptive control for the original nonlinear system can be realized. The effectiveness of the proposed overall control strategy is verified by applying the strategy to a 2-MW WECS in MATLAB/Simulink. The results show that, compared with the feedback linearizing control (FLC) strategy and conventional vector control (VC) strategy, the proposed perturbation observer based adaptive control (PO-AC) strategy realizes the control objectives without knowing full state information and accurate system model, and improves the robustness of the WECS parameter uncertainties and FRTC.

Nonlinear adaptive sliding mode tracking control of an airplane with wing damage

2017 ◽  
Vol 232 (8) ◽  
pp. 1405-1420 ◽  
Author(s):  
D Asadi ◽  
SA Bagherzadeh
Keyword(s):  
Adaptive Control ◽  
Flight Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Robust Adaptive Control ◽  
Adaptive Sliding Mode Control ◽  
Damage Effect ◽  
Outer Loop ◽  
Adaptive Sliding Mode ◽  
Wing Damage

This paper investigates a dual-timescale autopilot for a wing-damaged airplane applying nonlinear adaptive sliding mode approach. The adaptive flight control strategy is used to track outer-loop angle commands while accommodating wing damage effect. Two distinct adaptive sliding mode control strategies are designed for the inner- and outer-loop dynamics. The airplane nonlinear model is developed considering center of gravity shift and aerodynamic changes due to the asymmetric wing damage. The performance of the proposed nonlinear adaptive sliding mode controller is evaluated through numerical simulation on NASA generic transport model and is compared with two adaptive algorithms: model reference adaptive control and a robust adaptive control strategy. The results demonstrate that the proposed control law achieves closed-loop stability in the presence of wing damage and accelerometers bias, and also provides satisfactory tracking performance.

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