低尖速比下垂直轴风力机攻角一般较大,流动分离现象较严重,可通过变桨调整叶片攻角以减少叶片流动分离提高其气动效率。以H型Darrieus垂直轴风力机为研究对象,基于攻角随相位角变化规律,提出一种俯仰角控制策略,此控制方式特点是在不同相位角时攻角成比例地减小,在大攻角时大幅减小攻角,而在小攻角时变化幅度较小,之后通过数值计算验证其效果。结果表明：所提俯仰角控制策略可显著提升功率系数;相较单一参数控制策略,不同参数组合的控制策略方式虽然在0°~180°（迎风区）与180°~360°（背风区）的风能捕获效率会相互影响,但提升效果也更好。此外,不连续的俯仰角速度将导致扭矩波动,通过采用权函数对俯仰曲线进行拟合可消除该波动。
Abstract
Vertical axis wind turbines with large angle of attack at low tip speed ratios suffer from severe flow separation. The blade angle of attack can be adjusted by pitch to reduce the blade flow separation and improve its aerodynamic efficiency. The H-type Darrieus vertical axis wind turbine is used as the research object. Based on the variation law of angle of attack with phase angle, a pitch angle control strategy is proposed. This control method is characterized by a proportional decrease in the angle of attack at different phase angles. The angle of attack decreases significantly at large angles of attack, while the change is small at small angles of attack. The effect is then verified by numerical calculation. The results show that the proposed pitch angle control strategy can significantly improve the power coefficient. The control strategy approach with different parameter combinations is also better than the single parameter control strategy, although the wind energy capture efficiency in 0°-180° (windward region) and 180°-360° (leeward region) will affect each other. In addition, the discontinuous pitch angle velocity will lead to torque fluctuation, which can be eliminated by fitting the pitch curve with a weight function.
关键词
垂直轴风力机 /
变桨 /
控制策略 /
参数组合 /
气动分析
Key words
vertical axis wind turbines /
pitch /
control strategy /
parameter combination /
aerodynamic analysis
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参考文献
[1] 李春, 叶舟, 高伟, 等. 现代陆海风力机计算与仿真[M]. 上海: 上海科学技术出版社, 2012: 1-12.
LI C, YE Z, GAO W, et al.Computation and simulation of modern land-sea wind turbine[M]. Shanghai: Shanghai Scientific & Technical Publishers, 2012: 1-12.
[2] 张立勋, 张松, 焦启飞, 等. 智能变桨垂直轴风力发电机的变桨规律设计[J]. 太阳能学报, 2013, 34(8): 1427-1433.
ZHANG L X, ZHANG S, JIAO Q F, et al.Pitching laws of smart variable-pitch vertical axis wind turbine[J]. Acta energiae solaris sinica, 2013, 34(8): 1427-1433.
[3] BHUTTA M M A, HAYAT N, FAROOQ A U, et al. Vertical axis wind turbine:a review of various configurations and design techniques[J]. Renewable and sustainable energy reviews, 2012, 16(4): 1926-1939.
[4] SHARIFI A, NOBARI M R H. Prediction of optimum section pitch angle distribution along wind turbine blades[J]. Energy conversion and management, 2013, 67: 342-350.
[5] SAGHARICHI A, ZAMANI M, GHASEMI A.Effect of solidity on the performance of variable-pitch vertical axis wind turbine[J]. Energy, 2018, 161: 753-775.
[6] KOSAKU T, SANO M, NAKATANI K.Optimum pitch control for variable-pitch vertical-axis wind turbines by a single stage model on the momentum theory[C]//IEEE International Conference on Systems, Man and Cybernetics, IEEE, Yasmine Hammamet, Tunisia, 2002: 482-487.
[7] CHEN W Y, ZHOU C Y.Application of numerical simulation to obtain the optimization pitch angle for VAWT[C]//World Non-Grid-Connected Wind Power and Energy Conference, Nanjing, China, 2009.
[8] BIANCHINI A, FERRARA G, FERRARI L.Pitch optimization in small-size Darrieus wind turbines[J]. Energy procedia, 2015, 81: 122-132.
[9] MACPHEE D, BEYENE A.Fluid-structure interaction of a morphing symmetrical wind turbine blade subjected to variable load[C]//Proceedings of the 6th International Conference on Mechanics and Materials in Design, Meguid, P.Delgada/Azores, India, 2015.
[10] 张立勋, 梁迎彬, 尉越啸, 等. 垂直轴风力机主动式变桨距控制规律[J]. 中南大学学报(自然科学版), 2013, 44(6): 2561-2568.
ZHANG L X, LIANG Y B, YU Y X, et al.Active variable-pitch control laws for vertical axis wind turbine[J]. Journal of Central South University(science and technology) , 2013, 44(6): 2561-2568.
[11] 郑旭阳, 孙志毅, 刘立群, 等. 垂直轴风力发电机的建模与变桨距研究[J]. 自动化仪表, 2013, 34(9): 52-55, 59.
ZHENG X Y, SUN Z Y, LIU L Q, et al.Modeling of vertical axis wind turbine and research on the variable pitch[J]. Process automation instrumentation, 2013, 34(9): 52-55, 59.
[12] 张立军, 赵昕辉, 王旱祥, 等. H型垂直轴风力机实时高效攻角调节方法研究[J]. 机械工程学报, 2018, 54(10): 173-181.
ZHANG L J, ZHAO X H, WANG H X, et al.Study on the realtime and efficient adjustment law for H-type vertical axis wind turbine[J]. Journal of mechanical engineering, 2018, 54(10): 173-181.
[13] CHEN B, SU S S, VIOLA I M, et al.Numerical investigation of vertical-axis tidal turbines with sinusoidal pitching blades[J]. Ocean engineering, 2018, 155: 75-87.
[14] ZHAO Z Z, QIAN S Y, SHEN W Z, et al.Study on variable pitch strategy in H-type wind turbine considering effect of small angle of attack[J]. Journal of renewable and sustainable energy, 2017, 9(5): 053302.
[15] LI C, XIAO Y Q, XU Y L, et al.Optimization of blade pitch in H-rotor vertical axis wind turbines through computational fluid dynamics simulations[J]. Applied energy, 2018, 212: 1107-1125.
[16] CHEN L J, YANG Y Z, GAO Y, et al.A novel real-time feedback pitch angle control system for vertical-axis wind turbines[J]. Journal of wind engineering and industrial aerodynamics, 2019,195: 104023.
[17] REZAEIHA A, KALKMAN I, BLOCKEN B.Effect of pitch angle on power performance and aerodynamics of a vertical axis wind turbine[J]. Applied energy, 2017, 197: 132-150.
[18] BIANCHINI A, BALDUZZI F, BACHANT P, et al.Effectiveness of two-dimensional CFD simulations for Darrieus VAWTs: a combined numerical and experimental assessment[J]. Energy conversion and management,2017, 136: 318-328.
[19] ELKHOURY M, KIWATA T, AOUN E.Experimental and numerical investigation of a three-dimensional vertical-axis wind turbine with variable-pitch[J]. Journal of wind engineering and industrial aerodynamics, 2015, 139: 111-123.
[20] MENTER F R.Two-equation eddy-viscosity turbulence models for engineering applications[J]. AIAA journal, 1994, 32(8): 1598-1605.
[21] WILCOX D C.Comparison of two-equation turbulence models for boundary layers with pressure gradient[J]. AIAA journal, 1993, 31(8):1414-1421.
[22] GUO Y H, LI X C, SUN L X, et al.Aerodynamic analysis of a step adjustment method for blade pitch of a VAWT[J]. Journal of wind engineering and industrial aerodynamics, 2019, 188: 90-101.
基金
国家自然科学基金（51976131; 52006148）; 上海“科技创新行动计划”地方院校能力建设项目（19060502200）
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