基于一种新型算法的偏航控制系统设计

风能是绿色能源.风力发电在解决能源和环境问题上的积极意义,正在世界范围内得到快速发展,成为当今世界增长速度最快的能源.本文在介绍了风力机的偏航控制系统的软硬件设计的基础上,首次提出一种新型适于大型风力发电机组的对风偏航控制算法--Vane_Hill Climbing算法,将风向传感器的应用和Hill Climbing算法结合设计了控制器.     

基于微控制器的风速计在线控制和测量系统设计

针对两种基于对称热电偶结构和基于晶体管的圆形加热条结构的二维集成风速风向微传感器及其风向测量的问题,设计了采用微控制器进行在线控制和利用软件算法实现风速风向测量的传感器系统.系统集微传感器结构、控制与测量电路于一体,显著提高了二维风速风向传感器的在线控制和测量能力及其系统兼容性,并且便于系统扩展功能.测试结果表明,风速计设计满足实际风速和风向的测量要求.     

基于模糊控制和功率控制的风电偏航研究

就整个风电系统来说控制技术是机组高效稳定运行的关键,而偏航控制系统是水平轴风电机组控制系统的重要组成部分.风力发电机的偏航系统是一个典型的非线性系统,且难以建立精确的数学模型.针对风向变化的随机性和不确定性等特点,将模糊逻辑控制技术和功率控制相结合设计了控制器,实现了对风过程可控,能够准确跟踪风向,完成了最大捕获风能的控制策略.利用MATLAB进行仿真,证明所确定的方法符合偏航系统的控制要求,由仿真图可以看出,效果良好,具有较高稳定性、可靠性等.     

兆瓦级风力发电机组偏航反时限优化控制

为解决兆瓦级风力发电机组不能频繁偏航和及时响应的矛盾,采用体现能量特征的反时限方法获得相对风向阈值及延时时间。考虑输入信号的稳定性,使用均值对风速和风向进行处理。在流程上对相邻两次动作进行时间限制,提高设备使用寿命。在PLC控制器上构建了仿真环境,实测结果验证了该算法的可行性及可靠性,为偏航系统优化运行提供可行指导。     

风力发电技术与功率控制策略研究

对风力发电技术进行综述,分析研究了变速恒频双馈风力发电机组实现风能最大捕获的功率控制策略,即当风速在切入风速和额定风速之间时,控制发电机转子励磁电流及频率,追踪最佳功率曲线;在额定风速和切出风速之间时,调节风力机叶片桨距角,保持额定功率不变.研究表明,基于风速的功率控制方法,提高了风力发电机组风能利用效率;同时,基于风向标和输出功率的偏航控制策略,能缩短风力机对风时间,提高风力机对风精度和使用寿命.     

基于估计的风力机最大功率跟踪控制

在额定风速以下,变速恒频风力发电机组应采用可靠控制策略,保证最大风功率跟踪;在不估计风速的情况下,提出一种风力机最大功率跟踪方法;首先,利用状态观测器和非线性扩展卡尔曼滤波,估计风力机最佳转速,采用PI控制器给出风力机转矩估值;其次,以风力机转矩、转速估值为输入,采用风力机转矩前馈控制,在计算风力机最优转速后,给出发电机转矩控制量,从而实现低风速时的最大功率跟踪;在Matlab/Simulink软件上搭建了仿真平台,仿真验证了估计的有效性和控制的正确性。     

热式风速计恒温差控制的软件实现及其性能测试

介绍了一种利用软件实现热式风速风向传感器恒温差模式（CTD）控制的方案。传感器系统采用单片机作为主控单元,对芯片温度和环境温度进行采样,并以此为依据调节输出功率,从而实现恒温差状态的控制。实验表明,采用这种软件控制方案,在无风状态下,在-20℃到40℃的环境温度变化范围内,热式风速风向传感器能够基本维持输出信号恒定不变。除此之外,该风速风向传感器系统还可以实现对0~20 m/s风速范围内的风速测量,最大测量误差不超过8%,并且具有低于15 s的响应速度。     

风速风向的移动测量系统设计

针对传统测风仪器无法直接用于移动条件下(如车载或船载时)的风速风向测量的问题,设计了一种可以在移动平台上应用的超声波风速风向测量系统。该系统使用超声波时差法测量平面内二维风向风速,同时使用霍尔传感器和电子罗盘测量基座的移动速度和方向,通过微处理器对测得的风速风向进行修正,得到实际风速和风向。系统采用ARM作为核心控制器,提高了时差的测量精度,并降低了功耗。     

风力发电系统独立变桨距载荷优化控制研究

对风力发电系统独立变桨距控制原理进行阐述。建立了风力发电机组桨叶载荷的数学模型,利用Coleman坐标变换实现了将桨叶上的载荷转换成轮毂处倾斜方向和偏航方向的疲劳载荷,并且实现了二者的解耦,简化了控制器的设计;之后利用Coleman逆变换实现了桨距角的微调。该控制系统根据随机风速的变化,利用独立变桨控制对风力机桨叶桨距角进行实时调节,以达到减小风电机组关键部件载荷的目的。仿真结果表明,当风速达到额定值以上时,该控制策略在统一变桨距控制的基础上,不仅保证输出功率近似相等,而且减小了桨叶所承受的疲劳载荷,也减小了风力机组其他关键部件的疲劳载荷。     

基于DSP和CPLD的无位置传感器无刷直流电动机控制系统

本文提出了一种基于DSP＋CPLD的无位置传感器的无刷直流电动机控制系统,该系统以DSP控制器TMS320LF2407A为控制核心。它研究了转子位置的检测,同时,进行了该控制系统的控制策略分析和硬件电路及应用软件设计。采用专家智能系统以实现换向控制,使用外部参考电压提高DSP的A／D转换精度。该系统大大简化了硬件结构,使电机控制更加稳定。     

基于微分几何的风力发电机组恒功率控制

当风速超过额定值时, 可以通过降低风力机的转速实现恒功率控制从而避免使用复杂的变桨距机构, 本文基于微分几何理论设计了非线性控制器, 实现了变速风力发电机组的恒功率控制. 首先, 分析了风力机的空气动力学特性, 这是所提出的恒功率控制方法的理论依据; 然后, 通过微分几何反馈线性化变换, 将风力机的非线性模型全局线性化; 最后, 基于新的线性化模型设计了非线性控制器, 实现了变速风力机的全局精确线性化控制. 仿真结果表明, 所提出的控制方法在风速大范围变化的情况下能有效的实现变速风力发电机组额定风速以上的恒功率控制.     

Feedforward Control for Wind Turbine Load Reduction with Pseudo-LIDAR Measurement

A gain-scheduled feedforward controller, based on pseudo-LIDAR (light detection and ranging) wind speed measurement, is designed to augment the baseline feedback controller for wind turbine’s load reduction in above rated operation. The pseudo-LIDAR measurement data are generated from a commercial software – Bladed using a designed sampling strategy. The nonlinear wind turbine model has been simplified and linearised at a set of equilibrium operating points. The feedforward controller is firstly developed based on a linearised model at an above rated wind speed, and then expanded to the full above rated operational envelope by employing gain scheduling strategy. The combined feedforward and baseline feedback control is simulated on a 5 MW industrial wind turbine model. Simulation studies demonstrate that the proposed control strategy can improve the rotor and tower load reduction performance for large wind turbines.     

具有尾缘襟翼风力机的恒功率反步法控制

尾缘襟翼风力机控制技术在大型风力机领域具有巨大的应用潜力.本文首先基于修正的叶素动量方法建立了具有可变尾缘襟翼的风力机气动模型.针对襟翼风力机的非线性模型,采用反步法设计了非线性控制器,保证系统的控制量和状态变量全局有界,并且风机的输出功率可以收敛到额定功率的一个小邻域内.此外,控制器设计过程中没有将实时风速信息纳入反馈系统,因而降低了工程实施的难度.最后针对12 m/s～15 m/s的阶跃风、基于四分量模型模拟的风载扰动、执行机构受到外部扰动以及总转动惯量具有10%不确定性的工况进行了仿真,仿真结果表明所设计的控制器能有效地稳定风力发电系统的输出功率,控制系统具有较强的鲁棒性.     

Modeling and robust control of a twin wind turbines structure

The control of a new structure of twin wind turbines (TWT) is presented in this paper. This new concept includes two identical wind turbines ridden on the same tower, which can pivot face the wind with no additional actuator. The motion of the arms carrying the TWT is free. The control law based on sliding mode controller is designed to track the maximum power, by controlling the rotor speed of the TWT and the yaw rotation but without yaw actuator. Finally, performances of the proposed control strategy are compared to standard proportional integral controller, for several scenarios (time varying direction or magnitude of the wind, error on the inertia of the system, …).     

自适应控制在变速风力发电系统中的应用

针对变速风力发电系统提出了一种自适应反馈线性化控制器。该控制器通过对涡轮轴转矩的自适应估算,将其作为参考转矩提供给磁场定向控制的鼠笼式异步电机。异步电机通过变速箱与涡轮轴相连接。反馈线性化控制器用于保持涡轮转速与用户自定义的辅助输入量的线性关系。控制器的参考转速是风速的函数,它的选择随风力状况的变化而变化,目的是为了获取最大风能。仿真结果表明,该控制器能够获取最大可用风能,控制效果良好。     

基于极点配置控制的风机叶片颤振控制研究

针对风力机叶片的颤振会严重影响风力机的发电效率和运行安全问题,设计了一种基于极点配置的振动控制器在抑制叶片颤振的同时可以取得良好的闭环控制特性,并且能够有效抑制来自阵风的干扰.重点研究了利用Diophantine方程求解极点配置(PPC) PID控制器的方法,并选取有效的系统输出信号来设计反馈控制器,达到抑制叶片颤振的目的.Matlab/Simulink仿真结果表明,在叶片颤振控制系统中极点配置PPC-PID控制器比传统PID控制器具有更好的抗干扰性和动态特性.     

Wind turbine integrated structural and LPV control design for improved closed-loop performance

An iterative redesign algorithm is proposed to integrate the design of the structural parameters and a linear parameter-varying (LPV) controller for a three-bladed horizontal-axis wind turbine. The LPV controller is designed for an eighth-order lumped model of the wind turbine consisting of blades, drive-train and the tower. The lumped model response is matched with detailed open-loop numerical simulations using the Fatigue, Aerodynamics, Structures and Turbulence (FAST) code. The controller is scheduled in real-time based on the mean wind speed to account for the varying system dynamics. The objective is to track the operating trajectory meanwhile minimise the H _∞ performance index from the wind turbulence to the controlled output vector consisting of pitch angle, blade tip deflection, and the generator speed and torque. Sensitivity analysis of the closed-loop performance index with respect to the structural parameters of the system is examined. The integrated design problem is formulated as an iterative sequential controller/structure redesign to obtain the structural parameters and controller matrices corresponding to a local optimal performance index. Each step of the iterative procedure is formulated as a linear matrix inequality (LMI) optimisation problem that can be solved efficiently using available LMI solvers. The evolution of the structural parameters and performance index through the integrated design is illustrated. The FAST closed-loop simulations for two selected designs with the smallest values of the performance index demonstrate the improved performance of the overall system through the integrated structure/control redesign in both minimising the effect of the wind disturbance on the generator output power, and reducing the structural loads on the wind turbine.     

Robust Wind Speed Estimation and Control of Variable Speed Wind Turbines

In this work, a robust control scheme for variable speed wind turbine system that incorporates a doubly feed induction generator is described. The sliding mode controller is designed in order to track the optimum wind turbine speed value that produces the maximum power extraction for different wind speed values. A robust sliding mode observer for the aerodynamic torque is also proposed in order to avoid the wind speed sensors in the control scheme. The controller uses the estimated aerodynamic torque in order to calculate the reference value for the wind turbine speed. Another sliding mode control is also proposed in order to maintain the dc‐link voltage constant regardless of the direction of the rotor power flow. The stability analysis of the proposed controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally, the simulation results show that the proposed control scheme provides a high‐performance turbine speed control, in order to obtain the maximum wind power generation, and a high‐performance dc‐link regulation in the presence of system uncertainties.     

A second-order sliding mode and fuzzy logic control to optimal energy management in wind turbine with battery storage

The optimal control of large-scale wind turbine has become a critical issue for the development of renewable energy systems and their integration into the power grid to provide reliable, secure and efficient electricity, despite any possible constraints such as sudden changes in wind speed. This paper deals with the modeling and control of a hybrid system integrating a permanent magnet synchronous generator (PMSG) in variable speed wind turbine (VSWT) and batteries as energy storage system (BESS). Moreover a new supervisory control system for the optimal management and robust operation of a VSWT and a BESS is described and evaluated by simulation under wind speed variation and grid demand changes. In this way, the proposed coordinated controller has three subsystems (generator side, BESS side and grid side converters). The main function of the first one is to extract the maximum wind power through controlling the rotational speed of the PMSG, for this a maximum power point tracking algorithm based on fuzzy logic control and a second-order sliding mode control (SOSMC) theory is designed. The task of the second one is to maintain the required direct current (DC) link voltage level of the PMSG through a bidirectional DC/DC converter, whereas in the last, a (SOSMC) is investigated to achieve smooth regulation of grid active and reactive powers quantities, which provides better results in terms of attenuation of the harmonics present in the grid courant compared with the conventional first-order sliding controller. Extensive simulation studies under different conditions are carried out in MATLAB/Simulink, and the results confirm the effectiveness of the new supervisory control system.

     

风力发电系统的恒功率非线性H∞鲁棒控制

风力发电系统传统控制器的缺点在于, 基于某一工况点的局部线性化方法无法实现全局范围的精确控制, 且传统的控制理论无法应对内外干扰. 本文将精确反馈线性化方法与线性H∞理论相结合设计非线性H∞控制器. 首先用微分几何精确线性化方法将非线性风电模型全局线性化, 然后运用线性H∞控制理论对此线性系统设计控制器, 将两者结合有原风电系统的非线性H∞变桨距控制器. 最后对12 m/s至24 m/s阶跃风, 12 m/至22 m/s骤变风, 18 m/s至20 m/s随机风, 以及风力机转动惯量下降10%的情况进行仿真, 能实现风机转速及输出功率的恒定. 验证了该控制器在全风速段的精确控制, 并且具有良好鲁棒性.