数字物理混合的变桨距控制器综合实验平台

为了对变桨距控制器及其执行机构进行研发和测试,提出一种数字物理混合的综合实验平台解决方案.将风电场风况、风力机、发电机等外部环境采用数字模型仿真,变桨距控制器及执行机构采用物理真机运行,结合计算机辅助设计技术,完成软硬件间的数据采集与转换,实现嵌入式变桨距控制器综合实验平台的数字物理混合设计.仿真结果表明,该平台可靠性高,稳定性好,成本低,能够解决变桨距控制器的实验室开发与研究.     

基于全局鲁棒滑模控制的变速恒频双馈风力发电机的研究

随着风力发电技术的发展,对变速恒频双馈风力发电机的控制方法方面的研究显得越发的重要.根据变速恒频双馈发电机对控制系统要求响应速度快、鲁棒性强的特点,将矢量转换方法与全局滑模控制方法结合,提出了一种全局鲁棒滑模变结构控制方案.针对双馈异步电机在内部参数变化和外部风机负载转矩扰动共同带来的扰动进行设计,并对比了传统PI控制.仿真证明,该控制方法可以提高双馈电机的动态性能,进一步增强了电机的抗干扰性.     

基于SVM实现风力机组控制系统参数优化

分析了风力机的基本特性,阐述了风力发电机组控制系统在低于额定风速时风力机的最大风能捕获及高于额定风速情况下的变桨距控制。在此基础上,利用SVM(support vector machines)优化风力机的风能利用系数以及变桨距控制系统的控制参数。仿真分析表明,风能转换系数的支持向量机模型具有很好的精度和泛化性能,而优化后的变桨距控制系统可对输出功率的调节获得较好的效果,保证风电系统的恒功率输出。     

A novel dynamic equivalence method for grid-connected wind farm

Dynamic equivalence of the wind farm is a fundamental problem in the simulation of a power system connected with wind farms because it is unpractical to model every generator in a wind farm in detail. In this paper, an Equivalence Method based on the Output Characteristics （EMOC） is proposed, with which the wind farm composed of Squirrel-Cage Induction Generators （SCIGs） can be equivalent to one generator. By considering the diversity of wind generators and special operating characteristics of a wind farm, the equivalent generator based on EMOC responds accurately in various faults. No matter whether the wind farm is integrated in grid or just programmed, EMOC can be used to acquire an accurate equivalent generator. Simulation of the dynamic equivalence of an SCIG wind farm validated the method.     

风力发电仿真实验平台开发及应用

分析了风力发电系统中各个子模块的仿真建模方法,叙述了Matlab/Simulink平台下仿真平台的开发思路和系统功能。结合在小型脱网风力发电系统中的应用,给出了风力机模拟、发电机系统建模和传动链建模的具体方法。应用表明,采用模块化设计思想,能够实现风力发电系统中子模块的建模仿真及系统集成仿真,系统易于扩展,可裁剪性高,该系统控制平台可灵活应用于风力发电系统的优化与控制,缩短控制系统的开发周期,为风力发电系统投入实际工程应用提供良好的技术支持。     

定子斜槽的混合励磁永磁同步发电机研制

在混合励磁永磁同步发电机基础上,研制了定子斜槽混合励磁永磁同步发电机。仿真结果表明:定子斜槽混合励磁永磁同步发电机可以动态实时输出功率,具有很小的电压调整率,可实现全自动调压,过载能力强,输出电压波形正弦畸变率低,不同负载之间相互干扰和影响降低到最低限度,供电品质显著改变,供电系统可靠性大大提高。     

微型风力发电取暖系统的设计与应用

设计组建了一个微型风力发电取暖系统,推出永磁同步发电机感生电动势E与叶片转速v关系式：E—Cv,并通过实验验证．利用该系统测试泉州师院风能大小,提出选择C值大于1．39的发电机,可利用泉州常年风力3～4级来达到日常供能供暖使用要求,同时推导出测量风速公式：Vwind=2πR×E/C×D,该公式可用于制作风速测量计,并获得实验验证．     

Direct driven wind energy conversion system based on hybrid excitation synchronous machine

A novel direct-drive type wind power generation system based on hybrid excitation synchronous machine (HESM) is introduced in this paper. The generator is connected to an uncontrollable rectifier, and a fully controlled voltage-source inverter is used to connect the system to utility grid. An intermediate DC bus exists between the rectifier and inverter. A new control strategy is proposed which achieves the maximum power point tracking (MPPT) with the control of excitation current of HESM and stabilizes the DC link voltage with the control of inverter output current simultaneously. Specially-designed buck circuit is used to control the excitation current of HESM, and grid voltage-oriented vector control strategy is employed to realize the decoupling of the inverter output power. Simulation results and experiment in 3 kW lab prototype show an excellent static and dynamic performance of the proposed system.     

Digitally controlled boost PFC converters operating with large scale load fluctuations

When boost power factor correction （PFC） circuit works with large scale load fluctuations, it is easy to cause a higher total harmonic distortion and a lower power factor because of traditional controllers and inductor cur- rent mode. To solve this problem, this paper proposes a PFC control system, which can operate with load fluctuations up to 1 000 W by using duty cycle feed-forward control theory to achieve smooth switching mode. The duty cycles in the next period of the control system are pre-estimated in the current cycle, which enhances the speeds of AD samplers and switching frequency, and reduces the cost and volume of the equipment to some extent. Introductions of system decoupling and feed-forward of input-voltage greatly improve the system performance. Both theoretical simulation and experimental results prove the advantage of the proposed scheme.     

风力发电系统建模与最优功率跟踪控制

风速的随机性、间歇性及不确定性,必将导致风电场的输出功率也具有随机波动性和间歇性,风电系统的输出功率影响电网的安全稳定运行和电能质量．通过构建了以鼠笼式感应电机为发电系统的定速变桨距风力发电系统,展开功率跟踪控制系统分析．给出了风力机空气动力学特性和建模方法,建立了传动链数学模型和感应发电机的数学模型．设计了转矩控制环、速度控制环,给出了实现功率跟踪的功率控制环设计思路,仿真结果表明,该系统能实现风电系统的最优功率跟踪控制．     

变速恒频双馈风力发电机稳态运行特性仿真

基于变速恒频双馈风力发电机组,通过调节发电机转侧子电流的大小调节系统的有功功率和无功功率,实现解耦控制。并在理论推导的过程中建立数学等效模型。最后运用MATLAB／Simulink电力系统建模与仿真平台分析发电机组在无功控制模式下风电系统在稳态和三相短路故障下运行输出特性。     

PWM逆变器的定向矢量控制策略

针对风力发电并网的优化问题。提出了三相电压源脉冲宽度调制（PWM）逆变器的定向矢量控制技术,并设计了数字控制的变换器一逆变器系统。给出了该变换器和逆变器的数学模型。提出了一种定向矢量控制的方案来实现对风能并网的控制策略。为了检验该系统的动态性能。采用MATLAB7／SIMULINK程序进行了仿真。仿真结果表明,提出的控制系统模型在不同的干扰下都展现出其良好的性能。     

Dynamic modeling and direct power control of wind turbine driven DFIG under unbalanced network voltage conditions

This paper proposes an analysis and a direct power control （DPC） design of a wind turbine driven doubly-fed induction generator （DFIG） under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.     

基于PWM控制的单相SVG装置设计

分析了SVG(Static Var Generator)的工作原理,详细阐述了其控制策略及通过硬件电路的实现方法,最后通过实验验证了所提出的控制方法的有效性,以及将SVG应用于低压动态无功补偿领域的可行性。     

3D wind-induced response analysis of a cable-membrane structure

Wind loading is a dominant factor for design of a cable-membrane structure. Three orthogonal turbulent components, including the longitudinal, lateral and vertical wind velocities, should be taken into account for the wind loads. In this study, a stochastic 3D coupling wind field model is derived by the spectral representation theory. The coherence functions of the three orthogonal turbulent components are considered in this model. Then the model is applied to generate the three correlated wind turbulent components. After that, formulae are proposed to transform the velocities into wind loads, and to introduce the modified wind pressure force. Finally, a wind-induced time-history response analysis is conducted for a 3D cable-membrane structure. Analytical results indicate that responses induced by the proposed wind load model are 10%-25% larger than those by the con- ventional uncorrelated model, and that the responses are not quite influenced by the modified wind pressure force. Therefore, we concluded that, in the time-history response analysis, the coherences of the three orthogonal turbulent components are necessary for a 3D cable-membrane structure, but the modified wind pressure force can be ignored.     

电池储能技术在可再生能源电站并网中的应用综述

与常规能源电站不同,可再生能源电站的出力具有间歇性和波动性,其大规模并网将对电网产生一系列的负面影响。文章在现有研究成果的基础上,总结了主流电池技术的特性,以及电池储能系统BESS在可再生能源电站并网中的应用现状,并对其应用前景和进一步的研究工作进行了展望。研究表明：电池储能系统可显著改善可再生能源电力固有的间歇性,实现对可再生能源电力的有效调度,且能平滑可再生能源发电系统的功率波动,降低其对电能质量和电网稳定运行的不利影响。因此,BESS具有广阔的应用前景,应继续加强对降低电池成本以及大型电池储能系统的集成、运行技术等的相关研究。     

A predictive controller for joint pitch-roll stabilization

Reduction of roll and pitch motions is critical in improving the safety and operability of a ship. In this paper, a predictive controller for a ship equipped with two pairs of active fins is proposed for joint pitch-roll stabilization. The proposed controller is developed on the basis of ship motion and hydrodynamic force prediction (SMHFP). The SMHFP controller consists of a short-term predictor, a force estimator, and a fin angle allocator. The short-term predictor adopts an autoregressive (AR) approach and serves to forecast ship motions. Then, predicted ship motions are used in an external hydrodynamic force estimator to evaluate the expected stabilizing forces. Finally, the optimal attack angles for active fins are allocated based on external hydrodynamic forces forecasts. The control system of the stabilizing fins and SMHFP controller is integrated into the sea-keeping program. The program was developed based on a weakly nonlinear 2.5D method, which shows better efficiency and accuracy compared with conventional 2D and 3D methods. To evaluate the performance of the proposed controller, numerical simulations of the joint pitch-roll stabilization under various sea states were investigated on a ship model. The results suggest that the SMHFP controller shows satisfactory performance in reducing pitch and roll motions simultaneously.     

直驱永磁风电机组低电压穿越的一种控制策略

为提高并网直驱永磁风电机组低电压穿越运行能力,提出一种适用于双PWM变换器并网的永磁直驱风电机组低电压穿越运行的电机侧及电网侧变换器协调控制策略。电网电压跌落时,根据输入电网的电磁功率的变化控制电机侧变换器来限制发电机的电磁功率以平衡输入直流侧电容的功率,稳定直流侧电压;根据电网电压跌落深度控制电网侧变换器,提供一定的无功电流,有利于电网电压稳定与恢复,提高风电机组的低电压穿越能力。仿真结果表明,所提控制方案无需硬件装置,能有效实现永磁直驱风电机组的低电压穿越运行。     

Adaptive rotor current control for wind-turbine driven DFIG using resonant controllers in a rotor rotating reference frame

This paper proposes an adaptive rotor current controller for doubly-fed induction generator （DFIG）, which consists of a proportional （P） controller and two harmonic resonant （R） controllers implemented in the rotor rotating reference frame. The two resonant controllers are tuned at slip frequencies ωslip＋ and ωslip-, respectively. As a result, the positive- and negative-sequence components of the rotor current are fully regulated by the PR controller without involving the positive- and negative-sequence decomposition, which in effect improves the fault ride-through （FRT） capability of the DFIG-based wind power generation system during the period of large transient grid voltage unbalance. Correctness of the theoretical analysis and feasibility of the proposed unbalanced control scheme are validated by simulation on a 1.5-MW DFIG wind power generation system.     

风力发电机组的独立变桨控制

为了实现风力发电机组3个桨叶的独立控制,依据风力机空气动力学原理和风剪切效应,提出了基于桨叶方位角信号的权系数分配独立变桨距控制方法.通过权系数对3个桨叶统一的桨距角进行重新分配,将统一变化的变桨角转化为每个桨叶独立变化的桨距角.以2MW变速变桨风力发电机组为研究对象,基于Bladed软件平台对该控制策略与传统的变桨控...