现代控制技术在风能转换系统中的应用

不同的风能转换系统具有不同的设计目标,控制系统是风能转换系统的重要组成部分,也是控制工程界一直十分关注的问题。然而,这类问题一直没有得到完善的解决,继续具有挑战性,大量的文献不断涌现。综述了近年来滑模变结构控制、微分几何控制、H∞鲁棒控制、最优控制、自适应控制、神经网络控制、模糊控制、专家系统及综合智能控制在风能转换系统稳定．最大风能捕获及调速系统控制等方面应用研究的主要成果与方法,并提出若干需要解决的问题。     

基于事件触发机制的网络化风能转换系统鲁棒容错控制

本文对存在传感器和执行器故障的变速风能转换系统,提出了一种基于事件触发通信机制的鲁棒容错控制方法.建立了具有事件触发机制的非线性风能转换系统Takagi-Sugeno模糊模型模型.通过李雅普诺夫稳定性分析理论,给出了具有事件触发机制的风能转换系统鲁棒容错控制器的参数化表达式.与现有的风能转换系统容错控制方法相比,该方案...     

基于奇异摄动模型的风能转换系统H∞容错保性能控制

在风能转换过程中,针对执行器故障、容错控制成本高等问题,设计了H_∞最优容错保性能控制器,并基于PI观测器进行了故障诊断。首先,将风电系统中存在的时滞、参数不确定、执行器故障等问题用奇异摄动LPV模型表达;然后,设计PI观测器进行执行器故障重构,并在H_∞性能指标和成本性能指标双重约束下,进行凸优化计算,得到最优容错保性能控制律。仿真表明,低风速时,控制器能有效跟踪最优风轮转速,实现最大风能捕获。     

链传动式风能转换装置理论模型的研究

针对传统风力机的特点及研究现状.设计了一种全新的链传动式风能转换装置.通过建立的理论模型,分析计算了在理想状况下叶片的最佳迎风角度,计算结果与试验数据基本吻合,为今后装置结构的进一步优化奠定了理论基础.     

动态矩阵控制及其在燃气轮机排气温度控制中的仿真应用

本文设计了一个多变量动态矩阵控制器,通过对控制器重要参数的整定,实现了对燃气轮机的排气温度最优仿真控制,解决了传统燃机控制系统中排气温度控制品质差的问题。该控制器对模型的依赖性较低,在线计算方便且运算量很小,易于工程实现,具有良好的应用前景。     

双馈风力发电系统最大风能追踪控制

在分析风力机功率特性和DFIG运行特性的基础上,通过对双馈机转速控制进行最大风能追踪具体过程的深入研究,提出一种基于最大风能追踪的双馈电机有功、无功功率的解耦控制方法。建立了基于发电机定子磁链定向矢量控制的双馈风力发电系统最大风能追踪系统模型,并利用PSCAD／EMTDC对其进行仿真,结果验证了控制策略的正确性。     

Hybrid Control of a Grid-Interactive Wind Energy Conversion System

Without storage provision, a wind energy conversion system (WECS) does not have fault ride-through capability for most temporary faults on the utility feeder. This paper proposes a hybrid valve switching and control strategy for a voltage-sourced converter (VSC) used for interfacing a WECS to the utility grid. The hybrid control of the VSC ensures continuous operation of the system in the presence of temporary single line to ground faults on the utility feeder without the need for a storage provision. The fast acting hybrid control also limits reactive fault current contribution by the converter, and therefore, avoids problems associated with overcurrent protection of the feeder. The hybrid valve switching and control of the VSC consists of: 1) sinusoidal pulse width modulation (SPWM) based valve switching and current-controlled voltage-source operation of the VSC during normal system operating conditions and 2) hysteresis space vector modulation (HSVM) based switching together with controlled current-source operation of the VSC during temporary fault conditions. The hybrid control of the VSC isolates the WECS from the grid side disturbances to ensure uninterrupted operation of the unit. Simulation studies of the grid-interactive WECS in PSCAD/EMTDC confirm the validity of the proposed hybrid control scheme.      

Multistate Wind Energy Conversion System Models for Adequacy Assessment of Generating Systems Incorporating Wind Energy

Wind energy is considered to be a very promising alternative for power generation because of its tremendous environmental, social, and economic benefits. Electrical power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of those facilities, therefore, affect the power system reliability in a manner different from that of the conventional systems. This paper is focused on the development of suitable models for wind energy conversion systems, in adequacy assessments of generating systems, using wind energy. These analytical models can be used in the conventional generating system adequacy assessment utilizing analytical or Monte Carlo state-sampling techniques. This paper shows that a five-state wind energy conversion system model can be used to provide a reasonable assessment of the practical power system adequacy studies, using an analytical method, or a state-sampling simulation approach.     

提高风储发电经济性的双储能系统模型预测控制方法

储能系统可以有效降低风电规模化接入对电力系统造成的影响。在储能电池平滑风电功率波动的典型应用场景下,单储能频繁充放电切换将影响储能电池的使用年限,降低经济性。因此,文中提出了一种双储能电池的模型预测控制方法。首先,建立双储能风力发电系统的数学模型,分析储能输出功率对未来出力能力的影响;然后,设计以储能出力最优和基于储能能量状态改变双储能出力约束的模型预测控制策略;最后,利用实际风场数据,与单一储能模型预测控制对比,仿真结果表明在相同储能容量和平滑效果下,所提方法显著地降低了储能充放电切换,延长储能使用周期,并通过分析储能运行成本的经济性,验证了所提方法的优越性。     

High-Order Sliding Control for a Wind Energy Conversion System Based on a Permanent Magnet Synchronous Generator

This paper presents the output power control of a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). It is assumed that the considered wind module integrates a stand-alone hybrid generation system, jointly with a battery bank, a variable ac load, and other generation subsystems. The operation strategy of the hybrid system determines two possible operation modes for the WECS, depending on the power requirements of the load and the wind availability. The paper deals with the design of a combined high-order sliding mode (HOSM) controller for the power control of the WECS on both operational modes. The main features of the obtained controller are its chattering-free behavior, its finite-time reaching phase, its simplicity, and its robustness with respect to external disturbances and unmodeled dynamics. The performance of the closed-loop system is assessed through representative computer simulations.      

Sliding Mode Power Control of Variable-Speed Wind Energy Conversion Systems

This paper addresses the problem of controlling power generation in variable-speed wind energy conversion systems (VS-WECS). These systems have two operation regions depending on the wind turbine tip-speed ratio. They are distinguished by minimum phase behavior in one of these regions and a nonminimum phase in the other one. A sliding mode control strategy is then proposed to ensure stability in both operation regions and to impose the ideal feedback control solution despite model uncertainties. The proposed sliding mode control strategy presents attractive features such as robustness to parametric uncertainties of the turbine and the generator as well as to electric grid disturbances. The proposed sliding mode control approach has been simulated on a 1.5-MW three-blade wind turbine to evaluate its consistency and performance. The next step was the validation using the National Renewable Energy Laboratory (NREL) wind turbine simulator called the fatigue, aerodynamics, structures, and turbulence code (FAST). Both simulation and validation results show that the proposed control strategy is effective in terms of power regulation. Moreover, the sliding mode approach is arranged so as to produce no chattering in the generated torque that could lead to increased mechanical stress because of strong torque variations.     

风力发电机组的非线性控制--变结构控制与鲁棒控制

风速、风向及负载的随机性、湍流、尾流效应、塔影效应等的影响，使风力发电系统不但要解决最大风能捕获、电能品质控制两类关键问题，还要解决传动链的疲劳负载、叶片的振颤与翦切、塔身的弯曲与抖振等问题，这些问题实际上都可归结为非线性控制的范畴。该文综述了近年来滑模变结构控制、H∞鲁棒控制在风力发电系统稳定，最大风能捕获及调速系统控制等方面应用研究的主要成果与方法，并提出若干需要解决的问题。参18     

Voltage and Frequency Controller for a Three-Phase Four-Wire Autonomous Wind Energy Conversion System

This paper deals with control of voltage and frequency of an autonomous wind energy conversion system (AWECS) based on capacitor-excited asynchronous generator and feeding three-phase four-wire loads. The proposed controller consists of three single-phase insulated gate bipolar junction transistor (IGBT)-based voltage source converters (VSCs) and a battery at dc link. These three single-phase VSCs are connected to each phase of the generator through three single-phase transformers. The proposed controller is having bidirectional flow capability of active and reactive powers by which it controls the system voltage and frequency with variation of consumer loads and the speed of the wind. VSCs along with transformer function as a voltage regulator, a harmonic eliminator, a load balancer, and a neutral current compensator while the battery is used to control the active power flow which, in turn, maintains the constant system frequency. The complete electromechanical system is modeled and simulated in the MATLAB using the Simulink and the power system blockset (PSB) toolboxes. The simulated results are presented to demonstrate the capability of the proposed controller as a voltage and frequency regulator, harmonic eliminator, load balancer, and neutral current compensator for different electrical (varying consumer loads) and mechanical (varying wind speed) dynamic conditions in an autonomous wind energy conversion system.     

基于动态矩阵算法的湿法脱硫控制系统设计

针对由燃料、负荷剧烈变化而导致湿法脱硫系统难以稳定经济高效运行的问题,提出了基于动态矩阵算法(DMC)的湿法脱硫系统优化策略。通过引入浆液循环泵,实现浆液喷淋量的局部连续调节,并通过粒子群优化算法结合机理模型对传递函数进行参数寻优,建立DMC控制策略,在保证控制品质的情况下实现节能控制。将优化后的DMC控制和PID控制引入负荷为220t/h的电厂锅炉湿法脱硫系统。结果表明:与PID控制相比,在DMC控制下出口SO_2质量浓度变化范围更小,出口SO_2质量浓度分布更集中,控制品质更好;与传统人工控制相比,变频控制总电流降幅为50～110A,具有很好的节能效果。     

双馈风电机组并网运行改进控制策略研究

针对国内广泛采用基于定子磁链定矢量的控制方案,提出了双馈感应发电机并网运行的改进策略,以实现规定扰动下双馈风电机组的不间断运行稳定运行能力的提高,构建了DFIG机组的数学模型,分析了并网能量转换过程及扰动下的转矩不平衡与转子过电流的改进控制方案.仿真计算结果验证了该控制方案提高并网风电机组稳定性策略的有效性.     

Propagation and Elimination of Torque Ripple in a Wind Energy Conversion System

The 2P and 4P harmonics of the torque supplied by a two blade vertical axis wind turbine propagates in the drive train of the wind turbine and deteriorates the quality of the electric power transmitted to the network. This paper shows how the torque ripple propagates and how it can be eliminated by electrical instead of mechanical means. This elimination is obtained by using a converter-fed synchronous generator and by adopting suitable control strategies.