基于MSP430的风力发电机振动监测系统

系统搭建了风力发电机传动链的振动测试平台.以MSP430F149、MAX197、MAX291、无线通讯模块SRWF-1021等器件设计的数据采集无线传输系统,配合PC机和虚拟仪器软件,就可以在线观测振动波形、存储振动数据.利用MATLAB软件进行频谱分析,最终实现了风力发电机工作状态的诊断.系统设计具有耗电量低、传输距离远、速度快、可靠性高等优点.     

温度检测无线传输系统

本课题是"基于Cortex-M3处理器的低温风力发电机"的拓宽项目,原项目中风力发电机野外工作坏境恶劣,监控站距离风力发电机较远。使用信号直接传输的将会造成一定的浪费及不便,无线传输则可以改善以上不足。本系统已经通过实验测试。测试结果表明整个系统的温度测量误差已经达到设计±0.5℃的要求。整个仪表系统测量精度为0.5级。无线传输距离达到了300米。在300米的范围内,系统性能保持稳定。系统还具有良好的抗电磁干扰能力。目前整个系统各项性能已经完全达到设计预期要求。本系统不仅可以用于"基于Cortex-M3处理器的低温风力发电机"系统,可以用于遥感、遥控、无线抄表、工业数据采集及家庭自动化等领域。有一定的实用价值。     

风力发电机控制系统的可靠性设计

风力发电机控制系统作为风力发电机系统的核心,对于控制系统的可靠性研究是有很重要的现实意义。本文提出了风力发电机控制系统的可靠性设计,包括变桨系统、偏航控制、励磁系统、变流系统、雷电保护和冗余系统。本文将可靠性设计的方法应用到风力发电机控制系统的设计上,大大提高了机组的可靠性。     

基于MCU的嵌入式风机在线监测系统研究

本文介绍了一种基于多台MCU和一台PC机构成的分布式风力发电机在线监测系统,采用嵌入式数据采集方式,通过对风力发电机组的转速、振动频率、温度、湿度等参数进行实时监测,将模拟信号转化为数字信号后传送给PC机,以便保证安全运行和在线故障监测,从而确保对风力发电机组的运行情况进行实时掌控。     

基于80C196KC的风力发电系统功率控制器设计

通过对独立运行风力发电系统的能量流动关系的分析与研究,得出了系统运行的工作模式。提出了通过调节电磁转矩-转速特性调节功率的一种控制策略,使风力发电机输出在额定风速以下自动跟踪负载用电量。为了运用此控制策略,采用单片机80C196KC作为控制芯片,设计了用于控制发电机输出功率的电子调节装置。搭建了小型风力发电系统实验平台并进行了实验研究,实验结果验证了本文设计的功率控制器有效地解决了独立运行小型风力发电系统功率平衡问题。     

基于欧姆龙PLC的风电机组变桨距系统

在风力发电系统中,变桨距控制技术关系到风力发电机组的安全可靠运行,影响风力机的使用寿命,通过控制桨距角使输出功率平稳、减小转矩振荡、减小机舱振荡,不但优化了输出功率,而且有效的降低的噪音,稳定发电机的输出功率,改善桨叶和整机的受力状况。变桨距风力发电机比定桨距风力发电机具有更好的风能捕捉特性,现代的大型风力发电机大多采用变桨距控制。本文针对国外某知名风电公司液压变桨距风力机,采用可编程控制器（PLC）作为风力发电机的变桨距控制器。这种变桨控制器具有控制方式灵活,编程简单,抗干扰能力强等特点。本文介绍了液压变桨距系统的工作原理,设计了变桨控制器的软件系统。最后在国外某知名风电公司风力发电机组上做了实验,验证了将该变桨距控制器可以在变桨距风力机上安全、稳定运行的。     

风力发电机试验电源监控系统设计与实现

风力发电机试验电源系统复杂,需要利用监控系统来检测控制系统的运行状态并完成各项试验。基于可编程逻辑控制器(PLC)和组态软件WinCC,设计风力发电机试验电源监控系统。PLC与变频器的控制器完成对现场设备状态检测与控制。WinCC与PLC通过工业以太网通信,与DSP通过CAN总线通信。为实现WinCC与DSP通信,基于OPC设计CAN通信接口程序。使用WinCC建立监控界面,使画面随现场实际情况动态显示。监控系统应用于无锡航天万源新大力电机有限公司风力发电机试验系统中,运行稳定、安全性高。     

风力发电机网侧变换器的磁极约束控制

对风力发电机来说,机械部分和电网部分的优良动力性能是至关重要的。在电网侧,需要满足故障穿越和低短路功率弱电网连结的要求。本文采用联排电力电子器件,给出了一个磁约束控制(pole-restraining control,PRC)的网侧变换器。和现有的控制方法比较,磁约束控制可消除电力电子变换器内部系统的不稳定性,并能极大的增强动态性能。改进的性能通过一个风力发电机的网侧变换器做了验证。并对磁约束控制的原理作了说明,仿真结果表明了瞬态性能有所提高。     

TD-SCDMA网络Iub接口数据采集监测系统的设计与实现

针对Iub接口传输特征和数据采集技术,在综合考虑网络优化的功能需求,设计了一个基于嵌入式Web技术的Iub接口数据采集监测系统.从Web工作机制及嵌入式环境平台的搭建出发,着重分析了PHP库层次化、模块化的设计,并通过模拟的数据采集环境,验证数据采集监测系统的可靠性,测试表明,该数据采集监测系统具有较好的灵活性、兼容性.     

用于风力发电机偏航控制的激光测风系统设计与试验

为实现风力发电机迎风信息的精确测量,采用连续波相干探测技术,设计了针对风力发电机偏航控制需求的激光测风系统。该系统的扫描装置中由直驱电机带动15°顶角楔形镜旋转实现激光对大气的圆锥扫描,设置扫描一圈用时为15 s,每圈采样点数为30个,利用正弦拟合方法反演风力发电机前方的风场信息。将激光测风系统安装在深圳市气象观测梯度塔下,与塔上超声波风速仪进行了对比测风试验。经过数据分析,水平风速相关系数达0.98,标准差为0.22 m/s,风向相关系数达0.97,标准差为3.04°,表明所设计的激光测风系统性能优良,工作稳定可靠,能够为风力发电机提供精确风场参数,提高风能的利用效率。     

基于单–双高斯模型拟合法的测风激光雷达海上风电机组尾流特征分析

当气流经过风电机组的扫风平面时, 风电机组下风处产生的尾流效应会对风电机组的发电效率、疲劳载荷产 生不同程度的影响。基于相干多普勒测风激光雷达在江苏某海上风电场开展了全天候风场观测实验。由于紧邻风电 机组的尾流垂直截面上风速呈双高斯分布规律, 利用传统单高斯拟合算法存在计算误差较大, 无法反映真实流场风速 变化规律, 提出了一种单–双高斯模型拟合改进算法, 分析了目标风电机组尾流的尾流宽度、风速损失率和尾流长度 等参数特征, 研究结果验证了单–双高斯拟合算法对尾流横向风速拟合的可行性和准确性。     

锅炉多路风压风速监测仪的设计与应用

介绍燃煤锅炉多路风压风速数字监测仪,该仪表是以微处理器89C52单片机为核心的多路信号数字采集监测系统。仪表外部接口通过热电阻、差压仪表进行温度、压力检测,实现对工业燃煤锅炉多路风压、风速、温度的实时采集、实时测量、显示与报警。热电阻接成三线制形式,消除阻值漂移和导线电阻的影响,实现阻抗自动补偿。输出的电流信号经模拟开关进行采样,并转换成电压信号,经信号放大后送入A/D转换器,最后通过CPU处理后,输出风速、风压、相应通道编号等。     

An intelligent maximum power extraction algorithm for inverter-based variable speed wind turbine systems

This paper focuses on the development of maximum wind power extraction algorithms for inverter-based variable speed wind power generation systems. A review of existing maximum wind power extraction algorithms is presented in this paper, based on which an intelligent maximum power extraction algorithm is developed by the authors to improve the system performance and to facilitate the control implementation. As an integral part of the max-power extraction algorithm, advanced hill-climb searching method has been developed to take into account the wind turbine inertia. The intelligent memory method with an on-line training process is described in this paper. The developed maximum wind power extraction algorithm has the capability of providing initial power demand based on error driven control, searching for the maximum wind turbine power at variable wind speeds, constructing an intelligent memory, and applying the intelligent memory data to control the inverter for maximum wind power extraction, without the need for either knowledge of wind turbine characteristics or the measurements of mechanical quantities such as wind speed and turbine rotor speed. System simulation results and test results have confirmed the functionality and performance of this method.     

Maximum Power Point Tracking in Variable Speed Wind Turbine Based on Permanent Magnet Synchronous Generator Using Maximum Torque Sliding Mode Control Strategy

The present study was carried out in order to track the maximum power point in a variable speed turbine by minimizing electromechanical torque changes using a sliding mode control strategy. In this strategy, first, the rotor speed is set at an optimal point for different wind speeds. As a result of which, the tip speed ratio reaches an optimal point, mechanical power coefficient is maximized, and wind turbine produces its maximum power and mechanical torque. Then, the maximum mechanical torque is tracked using electromechanical torque. In this technique, tracking error integral of maximum mechanical torque, the error, and the derivative of error are used as state variables. During changes in wind speed, sliding mode control is designed to absorb the maximum energy from the wind and minimize the response time of maximum power point tracking (MPPT). In this method, the actual control input signal is formed from a second order integral operation of the original sliding mode control input signal. The result of the second order integral in this model includes control signal integrity, full chattering attenuation, and prevention from large fluctuations in the power generator output. The simulation results, calculated by using MATLAB/m-file software, have shown the effectiveness of the proposed control strategy for wind energy systems based on the permanent magnet synchronous generator (PMSG).     

风电机组变流系统驱动及保护电路设计

针对风电机组变流系统的变流电路以及运行中出现的问题,提出了一套风电机组PWM四象限变流器的驱动、缓冲吸收及保护电路.详细论述了驱动及保护电路设计的必要性和重要性,并给出了用Protel设计的电路和各个重要参数,旨在提高风电机组变流系统运行的可靠性,减少损失.     

供变速风机使用的电力电子变流器

在风力发电系统中变速驱动方式的引入给系统带来了许多好处，但是变速风力发电机产生的电能与电网要求的标准不相适应，必须在发电机和电网之间安装电力电子变流器，才有可能将风力能源送入电网。文章主要介绍了在变速风力发电系统中使用的几种不同电力电子变流器的拓扑结构和它们在其它系统中的应用及目前的发展情况。     

A Fuzzy Logical MPPT Control Strategy for PMSG Wind Generation Systems

Making full use of wind power is one of the main purposes of the wind turbine generator control. Conventional hill climbing search (HCS) method can realize the maximum power point tracking (MPPT). However, the step size of HCS method is constant so that it cannot consider both steady-state response and dynamic response. A fuzzy logical control (FLC) algorithm is proposed to solve this problem in this paper, which can track the maximum power point (MPP) quickly and smoothly. To evaluate MPPT algorithms, four performance indices are also proposed in this paper. They are the energy captured by wind turbine, the maximum power-point tracking time when wind speed changes slowly, the fluctuation magnitude of real power during steady state, and the energy captured by wind turbine when wind speed changes fast. Three cases are designed and simulated in MATLAB/Simulink respectively. The comparison of the three MPPT strategies concludes that the proposed fuzzy logical control algorithm is more superior to the conventional HCS algorithms.     

某车载雷达风洞试验数值模拟

为了验证风洞试验数值模拟的精确度,利用数值风洞技术对某车载雷达外流场进行了三维、粘性、不可压缩、定常流数值仿真计算,并进行了缩比模型的同条件风洞试验。通过数据的对比分析,得出数值风洞技术的计算精度,为雷达天线的结构设计提供技术支撑。     

Wind turbine speed control of a contactless piezoelectric wind energy harvester

ABSTRACT

Wind turbine control is an important task to make the electricity generation secure in terms of energy demand and machine safety. It also yields to control the desired power level and optimized energy because of the assignment of turbine speed. The contactless piezoelectric wind energy harvester (CPWEH) used in this study has three piezoelectric layers located around the shaft with 120 degrees apart and they are buckled by the magnetic force without any physical contact. The superiority of this device is to generate energy for low wind speeds such as 1.5 m/s. However, for high speeds, high total harmonic distortions (THDs) govern the waveforms, thus controlling the turbine speed becomes necessary for optimizing the output power. Encouraged by this, a small low inertia dc generator is coupled with the wind turbine, and the generator terminals are connected to a resistor through a power switch to generate a braking torque that opposes to wind speed direction. By controlling the switch properly, turbine speed is ensured to remain within a certain band, which accordingly prevents the turbine from rotating very fast at damaging wind speeds. Several experiments are performed on the developed CPWEH with/without the presented control scheme which prove the existence of promising performance of our proposal.     

基于半物理仿真平台的风力机PID控制研究

针对变速变桨风力机组的特点,基于风力机半物理仿真平台,根据建立的组合风速模型及风力机不同的运行区域,研究了考虑机械传递、阻尼等因素的风力机PID控制方法,并进行了实验验证。结果表明,真实物理平台实验更能体现风力机的机械特性,建立的PID控制方法也较为贴近真实风机的控制特性。