锅炉汽包水位模糊免疫PID的应用研究

针对工业锅炉控制系统的特点,采用将常规PID控制与模糊免疫PID控制相结合的控制策略,在常规PID调节器的基础上,采用模糊免疫PID控制对PID参数进行自校正.对锅炉汽包水位的实验仿真,表明了这种模糊免疫PID控制器可明显提高系统的性能.     

基于内模控制器的再热汽温控制应用

再热汽温控制始终是火电厂运行控制的难点,减少再热器减温水的用量对提高机组的热经济性有十分重要的意义。文中采用燃烧器摆角和再热器喷水减温联合调整再热汽温的控制策略,其中燃烧器摆角调节控制器采用内模控制器IMC以提高其控制性能。在某电厂300MW机组上进行再热汽温优化控制系统试验,试验结果表明IMC内模控制器更好地解决大时滞问题,联合控制策略可极大地降低减温水投放量。     

基于内模控制器的变速恒频风力发电并网控制方法

在分析定子磁链定向的双馈电机控制的基础上,将矢量控制技术和内模控制器结合起来应用于定子电压并网控制中,得到了一种新型的并网控制方法.该控制方法并不需要建立精确的感应电机模型,动态响应快,无超调,控制器结构简单,参数单一,工程上易于实现.利用Matlab进行的仿真结果表明,该方法具有优良的动态性能.     

基于模糊内模控制的汽轮机调速系统研究北大核心

针对汽轮机DEH控制系统中存在时滞、死区、干扰等非线性环节,提出一种模糊内模控制策略。基于粒子群算法对广义被控对象进行模型简化处理,利用内模控制原理将其设计为内模-PID,根据最大灵敏度函数与τc之间的关系进行参数初始选取,并用模糊控制器对仅有的一个参数进行在线整定。通过建模仿真并对比分析:该方法有效避免了参数盲目选取问题,提高了系统响应速度、减少超调量、具有较强的抗干扰性,明显改善了汽轮机调速系统控制品质,对汽轮机调速系统设计提供了参考。     

过热汽温多内模控制

针对火电厂过热汽温被控对象具有大迟延、大惯性的特点,且对象特性随负荷变化较大等因素,很难实现稳定和高性能的控制。针对这一特点,提出了基于多模型的内模控制策略,通过在不同工况辩识得到局部模型,根据加权因子计算出全局多模型,设计出相应的内模控制器,根据运行工况选择相应的控制器,从而实现全工况运行的自适应控制。仿真结果表明,该控制策略比常规的单内模控制在更大范围具有较好的控制品质。     

变速变桨风力机叶片载荷控制策略

针对变速变桨风力机叶片受力特点,提出叶片载荷控制策略。将叶片载荷分为静态和动态两部分。静态部分采取单神经元PID控制器对桨距角和电机转矩进行控制;动态部分采取多叶片坐标转换理论将变量从旋转坐标系转换到固定坐标系,再将力矩转换为桨距角,然后通过多叶片坐标逆变换将控制得到的参数转换为旋转坐标系中的参数。最后将动态部分的参数值和静态部分的单神经元PID控制器的输出桨距角相加,一起构成风力机变桨所需的控制值。采用风力机专业软件Bladed开发外部控制器,并对控制策略进行仿真研究。将外部控制器和内置控制器的控制性能进行了仿真对比,仿真结果表明:外部控制器能够有效降低叶片根部的倾斜力矩和叶片拍打力矩,外部控制器的控制性能更优,验证了所采用的叶片载荷控制策略的正确性。     

基于模糊内模控制的汽轮机调速系统研究

针对汽轮机DEH控制系统中存在时滞、死区、干扰等非线性环节,提出一种模糊内模控制策略。基于粒子群算法对广义被控对象进行模型简化处理,利用内模控制原理将其设计为内模-PID,根据最大灵敏度函数与τc之间的关系进行参数初始选取,并用模糊控制器对仅有的一个参数进行在线整定。通过建模仿真并对比分析:该方法有效避免了参数盲目选取问题,提高了系统响应速度、减少超调量、具有较强的抗干扰性,明显改善了汽轮机调速系统控制品质,对汽轮机调速系统设计提供了参考。     

核电稳压器内模PID优化控制

针对核电站稳压器非线性、时变和多扰动的特点,基于内模控制理论设计了内模PID控制系统,为进行内模PID控制器参数整定,提出了一种高速收敛的量子粒子群算法,经典型函数测试验证了算法的有效性并应用于参数寻优.仿真结果表明：所提出的内模PID控制系统的控制效果优于常规PID控制系统,在对象模型特性改变或模型具有扰动的情况下,内模PID控制器仍能取得较好的控制效果,在鲁棒性和抗干扰能力方面均具有较强优势.     

直驱式波浪发电系统功率优化鲁棒控制

为应对海洋复杂波浪环境,改善不规则激励力下直驱式波浪发电系统的功率捕获效果,降低参数变化影响,建立水动力和直线电机模型,采用线性二次型调节器方法设计系统状态反馈,通过控制代价方程中的权重矩阵,权衡系统输出功率、运动部件位移和速度三者之间的关系;计算理想电磁力,得到q轴期望电流跟踪值。根据系统摄动数学模型,将控制器设计问题转化为H∞鲁棒控制标准型问题,通过选取适当权函数求解控制器参数,增强系统抗干扰能力。仿真结果表明,在浮子位移和速度受限制情况下,当系统模型存在参数摄动时,所提控制策略系统输出功率更高、鲁棒性更强,可较好地应对复杂海况,提高波能转换效率。     

双馈风力发电系统空载并网模糊PI控制

基于定子磁链定向矢量控制原理,分析双馈风力发电系统并网运行机理,提出了系统空载并网模糊PI控制策略.在此基础上,该文对双馈风力发电系统空载并网过程进行了研究,并与模糊控制及PI控制进行比较.研究结果表明,并网模糊PI控制策略的动态响应快,稳态精度高,对电网电压波动和电机参数变化具有较强的鲁棒性,且并网过渡过程短暂,并网前后运行平稳.模糊PI控制方式既具有模糊控制器动态响应快、鲁棒性强的特点,又兼有PI控制器稳态精度高的优点,是一种优良的并网控制策略.     

Integrated fuzzy logic generator controller for stabilityenhancement

An integrated fuzzy logic controller is proposed in this paper for the generator excitation and speed governing control. The proposed controller has three control loops: the first one is the voltage control loop which has the function of automatic voltage regulator (AVR), the second one is the damping control loop which has the function of power system stabilizer (PSS), and the last one is the speed governing control loop which has the function of governor (GOV). A simple fuzzy logic control scheme is applied to all these three loops. The control scheme is simple enough so as not to require heavy computation for the controller, therefore, its real time application is feasible. The effectiveness is demonstrated through nonlinear simulations using a one machine infinite bus system. Comparison studies are also performed to show the advantages of the proposed controller with conventional excitation and speed governing control systems     

基于模糊PID的风电系统转速控制仿真研究

由于风速具有随机性、不确定性、变化范围大等特点,风力发电机转速若采用传统PID控制,仅一组固定的参数难以在不同风速下均有好的控制效果。分析了风力发电系统各参数之间的关系,结合PID控制和模糊控制各自的特点,设计了模糊自适应PID控制器。在额定风速以下,该控制器用于改变发电机定子电压,从而改变发电机反力矩,调节转速,使得输出功率快速跟随风速变化。MATLAB/Simulink仿真结果证实其稳定性、动态速度响应均优于传统的PID控制,取得了较为理想的控制效果。     

自适应学习误差模型船舶柴油机调速器的研究

船速控制的重要功能是维持船舶航速稳定和主机的热平衡,从而提高船舶操纵性能,以船-机-桨系统为控制对象的船舶调速器能够较好地实现这些功能.在分析船舶航速误差模型变化特性的基础上,应用激励函数的自适应神经网络和最陡下降法的非线性优化技术,提出了自适应学习误差模型控制方法,应用于船舶柴油机调速器控制系统.为验证新方法的有效性,在实验室条件下,建立了船舶柴油机调速器半实物仿真系统.仿真结果表明,新的船舶柴油机调速器在系统模型不确定和参数摄动情况下,能在线学习被控系统的动态特性,具有抑制扰动和参数摄动的能力,系统调节过程的稳定性和快速性都有提高.     

Investigation of maximum wind power extraction using adaptive virtual lookup‐table approach

With the advance of power electronic technology, direct‐driven permanent magnet synchronous generators (PMSG) have increasingly drawn interests to wind turbine manufacturers. Unlike a fixed‐speed wind turbine, the maximum power extraction of a PMSG wind turbine is affected by (1) electrical characteristics of the generator, (2) aerodynamic characteristics of the turbine blades, and (3) maximum power extraction strategies. In an environment integrating all the three characteristics, it is found in this paper that the existing commercial lookup‐table maximum power extraction mechanism suitable to a DFIG wind turbine is not suitable to a PMSG wind turbine. Through the integrative study of all the three characteristics, this paper proposes a novel PMSG maximum power extraction design. The special features of the proposed strategy include (i) an adaptive virtual lookup‐table approach for PMSG maximum power extraction and (ii) an implementation of the peak power‐tracking scheme based on a novel direct‐current vector control configuration. The proposed maximum power extraction mechanism with a nested speed‐ and current‐loop control structure is built by using MatLab SimPowerSystems. Simulation studies demonstrate that the proposed PMSG peak power‐tracking strategy has superior performance in various aspects under both stable and gust wind conditions. Copyright © 2010 John Wiley & Sons, Ltd.     

基于内模控制的水轮机调节器仿真研究

水轮机调节系统是非最小相位系统,是较难控制的一类系统。针对水轮机调节系统的特点,采用内模控制系统结构,使系统具有良好的抗扰性和鲁棒性。给出了在希望的幅值和相角裕量下控制器参数的计算方法。设计例子与仿真结果表明,根据该方法设计的系统有比较理想的鲁棒性和稳定性。     

Control of a grid-connected direct-drive wind energy conversion system

This paper investigates the current control for a grid-connected direct-drive wind energy conversion system (DDWECS) with a permanent magnet synchronous generator (PMSG), which utilizes a back-to-back pulse width modulation (PWM) converter. For the machine-side, the controller adopts a current vector control method based on the rotating reference frame (RRF) and the maximum power extraction (MPE) is realised through the tip speed ratio (TSR) method. For the grid-side, a novel controller is proposed for the first time to be successfully used for the DDWECS, which combining a proportional complex integral (PCI) current inner loop based on stationary reference frame (SRF) for regulating the grid-side current with a dc voltage outer loop for stabilizing the dc bus voltage and compare with the proportional resonant (PR) controller. A system simulation model is established by using the Matlab/Simulink to simulate the performance of the DDWECS and a prototype system has been build and tested to verify the validity of the developed control methods for both machine-side and grid-side and the excellent performance of the DDWECS.     

A novel online training neural network-based algorithm for wind speed estimation and adaptive control of PMSG wind turbine system for maximum power extraction

In this paper, an adaptive control scheme for maximum power point tracking of stand-alone PMSG wind turbine systems (WTS) is presented. A novel procedure to estimate the wind speed is derived. To achieve this, a neural network identifier (NNI) is designed in order to approximate the mechanical torque of the WTS. With this information, the wind speed is calculated based on the optimal mechanical torque point. The NNI approximates in real-time the mechanical torque signal and it does not need off-line training to get its optimal parameter values. In this way, it can really approximates any mechanical torque value with good accuracy. In order to regulate the rotor speed to the optimal speed value, a block-backstepping controller is derived. Uniform asymptotic stability of the tracking error origin is proved using Lyapunov arguments. Numerical simulations and comparisons with a standard passivity based controller are made in order to show the good performance of the proposed adaptive scheme.     

基于Matlab/xPC Target的BPH调速器实时仿真试验台研究

利用M atlab提供的Sim ulink、R A W和xPC Target工具箱建立了柴油机的实时仿真模型,并通过输入输出接口电路将仿真柴油机与实际调速器相连接构成闭环控制系统。采用这种半实物实时仿真方式在试验台上可实现反映柴油机调速特性的反馈调试功能,从而能够在调速器装机前实现其性能与状态的检查与调整。