风电交直流通道互联电力系统暂态稳定线性变参数鲁棒反馈控制

针对交直流系统中影响暂态稳定电磁转矩和机械转矩平衡控制问题变参数特性,结合大规模风电功率的不确定性,提出了将直流通道功率控制与互联系统内机械功率作为控制目标的互联系统暂态稳定的线性变参数鲁棒反馈控制方法,以提高经交直流风电通道互联的系统的暂态稳定性。针对互联系统暂态过程的强非线性特性,建立了线性变参数模型;根据暂态过程系统出现的功率差额和风电出力不确定度,将系统暂态过程设计为变参数的线性化模型。对线性变参数模型设计H∞鲁棒输出反馈控制器及其在线求解算法。根据线性变参数设计点和鲁棒控制器,提出了互联系统暂态稳定控制策略拓扑及传递函数。应用交直流联络线互联形成的4个等值电网互联系统进行数字仿真,结果表明,文章所提出线性变参数鲁棒反馈控制模型,具有较好的响应特性和暂态稳定控制效果。     

基于H_∞的锅炉再热汽温状态变量的控制

为了提高电站锅炉再热汽温的控制品质,改善目前锅炉再热汽温控制的技术,讨论了基于非线性状态空间模型的锅炉再热汽温控制系统的鲁棒H∞控制方法.通过建立锅炉再热汽温控制系统的非线性时滞不确定性状态空间模型,利用鲁棒H∞控制方法,给出了其状态变量控制器的设计,结果由线性矩阵不等式(LMI)描述.控制器是否存在取决于LMI是否可解,所得控制器不需要调整额外的参数.通过仿真研究,验证了本方法的有效性.     

基于双闭环策略的光伏并网逆变器鲁棒H_∞控制

光伏并网系统中,为了抑制逆变器参数不确定和外界干扰对输出电能的影响,提出了鲁棒双闭环控制策略。首先设计电压环线性化自抗扰鲁棒控制器,以稳定直流侧母线电压;其次建立系统电流环的广义参数不确定模型,并利用LMI设计了电流环鲁棒H∞控制器,实现对逆变器有功电流和无功电流的精确控制。通过仿真与传统PI控制方法进行比较,验证了该控制策略可以有效地消除模型不确定因素和外界扰动对系统输出性能的影响,增强光伏并网系统的鲁棒稳定性。     

火电机组负荷多模型鲁棒预见控制方法

提出一种火电机组负荷多模型鲁棒预见控制方法，该方法首先对负荷区间进行模糊划分，然后在每个模糊子区间建立相应的结构参数摄动模型，并使用鲁棒预见控制方法设计控制器，最后总的控制量为多个子控制器输出的加权平均。仿真研究表明，该方法能够使负荷系统获得良好的全局控制性能。     

一种协调控制系统参数的鲁棒整定方法

对某330MW机组简化非线性动态模型进行线性化后，利用环路成形H∞方法设计鲁棒控制器。通过遗传算法寻优发现。性能指标较好的鲁棒控制器分布在一特定空间内，将鲁棒控制器分解为控制阵和解耦阵，发现其解耦的原则是：在汽轮机调门扰动时要尽快补充锅炉燃料量并保证机前压力不发生过调。按此原则设计简单的单向解耦，并采用工程方法整定PID控制器，其传递函数同鲁棒控制器低阶项极为相似。仿真实验证明，按此方法设计的协调控制系统具有较好的动态特性和鲁棒性。     

蒸汽发生器水位控制器的多目标GA和静态H_∞回路成形优化设计

提出了一种基于多目标遗传算法和静态H∞回路成形综合的给定结构鲁棒控制器设计方法,采用该方法设计了低负荷下蒸汽发生器水位的比例微分串联滤波器型控制器,并进行了水位给定值阶跃变化、蒸汽流量阶跃扰动和给水压力波动下控制系统响应的仿真试验.结果表明:所设计控制系统的鲁棒稳定性和鲁棒性能优于其他3种基于H∞回路成形的控制器设计方案;所得控制器在给定值阶跃变化、给水和流量扰动下均能保持较好的控制品质,具有良好的鲁棒性.     

混流式水轮机调节系统的鲁棒控制策略研究

水轮机及其调节系统是水力发电系统中的重要组成部分,承担着能量转换的重要作用。水轮机运行于复杂工况下,往往表现出各种复杂的非线性行为,危害水力发电系统安全。基于刚性水击下混流式水轮机调节系统的数学模型,采用T-S模糊控制方法建立了水轮机调节系统的非线性T-S模糊模型,基于Lyapunov稳定性定理,提出了一种鲁棒控制策略,设计了相应的鲁棒控制器。仿真计算表明,所设计的鲁棒控制器能够极大地抑制水轮机调节系统的振荡,并在较短时间内将水轮机调节系统的运动控制到稳定运行状态,研究结果可为混流式水轮机调节系统的安全稳定运行控制提供参考依据。     

基于载荷优化的大型风电机组μ-synthesis鲁棒控制

基于结构奇异值μ理论,针对大型风电机组柔性结构不确定性,提出动态载荷控制系统的鲁棒控制器设计方法。考虑结构的模态参数不确定性和高阶未建模动态,通过选取适当加权函数分离出系统的不确定部分,设计独立变桨距鲁棒μ控制器,用DK迭代算法求解控制器,以使闭环系统同时满足鲁棒性和稳定性要求,利用Matlab/S4WT软件进行仿真试验验证,仿真结果表明对载荷振动有很好的抑制效果。     

基于H_2/H_∞混合优化的大型风电机组变桨距鲁棒控制技术研究

基于线性矩阵不等式(LMI)设计多目标鲁棒H2/H∞状态反馈变桨距控制器,并通过极点配置,保证闭环系统的动态和稳态性能。变桨距控制器设计时充分考虑了减缓传动链疲劳载荷,达到减小机组关键部件载荷的目的。使用FAST软件进行仿真,仿真结果表明新型控制策略可有效平稳风电机组输出功率并降低机组疲劳载荷,实现了优化H2/H∞鲁棒控制性能。     

基于自适应遗传算法的协调控制系统优化

针对火电单元机组的协调控制系统,提出了一种基于自适应遗传算法的多变量鲁棒PID控制器参数寻优方法.以控制器设定点跟踪性能为优化目标,鲁棒性能为动态约束,采用具有自适应交叉概率和变异概率的遗传算法寻优PID控制器参数.仿真结果表明,与传统遗传算法寻优所得PID控制器相比,基于自适应遗传算法的鲁棒PID控制器具有良好的负荷...     

Design of a wind turbine pitch angle controller for power system stabilisation

The design of a PID pitch angle controller for a fixed speed active-stall wind turbine, using the root locus method is described in this paper. The purpose of this controller is to enable an active-stall wind turbine to perform power system stabilisation. For the purpose of controller design, the transfer function of the wind turbine is derived from the wind turbine's step response. The performance of this controller is tested by simulation, where the wind turbine model with its pitch angle controller is connected to a power system model. The power system model employed here is a realistic model of the North European power system. A short circuit fault on a busbar close to the wind turbine generator is simulated, and the dynamic responses of the system with and without the power system stabilisation of the wind turbines are presented. Simulations show that in most operating points the pitch controller can effectively contribute to power system stabilisation.     

Design of a robust adaptive controller for a water turbinegoverning system

The prospective of parameter space methods for robust control and an algorithm for a robust controller based on a pole-shifting adaptive control technique are presented in this paper for a hydroelectric turbine generator. Mathematical development of the robust adaptive controller algorithm, calculation procedure and results of simulation studies when applied to a water turbine governing system are described in this paper     

Robust PID Controller Design for Hydroturbines

The design and analysis of a robust proportional, integral, derivative (PID) controller for a hydraulic turbine generator governor using a frequency-response technique is presented. The approach uses data from literature on the turbine and on the interconnected system in various modes of operation through a model in the literature to design a single PID controller to guarantee stability and performance over the entire operating range. To ensure stability of the loop for as yet unanticipated operating situations, gain margin, and phase margin, constraints are imposed during the design of the controller. The new PID governor is compared with a high-order controller designed by the$H_infty$method.     

风气互补发电系统与电力系统相互影响的研究

为研究风气互补发电系统对电网的影响,首先搭建了由风电机组、燃气轮机、电网线路、静止无功补偿器、电力系统稳定器和大型水力发电机组成的仿真系统,并对该系统的负载侧和电网线路中部节点进行了稳定性分析。仿真结果表明,电网在加载了风气互补系统后运行能保持稳定,并能在发生短时故障后恢复到原来状态。该文为进一步研究风气互补系统与电网的相互影响提供了良好的模型基础。     

水轮机调节系统被控对象模型辨识

建立了水轮机调节系统被控对象的非线性模型,用递推最小二乘法(RLS)对被控对象进行参数辨识。仿真实验证明,该模型与被控对象模型相吻合、过程简单、效果良好、易于实现编程。基于此对控制参数进行了优化,改善了系统的动态品质。具有实用价值。     

A decentralized controller design for a power plant using robustlocal controllers and functional mapping

This paper presents a design approach for a decentralized controller for a power plant. An electric power plant nonlinear model is decomposed into three subsystems: boiler, turbine, and generator. The interconnecting variables between the subsystems are treated as constant boundary conditions for the controller design. The local controllers are designed to be robust in order to accommodate fluctuations in the interaction variables once the overall system is considered. The drum pressure set-point is automatically obtained from the power demand through a functional mapping     

Controller for a small induction-generator based wind-turbine

Design of a low-cost micro-controller for a small induction-generator based grid-connected wind-turbine is presented in this paper. The controller senses the parameters of the wind-turbine generator and the grid, and makes decisions about grid connection and disconnection. Low-cost instrumentation circuitry has been developed to measure the generator and grid parameters. Based on the measurement of voltage and frequency of the wind-turbine generator and the grid side, a control decision is taken to connect the system to the grid. The controller makes decision to disconnect the system from the grid based on the power flow measurement between the wind turbine and the grid. The power flow between wind turbine and the grid depends upon the availability of the wind. The prototype controller has been developed based on a micro-controller PIC16F877 and has been tested in the laboratory.     

Robust pitch controller for output power levelling of variable-speed variable-pitch wind turbine generator systems

A robust pitch (RP) controller for variable-speed variable-pitch wind turbine generator systems (VSVPWTGS) is presented. The controller can not only level the wind energy conversion but also be applicable in a wide wind speed region even subject to large parametric or non-parametric disturbances. VSVP-WTGS consists of multi-subsystems with different time scales. The dominant `slow? dynamics are non-affine and high nonlinear. By considering `fast? subsystems as perturbations to the `slow? one, the dynamics of VSVP-WTGS can be represented by a nominal model and an error one. The RP controller is composed of a nominal inverse-system controller and a robust compensator. With the nominal inverse-system controller, the nominal closed-loop system can track its reference dynamics. With the robust compensator, turbine parameter uncertainties and non-parametric perturbations are tolerated. The performance of the RP controller is confirmed through theoretical analyses and computer simulations. Results show that RP controller can operate in a wider wind speed region robustly compared with a proportional-integral-derivative controller. Compared with other nonlinear controllers, the RP controller is simpler and can be more easily extended to other kinds of WTGS.     

Speed and active power control of hydro turbine unit

In the paper, the procedure is given for designing speed and active power controller of hydro turbine units. The procedure is based on mathematical models of the controlled system. The controller parameters are obtained from closed-loop poles and hydro turbine parameters by derived analytical formulas over a wide range of the hydro turbine operating points. The described procedure allows the fast and direct determination of the controller parameters. There is no need for heuristic controller parameters tuning. Results from two hydro turbine units with the controllers designed using the described procedure are given as an illustration.     

调速器液压系统的故障诊断及可靠控制策略

在分析水轮机微机调速器液压随动系统失效机理的基础上,总结了系统基于专家知识的故障诊断方法,并提出了一种模型参考故障诊断方法．同时应用智能技术将故障诊断与相应的可靠控制策略结合起来,在故障诊断定位的基础上,通过控制策略的变化,消除或弱化故障的影响,达到保证机组安全的目的．仿真研究和工业应用实践充分证明了这些理论和方法的实用性、有效性和可靠性