Improved Smith prediction monitoring AGC system based on feedback-assisted iterative learning control

The performance of Smith prediction monitoring automatic gauge control(AGC) system is influenced by model mismatching greatly in strip rolling process. Aiming at this problem, a feedback-assisted iterative learning control strategy, which learned unknown modeling error by using previous control information repeatedly, was introduced into Smith prediction monitoring AGC system. Firstly, conventional Smith predictor and improved Smith predictor with PI-P controller were analyzed. Secondly, on the basis of establishing of feedback-assisted iterative learning control strategy for improved Smith predictor, process control signal update law and control error were deduced, then convergence condition of this strategy was put forward and proved. Finally, after modeling the automatic position control system, the PI-P Smith prediction monitoring AGC system with feedback-assisted iterative learning control was researched through simulation. Simulation results indicate that this system remains stable during model mismatching. The robustness and response of monitoring AGC is improved by development of feedback-assisted iterative learning control strategy for PI-P Smith predictor.

AGC-ASC Synthetic Neural Net Control System in Rolling Process

Automation Gauge Control(AGC) and Automatic Shape Control(ASC) are coupling each other. The coupling models of AGC-ASC synthetic system for the thickness-crown have been established and two artificial neural networks controllers are given. The simulation of computer shows that the AGC-ASC synthetic system can obtain the expected thickness and shape precision with both schemes.

浅析一次调频及其与AGC的配合问题

一次调频是电网系统维持频率稳定的重要手段之一,由于水电站监控系统与水轮机调速器是相互独立的设备,这就导致监控的AGC或有功闭环调节的调节目的与调速器的一次调频目标有时会相互矛盾,因此要求一次调频和AGC做好协调工作。文章简述一次调频的基本概念,重点分析了一次调频的重要作用及与AGC的区别,以及其调节过程中与AGC的不同配合方式。

新能源电力系统AGC调频容量监测设计

文章提出了用于新能源电力系统自动发电控制(Automatic Generation Control,AGC)的实时调频容量评估方法,以满足控制区的自动发电控制调频能力分析需求。根据AGC调频容量考核标准,整理了影响调频容量的主要因素,并运用历史数据预测调频标准差。以贵州黔源电力镇宁某水电站和光伏站作为例,评估AGC调频容量。实验结果证实,应用所提方法能有效地分配调频容量。

Design and implementation of digital closed-loop drive control system of a MEMS gyroscope

In order to effectively control the working state of the gyroscope in drive mode, the drive characteristics of the micro electromechanical system （MEMS） gyroscope are analyzed in principle. A novel drive circuit for the MEMS gyroscope in digital closed-loop control is proposed, which utilizes a digital phase-locked loop （PLL） in frequency control and an automatic gain control （AGC） method in amplitude control. A digital processing circuit with a field programmable gate array （FPGA） is designed and the experiments are carried out. The results indicate that when the temperature changes, the drive frequency can automatically track the resonant frequency of gyroscope in drive mode and that of the oscillating amplitude holds at a set value. And at room temperature, the relative deviation of the drive frequency is 0.624 ×10^-6 and the oscillating amplitude is 8.0 ×10^-6, which are 0. 094% and 18. 39% of the analog control program, respectively. Therefore, the control solution of the digital PLL in frequency and the AGC in amplitude is feasible.

Design of a Proportional-Integral-Derivative Controller for an Automatic Generation Control of Multi-area Power Thermal Systems Using Firefly Algorithm

Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PSO) technique(PSOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.

MAS Based Distributed Automatic Generation Control for Cyber-Physical Microgrid System

The microgrid is a typical cyber-physical microgrid system (CPMS). The physical unconventional distributed generators (DGs) are intermittent and inverter-interfaced which makes them very different to control. The cyber components, such as the embedded computer and communication network, are equipped with DGs, to process and transmit the necessary information for the controllers. In order to ensure system-wide observability, controllability and stabilization for the microgrid, the cyber and physical component need to be integrated. For the physical component of CPMS, the droop-control method is popular as it can be applied in both modes of operation to improve the grid transient performance. Traditional droop control methods have the drawback of the inherent trade-off between power sharing and voltage and frequency regulation. In this paper, the global information (such as the average voltage and the output active power of the microgrid and so on) are acquired distributedly based on multi-agent system (MAS). Based on the global information from cyber components of CPMS, automatic generation control (AGC) and automatic voltage control (AVC) are proposed to deal with the drawback of traditional droop control. Simulation studies in PSCAD demonstrate the effectiveness of the proposed control methods. © 2014 Chinese Association of Automation.

Research on Wind Farm Participation in Power Grid AGC Control

Since wind power has the features of being intermittent and unpredictable, and usually needs transmission over long distances, grid integration of large-scale wind power will exert signif icant influence on power grid planning and construction, and will make a heavy impact on the safe and reliable operation of power systems. To deal with the diff iculties of large scale wind power dispatch, this paper presents a new automatic generation control (AGC) scheme that involves the participation of wind farms. The scheme is based on ultra-short-term wind power forecast. The author establishes a generation output distribution optimization mode for the power system with wind farms and verif ies the feasibility of the scheme by an example.

基于粒子群算法的精轧AGC系统智能参数优化及实验设计

将经典粒子群(particleswarmoptimization,PSO)算法和4种不同改进形式的PSO算法应用于精轧自动厚度控制(automatic gauge control,简称AGC)系统PI控制参数的优化整定,设计了基于PSO-PI控制策略的精轧AGC智能优化控制系统。在控制参数的整定过程中,通过加权系数法将控制精度、动态响应特性等多项性能指标的优化问题转化为单目标优化问题,并通过仿真实验研究了各项控制指标权重系数对控制效果的影响。最后,基于PSO算法研究成果构建了精轧AGC智能优化控制虚拟仿真实验系统,为学生解决冶金自动化领域复杂工程问题能力培养提供了有力支撑。

区域新能源电力系统AGC调频容量实时评估方法

针对高比例可再生能源接入下电力系统惯量水平持续降低、弱频率调节能力会危及电网安全运行等问题,提出一种区域新能源电力系统自动发电控制AGC(automatic generation control)调频容量实时评估方法,以确定控制区的AGC调频能力分析需求。首先,依据AGC调频容量考核标准,梳理调频容量的主要影响因素,并获取调频容量、调频标准差与调频表现间的联系。其次,综合应用传统机组、负荷、新能源、联络线历史数据,基于极限学习机ELM(extreme learning machine)模型预测调频标准差,利用调频表现达标概率分布确定区域电力系统的调频容量。最后,以河北某电网为例进行AGC调频容量的评估,验证了所提方法AGC调频容量更小,调频表现更优,具有更好的安全性和经济性。

AGC-ASC Decoupled Neural Networks Predictive Control Method

The coupling models for the thickness-crown objects is established. A Dynamic Matrix Controller based on the TH neural networks is given with the convergence property. The computer simulations with the AGC-ASC decoupled neural networks predictive control system is complemented and it shows that the stable states of neural networks are reached with on more that one μs, this has not only sahsfied the fast property of rolling process, but also obtained a higher control index.

机组AGC及深度调峰控制性能优化

江苏徐矿综合利用发电有限公司2台300 MW亚临界燃煤发电机组,自2010年投产以来经历多次检修,机组主辅机性能产生变化,且由于机组增加对外供热,原设计控制方式无法协调锅炉能量—汽机需求—电气功率三者的平衡,加剧了AGC、一次调频调节品质的恶化,且无法适应当前电网深调工况需求。通过对机组自动控制系统进行相应逻辑优化、参数调整,在保证各主辅机安全运行的前提下,有效提高机组“两个细则”性能指标,同时实现30%~100%深度调峰下机组稳定经济运行。

盐锅峡水电厂AGC调节优化

在“双碳”目标以及新型能源体系建设迅速发展的趋势下,西北电网新能源电量渗透率逐年升高,使得区域电力系统安全稳定运行面临严峻挑战。自动发电控制(Automatic Generation Control, AGC)系统对区域电力系统稳态频率控制等具有重要意义。通过对盐锅峡水电厂,对其机组AGC系统进行调节优化,提出了一种基于PID控制的精确式调节策略。最后,通过现场动态实验运行测试数据对比,验证表明所提出的精确式调节策略对AGC的响应时间和调节速度均有更优表现,具有良好的安全性和稳定性。

水电机组一次调频与AGC典型控制策略的工程分析及优化

分析了云南省内已投运水电机组一次调频与自动发电控制(AGC)的典型控制策略,通过工程试验及数据分析,逐一指出其特点及不足。提出功率控制模式下机组采用斜坡函数作为AGC负荷指令,及采用比例—积分—微分(PID)变参数控制分别满足AGC负荷调节和一次调频响应的不同要求;开度控制模式下机组一次调频动作方向与AGC负荷指令方向相反时应屏蔽AGC负荷指令,以及AGC负荷指令首先响应时,应短暂屏蔽一次调频功能等策略。优化了一次调频与AGC间的逻辑关系,并对文中的典型控制策略给出了合理的可行性建议,为水电机组一次调频与AGC寻找更理想的配合策略提供了参考依据。

协调控制系统快速响应AGC指令的设计新方法及其工程应用

自动发电控制(Automatic Generation Control,AGC)是当代电网自动控制的一项基本要求。目前参与AGC控制的火电机组存在响应速度慢等问题,使电网AGC的控制效果较差。姚孟发电有限责任公司的1号和2号300MW本生直流炉式单元机组采用了增量型状态观测器与传统PID控制相结合的协调控制方案,并采用了文章给出的AGC与CCS的接口控制逻辑,使协调控制系统中的预给煤运算等功能在AGC方式下能得以实现,从而使机组能快速响应AGC负荷指令。两台机组AGC联调试验实时趋势曲线证明了这一点。

基于模糊控制的电池储能系统辅助AGC调频方法

针对AGC控制中火电机组响应时滞长、机组爬坡速率低的问题,提出了一种基于模糊控制策略的电池储能系统(Battery Energy Storage System,BESS)辅助AGC调频方法。该方法以区域控制偏差(Area Control Error,ACE)及其变化率作为模糊控制器的输入量,BESS的参考功率变化量作为输出量,根据系统的运行状态调节BESS输出功率,辅助火电机组改善电网的动态调频性能。基于Matlab/Simulink平台的仿真结果表明,BESS能够迅速响应负荷扰动,减小了系统频率偏差和联络线功率偏差,降低了系统的超调作用,有助于提高电网AGC调频能力和增强系统的稳定性。

用AGC实现稳定断面越限的预防和校正控制

提出将自动发电控制(AutomaticGenerationControl,AGC)与安全约束调度结合在一起,构成闭环控制系统,实现稳定断面越限的预防和校正控制。当稳定断面重载时,根据该断面有功功率相对于机组有功出力的灵敏度系数对机组出力的调节方向加以限制,防止由于AGC的正常调节导致重载程度的进一步加剧(简称预防控制);当稳定断面越限时,由安全约束调度提供校正控制策略,并在AGC控制下执行,自动完成解除越限的调节(简称校正控制)。在江苏省调EMS中的实际工程应用表明,该方法可以有效地将稳定断面有功功率控制在允许范围内,保证电力系统的安全稳定运行。

冷连轧机液压AGC系统中的分布式计算机控制

高速冷连轧机是典型的复杂机电系统,而液压AGC是其消除厚差,提高成品精度的重要手段。随着计算机技术的发展,带钢冷轧生产规模的扩大,对带钢成品精度要求的进一步提高,要求冷连轧机液压AGC系统综合控制进一步完善,集中式计算机控制系统已经不能满足液压AGC系统高速控制的要求,分布式计算机系统已成为其主流控制系统。本文结合冷连轧生产实际,对分布式控制系统以及连轧自动化计算机控制的发展历程做了论述,同时给出了基于分布式工业控制系统的连轧过程自动化液压AGC计算机控制系统结构。冷连轧机液压AGC计算机控制系统分为基础自动化级和过程自动化级,它们之间的通信由以太网来完成,以适应连轧控制系统控制高速化、精密化、智能化的要求。

首钢中厚板轧机AGC计算机控制系统

介绍了首钢中厚板轧钢厂 334 0mm中厚板轧机液压AGC系统工艺参数和计算机系统的硬件配置和传感器配置 ,给出了轧机弹跳模型和液压缸HCC的控制原理和液压缸的系统频率响应特性 ,描述了本系统所采用的头部锁定AGC和绝对AGC的控制策略 ,并对支撑辊偏心补偿、油膜厚度补偿等厚度控制补偿方法进行了说明。

提高机炉协调控制系统AGC响应速率的方法

针对目前河北省南部电网火电机组协调控制系统AGC响应速率比较慢的现状,分析了影响AGC变负荷速率的几种因素,提出几种能够有效提高协调控制系统响应速率的方法,如增加电网调度中心与火力发电厂之间AGC传输信号的数量、改进AGC的调度方式等。对于配备了火电厂厂级监控信息系统(SIS)的机组,以全厂作为一个整体进行AGC控制,而不再对单机直接进行AGC控制,有效提高了机组调节速率与品质。