PLC在热电站燃料准备系统中的应用

本文阐述了热电站燃料准备系统中皮带运输机的电气控制系统及其主要特点,PLC控制的硬件组成和软件控制的设计方法,从硬件和软件两方面,介绍了PLC在工业控制系统中的应用。     

冷热电联供系统多目标运行优化

冷热电联供系统能够提高能源利用率和减少碳排放,是解决能源和环境危机的重要途径.本文提出了冷热电联供系统多目标优化运行方法,以运行成本日节约率、一次能源日节约率、CO2日减排率综合最优为目标,利用遗传算法求解,得到关键设备的逐时出力计划,并以此为基础,设计了由MATLAB和LABVIEW构成的运行优化器.最后本文基于TRNSYS与LABVIEW搭建了冷热电联供系统(CCHP)软硬件混合实时仿真系统,验证了运行优化器的有效性,结果表明本文提出的优化运行方法较传统运行模式,可有效提高冷热电联供系统的经济性、节能性和环保性.     

Residential virtual power plant with photovoltaic output forecasting and demand response

Decreasing conventional power supply is promoting the development of the distributed renewable energy sources, such as solar power and wind power. Recently rooftop photovoltaic has been widely applied, and accordingly efficient energy management is getting increasingly important for fully use of renewable energy and the peak shaving of the main grid. This paper investigates the residential energy management as a small‐scale virtual power plant (VPP) connected to the main grid includes distributed energy resources, energy storages and residential loads. The self‐organizing map (SOM) and the radical basis function (RBF) networks are adopted to classify the weather types and predict hourly photovoltaic output precisely. In a time‐of‐use electricity market, price‐based demand response is applied to adjust the demand. The residential VPP has two goals: maximum profit by selling surplus power to grid and minimum power purchased from grid. The two goals are integrated as an optimization object by introducing a weight parameter. The algorithm combining receding horizon optimization and linear programming is proposed to solve the optimization problem in residential VPP. Numerical simulation tests can help to find the most suitable value of the weight parameter. Different scenarios are simulated and discussed to demonstrate the performance of the VPP and the proposed algorithm.     

太阳能热发电蓄热系统的混杂建模与仿真

蓄热系统是太阳能热发电站中保证电站可靠性和经济性的重要组成部分,其工作状况直接影响到太阳能热发电站的正常运行。本文针对单罐式蓄热系统,分析了系统在蓄热和放热模式下的动态数学模型,在此基础上,提出了蓄热系统的混杂动态系统模型。该模型将蓄热和放热模式统一在一个框架下,能够对蓄热系统的各种操作模式及其循环交替过程进行动态模拟。混杂模型采用MATLAB软件进行仿真,仿真结果:表明了模型的有效性。     

基于虚拟仪器变压器运行参数采集系统

配电变压器是输电系统的关键环节。本文设计的配电变压器运行参数采集系统旨在实时全面监测环境温度和变压器运行时各种参数,掌握其负载、温升的规律。研究挖掘其潜在运载能力,探讨适当提高其运行温度的可行性。本运行参数采集系统,为此研讨工作提供数据支持。     

贵州火电厂SCR脱硝运行情况分析

贵州火电目前主要燃用高硫份、高灰份煤,主要采用SCR脱硝技术,少部分电厂采用SCR+SNCR脱硝技术,在实际运行过程中出现了烟风系统积灰、空气预热器堵塞、脱硝催化剂损坏等问题,给正常生产运行带来很多安全隐患,影响机组安全、经济运行。为解决贵州省最近几年SCR脱硝技术运行中出现的问题,从原理上分析在高硫分、高灰分烟气环境下,因烟气系统各段堵灰,容易造成逃逸氨量大,硫酸氢氨堵塞的原因。通过总结近几年贵州各火力发电厂脱硝系统的治理经验,提出解决火电厂脱硝问题的关键,是通过调整烟气流场均匀性和喷氨均匀性来降低脱硝氨耗量,提出脱硝催化剂管理,热控元件维护的方法,锅炉长周期运行时可采用提高冷端综合温度,空预器冲洗、热分解等措施。     

核电站KSN系统操作监控软件的仿真技术研究

针对核电站"三废"分布式控制系统的仿真需求,从组件化设计的角度出发,以Qt(C++图形界面库)为基础,结合图形化组态技术,对操作监控软件进行了仿真。该仿真软件系统采用层次化软件结构,充分利用Qt优良的跨平台特性、良好的封装和可重用性,以及丰富的API(应用程序编程接口),开发了跨平台的网络通信程序,与仿真模型服务器相连进行数据交互,不仅人机界面逼真度高、开发周期短,而且具有高内聚、低耦合等优良软件特性,且支持灵活的分布式配置部署。该软件系统在岭澳"三废"控制系统仿真项目中的工程应用证明其具有易用性强、可靠性高和逼真度优等特点。     

发电厂DCS网络异常引起的非停事件

主要论述一起发电厂DCS系统网络交换机电源切换装置故障引发的发电机组非停事件,重点对DCS系统失灵后的应急操作、原因分析和善后措施进行了详细阐述,同时结合事故案例提出DCS系统电源设计时必须遵循的的一些设计原则,对于新建电厂或已投产电厂在DCS系统电源方面的设计思路有一定的启示作用.     

基于虚拟仪器的电源测试系统设计与实现

为了解决传统电源测试方法所带来的测试过程不连续、动态瞬时状态难以发现和定位的问题,提出了基于LabWin-dows/CVI虚拟仪器技术的电源性能参数自动测试方法.利用虚拟仪器软件体系结构,建立多台仪器设备之间的同步与通讯,实现工控机对测试仪器的自动控制,完成自动测试任务.实际测试结果达到设计要求,极大地提高了测试工作的效率、精确度以及自动化程度.     

基于虚拟仪器的智能功放测试系统

主要介绍了一种基于虚拟仪器开发的智能功放测试系统。该系统利用自动量程切换电路和霍尔电流传感器有效地实现了电压信号的宽范围测量和大电流信号的转换,并采用图形化的编程语言LabVIEW和专家系统思想,实现了对所采集信号的分析处理、显示和打印等功能以及功放单元故障的自动诊断。实验结果表明:通过充分利用虚拟仪器的运算、存储和显示功能,在降低仪器成本的同时,使仪器的灵活性和数据处理能力大大提高,可以更方便地组建测试系统,更好地满足多种测量要求。     

Compensation of control-loop interaction for power plant wide-range operation

Power plants are being required to undertake large power variations to satisfy electricity demand, whereas their control systems comprise decentralized control loops and ad-hoc compensation schemes, to deal with loop interaction, for regulation and disturbance rejection at base load. This paper presents a compensation scheme that lessens control loop interaction, caused by the nonlinear coupled process dynamics, to ease power generation control throughout the power plant operating space. Compensation factors are systematically determined from a process gain matrix that conveys all interaction information. Numerical analysis and simulation experiments demonstrate the feasibility of power plant wide-range operation with the proposed compensator.     

Differential evolution with Gaussian mutation for combined heat and power economic dispatch

This paper presents differential evolution with Gaussian mutation to solve the complex non-smooth non-convex combined heat and power economic dispatch (CHPED) problem. Valve-point loading and prohibited operating zones of conventional thermal generators are taken into account. Differential evolution (DE) is a simple yet powerful global optimization technique. It exploits the differences of randomly sampled pairs of objective vectors for its mutation process. This mutation process is not suitable for complex multimodal optimization. This paper proposes Gaussian mutation in DE which improves search efficiency and guarantees a high probability of obtaining the global optimum without significantly impairing the simplicity of the structure of DE. The effectiveness of the proposed method has been verified on five test problems and three test systems. The results of the proposed approach are compared with those obtained by other evolutionary methods. It is found that the proposed differential evolution with Gaussian mutation-based approach is able to provide better solution.     

利用虚拟仪器构建的注水机组故障预测系统

大型注水机组故障预测系统由于系统复杂,采用传统的开发方式,开发周期长并且硬件系统庞大。虚拟仪器可以通过软件把计算机强大的计算处理能力和仪器硬件的测量、控制能力有机的结合起来。利用PC-DAQ与LabWindows/CVI构建大型旋转机组故障分析系统,减少了系统所需的硬件资源,加快了系统软件的开发速度,实现集成运行环境,使操作人员操作起来更加方便。     

源荷不确定冷热电联供微网能量调度的建模与学习优化

针对含光伏,微型燃气轮机组等分布式能源的冷热电联供微网系统,研究源荷双侧不确定情况下多类型能量调度动态优化问题.首先,针对光伏出力和异类负荷的随机不确定性,将光伏和负荷的变化描述为连续马尔科夫过程;然后以决策时刻,负荷需求以及分布式能源出力的离散值为状态分量,以微型燃气轮机组启停行动和储能充放行动为动作分量,在分时电价模式下,以降低包括购电成本,燃料代价,启停代价等在内的日运行成本为调度优化目标,将源荷不确定冷热电联供微网系统调度动态优化问题描述为马尔科夫决策过程模型,并引入强化学习方法对该问题进行策略求解.最后通过算例仿真对不同策略进行了比较,验证了优化方法的有效性.     

Probabilistic temporal reasoning and its application to fossil power plant operation

Many real-world applications, such as industrial diagnosis, require an adequate representation and inference mechanism that combines uncertainty and time. In this work, we propose a novel approach for representing dynamic domains under uncertainty based on a probabilistic framework, called temporal nodes Bayesian networks (TNBN). The TNBN model is an extension of a standard Bayesian network, in which each temporal node represents an event or state change of a variable and the arcs represent causal–temporal relationships between nodes. A temporal node has associated a probability distribution for its time of occurrence, where time is discretized in a finite number of temporal intervals; allowing a different number of intervals for each node and a different duration for the intervals within a node (multiple granularity). The main difference with previous probabilistic temporal models is that the representation is based on state changes at different times instead of state values at different times. Given this model, we can reason about the probability of occurrence of certain events, for diagnosis or prediction, using standard probability propagation techniques developed for Bayesian networks. The proposed approach is applied to fossil power plant diagnosis through two detailed case studies: power load increment and control level system failure. The results show that the proposed formalism could help to improve power plant availability through early diagnosis of events and disturbances.     

虚拟工厂安全仿真系统设计与实现

化工厂安全至关重要,进行安全培训是安全体系的重要组成部分,除传统的培训方式外,还可利用计算机网络技术实施培训.本文介绍了利用计算机网络技术开发的仿真系统的设计过程、实现方法以及技术细节.该系统利用AJAX、Web Service、VRML等技术构建了基于地理信息系统的厂区电子地图,并模拟了基于虚拟现实系统的工厂内部的虚拟场景,通过2个系统的结合并使其具有自由交互能力,提供了比单一技术更丰富更有效的培训方式.这种方式是网络化的,使培训更容易实施,也避免了实地培训的限制性和危险性;这种方式是自主学习式的,在计划的培训之外还可使用该系统自我培训.系统中的数据均取自工厂内部资料以及实地考察,保证了内容的真实性以及培训的可靠性.该系统目前成功应用在某化工企业职工安全培训中,取得了预期的效果.     

独立、并网双模式户用光伏发电装置的研究与设计

针对户用光伏发电系统的特点和要求进行了系统的研究与设计。系统设计将独立逆变与并网逆变相结合,使系统既可以工作在独立逆变状态,为负载提供正弦交流电源,也可以工作在并网逆变状态,将太阳的能量或蓄电池的能量回馈到电网。本系统采用TI公司32位定点DSP芯片TMS320F2812为控制核心,利用PIC16F877A单片机构成系统的人机操作界面。本文所设计的系统具有完善的保护功能、键盘监控和液晶显示、串口通讯功能,为家庭使用提供了方便。实验结果验证了方案的可行性。     

浅析沙角A电厂5号机组FGD装置烟气系统的设计和运行

概述了广东省第一台300MW燃煤机组-沙角A电厂5号机组采用湿法脱硫投产后取得的成效,介绍了石灰石-石膏湿法脱硫装置烟气系统的设计情况,重点介绍烟气系统的运行情况,对存在的问题提出建议。     

风-光-抽水蓄能联合互补发电系统研究

针对废旧地下矿井极易造成地表塌陷、水土流失的问题,提出将井下相应区域改造成抽水蓄能电站,进而与风-光互补系统结合,建立风-光-抽水蓄能联合互补发电系统。以跟踪负荷曲线和系统出力波动性最小为优化目标,分别对风力发电、光伏发电和抽水蓄能电站建立出力数学模型,并在考虑风-光互补特性、电网传输功率等约束条件下,利用改进粒子群算法对模型进行求解。算例仿真结果验证了所建模型可以很好地跟踪优化目标,有效解决了新能源并网时的功率波动和消纳问题。     

Measures against the adverse impact of natural wind on air-cooled condensers in power plant

The natural wind plays disadvantageous roles in the operation of air-cooled steam condensers in power plant.It is of use to take various measures against the adverse effect of wind for the performance improvement of air-cooled condensers.Based on representative 2×600 MW direct air-cooled power plant,three ways that can arrange and optimize the flow field of cooling air thus enhance the heat transfer of air-cooled condensers were proposed.The physical and mathematical models of air-cooled condensers with var...