Research on the Prediction of Load Regulation Capacity for Supercritical Thermal Power Unit

Both the modeling and the load regulation capacity prediction of a supercritical power plant are investigated in this paper. Firstly, an indirect identification method based on subspace identification method is proposed. The obtained identification model is verified by the actual operation data and the dynamic characteristics of the system are well reproduced. Secondly, the model is used to predict the load regulation capacity of thermal power unit. The power, main steam pressure, main steam temperature and other parameters are simulated respectively when the unit load is going up and down. Under the actual constraints, the load regulation capacity of thermal power unit can be predicted quickly.

Primary Frequency Control Ability Evaluation of Valve Opening in Thermal Power Units Based on Artificial Neural Network

With the development of new energy,the primary frequency control(PFC)is becoming more and more important and complicated.To improve the reliability of the PFC,an evaluation method of primary frequency control ability(PFCA)was proposed.First,based on the coupling model of the coordinated control system(CCS)and digital electro-hydraulic control system(DEH),principle and control mode of the PFC were introduced in detail.The simulation results showed that the PFC of the CCS and DEH was the most effective control mode.Then,the analysis of the CCS model and variable condition revealed the internal relationship among main steam pressure,valve opening and power.In term of this,the radial basis function(RBF)neural network was established to estimate the PFCA.Because the simulation curves fit well with the actual curves,the accuracy of the coupling model was verified.On this basis,simulation data was produced by coupling model to verify the proposed evaluation method.The low predication error of main steam pressure,power and the PFCA indicated that the method was effective.In addition,the actual data obtained from historical operation data were used to estimate the PFCA accurately,which was the strongest evidence for this method.

500 MW Unit Simulator for Panshan Thermal Power Plant Passed Acceptance

After a thorough demonstration in Panshan Thermal Power Plant, the 500 MW super critical pressure unit simulator developed by the Simulation & Control Institute under the North China University of Electric Power was accepted by experts from the North China Electric Power Group Company on 3rd August 1996.

Study on Coal Consumption Curve Fitting of the Thermal Power Based on Genetic Algorithm

Coal consumption curve of the thermal power plant can reflect the function relationship between the coal consumption of unit and load, which plays a key role for research on unit economic operation and load optimal dispatch. Now get coal consumption curve is generally obtained by least square method, but which are static curve and these curves remain unchanged for a long time, and make them are incompatible with the actual operation situation of the unit. Furthermore, coal consumption has the characteristics of typical nonlinear and time varying, sometimes the least square method does not work for nonlinear complex problems. For these problems, a method of coal consumption curve fitting of the thermal power plant units based on genetic algorithm is proposed. The residual analysis method is used for data detection;quadratic function is employed to the objective function;appropriate parameters such as initial population size, crossover rate and mutation rate are set;the unit’s actual coal consumption curves are fitted, and comparing the proposed method with least squares method, the results indicate that fitting effect of the former is better than the latter, and further indicate that the proposed method to do curve fitting can best approximate known data in a certain significance, and they can real-timely reflect the interdependence between power output and coal consumption.

Optimization of Minimum Power Output for Combined Heat and Power Units Considering Peak Load Regulation Ability

Northern China has rich wind power and photovoltaic renewable resources. Combined Heat and Power (CHP) Units to meet the load demand and limit its peaking capacity in winter, to a certain extent, it results in structural problems of wind-solar power and thermoelectric. To solve these problems, this paper proposes a plurality of units together to ensure supply of heat load on the premise, by building a thermoelectric power peaking considering thermal load unit group dynamic scheduling model, to achieve the potential of different thermoelectric properties peaking units of the excavation. Simulation examples show, if the unit group exists obvious relationship thermoelectric individual differences, the thermal load dynamic scheduling can be more significantly improved overall performance peaking unit group, effectively increase clean energy consumptive.

基于逐次变分模态分解的飞轮-火电一次调频控制策略

随着新型电力系统的大力建设与推广,火电机组面临的调频压力增大,提出一种逐次变分模态分解的飞轮-火电一次调频控制策略。首先,以飞轮储能和火电机组为研究对象,建立考虑新能源占比的飞轮-火电一次调频模型;其次,将一次调频功率指令利用逐次变分模态方法分解,由火电机组响应分解后的低频功率指令,同时设计飞轮储能下垂优化控制方法,实现飞轮储能与火电机组响应频率变化的协同控制;最后在不同工况下仿真验证,结果表明所提策略可有效避免火电机组一次调频时的频繁出力,减小火电机组响应频率变化时的调控要求,同时可最大限度地利用飞轮储能调频容量并保证飞轮储能调频期间的运行安全,进一步提升了系统的频率响应能力。

基于火电灵活性改造的可再生能源消纳系统成本优化

随着风电等可再生能源的大规模发展,带来了消纳难等新挑战,通过火电灵活性改造可以增强电力系统灵活调节能力、提升可再生能源消纳空间,同时需要考虑火电灵活性改造的经济性和对可再生能源消纳的影响。因此,综合考虑火电机组常规运行成本及灵活性改造后增加的各项成本,结合碳排放成本和弃风成本,建立以总成本最小为目标的火电灵活性改造前后优化调度模型,采用对比差值法计算基于火电灵活性改造的可再生能源消纳系统成本。通过算例,将所建模型应用于对比改造前后、不同碳排放强度、是否考虑弃风等不同方案下的机组运行状况及消纳系统成本大小,并拟合得到可再生能源渗透率和消纳系统成本的关系曲线,验证了模型的有效性。

基于蝙蝠优化算法的电力系统经济调度

针对电力系统的优化调度问题,提出基于蝙蝠优化算法的运行策略,旨在降低发电机组的总燃料成本和减少污染物排放量.然而由于约束条件的复杂性,一般的数学方法难以解决这个难题.采用优化过的蝙蝠算法(NBA)来解决电力系统动态经济调度问题,为了验证优化过的NBA算法的性能,对一个含有6台火电机组的电力系统进行优化调度,并在Matlab软件中对模型进行了仿真和测试.以运行成本最小为目标函数,约束条件包含功率平衡约束、火电机组最大最小出力约束、火电机组爬坡约束、网络潮流约束等,然后使用NBA算法完成对电力系统优化调度决策任务,结果表明,优化过后的算法减少污染的同时降低了发电成本,提升了电力系统的效益.

新型电力系统下燃煤火电机组一次调频面临的挑战与展望

频率稳定是未来新型电力系统运行的最关键要求之一。中国的能源禀赋决定了燃煤火电机组是最核心、最可靠的一次调频资源。然而,燃煤火电已开始出现一次调频能力不足的趋势。为了满足当前和长远发展的需要,文中综述了燃煤火电在一次调频领域所面临的挑战、研究现状和关键科学问题。首先,总结了新型电力系统发展背景下火电一次调频的4个重要趋势,分析了下一步调频在电网和火电厂运行中的不足,提炼出提高一次调频能力和快速准确模拟调频的关键挑战。其次,从电网和火电厂运行的双向视角,综述了调频能力提升和调频动态仿真的研究现状和存在的问题。最后,结合上述挑战和瓶颈,展望了未来新型电力系统火电一次调频的关键技术问题。

深度调峰工况下超临界机组的干湿态转换策略研究

为寻求深度调峰工况下合适的干湿态转换方式,在2台超临界机组上,采用2种不同的干湿态转换策略,对协调控制方式下的干湿态转换及其对系统稳定性的影响进行了研究。结果表明:2种策略均能够实现协调方式下的干湿态转换,可以通过转态进行进一步的深调工作;通过煤、水协同控制或给水流量控制均可实现干湿态转换,但水煤比变化情况不同;干转湿过程中,受到2种策略的影响,系统稳定性(主汽温度、主汽压力)区别明显;在湿转干过程中,2种策略下的系统都表现出良好的稳定性。

应用集成极限学习机的电站SCR脱硝系统建模与分析

针对火电机组普遍采用的选择性催化还原(selective catalytic reduction,SCR)脱硝反应容易受到环境因素影响,且具有非线性、大迟延、强扰动特点,难以建立准确反应模型的问题,提出一种基于集成极限学习机的SCR脱硝系统建模方法。首先,选择4种具有不同激活函数的极限学习机和核极限学习机作为基学习器,分别建立SCR脱硝系统模型;然后,利用偏最小二乘算法将各基学习器的结果进行集成;最后,采用某1000 MW超超临界机组实际运行数据与所提建模方法相结合建立SCR脱硝系统模型。实验结果验证模型的有效性;与其他方法所建模型对比,结果表明基于集成极限学习机的SCR脱硝系统模型具有更好的模型泛化能力。

火电机组深度调峰工况下炉侧蓄热系数对一次调频能力的影响分析

为研究火电机组深度调峰工况下炉侧蒸发段、过热段蓄热系数对机组一次调频能力的影响,以暂态稳定程序PSD-BPA中的典型模型为基础,同时考虑火电机组实际以炉跟机协调方式下的控制逻辑,搭建适用于火电深度调峰工况下的精细化仿真模型。通过某额定功率Pe为1 000 MW直流炉在35%Pe工况点的实际一次调频数据,验证了模型的正确性。以仿真模型为基础,定性分析深度调峰工况下炉侧蒸发段及过热段蓄热系数对机组一次调频能力的影响,结果发现:炉侧蒸发段蓄热系数越小,机组的一次调频响应能力越强;炉侧过热段蓄热系数越大,对机组一次调频越友好,通过增、减蒸发段和过热段蓄热系数可以提高机组的调频能力。另外,建立的一次调频精细化模型可以为电力生产、监管部门提供火电机组一次调频裕度分析,有利于新型电力系统的安全运行。

基于递推子空间的机组数字孪生模型预测精度优化方法

由于机理分析的简化假设条件或设备实际运行中参数特性偏移等因素,导致机理建模不可避免存在模型误差。针对该问题,提出一种基于递推子空间的火电机组数字孪生模型预测精度优化方法。分析机组关键设备的运行机制,结合典型工况小样本数据,建立火电机组的全设备多工况非线性动态机理模型,确保数字孪生系统模型具有较好的可解释性与泛化性能;基于递推子空间辨识方法,建立预测精度优化模型并实时进行在线更新,补偿机理模型产生的误差,提高整体模型的预测精度,保证数字孪生模型的高保真性。仿真实验验证了所提方法的有效性。

计及灵活经济环保运行的火电-飞轮储能系统容量配置与调频参数协同优化

提出了一种计及灵活经济环保运行的火储系统容量配置与调频参数协同优化方法。首先,设计了一种基于低通滤波自动分配火储功率和考虑储能荷电状态自恢复的火储联合一次调频协调控制策略;综合考虑系统调频性能、投入运行成本、污染物排放等,建立了火储容量配置与调频参数协同优化模型,并给出了基于粒子群算法的求解方法。最后,以某火储系统为例进行仿真验证。结果表明:协调控制策略和协同优化方法具有有效性。

深度调峰背景下火电机组热电解耦技术路径对比分析

新能源发电在出力和发电负荷上具有波动大、不稳定的特点,为解决新能源机组上网后带来的上述问题,利用多种热电解耦方式对火电机组进行改造,并对不同技术路径进行对比分析,探究火电机组解耦潜力与调峰能力。采用EBSILON Professional软件进行模拟仿真,对不同热电解耦方案下调峰负荷空间进行评估和对比分析。计算结果表明,低压缸零出力热电解耦改造方案可以使机组的调峰能力得到最大的改善。在原最大供热负荷304.60 MW下,最小发电量下降172.21 MW,最低电负荷率下降32.70%。火电机组经过热电解耦改造可显著提高热电机组与新能源机组的协调调峰能力,提高发电单元整体发电的稳定性。

火电机组耦合熔盐储热系统调峰性能研究

为提高火电机组的调峰性能及其灵活性,在某1000MW火电机组中引入了熔盐储热系统,并提出了多种火电机组耦合熔盐储热系统方案。建立了火电机组热力学系统模型,并分析了火电机组在不同耦合方案下调峰容量、调峰深度、耦合系统热效率等,提出了最优的火电机组耦合熔盐储热系统方案。研究表明:储热阶段电锅炉加热熔盐的耦合系统热效率最高,其调峰深度可达到14.45%,与调峰深度最高的抽取主蒸汽联合电锅炉加热熔盐的方案仅相差0.34%;释热阶段取水点从除氧器至1号高加,其耦合系统热效率依次降低,在4号高加入口处取水耦合系统效率最高可达到45.86%;在不同机组负荷下,释热阶段耦合系统热效率随着机组负荷的升高呈上升趋势,耦合系统热效率最高差值为4.45%,机组负荷对调峰系统的耦合系统热效率影响不大。研究结果对火电机组耦合熔盐储热系统调峰具有指导意义。