Study on integrated development and hybrid operation mode of nuclear power plant and pumped-storage power station

The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system;hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term;nuclear power shifted to pumped storage power participating in market competition in the middle term;and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.

A novel technology for control of variable speed pumped storage power plant

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control(DTFC) of a variable speed pumped storage power plant(VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP's control strategies is studied. At the first, a wind turbine with the capacity 2.2 k W and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts(including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter(2LVSC) and three-level voltage source converter(3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion(THD) and ripple of rotor torque and flux.

Present status of pumped hydro storage operations to mitigate renewable energy fluctuations in Japan

This paper focuses on pumped hydro energy storage(PHES)plants’current operations after electricity system reforms and variable renewable energy(VRE)installations in Japan.PHES plants have historically been developed to create electricity demand at night in order to operate base load power plants,such as nuclear power plants,in stable conditions.Therefore,many PHES plants are located midway between nuclear power plants and large demand areas.However,all nuclear power plants had to–at least temporarily–shut down after the Great East Japan Earthquake followed by a nuclear accident at Fukushima Daiichi in 2011,and renewable energy power plants have been deployed rapidly after the introduction of a feed-in-tariff(FIT)scheme.Therefore,PHES plants are being used to mitigate fluctuations of VRE,especially in areas where renewable energy has been significantly installed.The daily highest capacity ratio of PHES plants in Kyushu area has recorded three times higher than it in the other areas where the past operating mode is still conducted.But those operations on PHES plants are simply followed as a dispatch rule of the Organization for Crossregional Coordination of Transmission Operators(OCCTO),market-based operations have not been conducted enough yet.The market design shall be changed to harmonize VRE installation and PHES plants’operations are necessary to make the transition from the past operating mode of PHES plants across Japan.

考虑灵活碳捕集电厂与抽水蓄能联合的广义经济调度策略

“双碳”背景下,灵活碳捕集电厂成为风光大规模并网后保供电和低碳化的重要过渡电源之一;然而,因其储液容量制约和风光反调峰特性造成系统在应对持续增大的负荷峰谷差时存在局限,容易造成风光流失且碳经济性不高。为此,该文引入具有双向快速功率调节能力的大容量储能-抽水蓄能,提出一种基于灵活碳捕集电厂与抽水蓄能联合的广义经济调度策略;广义经济调度综合电厂运行成本、电网净负荷经济效益、碳经济效益等多种元素。首先充分利用能耗时移特性和抽水蓄能的双倍调节能力,结合净负荷典型峰谷特征制定二者联合运行在电碳解耦下“峰互补、谷协同”机制,实现深度调峰下兼顾碳捕集和新能源消纳;进而构建电-碳市场下考虑灵活性约束等因素的广义经济成本最小为目标的调度模型,用模糊参数表征净负荷的不确定性,采用改进灰狼算法求解。仿真结果表明所提两者联合的广义经济调度策略相较于仅考虑灵活碳捕集电厂,综合成本降低25.33%,碳排放量减少18.71%,弃风弃光成本下降98.70%,验证了所提联合调度策略的优越性。

基于改进DDPG的变速抽蓄机组参与系统调频研究

在挖掘双馈型抽水蓄能(DFIM-PSH)机组调频能力的基础上,提出一种基于改进深度确定性策略梯度(DDPG)算法的系统频率控制方法。首先,基于所确定的DFIM-PSH机组在发电与抽水工况下的频率控制环节,构建考虑风电接入的含DFIMPSH单区域系统频率控制模型。其次,在考虑机组运行约束的基础上以最小化系统频率偏差及调频出力为目标,引入DDPG算法对各机组的AGC控制指令进行优化。通过在预学习中同时引入随机外部扰动与模型参数变化,提高AGC控制器在具有强不确定性环境中的适应性。最后,在仿真验证DFIM-PSH调频优势的基础上,在不同风电接入及扰动等多场景进行仿真分析,结果表明,所提频率控制方法能有效改善新型电力系统的频率特性且具有强鲁棒性。

多能互补发电系统故障识别与测距方法

随着大量新能源的接入,使得多端柔性直流系统(modular multilevel converter based multi-terminal direct current, MMC-MTDC)故障特征愈加复杂,快速准确的故障识别与测距是亟需解决的关键难题之一。为此,提出了一种风-光-储-蓄互补发电站经柔性直流输电外送系统故障识别与测距方法。首先,搭建风-光-储-蓄互补发电站经柔直外送系统,在此基础上,提出了一种Teager能量算子能量熵的新方法,利用测量点正负极Teager能量算子能量熵的比值构建故障选极及区段识别判据。接着,针对已识别的故障线路,提出变分模态分解(variational mode decomposition, VMD)与Teager能量算子(teager energy operator, TEO)相结合的故障测距方法。最后,利用PSCAD/EMTDC进行仿真,结果表明所提识别方法可以准确判断故障所在线路,所提测距方法能在故障发生2 ms时间窗内实现故障测距,误差率不超过2.55%,并具有较高的耐过渡电阻能力。

考虑绿证交易机制与碳捕集电厂深度调峰补偿的多主体联合调峰优化调度

为解决大规模风电不断并网引起的系统调峰负担增加问题,提出了一种考虑绿证交易机制与碳捕集电厂深度调峰补偿的碳-储-荷联合调峰双层优化方法。首先,分析了碳捕集电厂参与深度调峰成本损失,提出了深调服务补偿模型。其次,分析了绿证交易机制对碳-储-荷联合调峰的积极作用;上层以电价引导型需求响应、改善净负荷曲线平滑性程度最优为目标,旨在降低负荷峰谷差,提高风电消纳空间,缓解深度调峰机组压力;下层基于上层优化后的调峰容量,考虑绿证交易机制与碳捕集电厂深调补偿收益的碳-储联合深度调峰综合成本最优为目标,旨在发掘绿证交易机制与调峰辅助服务对深度调峰作用,发挥碳-储联合深度调峰的能力,优化系统经济性、风电消纳量、碳排放量。最后,在改进的IEEE 30节点系统进行仿真,结果验证了所提模型的有效性。

抽水蓄能电站水库岩质边坡消落带生态修复探讨

抽水蓄能电站是我国水利水电开发的重要组成部分,建成运行后将形成库水周期性涨落的消落带,生境条件极为脆弱,是生态环境修复的重难点区域。对岩质边坡生态修复关键技术和水库消落带生境改善方法开展系统分析,结合河南天池抽水蓄能电站上水库岩质边坡消落带生境特征,提出土工格室+生态袋+挂网复合工程技术可作为水库岩质边坡消落带生态治理的关键措施。基于消落带库水涨落节律和植物自身遗传特性,指出消落带下端优先配置长期耐淹多年生草本植物(如狗牙根),消落带中端配置耐淹能力较强的灌木和草本(如秋华柳、黄荆、紫穗槐、中华蚊母和狗牙根等),消落带上端可综合配置抗旱耐淹能力较好的乔木、灌木和草本(如银合欢、桑树、紫穗槐、黄荆、秋华柳、狗牙根和苘麻等),以及生态适应性较强的乡土植物(如藜和诸葛菜等)。研究成果对抽水蓄能电站水库岩质边坡消落带生态治理具有重要指导意义。

Effect of dry-wet cycles on dynamic properties and microstructures of sandstone:Experiments and modelling

Underground pumped storage power plant(UPSP)is an innovative concept for space recycling of abandoned mines.Its realization requires better understanding of the dynamic performance and durability of reservoir rock.This paper conducted ultrasonic detection,split Hopkinson pressure bar(SHPB)impact,mercury intrusion porosimetry(MIP),and backscatter electron observation(BSE)tests to investigate the dynamical behaviour and microstructure of sandstone with cyclical dry-wet damage.A coupling FEM-DEM model was constructed for reappearing mesoscopic structure damage.The results show that dry-wet cycles decrease the dynamic compressive strength(DCS)with a maximum reduction of 39.40%,the elastic limit strength is reduced from 41.75 to 25.62 MPa.The sieved fragments obtain the highest crack growth rate during the 23rd dry-wet cycle with a predictable life of 25 cycles for each rock particle.The pore fractal features of the macropores and micro-meso pores show great differences between the early and late cycles,which verifies the computational statistics analysis of particle deterioration.The numerical results show that the failure patterns are governed by the strain in pre-peak stage and the shear cracks are dominant.The dry-wet cycles reduce the energy transfer efficiency and lead to the discretization of force chain and crack fields.

天台抽水蓄能电站岩壁梁爆破开挖精细化控制技术

岩壁梁具有经济可靠、方便施工、加快进度等优点,在地下厂房的建设中得到广泛使用。以浙江天台抽水蓄能电站中岩壁梁的开挖爆破施工为工程背景,基于现场爆破试验,提出了精细化爆破参数与网路设计方案,总结了现场采用的岩壁梁爆破施工精细控制方法,对比分析了各种施工措施实际应用后的现场效果与监测结果,可供类似工程参考。

基于NSGA-Ⅱ串行模式搜索的新能源发电与抽水蓄能电站联合系统多时间尺度优化调度方法

针对新能源发电与抽水蓄能电站联合发电系统,提出一种多时间尺度优化调度策略,并提出一种结合快速非支配排序遗传算法(NSGA-Ⅱ)和模式搜索算法的NSGA-Ⅱ-PS算法,该策略针对不同的时间尺度分别设定目标函数与约束条件,对比NSGA-Ⅱ与NSGA-Ⅱ-PS在解决本调度问题结果上的优劣性。在日前、日中时间尺度对联合系统进行优化调度,制定调度计划。结果表明:在高比例新能源消纳的基础上,新能源发电与抽水蓄能电站联合系统多时间尺度优化调度可在日前、日中尺度实现联合系统经济安全运行。

季节水温变化对充水保压蜗壳承载特性的影响

抽水蓄能电站钢蜗壳一般均采用充水保压埋入方式,在正常运行过程中,蜗壳内季节水温变化将影响钢蜗壳—混凝土接触关系,继而影响充水保压蜗壳的承载特性。为此,基于运行期钢蜗壳温度监测结果,研究了运行期钢蜗壳实际温度变化情况,并采用有限元方法研究了运行期钢蜗壳—混凝土接触关系的变化规律、结构承载特性及不平衡水推力分载情况。结果表明,在机组投产后正常运行年内,钢蜗壳内季节水温变化对钢蜗壳—混凝土接触闭合时机及空间分布影响显著;夏季水温升高将导致蜗壳外包混凝土承载比显著升高,应确保混凝土配筋满足强度和正常使用要求;而在冬季水温降低时止推环将起到承担不平衡水推力的主要作用,与此同时,座环也承担了约30%~40%的不平衡水推力,说明充水保压蜗壳设置止推环和加强座环锚固非常必要。

抽水蓄能电厂后勤服务智能化综合管理平台构建

针对传统平台用户满意度、平台运行效率以及安全性低的问题,构建新的抽水蓄能电厂后勤服务智能化综合管理平台。通过弱化算子对后勤测点数据进行预处理,利用改进的灰色模型计算拟合度,进而实现数据预处理。根据数据预处理结果,分析综合管理平台需求,结合数据共享以及综合决策等目标,构建抽水蓄能电厂后勤服务智能化综合管理平台,分别介绍平台中各个关键子模块的功能,进而为抽水蓄能电厂后勤服务智能化综合提供重要支撑。测试结果表明,所设计平台能够有效提升用户满意度,同时还能够提高平台运行效率和安全性。

基于DEMATEL-ISM法的斜井TBM施工作业风险评估

以斜井TBM施工作业风险因素为研究对象,从人、物、环境、管理4个方面识别提取出21个风险因素,并运用DEMATEL-ISM法分析风险因素作用关系和层次结构,确定关键风险因素。结果表明:斜井TBM施工作业风险因素可划分为7级递阶层次结构;关键风险因素为安全措施费用投入、应急管理、管理层决策能力、安全生产教育培训、安全生产管理制度等。研究结论可为我国斜井TBM施工作业风险防范提供参考。

New Analytical Model for Optimal Placement of Wind Turbines in Power Network under Pool and Reserve Markets Conditions

In this paper a new market based analytical model is proposed for optimal placement of Wind Turbines (WTs) in power systems. In addition to wind turbines, thermal units (THUs) and Pumped Storage Hydro Power Plants (PSHPPs) owners participate in power market. Objective function is defined as participants’ social welfare achieved from power pool and ancillary markets in yearly horizon. Wind turbines have been modeled by probability-generation tree scenarios based on statistical information. We concentrate on investment profits of WTs numbers and its generation capacity beside to PSHPPs and THUs power plants in power systems due to increase in high flexible tools for Independent system operator into the planning and operation planning time interval. For effectiveness evaluation of proposed model, simulation studies are applied on 14-Bus IEEE test power system.

风-光-火-蓄联合系统两阶段优化调度

由于间歇性能源出力具有不确定性,该文利用抽水蓄能容量大、响应速度快的优势,建立风-光-火-蓄两阶段动态调度模型。长时间尺度以总成本最低为目标,综合考量系统运行成本、SO2、NOX、PM排放量、弃风弃光量惩罚,来优化可控电源出力。短时间尺度以长时间尺度为基准,基于模型预测控制原理滚动求解出力增量,使抽蓄机组有功出力偏差最小,以增强调度的平滑性。最后根据东北某地区抽蓄机组实际数据及改进的IEEE-30节点系统仿真验证了该文所提模型的有效性,以此来降低系统的污染物排放水平,提升系统对风电、光伏的消纳能力。

融合改造的混合式抽水蓄能与风电联合运行短期调度模型

依托规模庞大的常规水电增建混合式抽水蓄能是加快抽蓄发展的重要途径。相比传统抽蓄电站,融合改造的混合式抽水蓄能电站具有水力联系更紧密、抽-发工况转换更复杂、“量调并重”角色更鲜明等显著特点,为探索其运行模式,本文提出一种融合改造的混合式抽水蓄能与风电联合运行短期调度模型。该模型以联合体整体收益最大为目标,以机组为最小调度单元,针对常规机组和抽蓄机组的差异化运行特性分别精细化建模,并引入状态变量实现运行状态的解耦与关联切换。在模型求解方面,通过线性化方法及建模技巧将原模型转换为混合整数线性规划(Mixed Integer Linear Programming,MILP)模型,最后在JAVA环境中采用CPLEX工具进行求解。以西南某流域电站为参考构建的应用示例验证了本文模型和求解方法的有效性,可为推进常规水电站的融合改造提供借鉴。

风-光-抽蓄零碳电力系统多时间尺度协调调度模型

高比例新能源并网带来的波动性影响和新能源消纳水平不足已成为新型电力系统中亟须解决的问题。为此,基于风、光、负荷预测精度随时间尺度缩短而逐级提高的特点和抽蓄机组日内灵活调节特性,建立风-光-抽蓄零碳电力系统多时间尺度协调调度模型。以运行成本最小为目标,建立日前24 h发电计划、日内1 h发电计划和实时15 min发电计划。通过多时间尺度的协调配合,保证风、光、抽蓄出力良好跟踪负荷,逐级修正发电计划。以含6台抽蓄机组的风-光-抽蓄零碳电力系统为例开展仿真分析,结果表明所提多时间尺度协调调度模型有利于减少系统弃风、弃光量,且系统消纳风光的能力与抽蓄电站装机容量有关。

基于AHP-熵权法-TOPSIS的广东省抽水蓄能站点优选评价

基于AHP-熵权法构建评价指标的综合权重,在建立抽水蓄能站址评价指标体系的基础上,结合TOPSIS评价法对广东省内的10个站点进行量化评价。结果显示:抽水蓄能电站选址中平均水头、调节库容、设计移民及耕地数量是站址优劣评价的主要指标。10个站点按照优劣次序排列分别为阳蓄二期、中洞、三江口、梅蓄二期、水源山、新丰、浪江、岑田、走马坪、龙川。