Difference between grid connections of large-scale wind power and conventional synchronous generation

In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is relatively simple. Thus, connecting large-capacity wind power units complicates the peak load regulation and stable operation of the power grids in these regions. Most wind turbines use power electronic converter technology, which affects the safety and stability of the power grid differently compared with conventional synchronous generators. Furthermore, fluctuations in wind power cause fluctuations in the output of wind farms, making it difficult to create and implement suitable power generation plans for wind farms. The generation technology and grid connection scheme for wind power and conventional thermal power generation differ considerably. Moreover, the active and reactive power control abilities of wind turbines are weaker than those of thermal power units, necessitating additional equipment to control wind turbines. Hence, to address the aforementioned issues with large-scale wind power generation, this study analyzes the differences between the grid connection and collection strategies for wind power bases and thermal power plants. Based on this analysis, the differences in the power control modes of wind power and thermal power are further investigated. Finally, the stability of different control modes is analyzed through simulation. The findings can be beneficial for the planning and development of large-scale wind power generation farms.

Industrial Arrangement of Large-scale,Non-grid-connected Wind Power Industrial Zones in Coastal Areas of China

Constructing an industrial system for a large-scale,non-grid-connected wind power industry is a key step towards the diverse utilization of wind power.However,wind power exploitation is not only a technical challenge but an industrial problem as well.The objective of this study is to introduce a concept of large-scale,non-grid-connected wind power(LSNGCWP) industrial zones and establish an evaluation model to assess their industrial arrangement.The data of wind energy,industry,nature resources and socio-economy were collected in this study.Using spatial overlay analysis of geographic information system,this study proposes a spatial arrangement of the LSNGCWP indus-trial zones in the coastal areas of China,which could be summarized as the 'one line and three circles' structure,which will contribute to the optimization of the industrial structure,advance the wind power technology,coordinate the multi-industrial cooperation,and upgrade the industrial transformation of China's coastal areas.

Design of Large-Scale Prestressing Bucket Foundation for Offshore Wind Turbines

The key in the force transmission between the tower and the foundation for offshore wind turbines is to transfer the large moment and horizontal loads. The finite element model of a large-scale prestressing bucket founda- tion for offshore wind turbines is set up and the structural characteristics of the arc transition structure of the founda- tion are analyzed for 40-60 channels(20-30 rows) arranged with prestressing steel strand under the same ultimate load and boundary conditions. The mechanical characteristics of the key parts of the foundation structures are illus- trated by the peak of the principal tensile stress, the peak of the principal compressive stress and the distribution areas where the principal tensile stress is larger than 2.00 MPa. It can be concluded that the maximum principal tensile stress of the arc transition decreases with the increasing number of channels, and the amplitude does not change signifi- cantly; the maximum principal compressive stress increases with the increasing number of channels and the amplitude changes significantly; however, for the distribution areas where the principal tensile stress is larger than 2.00 MPa, with different channel numbers, the phenomenon is not obvious. Furthermore, the principal tensile stress at the top of the foundation beams fluctuantly increases with the increasing number of channels and for the top cover of the bucket, the principal tensile stress decreases with the increasing number of channels.

Providing Frequency Support of Hydro-Pumped Storage to Taiwan Power System with Wind Power Integration

The combination of wind and pumped storage is a useful method to compensate the fluctuation of wind power generation, which would exploit the abundant wind potential and increase wind power penetration. Taiwan Power Company (TPC) develops renewable energy actively in recent years. Moreover, TPC has started planning a high penetration wind power system and building offshore wind farms around the coast of Zhangbin, Yunlin and Penghu. The target of the offshore wind power installed capacity is up to 3 GW by 2025. However, the integration of the large scale of wind power would give huge challenges to the system operator because wind is randomly characterized. In this study, after high penetration wind power is integrated, the impacts of system frequency and the dispatch of conventional units will be discussed. Additionally, the hybrid system combing wind power with pumped-storage will be planning to reduce the effect of system frequency.

Collaborative Planning of Distributed Wind Power Generation and Distribution Network with Large-scale Heat Pumps

With the advancement of clean heating projects and the integration of large-scale distributed heat pumps into rural distribution networks in northern China,power grid companies face tremendous pressure to invest in power grid upgrades,which bring opportunities for renewable power generation integration.The combination of heating by distributed renewable energy with the flexible operation of heat pumps is a feasible alternative for dealing with grid reinforcement challenges resulting from heating electrification.In this paper,a mathematical model of the collaborative planning of distributed wind power generation(DWPG)and distribution network with large-scale heat pumps is developed.In this model,the operational flexibility of the heat pump load is fully considered and the requirements of a comfortable indoor temperature are met.By applying this model,the goals of not only increasing the profit of DWPG but also reducing the cost of the power grid upgrade can be achieved.

Probabilistic load flow method considering large-scale wind power integration

The increasing penetration of wind power brings great uncertainties into power systems,which poses challenges to system planning and operation.This paper proposes a novel probabilistic load flow(PLF)method based on clustering technique to handle large fluctuations from large-scale wind power integration.The traditional cumulant method(CM)for PLF is based on the linearization of load flow equations around the operation point,therefore resulting in significant errors when input random variables have large fluctuations.In the proposed method,the samples of wind power and loads are first generated by the inverse Nataf transformation and then clustered using an improved K-means algorithm to obtain input variable samples with small variances in each cluster.With such pre-processing,the cumulant method can be applied within each cluster to calculate cumulants of output random variables with improved accuracy.The results obtained in each cluster are combined according to the law of total probability to calculate the final cumulants of output random variables for the whole samples.The proposed method is validated on modified IEEE 9-bus and 118-bus test achieve a better performance with the consideration of both traditional CM,2 m+1 point estimate method(PEM),Monte Carlo simulation(MCS)and Latin hypercube sampling(LHS)based MCS,the proposed method can achieve a better performance with the consideration of bothcomputational efficiency and accuracy.

风光互补发电系统混合储能系统容量优化方法研究

风光互补发电系统受风光资源影响发电功率波动较大,配置适当的储能系统可提高新能源发电的消纳能力和电能质量。针对风光互补发电系统储能容量优化配置问题,将运行投入成本作为优化目标,提出以抽水蓄能为基础,蓄电池和超级电容参与的混合储能系统模型。该储能模型以跟踪负荷曲线作为平抑目标函数,利用集合经验模态分解和滑动平均法,对抽水蓄能机组、蓄电池和超级电容设备进行功率分配。建立了风光发电系统模型,利用带免疫的粒子群算法对储能配置容量进行寻优求解。计算结果表明,所提基于抽水蓄能的混合储能容量优化模型,对发电系统输出功率波动情况改善明显,电能消纳能力和运行经济性有所提高。

水火风光多能互补系统联合调度问题两层优化建模方法研究

为解决水火风光多能互补发电系统联合优化复杂问题,提出了一种水火风光多能互补系统联合调度问题两层优化建模和求解方法,上层以余荷均方差和期望均值最小为目标函数对水风光清洁能源打捆进行联合优化,下层以成本经济指标最小为目标函数对火电适配余荷进行优化。以江西省典型春秋季、夏季和冬季江西省的电网负荷以及风电、光电的出力过程为研究对象进行实例分析,采用研究团队提出的DPSA-POA和智能算法混合优化方法进行模型求解,验证了本文所提两层优化建模和求解方法的有效性。并发现了风光可弃情境相比风光完全消纳情景虽然在火电出力上有所提高,但在整体运行费用上有所降低。在以春秋季江西省的电网负荷和风电、光电的出力过程为研究对象进行的实例分析结果显示,火电出力总和提升了5.79%,多能互补系统整体运行费用减少了4.97%;在以夏季江西省的电网负荷和风电、光电的出力过程为研究对象进行的实例分析结果显示,火电出力总和提升了0.32%,多能互补系统整体运行费用减少了1.95%;在以冬季江西省的电网负荷和风电、光电的出力过程为研究对象进行的实例分析结果显示,火电出力总和提升了10.70%,多能互补系统整体运行费用减少了6.78%。该方法为求解水火风光多能互补联合优化复杂问题提供了一种新的思路。

基于模糊场景聚类的新能源风电消纳误差修正系统

电网容易受到场景约束的影响,新能源风电场无法送出大量风电,为了修正风电消纳数据,设计了基于模糊场景聚类的新能源风电消纳误差修正系统。分析系统运行场景,使用S5PV210微处理器,为系统提供丰富接口。设计误差修正控制器,避免系统修正过程出现误差。在多目标求解原则支持下,搭建模糊场景。根据风电场历史运行数据,计算基准调度方案对新能源风电消纳的结果,获取新能源风电消纳误差序列。确定最佳聚类数,结合历史异常数据修正误差。由实验结果可知,该系统风电功率序列统计结果与理想数据存在最大为1 MW的误差,弃风功率序列统计结果与理想数据一致,所设计系统误差修正结果较好。

考虑火电-熔盐储热耦合特性的风光火储能源调度

构建以可再生能源为主体的新型电力系统已经成为中国能源发展的必然趋势。以某大型能源基地为仿真对象,建立含有熔盐储热的多能互补系统运行收益模型。该系统通过将火电机组耦合熔盐储热系统,实现能源的存储、错峰利用,提高可再生能源的消纳率。该模型考虑了火电机组多级调峰收益和爬坡成本、储能系统运行成本及可再生能源弃电惩罚成本,以系统运行净收益最高为目标对模型进行优化求解,探究火电机组储热改造对可再生能源消纳和系统运行经济性的影响。加入熔盐储热系统后,系统的整体经济性和可再生能源利用率得到显著提升,场景2每日运行净收益为838.14万元,较场景1增加了47.36万元。场景2的风能利用率从93.91%增加到97.33%,光伏利用率也从95.51%增加到98.44%。

面向风光消纳的并网型绿电铝评价企业优化运行策略

为有效解决高耗能电解铝企业高污染、高排放问题并降低其工业电网内弃风、弃光率,提出一种面向风光消纳的并网型绿电铝评价企业优化运行策略。分析并网型绿电铝评价企业运营模式和基于生产过程的电解铝负荷功率特性,在此基础上综合考虑工业电网电力电量平衡约束、电解铝负荷约束、自备风光火机组约束和外部电网交互约束,以综合用电成本最小为优化目标,构建了并网型绿电铝评价企业优化运行模型;通过引入4组反映电解铝负荷调节特性的0-1辅助变量,能够精确地描述电解铝负荷不能即时调节和频繁调节的特性,实现其调节性能对风光出力不确定性适应能力的解析表达,并将优化模型表达为线性0-1混合整数规划模型。通过算例分析,验证了所提模型方法的有效性,以及并网型绿电铝评价企业在大幅降低企业碳排放成本和提高风光发电利用率方面的优势。

新能源风力发电系统中储能技术的应用探索

[目的]针对风力发电系统中风电出力的波动性和间歇性给电网调度运行带来的挑战,探索储能技术与风电系统相结合的解决方案,以提高风电的消纳水平和经济性。[方法]在分析风力发电和储能技术特点的基础上,重点研究储能在风电系统中的应用与集成优化,包括储能系统的集成设计原则、功率管理与能量调度策略及储能控制和优化算法。[结果]通过合理配置储能系统,优化其控制和调度策略,能有效平滑风电出力波动,提高风电的利用效率,减少弃风限电,增强电网对风电的消纳能力。[结论]将储能技术与风力发电系统进行深度融合,对促进风电的大规模发展应用、提高其经济性和供电可靠性具有重要意义。该研究为风电场的规划设计和运行优化提供有益参考。

含风电电力系统的多时间尺度模糊机会约束动态经济调度模型

风电出力的模糊不确定性增加了调度决策的难度。将风电和负荷预测值用模糊参数表示,基于可信性理论,将传统确定性系统约束转化成模糊机会约束。由于风电和负荷预测精度具有随预测时间尺度的缩短而提高的特点,因此,将模糊置信度设置为递增向量,以反映预测精度的变化。建立多时间尺度下含多模糊参数的模糊机会约束动态经济调度模型。多时间尺度调度分为日前24 h计划、日内4 h滚动计划、实时15 min计划和自动发电控制(automatic generation control,AGC)。各时间级的调度计划协调配合,兼顾经济性与可靠性。根据风电及负荷的最新预测信息,滚动修正原有发电计划,逐级消纳预测偏差量。算例采用山西某实际风电场数据,验证了上述模型能够有效降低风电及负荷预测不确定性的影响,减轻调度人员及AGC机组的调节压力。

消纳风电预测偏差功率的电采暖负荷群运行调度策略

构建以新能源为主体的新型电力系统将面临尖锐的调节资源供需矛盾,电采暖负荷具有可时移特性,是优质的存量可调节资源。拟挖掘电采暖负荷调节功率作为电网辅助备用,针对风电功率预测偏差消纳问题,设计了负荷聚合商响应风电预测偏差功率的调度架构,构建了电采暖负荷群响应风电预测偏差功率的轮流调控响应策略以最大化消纳偏差功率,设计了电采暖负荷群-风电场算例系统,基于此对所提出的电采暖负荷群响应风电预测偏差调控方法的有效性进行了仿真验证,并分析了负荷群参与响应后的经济性。

大型分布式光伏发电消纳数据的智能调度方法研究

以大型分布式光伏风电发电为对象,基于电网电力平衡对智能调度发电消纳数据的方法进行研究。通过对风电发电在不限制风电出力最大消纳能力、限制风电出力最大消纳能力的计算,以全网负荷预测为依据,按照光伏发电站并网运行特性进行电站接纳能力评价排序、分配,从而进行消纳数据的实时调整。使用消纳数据实时调度AGC模块,通过SDH消纳数据调度自动化配置,实现光伏发电消纳数据的智能调度。通过AGC目标值与实际值对比表明,在限电时段,风电场总机出力AGC目标值曲线与实际值曲线比较接近,偏差较小。智能调度方法能够自动准确地统计各风电场发电出力受阻时段,使风电理论功率的计算误差最小化。

燃气蒸汽联合循环机组消纳风电水平对系统运行指标影响研究

依据燃气蒸汽联合循环(CCGT)机组的模式模型与组件模型,提出既降低变量维数又可快捷计算各元件出力的CCGT双层模型。构建CCGT参与消纳风电对系统运行成本、机组容量利用率与重爬坡持续时间、切负荷持续时间、风电利用率等系统安全经济运行指标影响的分析模型,并采用混合整数规划法求解。算例分析结果表明,单纯追求过大的风电注入量会引起系统运行指标趋坏,引入CCGT能显著提高系统的可靠性和经济性运行指标。

基于多目标两阶段规划的虚拟电厂优化调度

虚拟电厂(virtual power plant,VPP)聚合分布式电源和负荷侧可调资源以统一整体参与能源市场交易,成为了提升新能源消纳、挖掘负荷侧需求响应潜力的有效途径。在此背景下,构建了基于多目标两阶段规划的虚拟电厂优化调度模型。日前阶段以市场运营收益和用户用能满意度最大化为目标,构建了虚拟电厂多目标优化模型,采用NSGA-Ⅱ算法求解多目标问题的帕累托最优解,并提出综合效益指标对解进行筛选;实时阶段以偏差惩罚成本和弃风成本最小化为目标,构建了虚拟电厂鲁棒优化模型,考虑了热电联产机组(combined heat and power,CHP)灵活热电比对风电消纳的促进作用。最后,对某实际虚拟电厂进行算例分析,研究结果表明所提方法能够在保证虚拟电厂综合效益的前提下提高其能源利用效率。

辽宁省海上风电消纳能力分析研究

随着辽东庄河地区190万k W海上风电项目的建设,辽宁电网调峰形势将进一步恶化。文中介绍了国内外海上风电发展的现状,着重分析了辽宁省的海上风电资源情况,并对辽宁电网调峰能力进行定量分析,探讨辽宁省海上风电项目消纳问题,据此提出几点应对策略,可供海上风电企业参考。

智能电网环境下负荷响应对系统消纳风电能力影响模型探析

为了更多消纳智能电网环境中风力发电,依据需求与负载的交互响应,提出了一种多层时间尺度连续调度操作模型。分析了风力发电不确定性的产生机理,在此基础上建立了风电功率预测算法,再引入基于风电消纳的需求响应概率的多级调度概念,提高了电网调度模型对风力发电随机性、间歇性的整体适应性。通过案例验证该方法的可靠性和有效性,数据证实该方法能在保证智能电网调度经济可靠的条件下有效地提升风力发电的消纳水平。

计及碳捕集设备的电-气互联综合能源系统低碳经济调度

基于碳捕集设备与综合能源系统的结合能够有效提高系统风电消纳能力。提出了一种含电转气、燃气轮机、碳捕集电厂、风电场联合运行的低碳经济调度模型,并引入碳交易机制,以系统综合经济成本最低为目标函数,以电转气功率、燃气轮机有功出力、机组有功出力、碳捕集率为决策变量,考虑电力网络与天然气网络相关约束、电气平衡及机组爬坡约束等。通过算例仿真,分析比较了系统CO 2排放量、系统综合经济成本以及弃风量,验证了所提模型能够有效提高风电消纳能力,具有降低CO 2排放量以及综合经济成本的作用。最后,分析了碳交易价格对系统CO 2排放和运行的影响。