Optimization dispatching strategy for an energy storage system considering its unused capacity sharing

In renewable energy systems,energy storage systems can reduce the power fluctuation of renewable energy sources and compensate for the prediction deviation.However,if the renewable energy prediction deviation is small,the energy storage system may work in an underutilized state.To efficiently utilize a renewable-energy-sided energy storage system(RES),this study proposed an optimization dispatching strategy for an energy storage system considering its unused capacity sharing.First,this study proposed an unused capacity-sharing strategy for the RES to fully utilize the storage’s unused capacity and elevate the storage’s service efficiency.Second,RES was divided into“deviation-compensating energy storage(DES)”and“sharing energy storage(SES)”to clarify the function of RES in the operation process.Third,this study established an optimized dispatching model to achieve the lowest system operating cost wherein the unused capacity-sharing strategy could be integrated.Finally,a case study was investigated,and the results indicated that the proposed model and algorithm effectively improved the utilization of renewable-energy-side energy storage systems,thereby reducing the total operation cost and pressure on peak shaving.

Applications of Lithium-Ion Batteries in Grid-Scale Energy Storage Systems

In the electrical energy transformation process,the grid-level energy storage system plays an essential role in balancing power generation and utilization.Batteries have considerable potential for application to grid-level energy storage systems because of their rapid response,modularization,and flexible installation.Among several battery technologies,lithium-ion batteries(LIBs)exhibit high energy efficiency,long cycle life,and relatively high energy density.In this perspective,the properties of LIBs,including their operation mechanism,battery design and construction,and advantages and disadvantages,have been analyzed in detail.Moreover,the performance of LIBs applied to grid-level energy storage systems is analyzed in terms of the following grid services:(1)frequency regulation;(2)peak shifting;(3)integration with renewable energy sources;and(4)power management.In addition,the challenges encountered in the application of LIBs are discussed and possible research directions aimed at overcoming these challenges are proposed to provide insight into the development of grid-level energy storage systems.

Power management in co-phase traction power supply system with super capacitor energy storage for electrified railways

Increasing railway traffic and energy utilization issues prompt electrified railway systems to be more economical,efficient and sustainable.As regenerative braking energy in railway systems has huge potential for optimized utilization,a lot of research has been focusing on how to use the energy efficiently and gain sustainable benefits.The energy storage system is an alternative because it not only deals with regenerative braking energy but also smooths drastic fluctuation of load power profile and optimizes energy management.In this work,we propose a co-phase traction power supply system with super capacitor(CSS_SC)for the purpose of realizing the function of energy management and power quality management in electrified railways.Besides,the coordinated control strategy is presented to match four working modes,including traction,regenerative braking,peak shaving and valley filling.A corresponding simulation model is built in MATLAB/Simulink to verify the feasibility of the proposed system under dynamic working conditions.The results demonstrate that CSS_SC is flexible to deal with four different working conditions and can realize energy saving within the allowable voltage unbalance of 0.008%in simulation in contrast to 1.3%of the standard limit.With such a control strategy,the performance of super capacitor is controlled to comply with efficiency and safety constraints.Finally,a case study demonstrates the improvement in power fluctuation with the valley-to-peak ratio reduced by 20.3%and the daily load factor increased by 17.9%.

Combined hybrid energy storage system and transmission grid model for peak shaving based on time series operation simulation

This study proposes a combined hybrid energy storage system(HESS) and transmission grid(TG) model, and a corresponding time series operation simulation(TSOS) model is established to relieve the peak-shaving pressure of power systems under the integration of renewable energy. First, a linear model for the optimal operation of the HESS is established, which considers the different power-efficiency characteristics of the pumped storage system, electrochemical storage system, and a new type of liquid compressed air energy storage. Second, a TSOS simulation model for peak shaving is built to maximize the power entering the grid from the wind farms and HESS. Based on the proposed model, this study considers the transmission capacity of a TG. By adding the power-flow constraints of the TG, a TSOS-based HESS and TG combination model for peak shaving is established. Finally, the improved IEEE-39 and IEEE-118 bus systems were considered as examples to verify the effectiveness and feasibility of the proposed model.

可再生能源电制氢合成氨系统的并/离网运行方式与经济性分析

可再生能源电制氢合成氨(renewablepowerto ammonia,Re Pt A)是风力发电、光伏发电等可再生能源的大规模消纳方式之一,也是化工行业实现低碳清洁发展的重要技术路线之一。利用风电光伏电解水制氢合成氨系统模型,分析电网调峰型系统、电网友好型系统、工艺离网型系统的绿氨成本,并对电化学储能设备规模、储氢设备规模、电解水制氢设备规模、电解水制氢设备效率等影响因素进行敏感性分析。基于3种绿氨系统的设备配置方案和运行方式评估不同类型系统所需的电网调峰电量,提出3种系统所适合的应用场景。研究结论是近期应该发展电网友好型RePtA系统,远期应该发展工艺离网RePtA系统。

Potential of Rooftop PV Systems on Weekly Peak Load Shaving in Saudi Arabia

In recent years, high annual increasing load demand in Saudi Arabia has led to large investments in the construction of conventional power plants, which use oil or gas as the main fuel. The government is considering a large deployment of renewable energy for its 2030 vision plan. The Kingdom of Saudi Arabia is one of the best potential candidates for harvesting solar energy because of the country’s geographical location, clear sky, and vast land area. A recent energy policy announced by the government involves harvesting solar photovoltaic (PV) energy to reduce the country’s reliance on fossil fuel and greenhouse gas emissions. Using rooftop PV systems can help to shave the peak load and lead to a significant savings in the power sector through the reduction of annual installation of conventional power plants and standby generators. Employing solar PV at the end user level helps to reduce the overloading of transmission and distribution lines as well as decreases power losses. This paper will provide ratings for different rooftop PV systems that are being considered for installation for customers with various needs. The distribution of PV installation among the customers is as follows: 5% residential, 10% commercial, and 20% government. The effect of PV output power on weekly peak demand has been evaluated. The paper has also investigated the impact of the temperature on PV output power, especially during the summer. The PV power contribution is analyzed based on the assumption that weekly peak power production of solar PV coincides with weekly peak load demand. The PV model is implemented in Matlab to simulate and analyze the PV power.

锂电池储能用于削峰填谷优化配置方法研究

针对用户用电负荷不断增长,电网峰谷差进一步加大的问题,论文综合考虑削峰填谷效果和系统经济性,提出一种锂电池储能系统容量优化配置方法。首先,以储能系统综合成本最少和负荷标准差最小为优化目标,建立储能优化配置模型。其次,通过改进粒子群优化算法对模型进行求解,并使用负荷率作为评价指标对削峰填谷效果进行评估,得到综合成本和负荷标准差最优下储能系统最优配置容量。最后,结合某地区典型日负荷数据进行实验分析,结果表明,该模型在获得良好的削峰填谷效果的情况下系统具有一定的经济性,并且能够有效减少弃风弃光现象,从而提高电网整体运行效率。

计及深度调峰的风-光-水-火-抽蓄多能源联网系统优化调度研究

多种能源联网运行逐步成为未来电力系统发展的方向,多能源联网系统的优化调度是应对规模化新能源并网消纳的重要手段。文中建立了计及火电机组深度调峰成本的风-光-水-火-抽蓄联网系统成本模型和考虑调峰主动性的风-光-水-火-抽蓄联网系统日前优化调度模型。针对多能源耦合系统结构复杂的情况,提出了分层优化调度的模型求解策略。上层模型以净负荷波动最小为优化目标,得到等效负荷曲线;下层模型根据上层模型的调度结果,以调峰运行的经济性最优和新能源弃电率最低为目标函数,计及调峰主动性,求解考虑火电机组深度调峰煤耗特性的含新能源系统的经济调度问题。仿真算例表明所建模型实现了多能源联网系统的互补运行,提升了火电机组的深度调峰能力,降低新能源弃电率和系统运行成本。

煤矿智能化排水系统的应用研究

排水系统是煤矿井下的关键系统之一,对于排出煤矿井下涌水,保障煤矿安全生产具有重要意义。针对现有矿井排水系统智能化水平较低、系统耗电量较大等问题,提出一种矿井智能化排水系统,系统以可编程控制器PLC为核心,通过模糊控制算法分析井下水仓的液位和涌水变化率,得出排水系统的最佳运行方案,并将该模型结构输入到PLC中,结合排水主管路的流量、水泵压力等数据,达到水泵房智能运行与避峰填谷的目的,并通过随机森林算法解析水泵的振动信号,分析水泵的故障类型和健康状态。该系统有效地提升了井下排水效率,降低了设备磨损率,减少了煤矿排水系统电能消耗,对煤矿智能化排水系统设计具有一定的参考价值。

火-储耦合系统深度调峰综合经济性分析

火电机组耦合储热技术,可提高机组的热电解耦能力,减少深度调峰对系统安全性和经济性的影响。本工作提出了火电机组与填充床储热的耦合系统,在考虑了机组变工况、填充床储/释热过程动态时间序列基础上,通过EBSILON建立了耦合系统变工况仿真模型;分析深度调峰对耦合系统热力性和碳排放量的影响,通过汽水分离器筒体应力变化分析深调对锅炉寿命损耗的影响,通过转子寿命损耗率曲线分析深调对汽轮机寿命的影响,最终建立耦合系统调度运行经济性模型,开展综合经济性分析。结果表明:火-储耦合系统比自身变工况减小碳排放量7418 t/a(仅配置风电)~9216 t/a(仅配置光伏);深度调峰对锅炉寿命损耗的影响大于汽轮机,火-储耦合系统可提高系统运行寿命,深度调峰318次/年,相比于机组自身变工况(30%~20%额定负荷)可提高13.3%~15.3%;火-储耦合系统深度调峰收益高于火电机组自身变工况,当填充床释热量用于发电或供热时,耦合系统比自身变工况收益分别增加40万元/年、72万元/年。

光储式5G通信基站集群灵活性聚合与协同调度策略

5G通信基站通常配备光储,数量庞大、功耗可调,是一种优质的电力灵活性调节资源。提出了多类型光储式5G基站集群灵活性资源聚合方法以及参与电网调峰的协同调度策略。首先,分析休眠机制下多类型基站功耗可调特性与计及基站备用电量的储能调节能力。基于极限场景思想,构建了光储式5G基站的灵活性空间量化模型。在此基础上,利用闵可夫斯基和法刻画异构基站柔性资源的时空耦合能量轨迹,得到海量基站集群的灵活性资源聚合可调域。其次,建立了基站集群聚合资源参与电能量市场和辅助服务市场的协同调度优化模型,提出了基于交替方向乘子法(alternating direction method of multipliers, ADMM)的分层分布式基站集群协同优化调度策略,将大规模基站集群调度问题降维分解为统一协同调峰功率响应、聚合功率自治调度和基站集群功率分配3个子问题进行求解。通过算例对比分析可知,所提策略可降低通信基站69.86%的用能成本,为提升通信资源利用率和电力系统灵活调节能力提供了有效手段。

宫腔镜下刨削系统和电切术治疗子宫内膜息肉患者效果及对术后并发症和复发的影响

目的观察宫腔镜下刨削系统和电切术治疗子宫内膜息肉患者效果及对术后并发症和复发的影响。方法回顾性分析本院2020年6月至2022年7月收治的83例子宫内膜息肉患者临床资料。宫腔镜下刨削系统切除子宫内膜息肉的44例患者作为刨削系统组,选择同期进行宫腔镜电切术切除子宫内膜息肉的39例患者作为电切术组。比较两组患者治疗效果及术后并发症和复发情况差异。结果两组性别、年龄、平均病程等一般资料比较,差异无统计学意义(P>0.05)。刨削系统组手术时间、术中出血量、住院时间及膨宫液用量均低于电切术组(t值分别为10.421、18.310、7.651和8.983,P<0.001);术后并发症总发生率比较无明显差异(χ^(2)=2.789,P>0.05);刨削系统组月经恢复时间、首次月经量、首次月经经期持续时间显著低于电切术组(t值分别为7.695、3.457和2.869,P<0.001);术后24h,两组黄体生成素(LH)、卵泡刺激素(FSH)水平均升高,且刨削系统组显著高于电切术组(t值分别为10.609和2.986,P<0.05);刨削系统组术后复发率显著低于电切术组(χ^(2)=4.419,P<0.05)。结论通过宫腔镜刨削系统治疗能有效改善患者治疗效果,对卵巢功能影响较小,可降低术后复发率。

风-火-储耦合系统储能容量配置优化对比

为提升风电富集区域风电消纳水平及燃煤机组的灵活性,提出了基于热电共蓄式压缩空气储能的风-火-储耦合系统及系统调度策略,建立了系统的容量配置优化框架,并对7种布局方案进行了多目标优化。优化结果表明:电锅炉将弃风电量转化为热量时,燃煤机组的运行点向电力负荷下限更低的区域移动,风电上网空间增大,燃煤机组出力水平降低;加入热电共蓄式压缩空气储能子系统,使得燃煤机组电功率水平降低;换热器废热的回收进一步降低了燃煤机组产热水平;通过调整燃煤机组热出力,抽汽蓄热子系统能够实现抽汽热的时空平移,促使燃煤机组运行点向电力负荷下限更低的区域移动,可间接促进风电的消纳。综合来看,3种子系统相组合的最佳耦合方案可实现燃煤机组的热电解耦,从而提升了其深度调峰能力,在更大程度消纳风电能力的同时提升了系统的效率和环保性。

600 MW机组燃煤锅炉30%深度调峰下现场试验研究

随着新能源发电机组装机容量不断增加,需要提高电网的新能源消纳能力,因此对火电机组的调峰要求越来越高。为了研究燃煤机组深度调峰的能力及影响,基于广东省内某600 MW机组燃煤锅炉,开展低负荷稳燃现场试验研究。试验结果表明:该锅炉可以在30%额定负荷(180 MW)条件下稳定运行,且整个过程中现有的各系统经过调控后基本能正常工作;在降负荷过程和低负荷稳定运行过程中,机组环保参数无超标,各污染物排放指标符合环保要求。研究结果可作为机组深度调峰依据,为燃煤锅炉低负荷运行控制提供参考。

Peak Shaving Strategy of Concentrating Solar Power Generation Based on Multi-Time-Scale and Considering Demand Response

According to the multi-time-scale characteristics of power generation and demand-side response(DR)resources,as well as the improvement of prediction accuracy along with the approaching operating point,a rolling peak shaving optimization model consisting of three different time scales has been proposed.The proposed peak shaving optimization model considers not only the generation resources of two different response speeds but also the two different DR resources and determines each unit combination,generation power,and demand response strategy on different time scales so as to participate in the peaking of the power system by taking full advantage of the fast response characteristics of the concentrating solar power(CSP).At the same time,in order to improve the accuracy of the scheduling results,the combination of the day-ahead peak shaving phase with scenario-based stochastic programming can further reduce the influence of wind power prediction errors on scheduling results.The testing results have shown that by optimizing the allocation of scheduling resources in each phase,it can effectively reduce the number of starts and stops of thermal power units and improve the economic efficiency of system operation.The spinning reserve capacity is reduced,and the effectiveness of the peak shaving strategy is verified.

Numerical Simulation of Combustion in 660MWTangentially Fired Pulverized Coal Boiler on Ultra-Low Load Operation

In this paper,the combustion conditions in the boiler furnace of a 660 MWtangential fired pulverized coal boiler are numerically simulated at 15%and 20%rated loads,to study the flexibility of coal-fired power units on ultra-low load operation.The numerical results show that the boiler can operate safely at 15%and 20%ultra-low loads,and the combustion condition in the furnace is better at 20%load,and the tangent circles formed by each characteristic section in the furnace are better,and when the boiler load is decreased to 15%,the tangent circles in the furnace begin to deteriorate.The average flue gas temperature of different areas of the furnace shows that when the boiler furnace operates under ultra-low load conditions,the average smoke temperature of the cold ash hopper at 20%load is basically the same as the average smoke temperature at 15%load;in the burner area,the average smoke temperature of the cold ash hopper at 20%load is about 50 K higher than that at 15%load;in the burned out area,the average smoke temperature of the cold ash hopper at 20%load is slightly higher than that at 15%load.The average temperature of flue gas in the furnace showed a tendency to increase rapidly with the height of the furnace,then slow down and fluctuate the temperature in the burner area,and finally increase slightly in the burnout area due to the further combustion of combustible components to release heat,and then began to decrease.

风光储系统参与电网调频与消纳技术研究

结合电网调频需求,考虑储能荷电状态、充放电深度等边界因素,提出了风光储协调参与电网调频的控制策略,即考虑到风光的可发资源及响应调节特性,提出兼顾调峰消纳和调频响应的储能参与、光伏配合协调控制策略,在保证调频响应的基础上,充分挖掘光伏响应优势,预留储能充放电裕度,进一步提升了风光储电站调峰消纳能力,延长了储能系统使用寿命;最后,通过建立风光储电站调频仿真平台开展针对性试验,验证了控制策略的准确性和有效性。

大规模跨季节土壤储热系统研究现状及展望

为了解大规模跨季节土壤储热系统的研究进展,从设计参数、物理模型、数学模型、系统运行及优化和应用场景等方面对比分析跨季节土壤储热体发展现状。分析发现,现有研究对钻井间距、土壤热导率等关键设计参数之间的成比例关系研究较少,如钻井间距与钻井直径之比、钻井体积与埋管体积之比,后续工作可沿该思路展开。此外,研究认为从无需补充电力、燃煤、燃气等额外能源即可实现供热调峰的角度分析,利用跨季节土壤储热技术承担调峰任务要比调峰锅炉更具优势。

铁屑/竹纤维质量比对竹基耦合体系氮磷同步去除效能的影响

利用铁屑与竹纤维构建竹基耦合体系强化低碳氮比(C/N)废水中氮磷同步去除。采用连续流装置,搭建5组具有不同铁屑/竹纤维质量比(Fe/B)的耦合体系,探究Fe/B对氮磷去除效能的影响。耦合体系在进水平均总氮(TN)为31.32 mg/L,平均C/N为1.16,平均总磷(TP)为2.02 mg/L下连续运行113 d,水力停留时间(HRT)从16 h降至8 h,结果显示Fe/B≤0.500时,耦合体系氮磷去除效果与Fe/B呈正相关;当Fe/B为0.500时,氮磷去除最高,出水TN、TP可达《地表水环境质量标准》(GB 3838—2002)的Ⅳ类标准;Fe/B>0.500时,氮磷去除略有降低;耦合体系出水总铁整体较低,当Fe/B为0.250时,出水总铁波动最大;Fe/B≤0.500时,铁屑可显著促进脱氮除磷功能菌的生长,包括反硝化除磷菌,当Fe/B>0.500时,脱氮除磷功能菌群相对丰度明显降低,菌群结构亦发生显著变化。

计及火电锅炉蓄热的互联系统频率暂态模型及解析分析

高比例新能源接入电网挤占了火电机组的发电空间并带来了较强波动性,火电机组常处于深调状态且易受到扰动的侵扰,导致锅炉蓄热水平差,频率响应能力未达标称,威胁系统频率稳定性。文中针对火电机组蓄热动态变化的影响展开研究,基于直流潮流与经典锅炉模型,构建了计及锅炉蓄热动态的互联系统频率暂态分析模型;通过模型等值聚合、等效变换、解环与近似替代,降低了模型阶数;进一步,基于模型特点进行模态分解,推导两机等值模型的简单闭式解,并基于闭式解,分析了火电机组锅炉蓄热模型参数对互联系统频率暂态过程的影响。算例表明,所建模型与所提解析方法能够在频率暂态计算中准确计及锅炉蓄热对互联系统的影响,所得结果可为增强火电机组频率支撑能力提供参考。