Study on Optimizing Thermal Energy Storage Capacity for Heat Supply System

Thermal energy storage (TES) can increase the energetic efficiencies and, in many cases, the exergetic efficiencies of thermal energy systems. Steam boiler plant with a violently fluctuating load is a typical example when a steam accumulator is added to it. While the conparatively big first cost constitutes a barrier to the wide use of TES, the cost will notably be reduced through minimizing the necessary thermal capacity of it JThe structure and illustrations are given for the computer program designed for performing the optimization. This'program was applied to an existing boiler plant equipped with a steam accumulator. The results show that there would have been a big reduction in the necessary capacity, if the design of this steam accumulator had been optimized. Four conclusions have been reached.

Review on Capacity Optimization of Traction Transformer for High-Speed Railway

In electrified railways,traction load not only fluctuates between peaks and valleys,but also has a situation of low utilization rate of average load throughout the day and short overload.The traction transformer selects the capacity with the peak load as the demand boundary,which will cause the capacity utilization rate to be low and even lead to the economic decline of the traction power supply system.This article summarizes the existing configuration methods for capacity optimization of traction transformer.Then under the conditions of energy storage and new energy access to traction power supply system,the three aspects are described as follows.Firstly,the energy storage device is connected to the system,which can pull the capacity of traction transformer to achieve peak shifting and valley filling.Then,the possibility of integrated configuration of new energy and traction power supply system to optimize the capacity of traction transformer and the methods of optimal configuration of traction transformer capacity by using new energy such as wind and light are summarized.Finally,this paper discusses the current structure of new energy access to traction power supply system,and it looks forward to the feasibility of new energy access to traction power supply system cooperating with energy storage devices to optimize the capacity of traction transformer.

Game-theoretic energy management with storage capacity optimization in smart grids

With the development of smart grids, a renewable energy generation system has been introduced into a smart house. The generation system usually supplies a storage system with the capability to store the produced energy for satisfying a user's future demand. In this paper,the main objective is to determine the best strategies of energy consumption and optimal storage capacities for residential users, which are both closely related to the energy cost of the users. Energy management with storage capacity optimization is studied by considering the cost of renewable energy generation, depreciation cost of storage and bidirectional energy trading. To minimize the cost to residential users, the non-cooperative game-theoretic method is employed to formulate the model that combines energy consumption and storage capacity optimization.The distributed algorithm is presented to understand the Nash equilibrium which can guarantee Pareto optimality in terms of minimizing the energy cost. Simulation results show that the proposed game approach can significantly benefit residential users. Furthermore, it also contributes toreducing the peak-to-average ratio(PAR) of overall energy demand.

A Storage and Transmission Joint Planning Method for Centralized Wind Power Transmission

Centralized delivery has become the main operation mode under the scaled development of wind power.Transmission channels are usually the guarantee of out-delivered wind power for large-scale wind base.The configuration of transmission capacity,which has the features of low utilization and poor economy,is hardly matching correctly due to the volatility and low energy density of wind.The usage of energy storage can mitigate wind power fluctuations and reduce the requirement of out-delivery transmission capacity,but facing the issue of energy storage cost recovery.Therefore,it is necessary to optimize the allocation of energy storage while considering the problem of wind power transmission.This paper studies the joint optimization of large-scale wind power transmission capacity and energy storage,reveals the mechanism of energy storage in order to reduce the power fluctuation of wind power base and slow down the demand of transmission.Then,analyze the multi-functional cost-sharing mode of energy storage,improve the efficiency of energy storage cost recovery.Constructs the coordination optimization configuration model to deal with the problem of large-scale wind power transmission capacity and energy storage,and realizes the transmission capacity optimization coordination and optimization with energy storage.The proposed method is verified by a wind base located in Northeast China.

Optimal allocation of hybrid energy storage for microgrids based on multi-attribute utility theory

To satisfy the requirements of high energy density,high power density,quick response and long lifespan for energy storage systems(ESSs),hybrid energy storage systems(HESSs)have been investigated for their complementary characteristics of‘high energy density components’and‘high power density components’.To optimize HESS combinations,related indices such as annual cost,fluctuation smoothing ability as well as safety and environmental impact have to be evaluated.The multiattribute utility method investigated in this paper is aimed to draw an overall conclusion for HESS allocation optimization in microgrid.Building on multi-attribute utility theory,this method has significant advantages in solving the incommensurability and contradiction among multiple attributes.Instead of determining the weights of various attributes subjectively,when adopting the multi-attribute utility method,the characteristics of attributes and the relation among them can be investigated objectively.Also,the proper utility function and merging rules are identified to achieve the aggregate utility which can reflect comprehensive qualities of HESSs.

改进MOGOA及其在风储容量优化配置中的应用

针对传统方法在风储容量优化配置过程中求解精度低、效率低等问题,提出一种改进多目标蝗虫优化算法(improved multi-objective grasshopper optimization algorithm,IMOGOA),采用Fuch混沌映射、余弦自适应参数和莱维飞行三种策略进行改进,使算法的初始解分布更均匀、全局探索和局部开发更协调,同时增强了算法跳出局部最优的能力。对改进算法和多目标粒子群等多个算法进行性能测试对比,实验结果表明改进算法具有更好的寻优精度和稳定性。将该算法应用于风电场混合储能系统容量优化配置,对比其他算法,改进算法能够快速找出Pareto最优解集,在满足系统要求的同时,最大限度降低混合储能系统成本,可以验证算法改进策略的有效性和应用于实际优化问题的适用性。

面向季节性短时高峰负荷的虚拟配电馈线功能架构及协同配置

传统线路增容方式面对季节性短时高峰负荷时存在线路整体利用率低、紧急功率支撑能力差等问题。因此,文中以功能虚拟化为核心,研究了传统配电馈线与储能元件融合的虚拟配电馈线功能架构,利用双端储能元件搭建虚拟电能传输通道,以应对季节性短时高峰负荷、延缓传统线路增容改造工程,并在非高峰时期提供紧急功率支撑和辅助服务功能,提高储能元件整体利用率。为充分挖掘虚拟配电馈线的灵活传输和紧急功率支撑潜力,提出了配电网线路增容优化配置模型,在保证经济性和满足高峰负荷需求的前提下,优化虚拟配电馈线储能配置。算例研究表明,虚拟配电馈线能够有效延缓传统线路增容改造工程、应对季节性短时高峰负荷;对于线路负荷增长较稳定、线路长度较长和设计延缓增容年限较短的配电区域,虚拟配电馈线的优势更加凸显。

水电富集区域电量送出能力提升的源储协同优化运行方法

针对可再生能源出力的强波动性、间歇性导致电力外送断面出现短时间尺度重过载、清洁能源送出消纳困难等问题,提出了水电富集区域电量送出能力提升的源储协同优化运行方法,该方法定义了衡量断面外送电量的量化指标,以系统发电成本最小、断面输出电量最大、储能消耗电量最小为目标,建立多目标优化模型,通过求解帕累托前沿,结合熵权双基点法,得到折中最优点。对我国某省级电网算例的仿真结果表明,该方法可有效通过水电、火电和储能的协同优化运行提升断面外送可再生能源的发电量,在保证系统安全稳定运行的前提下提升了可再生能源的消纳率。

考虑负电价的建筑储能控制策略与优化配置设计方法

在双碳战略背景下,清洁能源已经成为城市能源供应的重要组成部分,与此同时建筑再电气化率也在不断提高,为了应对新形势下的能源供需平衡,我国电力市场不断完善,然而新市场规则带来的负电价现象,对建筑能源系统工程设计和运维带来了极大的挑战。本文以建筑光储系统为研究对象,考虑负电价情况,提出新市场机制下系统调度策略与容量配置方法,并通过Matlab进行模拟仿真,验证了该方法的有效性。

基于改进鲸鱼算法的混合储能系统容量优化配置

针对微电网中使用可再生能源的高随机性和间歇性等特征,提出了一种混合储能系统容量优化配置方法。该方法以混合储能系统成本最低、平抑可再生能源功率波动效果最优与电网联络线利用率最高为目标,通过建立混合储能容量优化配置模型并采用改进鲸鱼优化算法对所建立的模型进行求解得到最优混合储能系统容量优化配置。最终对比传统鲸鱼优化算法和传统粒子群算法来验证改进鲸鱼算法可以更合理地配置混合储能系统的容量,使可再生能源功率波动的平抑效果提高,同时也使微网联络线利用率变高,保证微电网可靠、经济地运行,进而实现资源的合理利用。

高容配比光伏电站储能运行方式及其容量配置研究

随着光伏产业的不断发展,高容配比逐步成为光伏电站设计的主流趋势。针对高容配比子阵内部储能优化充、放电策略的问题,文章提出了一种基于工作模式识别的储能运行方式,以实现能量搬移和平抑波动两种非协同的工作目标。综合考虑光伏储能联合系统的发电收益、储能成本、波动特性、典型日类别等信息,构建了以全生命周期净现值最大和平抑波动效果最优为目标的储能容量优化配置数学模型。以东北某大型光伏电站1.8容配比的1 MW光伏子阵作为案例研究对象,优化得到的最佳储能容量为700 kW·h。不同典型日的仿真结果表明,文章所提出的储能运行方式及配置模型可行有效。

提升光储充电站运行效率的多目标优化配置策略

光储充电站的运行效率直接影响到其经济效益及电网侧的电能质量。针对在进行容量配置时对运行效率考虑不足会导致非必要的电能损耗,文中提出一种提升光储充电站运行效率的多目标优化配置策略。通过分析光储充电站变换器与内源线路功率损耗对于运行效率的影响,提出充电站的运行效率评估指标与计算方法,并讨论光储充电站运行效率对其容量配置的影响。建立以充电站经济效益、运行效率、电网侧峰谷供电功率补偿能力最佳为优化目标的多目标容量优化配置策略。针对优化目标特性,提出一种改进二代非支配排序遗传算法得到优化策略求解方法。选取中国西南地区某典型光储充电站运营场景,通过算例验证了优化策略的有效性与优越性。

考虑电动汽车充电负荷及储能寿命的充电站储能容量配置优化

提出了一种优化电动汽车充电站储能容量配置的方法。该方法考虑了季节性电动汽车充电负荷波动与光伏出力之间的关系,并且考虑了储能寿命。论文利用蒙特卡罗法考虑了不同类型电动汽车的多种影响因素,对整体负荷进行预测。以每日运行成本最低为优化目标,在考虑四季光伏出力和储能寿命的影响下,采用了3种算法对目标函数进行优化,以得到最佳的光储充电站储能配置方案。研究以西北某地区为例。结果表明:冬季下综合成本为3.0432×10^(6)元,相比于其余3个季节综合成本最低;采用遗传算法时,在综合成本相差不多时,获得的储能配置最优,储能容量为22.82 MWh,储能功率为7.31MW,从而得到光储充电站最优的储能容量配置。

电动汽车虚拟储能支撑的多元调峰辅助服务优化

可再生能源出力的波动性加剧了电网调峰需求,大规模电动汽车(electric vehicle,EV)聚合为虚拟储能可大幅提升系统调峰能力。然而,调峰需求方(风电､光伏等可再生能源运行商)与调峰供应方(火电站､储能系统等)之间的交易机制尚未完善,如何调动EV作为调峰供应方的积极性,在多元主体间合理分摊调峰辅助服务费用,成为亟需解决的问题。提出EV虚拟储能支撑的多元调峰优化调度及辅助服务费用分摊机制:首先,构建多元调峰辅助服务市场主体,包括风电、光伏、火电及EV虚拟储能等。其次,设计EV虚拟储能参与辅助服务费用分摊机制,风电、光伏等调峰需求方按各自发电容量比例,分摊火电及EV虚拟储能等调峰供应方所需的辅助服务费用。特别地,每辆EV根据其调峰的具体贡献给予补偿,充分体现EV车主作为储能自主参与电力市场的价值,并调动其参与调峰的积极性。然后,以系统运行总成本最低为目标构建日前调峰调度模型。最后,以湖北省某区域为例进行算例仿真,分析表明所提模型中EV虚拟储能的加入可有效降低系统运行总成本8.5%,同时提高系统调峰裕度,促进EV虚拟储能等灵活资源可持续发展。

公路隧道风光水储互补发电系统容量配置研究

为降低公路隧道的电力运营成本,探究可再生能源互补发电系统在公路隧道的应用前景,研究合适的容量配置求解方法。建立利用风、光、水和储能设备的互补发电系统为公路隧道提供电力资源。以特长公路隧道(总长7.1 km)为估算模型,采用改进后的粒子群优化算法,即离散型自适应粒子群优化算法,以全生命周期的建设成本和设备维护成本最小为目标函数,以缺电负荷率(LPSP)和储能电池的状态为约束,对风力发电设备、光伏发电设备、水力发电设备和储能设备的最优容量配置进行求解。结果表明:1)对比标准粒子群算法,离散型自适应粒子群优化算法的总投入成本更少,寻优能力更强;2)对比该隧道1年的用电成本,前期投入将在5年内回本;3)在风光水储互补发电系统的设备全生命使用周期的20年内,该隧道可节省1 920.39万元电费。

燃料电池船复合储能容量优化与配置经济性分析

复合储能系统可改善由船舶负载功率波动引起的燃料电池寿命损耗问题,但配置成本限制了其在燃料电池船上的广泛应用。为合理配置储能容量,使船舶动力系统设计具备长期的可靠性,提出了一种计及复合储能系统全寿命周期的容量优化配置方法。在构建各电源系统模型的基础上,建立包括购置成本、维护成本、置换成本和能耗成本的复合储能系统全寿命周期成本模型,并采用雨流计数法来评估储能的置换成本。最后依据“Alsterwasser”号燃料电池船的典型功率需求数据,以储能设备的容量参数、燃料电池的输出功率和电源系统的运行参数为优化变量,采用灰狼优化算法进行求解。通过不同储能类型和优化目标下的配置方案对比,验证了所提方法的经济性。

含氢储能的微电网低碳-经济协同优化配置

【目的】传统电储能在规模、持续时间和环境影响等方面存在局限性,而且微电网中新能源消纳能力低,规划时无法兼顾低碳性和经济性。为解决以上问题,基于氢储能基本工作原理,将氢储能代替传统电储能纳入到微电网中,建立了含氢储能的微电网低碳-经济协同双层优化配置模型。【方法】上层规划模型以微电网综合等年值最小为目标,在电-氢联合运行的基础上,引入碳交易机制对微电网中各发电设备进行容量规划,提高了系统的低碳性;下层运行模型以最小化新能源出力与负荷需求之差的绝对值之和为目标,鼓励用户采取以精确追踪新能源出力曲线为目标的多样化需求侧响应行为,并将用户的用能行为调整反馈至上层模型,实现了对负荷曲线的优化。【结果】某工业园区微电网仿真验证表明,所提方法得到的规划方案具有良好的低碳性和经济性,与传统规划方法相比,低碳性和经济性分别提高了53.6%和37.1%。【结论】所建模型在提高新能源消纳能力的基础上进一步提高了系统的经济性,实现了微电网低碳性和经济性的协同优化。

光伏微电网储能系统多目标容量优化配置

储能是解决可再生能源消耗、提高系统运行可靠性的重要措施,为此,提出基于分时能量互补的光伏微电网储能系统多目标容量优化配置方法。根据光伏微电网储能系统的结构,分析其工作原理,为容量优化提供理论支撑。多目标容量优化模型以降低生命周期成本、抑制可再生能源功率波动和最大化联络线利用率3个目标构建。基于分时能量互补技术,设计一种具有互补特性的优化算法。通过多目标求解,得到容量优化配置的最佳方案。实验结果表明,所提方法提高了微电网联络线的利用率,有效抑制系统的功率波动,提高系统的综合收益。

阶梯成本下考虑混合租建模式的云储能优化配置

为解决盲目投建云储能造成资源浪费、成本增加的问题,提出阶梯成本下“自建+租赁”混合模式的园区云储能优化配置方法。首先,分析云储能的特点,构建园区内有大量光伏用户参与的云储能服务模式。其次,建立不同时间尺度、双主体的双层优化模型,上层求解长时间尺度下云储能的规划问题,下层求解短时间尺度下用户群的运行问题。然后,通过KarushKuhn-Tucker(KKT)条件将双层模型转化为单层模型,再利用Big-M法对所得单层模型进行线性化处理。最后,在3个不同场景下进行算例分析,结果验证了所提云储能配置模型的有效性,在降低储能投资成本、提高储能资源利用率的同时可节省用户用电成本。

基于时序运行模拟的水火风光储互补系统电源优化配置

系统时序运行模拟是水火风光储互补系统电源规模优化配置的关键环节。对于水火风光储多能互补系统8760逐小时运行模拟,按照小时尺度构建的模型规模很大,直接求解困难。本文提出按时间尺度逐层分解、递进优化的高效求解算法,精确模拟系统全年逐小时调度运行过程。在此基础上,构建双层规划模型对由风电、光伏、水电、火电、抽水蓄能、梯级水电站混合式抽水蓄能和电化学储能等电源组成的并网多能互补系统的电源容量进行优化配置。将模型应用在青海省电网系统中,对风电、光伏、抽水蓄能电站和基于水电站的可逆机组容量进行优化,得到电源最佳配置方案。