Capacity Optimization Configuration of Hydrogen Production System for Offshore Surplus Wind Power

To solve the problem of residual wind power in offshore wind farms,a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of residual wind power.By studying the mathematical model of wind power output and calculating surplus wind power,as well as considering the hydrogen production/storage characteristics of the electrolyzer and hydrogen storage tank,an innovative capacity optimization allocation model was established.The objective of the model was to achieve the lowest total net present value over the entire life cycle.The model took into account the cost-benefit breakdown of equipment end-of-life cost,replacement cost,residual value gain,wind abandonment penalty,hydrogen transportation,and environmental value.The MATLAB-based platform invoked the CPLEX commercial solver to solve the model.Combined with the analysis of the annual average wind speed data from an offshore wind farm in Guangdong Province,the optimal capacity configuration results and the actual operation of the hydrogen production system were obtained.Under the calculation scenario,this hydrogen production system could consume 3,800 MWh of residual electricity from offshore wind power each year.It could achieve complete consumption of residual electricity from wind power without incurring the penalty cost of wind power.Additionally,it could produce 66,500 kg of green hydrogen from wind power,resulting in hydrogen sales revenue of 3.63 million RMB.It would also reduce pollutant emissions from coal-based hydrogen production by 1.5 tons and realize an environmental value of 4.83 million RMB.The annual net operating income exceeded 6 million RMB and the whole life cycle NPV income exceeded 50 million RMB.These results verified the feasibility and rationality of the established capacity optimization allocation model.The model could help advance power system planning and operation research and assist offshore wind farm operators in improving economic and environmental benefits.

Dispersed Wind Power Planning Method Considering Network Loss Correction with Cold Weather

In order to play a positive role of decentralised wind power on-grid for voltage stability improvement and loss reduction of distribution network,a multi-objective two-stage decentralised wind power planning method is proposed in the paper,which takes into account the network loss correction for the extreme cold region.Firstly,an electro-thermal model is introduced to reflect the effect of temperature on conductor resistance and to correct the results of active network loss calculation;secondly,a two-stage multi-objective two-stage decentralised wind power siting and capacity allocation and reactive voltage optimisation control model is constructed to take account of the network loss correction,and the multi-objective multi-planning model is established in the first stage to consider the whole-life cycle investment cost of WTGs,the system operating cost and the voltage quality of power supply,and the multi-objective planning model is established in the second stage.planning model,and the second stage further develops the reactive voltage control strategy of WTGs on this basis,and obtains the distribution network loss reduction method based on WTG siting and capacity allocation and reactive power control strategy.Finally,the optimal configuration scheme is solved by the manta ray foraging optimisation(MRFO)algorithm,and the loss of each branch line and bus loss of the distribution network before and after the adoption of this loss reduction method is calculated by taking the IEEE33 distribution system as an example,which verifies the practicability and validity of the proposed method,and provides a reference introduction for decision-making for the distributed energy planning of the distribution network.

Wind power operation capacity credit assessment considering energy storage

Research on wind power capacity credit at the operational level plays an important role in power system dispatching.With the popularity of energy storage devices,it is increasingly necessary to study the impact of energy storage devices on wind power operational capacity credit.The definition of wind power operational capacity credit is given.The available capacity model of different generators and the charging and discharging model of the energy storage are established.Based on the above model,the evaluation method of wind power operation credible capacity considering energy storage devices is proposed.The influence of energy storage on the wind power operation credible capacity is obtained by case study,which is of great help for the power system dispatching operation and wind power accommodation.

Capacity Worth of Energy Storage System in Renewable Power Generation Plant

With the advance in renewable generation technologies, the cost of renewable energy becomes increasingly competitive when compared to fossil fuel-based generation resources. It is economically beneficial to integrate large amounts of renewable capacity in power systems. Unlike traditional generation facilities, however, using renewable resources for generation presents technical challenges in producing continuous power. In this report, an Energy Storage System (ESS) is integrated to smooth the variations in renewable power production and ensure the output power more controllable. Since it requires capital investment for the storage devices, it is important to obtain reasonable estimate of the storage capacities. This project is therefore formulated as an optimization problem in determining the two dominating factors of the capital cost for the ESS: the power capacity and the energy capacity. The objective is to make the renewable power more reliable and simultaneously maximize the economic benefits that can be obtained from the scheme. To make the results more convincing, analyses in this report start with wind generation, for wind has greater variability and unpredictability than other renewable sources. Selection of ESS type is narrowed down to battery energy storage system (BESS) in the scheme. However, the methods presented here are suitable for any type of energy storage methods and are also useful for intermittent renewable energy resources other than wind.

Two-stage ADMM-based distributed optimal reactive power control method for wind farms considering wake effects

Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption of wind generators.In this study,a two-stage reactive power optimization method based on the alternating direction method of multipliers(ADMM)algorithm is proposed for achieving optimal reactive power dispatch in wind farm-integrated distribution systems.Unlike existing optimal reactive power control methods,the proposed method enables distributed reactive power flow optimization with a two-stage optimization structure.Furthermore,under the partition concept,the consensus protocol is not needed to solve the optimization problems.In this method,the influence of the wake effect of each wind turbine is also considered in the control design.Simulation results for a mid-voltage distribution system based on MATLAB verified the effectiveness of the proposed method.

Challenges of Power Delivery from Jiuquan Wind Power Base

The 10-GW-class Jiuquan Wind Power Base in Gansu Province is to get its Phase I Project completed soon, and will further expand and become the world largest wind power base in the future. Whether electricity from the wind power base can be delivered on such a large scale becomes the focus of attention of the world. This paper analyzes four challenges facing the wind power base, including transmission capability, peak regulation and frequency modulation, capacity balance and generation accommodation, as well as system stability.

Impact of Wind Power on the ATC Values in Hydro-Dominated Power System

The wind power generation is increasing in many countries as a result of decreasing technology costs, active government policies for renewable energy sources, environmental concerns, etc.. This paper investigates the impact of wind power generation on ATC （available transmission capacity） calculation. In order to determine the maximum incremental MW transfer possible between two parts of a power system without violating any specified limits, ATCs are calculated. When calculating ATC values, it is necessary to assume production and consumption pattern in power system. Production of wind power depends on the wind speed, which is a random variable and it is impossible to forecast exactly the production of wind power that is needed for the ATCs calculation. In order to investigate influence of the stochastic wind power production on the ATCs value, computer model of Croatian electric power system is made in Power World Simulator. ATCs are calculated for southern part of Croatian power system in which besides wind power, hydro power plants are only type of power generation. Available wind speed measurements are used as input data for wind power production. The results of the ATC calculation for different scenario of wind power production and location in the Southern Croatian power system are presented and discussed in the paper.

Five Major Concerns about China’s Wind Power Development

Economic issue is the very focus of China's wind power development.Although all the security problems can be dealt with through technical measures,the compensation for supportive thermal power units and the subsidy from economically developed regions to resource-outputting regions would require a higher level of strategic considerations.The core purpose of developing wind energy is to reduce pollutant emissions,so planners should take into account the overall cost of all sides,without touching the bottom of social affordability.

风光热储互补发电系统容量配置技术研究

针对无常规电源支撑的风光热储互补发电系统,协调规划装机容量对提高发电系统运行经济性和利用率具有重要意义。提出了一种双层优化配置方法,上层以最小度电成本及弃电率为目标,确定系统装机容量;下层以新能源发电消纳最大为目标,解决功率分配问题。通过反复迭代寻优,得到系统容量配置;然后;通过纳什谈判对优化结果进行选择;最后,对甘肃河西地区数据进行仿真分析。结果表明:风光热储互补发电系统最优容量配置下的度电成本为0.3064元/(k W·h);风电场加光伏电站装机容量与光热电站装机容量的最优比为6:1,对比相同装机容量的风光互补发电系统,风光热储互补发电系统具有更高的稳定性。

基于单级多电平开关变流的超大容量海上风电变流器

海上风机正向超大容量方向发展,基于较低电平数目变流技术的风电变流器在电压、容量等级的提升方面受到限制。提出了基于单级多电平开关变流的超大容量海上风电变流器方案,采用直流电压可大范围调节的宽直流电压模块化多电平变流器(MMC),在单级多电平变流器中实现DC/DC和DC/AC两级变换功能。基于风电变流器的单向功率传输特性,采用单向电流型宽直流电压MMC优化开关器件用量,并基于负电平利用优化调制比大幅降低MMC的子模块电容用量。所提出的方案不仅具有电压与容量等级高、功率损耗低、谐波含量低的优势,还能最大限度降低开关器件和电容的用量。与现有风电变流器方案进行对比,结果表明所提方案在经济性、运行性能等方面具有显著优势。通过仿真验证了所提方案拓扑结构和控制策略的可行性和有效性。

考虑海缆实际载流量的海上风电集电系统拓扑优化

海缆实际载流量是海缆选型的重要依据,在海上风电场集电系统拓扑优化中,考虑不同敷设区段海缆载流量存在的差异以及海缆多回路并联敷设时磁热效应对载流量的影响,对保障集电系统的安全性具有重要意义。首先,采用模糊C均值算法对风机进行聚类分区,将集电系统拓扑优化分解为分区内、外拓扑优化。然后,在分区内采用基于Voronoi图的拓扑搜索算法进行求解;在分区外拓扑优化中,考虑海缆瓶颈区段、回路数对载流量的影响,构建混合整数非线性优化模型,线性化后采用优化求解器GUROBI进行求解。最后,以某实际风电场为例进行仿真验证。结果表明,所提模型能保证海缆实际载流量始终大于海缆工作电流,可有效保障集电系统的安全性。

海上风电五连筒导管架基础及筒顶节点受力分析

以广东某深远海域大容量风电机组五连筒导管架基础为研究对象,采用有限元软件对五连筒基础在倾斜率、极限承载力和屈曲特性等方面开展深入研究,并对筒顶处导管架与基础连接节点进行多参数敏感性分析,从而得到受力及承载最优的结构体型。研究结果表明:满足相同容量机组荷载运行要求的前提下,五连筒基础与单筒基础结构相比,前者在倾斜率、承载力及抗屈曲特性上优势明显;随着筒顶节点的外移,筒型基础边筒竖向变形逐渐增大,中筒则相反;当筒顶节点靠近中筒时,主要由中筒受力,应力最大部位主要集中在边筒和中筒筒裙底部连接处;当筒顶节点向外偏移时,受力部位由中筒转移到边筒,且应力最大部位转移到沿加载方向的边筒筒裙顶部;基础的极限承载力均随导管架根部开度增加呈线性趋势增长,在水平及弯矩荷载分别作用下,旋转中心附近的被动土压力受筒顶节点位置影响较大,筒顶节点越往外偏移,被动土压力越小;旋转中心以下的主动土压力受筒顶节点位置影响同样较大,筒顶节点越往外偏移,主动土压力越大。

海上风电单柱复合筒型基础承载特性

文章针对一种新型海上风机基础型式的单柱复合筒型基础的承载特性,在砂土中进行了小比尺物理模型试验。试验中采用了位移控制的水平单调加载方式,选择加载速度与压载为变量,得到水平承载力荷载位移曲线。试验结果表明,基础极限承载力与加载速度和压载质量均呈正相关。得出了基础在加载过程中不同舱内孔隙水压力的变化规律。

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。

离网型风光发电联合制氢系统的协调运行策略与容量配置优化

离网型风光发电制氢是降低风光发电对电网冲击、促进可再生能源消纳的重要手段,然而风光资源的波动性也对制氢系统高效稳定运行带来了负面影响。为提高离网型风光制氢系统运行稳定性,结合风力/光伏发电、碱性电解槽(alkaline electrolyzer,AE)和储能设备,提出电解槽模式分配与储能日前规划的协调制氢策略,并在计及单位制氢成本与弃风弃光率的基础上,采用改进的非支配排序遗传算法(non-dominated sorting genetic algorithm II,NSGA-II)进行容量配置优化。结合案例分析表明,与单一电解槽分配策略相比,协同策略的单位制氢成本和弃风弃光率分别降低了11.9%和55.6%。同时该策略有效平抑了电解槽的频繁波动,启停次数降低了44.3%,实现了风光制氢系统的高效运行。研究成果将为开发高效可再生制氢系统提供有益参考。

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。

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。

离网式风光氢醇一体化系统容量配置运行调度优化及经济性分析

为解决可再生能源消纳及氢能源存储、运输难题,提出一种离网式风光氢醇一体化系统。该系统离网运行,利用风力和光伏发电提供电能;通过蓄电池和储氢罐作为储能和储氢设备,以削峰填谷的方式稳定供应电能和氢能,确保电解槽和甲醇生成设备的稳定连续生产甲醇。以系统总收益最大化为目标构建了风光储氢醇的数学模型,并通过混合整数线性规划算法,结合风光真实数据分析,确定系统最佳设备容量与运行调度。以典型日分析其运行策略及系统能量,最后对所制绿色甲醇经济性分析。结果表明:系统能够根据外界条件的变化,合理切换工作状态,实现系统能量平衡;在满足各项约束条件下,提高了可再生能源利用率,降低了系统制甲醇的平准化成本。此研究为新能源消纳与氢能源利用提出了一条可行技术路线,并可为相关示范项目建设提供指导。

基于校正条件生成对抗网络的风电场群绿氢储能系统容量配置

以条件生成对抗网络(CGAN)为代表的半监督学习可计及风电波动并生成出力场景集合,生成的数据可输入氢气储能容量配置模型以支撑优化求解。为此,该文首先设计一种校正条件生成对抗网络(CCGAN),并基于风电预测误差构建条件校正器,对预测失准事件和风电爬坡事件下输入生成器的标签信息进行识别和校正;然后,以储能定容的综合成本和各风场弃风成本为目标函数,构建绿氢储能容量配置的多目标优化模型,并引入基于切比雪夫距离的膝区域数学概念,以指导多目标优化算法设计;最后,以新英格兰39节点系统为例进行算例分析,结果表明未经校正的条件信息将导致定容决策偏离实际,而CCGAN能生成计及风电不确定性的高置信出力场景,使得容量配置结果兼顾鲁棒性和经济性。