Dynamic and Power Generation Features of A Wind-Wave Hybrid System Consisting of A Spar-Type Wind Turbine and An Annular Wave Energy Converter in Irregular Waves

Combining wave energy converters(WECs)with floating offshore wind turbines proves a potential strategy to achieve better use of marine renewable energy.The full coupling investigation on the dynamic and power generation features of the hybrid systems under operational sea states is necessary but limited by numerical simulation tools.Here an aero-hydro-servo-elastic coupling numerical tool is developed and applied to investigate the motion,mooring tension,and energy conversion performance of a hybrid system consisting of a spar-type floating wind turbine and an annular wave energy converter.Results show that the addition of the WEC has no significant negative effect on the dynamic performance of the platform and even enhances the rotational stability of the platform.For surge and pitch motion,the peak of the spectra is originated from the dominating wave component,whereas for the heave motion,the peak of the spectrum is the superposed effect of the dominating wave component and the resonance of the system.The addition of the annular WEC can slightly improve the wind power by making the rotor to be in a better position to face the incoming wind and provide considerable wave energy production,which can compensate for the downtime of the offshore wind.

Short-term power generation scheduling rules for cascade hydropower stations based on hybrid algorithm

Power generation dispatching is a large complex system problem with multi-dimensional and nonlinear characteristics. A mathematical model was established based on the principle of reservoir operation. A large quantity of optimal scheduling processes were obtained by calculating the daily runoff process within three typical years, and a large number of simulated daily runoff processes were obtained using the progressive optimality algorithm （POA） in combination with the genetic algorithm （GA）. After analyzing the optimal scheduling processes, the corresponding scheduling rules were determined, and the practical formulas were obtained. These rules can make full use of the rolling runoff forecast and carry out the rolling scheduling. Compared with the optimized results, the maximum relative difference of the annual power generation obtained by the scheduling rules is no more than 1%. The effectiveness and practical applicability of the scheduling rules are demonstrated by a case study. This study provides a new perspective for formulating the rules of power generation dispatching.

Rolling Generation Dispatch Based on Ultra-short-term Wind Power Forecast

The power systems economic and safety operation considering large-scale wind power penetration are now facing great challenges, which are based on reliable power supply and predictable load demands in the past. A rolling generation dispatch model based on ultra-short-term wind power forecast was proposed. In generation dispatch process, the model rolling correct not only the conventional units power output but also the power from wind farm, simultaneously. Second order Markov chain model was utilized to modify wind power prediction error state (WPPES) and update forecast results of wind power over the remaining dispatch periods. The prime-dual affine scaling interior point method was used to solve the proposed model that taken into account the constraints of multi-periods power balance, unit output adjustment, up spinning reserve and down spinning reserve.

电-热-氢综合能源系统鲁棒区间优化调度

储能技术与风电相结合实现电能的时空平移是解决系统运行稳定性问题的有效手段。氢储能具有储存容量大、可实现电热联产联供的优点,具有很大的发展潜能。然而由于风电存在不确定性,氢储能系统在频繁切换工作模式时面临着不确定的热能需求。因此,文中综合考虑氢储能在间歇模式下的热能需求,首先,介绍了氢储能系统接入的电-热综合能源系统基本结构,将风电场与氢储能相结合构成风-氢混合系统;然后,提出考虑风-氢混合系统热平衡需求不确定性的电-热综合能源系统鲁棒区间优化调度模型;最后,基于对偶理论,对所提出的模型转化求解,通过算例对比分析各类情况优化结果,验证了氢储能在促进风电消纳、提高系统能源综合利用率方面的有效性,并证明了考虑电解槽和燃料电池工作温度能提高系统的工作效率并提高风电场并网功率。

Risk-averse Robust Interval Economic Dispatch for Power Systems with Large-scale Wind Power Integration

This paper presents a robust interval economic dispatch(RIED)model for power systems with large-scale wind power integration.Differing from existing interval optimization(IO)approaches that merely rely on the upper and lower boundaries of random variables,the distribution information retained in the historical data is introduced to the IO method in this paper.Based on the available probability distribution function(PDF),wind power curtailment and load shedding are quantified as the operational risk and incorporated into the decision-making process.In this model,we need not rely on the forecasted value of wind power,which is randomly fluctuating and quite unpredictable.Furthermore,when the PDFs of wind power are taken into account,the resulting dispatch solution makes a good tradeoff between the generation cost and the operational risk.Finally,the RIED model yields an optimal dispatch solution for thermal units and the allowable intervals of wind power for the wind farms,which efficiently mitigates the uncertainty in wind power generation and provides more practical suggestions for system operators.Simulation studies are conducted on a modified IEEE-118 bus system and the results verify the effectiveness of the proposed RIED model.

风电光伏混合系统中的储能技术研究与应用

介绍风电光伏混合系统的基本概念、组成以及运行特点,强调系统在提供稳定、可靠电力方面的优势。探讨电化学、机械和热储能等的优缺点及其在可再生能源系统中的应用,详细分析储能技术如何提升风电光伏混合系统的稳定性、经济性以及环境适应性,并通过实证数据和比较分析展示储能技术在系统优化中的效果,提出结合储能技术的系统优化策略,如模型预测控制(Model Predictive Control,MPC)等,强调其在提高系统效率和应对复杂气候条件中的关键作用。

混凝土-钢结构混合式风电塔架转接段制作工艺探索与实践

主要探讨混凝土-钢结构混合式风电塔架转接段制作过程中的关键环节,采用精确切割技术、焊缝温度控制以及精细化法兰组合操作等手段,对塔架整体制造工艺的科学性和可行性进行全面考究,并提出一套具有显著成效的制作方法。

Performance Analysis of Grid Connected and Islanded Modes of AC/DC Microgrid for Residential Home Cluster

This paper presents performance analysis on hybrid AC/DC microgrid networks for residential home cluster. The design of the proposed microgrid includes comprehensive types of Distributed Generators (DGs) as hybrid power sources (wind, Photovoltaic (PV) solar cell, battery, fuel cell). Details about each DG dynamic modeling are presented and discussed. The customers in home cluster can be connected in both of the operating modes: islanded to the microgrid or connected to utility grid. Each DG has appended control system with its modeling that will be discussed to control DG performance. The wind turbine will be controlled by AC control system within three sub-control systems: 1) speed regulator and pitch control, 2) rotor side converter control, and 3) grid side converter control. The AC control structure is based on PLL, current regulator and voltage booster converter with using of photovoltaic Voltage Source Converter (VSC) and inverters to connect to the grid. The DC control system is mainly based on Maximum Power Point Tracking (MPPT) controller and boost converter connected to the PV array block and in order to control the system. The case study is used to analyze the performance of the proposed microgrid. The buses voltages, active power and reactive power responses are presented in both of grid-connected and islanded modes. In addition, the power factor, Total Harmonic Distortion (THD) and modulation index are calculated.

基于混合蝙蝠算法的高比例风电电力系统调度方法

针对传统电力系统调度计算时间较长、均方根误差大、结果不准确的问题,文章提出一种基于混合蝙蝠算法的高比例风电电力系统调度方法。通过模糊机会约束规划和可信理论,将高比例风电电力系统约束转换为模糊机会约束,设定模糊置信度为递增向量,结合预测精度变化情况以及决策者对调度运行可靠性的期望变化,获取经过优化的调度结果。仿真实验结果表明,所提方法能够有效降低计算时间和均方根误差,同时还能够获取比较满意的高比例风电电力系统调度方案。

基于小波包分频的自适应模糊神经网络风电功率平抑策略

风电场频率波动导致风电发出功率不能及时准确跟踪电网调度指令,给电网调度带来很大困难,采用自适应模糊神经网络的小波包分频优化控制策略是一种新的策略,该策略能在风电跟踪调度指令的频率波动范围内优化小波包分频参数,得到优化后的混合储能充放电功率的初始功率指标值,将混合储能荷电状态的平均值和风电场出力与电网调度指令的平均值的偏差作为两个输入,再将风电历史数据训练后的自适应小波包分频模糊神经网络加入控制系统。采用大量风电历史数据在MATLAB/simulink中仿真,结果表明该策略减小了混合储能充放电时对电网频率波动的影响,充放电时混合储能荷电状态波动小,风电跟踪电网调度的效果更优。

Market-oriented Optimal Dispatching Strategy for a Wind Farm with a Multiple Stage Hybrid Energy Storage System

With the increased promotion of integrated energy power systems(IEPS),renewable energy and energy storage systems(ESS)play a more important role.However,the fluctuation and intermittent nature of wind not only results in substantial reliability and stability defects,but it also weakens the competitiveness of wind generation in the electric power market.Meanwhile,the way to further enhance the system reliability effectively improving market profits of wind farms is one of the most important aspects of Wind-ESS joint operational design.In this paper,a market-oriented optimized dispatching strategy for a wind farm with a multiple stage hybrid ESS is proposed.The first stage ESS is designed to improve the profits of wind generation through day-ahead market operations,the real-time marketbased second stage ESS is focused on day-ahead forecasting error elimination and wind power fluctuation smoothing,while the backup stage ESS is associated with them to provide the ancillary service.An interval forecasting method is adopted to help to ensure reliable forecast results of day-ahead wind power,electricity prices and loads.With this hybrid ESS design,supply reliability and market profits are simultaneously achieved for wind farms.

出力波动影响下的风电储能优化调度技术

针对现有风电储能调度技术受出力波动影响较大,导致风电储能调度目标与实际调度结果误差较大的问题,提出一种优化调度技术。首先,分析出力波动对风电储能的影响过程,获得判断波动特征量;然后,建立出力波动影响下的风电储能调度尺度模型;接着,优化风电储能调度目标函数,实现出力波动变量的全局优化,提升风电储能调度精准度,增强调度参量对出力波动影响系数的抗扰定力;最后,通过数据调试进一步证明了该优化调度技术的有效性与可实现性。

配电系统中电动汽车与可再生能源的随机协同调度

电动汽车和可再生能源发电的快速发展为电力系统的安全和经济运行带来了新的挑战。在此背景下,构建了能够计及可入网混合动力电动汽车(PHEV)和风电、光伏发电系统出力不确定性的随机协同优化调度模型。首先,分析了PHEV的行驶耗电和随机充放电行为。之后,在假设风速服从Rayleigh分布、光照服从Beta分布的前提下,导出了风电机组和光伏发电系统出力的期望、方差及二阶原点矩的表达式。在此基础上,发展了以平抑可再生能源出力波动为目标的电力系统随机协同优化调度模型,并应用交叉熵算法进行求解。最后,以33节点配电系统为例说明了所提出的随机协同优化调度模型的基本特征。

含多种分布式电源的微电网经济调度研究

微电网的优化调度是一个新的具有重要社会和经济效益的复杂问题。基于实际风光资源、负荷和微电网运行成本数据,将用户效益、环境保护以及社会效益量化为运行及维护成本、未满足负荷、污染气体排放量、容量短缺等指标,采用模糊评价函数将多目标转化为单目标,提出了针对该微网的短期经济优化调度模型。选取一年中的典型情况为算例进行经济运行分析,并采用小生境遗传算法进行求解,得出了在各典型情况下各微电源的最优出力和最佳电能交易计划,验证了所提调度策略的正确性与有效性。

风光互补技术及应用新进展

简要回顾国内外风电、光伏技术与应用发展态势,结合风光互补系统应用,分析、介绍了风光互补LED路灯照明系统、智能控制器设计、分布式供电电源、风光互补水泵系统,并着重分析生物质能、风能和太阳能互补分布式能源梯级系统原理,涉及的技术关键等。研究表明,风能、光伏发电应用需要实现低成本、规模化,风光互补技术应用前景广阔。

计及风电备用风险的电力系统多目标混合优化调度

风电功率不确定间歇波动给电力调度带来了困难。如何合理考虑风电备用风险,一体化制定经济发电与旋转备用计划,并使节能减排等指标满足期望水平,是亟待解决的问题。定义了一种以风电功率间歇波动引起系统备用紧张程度为指标的规范化风电备用风险,建立了一种同时计及风电功率间歇波动对系统上调和下调备用的风险影响、一体化制定经济发电与旋转备用计划、具有最优值与期望值混合形式的多目标优化调度模型。其中,电网公司购电总费用取最小值形式,系统发电总燃煤耗量、总污染物排放量、上调和下调备用风险取期望值形式。针对多目标混合优化调度模型,采用分解交替迭代求解策略:将原问题分解为经济发电和旋转备用2个混合优化子问题,并利用发电出力与旋转备用的特定关系交替迭代求解。算例验证了所提出方法的有效性。

含风电场的混合机会约束经济调度模型

风电出力具有不确定性和波动性,大规模风电功率注入电网给电力系统调度运行带来了严峻的考验。针对系统中普遍存在的多重不确定因素,引入不确定规划理论,将风电和负荷出力的不确定性表示为预测误差的不确定性,并根据其不同特性,进行区别建模,考虑火电机组的阀点效应,建立同时含有模糊变量和随机变量的混合机会约束经济调度模型。采用模糊模拟和随机模拟技术相结合的混合模拟求解策略进行求解。通过引入机会约束使得调度决策具有控制风险和成本的能力,建模计及火电机组的阀点效应,使得计算结果更加符合实际情况。算例分析验证了所建模型的可行性和有效性。

基于零相位低通滤波器的混合储能平抑直驱风电机组功率波动控制策略的研究

研究基于零相位低通滤波器的混合储能平抑直驱风电机组功率波动控制策略。该控制策略控制全钒液流电池(VRB)补偿中频功率波动和超级电容(SC)快速地吸收高频功率波动,从而平滑风电功率和提高电能质量;同时实现直驱式风力发电系统根据电网调度指令在最大功率跟踪运行和限功率运行2种模式下运行及平滑切换。提出采用基于零相位低通滤波器风电功率分配算法,分析零相位低通滤波器参数对滤波效果的影响,并给出参数优化设计方法。零相位低通滤波器无相位滞后问题,可实时准确地检测风电功率中高、中和低频功率,减小各频段功率之间的偶合,从而取得更好的平抑功率波动效果和减小储能单元的容量。最后在Matlab/Simulink环境下建立系统仿真模型,仿真验证所提出的功率分配算法及控制策略的有效性。

基于遗传算法的风光柴蓄复合发电系统优化设计

针对风光柴蓄复合发电系统的非线性特性,采用遗传算法和能量调度策略,以系统初期投资费用和运行费用最优为系统优化目标函数,结合实际工程系统的配置进行了优化设计,并选取与优化方案较接近的三种方案进行全年逐时仿真比较。实验结果表明,在满足用户负载要求的条件下,所采用的优化算法和策略正确,方案配置合理、经济、可行。

风光互补发电系统最大功率跟踪综述

风光互补发电系统的运行需要快速准确地进行最大功率点跟踪,为此综述了风光互补发电系统最大功率点跟踪的几种方法,包括在太阳能电池阵列部分日益成熟、改进和优化策略较多的扰动观察法、电导增量法和恒压控制法;风力发电机部分的叶尖速比控制法、功率信号反馈法、扰动观察法,分别说明了各种跟踪控制方法的优点和不足之处。最后探讨了最大功率点跟踪控制方法的发展思路,对该领域今后的研究方向做了展望。