新能源电力系统概率预测理论与方法及其应用

高比例新能源已成为中国电力系统发展的突出特征,间歇性新能源发电的不确定性给电力系统安全与经济运行带来极大挑战.准确可靠的供需预测是新能源电力系统分析与运行控制的基础,传统确定性预测难以消除预测误差,概率预测可实现对预测不确定性的有效量化,为电力系统分析与运行控制提供关键信息支撑.文中对新能源电力系统概率预测理论与方法及...     

An Interactive Operating Demand Response Approach for Hybrid Power Systems Integrating Renewable Energy Sources

The increased deployment of renewable energy in existing power networks has jeopardized rotational inertia, resulting in system degradation and instability. To address the issue, this paper proposes a demand response strategy for ensuring the future reliability of the electrical power system. In addition, a modified fuzzy logic control topology-based two-degree-of-freedom (fractional order proportional integral)-tilt derivative controller is designed to regulate the frequency within a demand response framework of a hybrid two-area deregulated power system. The test system includes thermal power plants, renewable energy sources (such as wind, parabolic trough solar thermal plant, biogas), and electric vehicle assets. To adaptively tune the controller''s coefficients, a quasi-opposition-based harris hawks optimization (QOHHO) algorithm is developed. The effectiveness of this algorithm is compared to other optimization algorithms, and the stability of the system is evaluated. The results demonstrate that the designed control algorithm significantly enhances system frequency stability in various scenarios, including uncertainties, physical constraints, and high penetration of renewables, compared to existing work. Additionally, an experimental assessment through OPAL-RT is conducted to verify the practicality of the proposed strategy, considering source and load intermittencies.     

可再生能源电源的电能传输线路损耗评估模型分析

针对可再生能源电源因线路长且分支多导致电源负荷受时间影响,无法通过独立元件损耗方法评估电能传输线路损耗,研究了可再生能源电源的电能传输线路损耗评估模型.通过失衡度界定可再生能源电网,确定可再生能源电网范围后,采用基于电量法的传输线路损耗评估方法,将线路等值电阻、线路均方根负荷电流、线路有功供电量、线路无功供电量、线路平...     

基于扩展拉丁超立方采样的电力系统概率潮流计算

概率潮流分析中,拉丁超立方采样(Latin hypercubesampling,LHS)算法比简单蒙特卡罗仿真(Monte Carlosimulation,MCS)的效率要高,但是传统LHS(conventionalLHS,CLHS)算法采样数必须事先确定并且固定。针对现有CLHS技术的不足,提出了扩展拉丁超立方采样算法(Extended LHS,ELHS)并应用于概率潮流计算。扩展方法根据已有的N点LHS采样构造2N点LHS采样并保证扩展前后的相关性相近,在增加采样数的同时保留已有的潮流计算结果。由于采样数无法事先确定,因此提出了以扩展前后估计值变化量的相对值作为ELHS的实用化收敛判据。采用MCS、CLHS和ELHS方法分别对IEEE 30节点和IEEE 118节点系统进行概率潮流分析,所提出的方法能够在保证计算精度的前提下获得ELHS在不同采样数下的收敛趋势。算例结果证明了所提方法的高效性、精确性和易扩展性。     

间歇式电源并网系统的中长期特性仿真研究

间歇式电源的大规模发展及并网运行,在带来巨大经济效益的同时,也给电网中长期过程的频率稳定和有功平衡带来了巨大的影响。在间歇式电源机电暂态模型的基础上,对风电、光伏中长期自动发电控制(automatic generation control,AGC)子站进行建模,该模型可以接受调控中心AGC总站的调度命令,对间歇式电源进行功率调节。然后,利用甘肃电网的某典型日负荷、风速及光照曲线,深入分析了间歇式电源的波动特性及风光互补特性,验证了上述模型具有模拟中长期频率波动的能力。在此基础上,以平抑间歇式电源带来的联络线功率波动为目标,对机组出力计划、二次调频系统等控制策略的效果进行了分析。最后通过仿真计算论证了机组出力计划和AGC系统具有平抑间歇式电源功率波动性的作用。     

可再生能源发电介绍

介绍了小水电、风力发电、太阳能发电、地热能发电、生物质能发电、海洋能发电等可再生能源发电的发展概况,分析了可再生能源发电存在的问题以及相应对策,阐述了可再生能源发电的发展前景与规划,得出可再生能源发电产业能解决我国西部及边远地区的供电问题的结论。     

Estimating the Spinning Reserve Requirements in Systems With Significant Wind Power Generation Penetration

Spinning reserve (SR) allows system operators to compensate for unpredictable imbalances between load and generation caused by sudden outages of generating units, errors in load forecasting or unexpected deviations by generating units from their production schedules. As the proportion of power produced by wind farms increases, it becomes more difficult to predict accurately the total amount of power injected by all generators into the power system. This added uncertainty must be taken into account when setting the requirement for SR. This paper proposes a technique to calculate the optimal amount of SR that the system operator should provide to be able to respond not only to generation outages but also to errors in the forecasts for load and wind power production. Using a Monte Carlo simulation, the proposed technique for setting the SR requirements is then compared with the traditional deterministic criterion (i.e., the capacity of the largest online infeed), an approach to cope with wind imbalances and an approach that combines the traditional criterion with the approach to cope with wind imbalances. The results show that, contrary to what is commonly believed, an increased wind power penetration does not necessarily require larger amounts of SR.      

输电网的蒙特卡罗模拟与线损概率评估

提出一种输电网状态模拟与线损概率评估方法。该方法包括系统状态模拟和蒙特卡罗抽样2部分，在系统状态模拟时，采用具有正态分布特点的随机数来模拟节点负荷功率状态，通过建立发电机组启停的经济调度模型及其启发式调度方法来模拟机组的启停状态与运行状态，通过变电站电压无功控制(voltage and reactive power control，VQC)和发电厂逆调压控制来模拟系统电压无功的运行状态。在蒙特卡罗抽样时，基于上述模拟方法，通过对随机样本的状态调整与潮流计算来确定网络线损率的概率分布。由于论文方法比较全面地考虑了电网线损的影响因素，相应确定的线损率指标能比较真实地反映实际系统状况，因而具有更大的实用价值。仿真算例验证了论文方法的有效性。     

基于扩展状态空间分割法的含风电场电力系统运行备用风险评估

风功率的随机波动特性要求电网合理安排运行备用容量。评估大规模风电接入后电力系统的运行备用风险成为合理安排电网运行备用需要解决的首要问题。提出了一种基于扩展状态空间分割法的含风电场的电力系统运行备用评估方法。该方法可以处理风机多状态模型,同时考虑了风机自身的随机停运和风速预测的不确定性,将全状态空间划分为2个区域,分别采用枚举法和模拟法对2个子空间的系统状态进行选择,从而实现快速精确的风险评估。对我国某实际区域电网的计算分析验证了该算法的正确性和有效性。     

多运行方式下含风电场电力系统的小干扰概率稳定性研究

为了考虑系统的多运行方式,采用概率方法对风电场接入对系统小干扰稳定性的影响进行研究。首先采用插入式建模技术(plug-in modeling technique,PMT)建立适合小干扰稳定分析的完整的双馈感应风力发电机组(doubly-fed induction generator,DFIG)线性化模型;然后进行概率潮流计算,得到系统状态变量的概率描述,形成系统状态矩阵;最后应用概率特征根方法对系统进行求解分析,得到系统小干扰概率稳定性。以2个系统为例对风电场接入后的电力系统小干扰概率稳定性进行仿真分析,结果表明：风电场的加入使机电振荡模态特征值实部的概率分布变得相对分散;系统本地振荡模态稳定概率大幅下降,区间振荡模态稳定概率略有上升;通过加装电力系统稳定器(power system stabilizer,PSS),可提高系统小干扰概率稳定性。     

Probabilistic Load Flow Evaluation With Hybrid Latin Hypercube Sampling and Cholesky Decomposition

Monte Carlo simulation method combined with simple random sampling (SRS) suffers from long computation time and heavy computer storage requirement when used in probabilistic load flow (PLF) evaluation and other power system probabilistic analyses. This paper proposes the use of an efficient sampling method, Latin hypercube sampling (LHS) combined with Cholesky decomposition method (LHS-CD), into Monte Carlo simulation for solving the PLF problems. The LHS-CD sampling method is investigated using IEEE 14-bus and 118-bus systems. The method is compared with SRS and LHS only with random permutation (LHS-RP). LHS-CD is found to be robust and flexible and has the potential to be applied in many power system probabilistic problems.     

Reliability Evaluation for Distribution System With Renewable Distributed Generation During Islanded Mode of Operation

Keen interest in the development and utilization of wind-based distributed generations (DGs) has been currently observed worldwide for several reasons. Among those is controlling the emission of environmentally harmful substances, limiting the growth in energy costs associated with the use of conventional energy sources and encouraging the independent power producers for participation in the electricity market system. One of the most important issues is to quantitatively assess the impact of such type of DGs on the distribution system reliability. This paper presents a probabilistic technique to evaluate the distribution system reliability utilizing segmentation concept and a novel constrained Grey predictor technique for wind speed profile estimation.     

计及可再生能源不确定性的孤岛微电网概率潮流计算

随着具有不确定性的可再生能源接入孤岛微电网的比例不断提高,传统确定性条件下孤岛微电网的潮流计算受到挑战。基于有功功率—频率/无功功率—电压(P-f/Q-U)控制和有功功率—电压/无功功率—频率(P-U/Q-f)控制两种下垂控制策略,在计及可再生能源的不确定性时,建立了综合控制下孤岛交流微电网的概率潮流计算模型,并提出了一种改进的三步LevenbergMarquardt(MTLM)算法对潮流方程进行求解。采用基于Sobol序列的拟蒙特卡洛模拟获得具有随机性的可再生能源出力和负荷的样本,进而对38节点孤岛交流微电网进行概率潮流计算,通过对比验证了MTLM算法的快速收敛性和鲁棒性,研究了不同下垂控制策略下系统频率和电压的概率分布情况,分析了具有随机性的高比例可再生能源接入对孤岛微电网的影响。     

电网运行状态下的概率优化调度

构建电网运行状态下的有功功率概率优化调度模型,该模型以期望运行效益最大化为目标,采用马尔可夫链对系统未来调度时段的预想事故状态概率进行预测,在满足所有预想事故发生前后状态所对应约束集下获取调度解。其中,在容许时间内,针对预想事故发生后可能出现的系统安全破坏情形,以发电机组允许的输出功率再调整、紧急负荷中断及输电元件短时允许过载量作为有机牵制扩展到约束集中,并考虑相应安全校正措施的费用代价。该模型实现了电网运行状态概率预测与有功调度决策的紧密结合,可得到系统期望最大运行收益的时序变化曲线及各时段下风险收益概率均衡的调度方式。以IEEE-14节点系统为例进行测试分析,论证所提模型的合理性和有效性。     

含多种可再生能源发电联盟的优化运行

为了因地制宜地利用偏远山区现有的梯级小水电资源,将梯级小水电群与分布式光伏和风电相结合,构成含多种可再生能源的发电联盟,深度发掘风光水的出力时空互补特性以及风光波动性较大和小水电启停调节迅速的出力特性.通过对梯级小水电出力的调节,平滑不确定可再生能源的输出,改善分布式电源并网的电能质量,提高可再生能源利用率.充分考虑梯...     

Risk Constrained Portfolio Selection of Renewable Sources in Hydrothermal Electricity Markets

Renewable sources have recently emerged as a generation option for many countries in order to promote clean energy development. In the case of Brazil, small hydro plants and cogeneration from sugarcane waste (bagasse) have been attractive alternatives during the past years, with hundreds of MW installed since 2004. Despite their advantages, both alternatives are hindered by seasonal yet complementary availability. This forces producers to discount (or price) the risks faced when selling firm energy contracts and may ultimately lead to projects being commercially unattractive. We propose a stochastic optimization model that defines the optimal composition of a portfolio based on these two renewable sources in order to maximize the revenue of an energy trading company. At the same time, this model mitigates hydrological and fuel unavailability risks, thus allowing the participation of both sources in the forward market environment in a competitive manner. A case study is presented, based on data from the Brazilian system.      

基于可再生能源不确定性的电力系统双侧备用容量优化

在全球能源互联网背景下,以风电为代表的新能源入网给电力系统安全稳定运行带来新的挑战,同时也对备用容量配置提出了更高的要求,为此提出以双侧备用成本期望最小为目标函数的备用容量优化模型。在考虑需求侧响应中的可中断负荷,以及风速预测偏差和负荷预测偏差等不确定性因素的基础上,建立了满足经济性和可靠性要求的备用容量配置原则。并基于蒙特卡罗随机模拟的遗传算法对改进10机测试系统进行了求解,经过算例求解得到考虑需求侧响应的备用容量优化决策的经济性更好。与以往传统的备用容量配置相比,双侧备用容量配置能够在系统整体内实现资源的优化分配,同时也可以提高风电消纳能力,实现电力系统安全性和经济性最优。     

考虑新能源资源及出力特性的全局备用容量优化方法

提出一种考虑新能源资源互补特性及预测出力特性、基于跨区特高压直流联络线的全局备用容量优化技术.首先,分析中国新能源资源的相关及互补特性,研究不同区域整体资源互补运行的可行性;然后,提出基于新能源预测统计特性的系统实时备用容量优化方法,建立基于时序生产模拟方法的跨区域全局备用容量优化技术;最后,以"三北"地区为例,开展考...     

考虑新能源出力相关性的电网电压暂降随机预估

针对含有风电、光伏及电动汽车充电站的新能源电力系统,提出了一种考虑新能源出力相关性的电网电压暂降随机预估方法。首先构建了故障信息随机模型及新能源出力随机模型,采用拉丁超立方采样（Latin hypercube sampling,LHS）得到故障信息样本,利用皮尔森相关分析法确定同一类型新能源出力的相关系数后,采用Nataf变换及LHS法得到含有相关性的新能源随机出力样本;然后通过故障仿真模拟,得到一系列暂降事件,计算各节点电压暂降指标,预估各节点电压暂降情况;最后以IEEE 30节点为例进行了仿真分析,研究相关系数变化下的新能源出力及不同类型新能源的接入对电网电压暂降的影响。     

含新能源接入的区域电网低碳电力调度方法

为实现电力行业低碳化的发展要求,在新能源广泛接入的背景下,建立了基于多目标概率最优潮流的区域电网低碳调度模型,并提出一种结合模糊满意度决策的改进帝国主义竞争算法,得到"最优"调度方案。该方法在传统以最小发电成本和碳排放量为优化目标的模型基础上,减小不同区域间的碳排放不平衡量,防止局部地区过污染。针对新能源接入电网带来的不确定性问题,采用计及相关性的随机响应面法进行概率潮流计算,避免节点电压越限或线路过载。最后,对Matpower 30节点系统和江苏某区域实际电网的算例测试表明:所提模型和方法有效实现了对整个系统和局部区域的碳排放量的综合管理,并能为新能源接入位置的选择提供指导。