计及网络安全约束和多能协同交互的多园区综合能源系统分散协调调度

多园区接入区域配电网与配气网构成多园区综合能源系统(MCIES),可有效提高其经济效益。针对配电网、配气网和不同园区等多利益主体,提出一种计及网络安全约束和多能协同交互的MCIES分散协调调度双层模型。区域调度层为多主体调度层,配电网和配气网在满足网络安全约束的前提下向园区运营商供能,三者分别以各自利益最大化为目标,协调配网-园区联络线功率;局域调度层为园区利益分配层,各园区互联以实现彼此间电能和天然气支撑,并基于区域层决策得到的配网-园区交互能量,分别以各自经济最优为目标参与利益分配,优化内部设备出力计划,协调园区间多能交互功率。采用双层目标级联分析法解耦协调变量,分别将各层优化调度主问题构建为上下两级优化调度子问题,进而对调度子问题独立建模、协调求解。天津某地MCIES算例分析表明,所提方法兼顾了网络运行安全性和不同主体利益诉求,并通过发挥园区间多能协同交互优势,实现了MCIES的安全经济优化运行。     

考虑断面约束的多能源电力系统时序性生产模拟

传统电力系统随机生产模拟方法难以描述新能源发电机组时序特性以及计算与时序特性有关的电力系统运行指标,导致生产模拟的准确性欠佳.提出含风电、光伏、水电、火电、光热及储能的多能源时序性随机生产模拟方法.将系统运行调度策略与随机生产模拟中各类型机组的加载顺序相结合,计及电力系统网架断面约束,充分保证新能源的优先消纳.为保留电...     

多能源发电系统控制策略建模研究

应用DIGSILENT仿真软件搭建含有多能源发电系统的仿真模型,主要包括光伏发电系统、风力发电系统和储能系统。针对不同特性的微源,在运行过程中采用不同的控制策略。利用该模型模拟了电网电压跌落下的风力发电系统输出特性,仿真结果表明,采用的仿真分析方法切实有效,模型输出与实际理论输出相似,能够快速地响应电网调度指令;利用该模型模拟了电网电压跌落下光伏发电系统和储能系统组成的微电网的输出特性,仿真结果表明,模型输出与工程运行相似,能够支持母线频率基本保持不变,提高供电可靠性。本模型可以用于实际多能源发电系统的并网分析,为实际工程研究奠定了基础。     

Multi-time period combined gas and electricity network optimisation

A multi-time period combined gas and electricity network optimisation model was developed. The optimisation model takes into account the varying nature of gas flows, network support facilities such as gas storage and the power ramping characteristics of electricity generation units. The combined optimisation is performed from an economic viewpoint, minimising the costs associated with gas supplies, linepack management, gas storage operation, electricity generation, and load shedding. It is demonstrated on the GB gas and electricity network.     

农网改造项目社会评价支持系统设计

介绍了为农网改造项目社会评价设计的一套评价支持系统软件。在该系统中设计了农网改造项目进行社会评价所需要的数据库、包括有无对比法和模糊层次综合评价在内的各种模型 ,以此辅助支持对农网改造项目进行社会评价     

面向有功潮流最优问题的配电网集群划分策略

新能源大规模馈入配电网的背景下,集群划分是配电网实现海量数据分析和设备调控的重要手段,但当前集群划分研究存在划分结果不合理,划分算法准确度低的问题。针对上述问题,本文阐述了分布式电源高渗透的配电网集群划分时应考量的因素,设计了规模限制指标;对遗传算法迭代过程进行观察记录,分析了遗传算法全局寻优能力受限的原因,并利用遗传过程中个体趋同的特征对算法进行了机理改进。经过仿真实验验证,本文所提出的规模限制指标能够有效的规避不合理的分区,避免了人为筛选结果的弊端;所提出的改进遗传算法较大程度的提高了计算的准确度,并降低了迭代次数。但由于遗传算法缺少收敛判据,降低迭代次数暂时不能减少单次实验耗时。综上,本文的研究成果有效的提高了配电网集群划分结果的准确度,提高了配电网分区控制的效率。     

气网动态潮流下多能源网与能量枢纽的联合调度

天然气系统与电力系统的时间响应特性之间存在显著差异,若在综合能源系统优化调度模型中进一步融入天然气系统动态潮流模型,则能够更精确地描述其实际运行状态。为此,建立了考虑气网动态过程的电力-天然气耦合系统,该系统基于能量枢纽相耦合,并在能量枢纽中引入考虑负荷特性的需求响应模型,提出了考虑需求响应的多能源网与能量枢纽的联合优化调度方法。通过对网络模型与能量枢纽模型进行线性化处理来降低模型复杂度,并采用分解求解法进行多能流潮流计算。以含有2个能量枢纽的综合能源系统为算例进行仿真分析,结果表明考虑气网动态潮流的模型能更准确地描述实际运行状态,且考虑需求响应对于降低峰谷差、提高经济效益效果显著。     

考虑多能流广义储能作用的配电网协调规划

能源互联网背景下配电网内逐渐形成能源耦合、能量交互的区域综合能源系统,对提高可再生能源渗透率、解决环境问题具有重要意义.通过网侧资源协同利用与多能流优化调度达到存储能量的目的,并构建多能流广义储能系统;在此基础上,考虑多能负荷和分布式电源的多重不确定性,采用随机优化和鲁棒优化相结合的方法建立基于分季节多场景的三阶段鲁棒...     

紧急功率支援下自适应重合闸附加稳定控制策略

能源分布和负荷需求逆向分布特征促成了我国形成多个大规模电力电能外送系统,在非预期大扰动下会出现系统首摆失稳且自适应重合闸仍难以改善系统稳定性的局面。基于此,提出了一种紧急功率支援下自适应重合闸附加稳定控制策略。首先分析了系统首摆失稳的场景以及失稳条件,并提出了基于功角超实时预测的首摆稳定性预判方法,论证了长时间要求的预测最优阶数。然后结合直流通道提供紧急功率支援能够消纳系统不平衡能量,提出基于超前预控的自适应重合闸附加稳定控制策略。结合失稳判断,分析预判控制时序。基于紧急功率支援协同最佳重合闸时间最大程度上减小了系统功角摇摆,解决了瞬时性故障首摆失稳时重合闸方案的缺失问题。最后,基于PSCAD/EMTDC建立大规模电力外送模型,仿真验证了所提自适应重合闸附加稳定控制策略的有效性。     

A knowledge based decision support algorithm for power transmission system vulnerability impact reduction

One of the main reasons for wide area blackouts is cascading failures due to critical contingencies. Since, several factors such as faults, misoperations, environmental effects and sabotage issues are involved; the analysis of such contingencies is a challenging process. Most available methods in literature deal mainly with a certain aspect of the problem. In this study, a more comprehensive methodology using operational and non-operational indices for power system vulnerability analysis is presented. The individual indices are defined for power system’s operational performance, terrorist attack and adverse weather conditions where a fuzzy inference system is used to obtain a single Total Vulnerability Index for each transmission system line. Additionally, a knowledge based decision support algorithm is proposed for the use of TSO’s defense activities in order to determine the weak points and counter measures like load shedding. The modeling approach is tested on IEEE reliability test network with imposed external constraints.     

光储直流配电网灵活虚拟惯性控制策略

针对光伏渗透率不断提高而带来的直流配电网惯性低的问题,考虑直流配电网储能设备的潜在惯性支持能力,提出光储直流配电网灵活虚拟惯性控制策略.分析了在直流配电网电压动态变化过程中蓄电池储能与电压变化量之间的关系,并通过建立蓄电池荷电状态与直流电压的函数表达式,进一步提出了在直流电压变化时引入双曲正切函数来灵活快速调节蓄电池换...     

考虑网络约束的市场力判别方法

市场力是阻碍电力市场正常运行的最大因素之一,美国加州电力市场中的部分发电商行使市场力哄抬电价,在一定程度上导致了该州电力危机的发生。国内外对市场力判别方面的研究早已进行,但至今仍缺乏较为明确直观的方法。传统方法中,一般根据市场集中度来分析市场力,本文改变从发电侧根据机组所占份额来分析市场力的这一做法,试图从负荷侧根据线路对负荷的供电情况来进行分析,并提出一种简单可行的市场力判据。     

An interpretative structural modeling based network reconfiguration strategy for power systems

The network reconfiguration is an important stage of restoring a power system after a complete blackout or a local outage. Reasonable planning of the network reconfiguration procedure is essential for rapidly restoring the power system concerned. An approach for evaluating the importance of a line is first proposed based on the line contraction concept. Then, the interpretative structural modeling (ISM) is employed to analyze the relationship among the factors having impacts on the network reconfiguration. The security and speediness of restoring generating units are considered with priority, and a method is next proposed to select the generating unit to be restored by maximizing the restoration benefit with both the generation capacity of the restored generating unit and the importance of the line in the restoration path considered. Both the start-up sequence of generating units and the related restoration paths are optimized together in the proposed method, and in this way the shortcomings of separately solving these two issues in the existing methods are avoided. Finally, the New England 10-unit 39-bus power system and the Guangdong power system in South China are employed to demonstrate the basic features of the proposed method.     

A developed control strategy for mitigating wind power generation transients using superconducting magnetic energy storage with reactive power support

The fast variations of wind speed during extreme wind gusts result in fluctuations in both generated power and the voltage of power systems connected to wind energy conversion system (WECS). This paper presents a control strategy which has been tested out using two scenarios of wind gusts. The strategy is based on active and reactive powers controls of superconducting magnetic energy storage (SMES). The WECS includes squirrel cage induction generator (SCIG) with shunt connected capacitor bank to improve the power factor. The SMES system consists of step down transformer, power conditioning unit, DC–DC chopper, and large inductance superconducting coil. The WECS and SMES are connected at the point of common coupling (PCC). Fuzzy logic controller (FLC) is used with the DC–DC chopper to control the power transfer between the grid and SMES coil. The FLC is designed so that the SMES can absorb/deliver active power from/to the power system. Moreover, reactive power is controlled to regulate the voltage profile of PCC. Two inputs are applied to the FLC; the wind speed and SMES current to control the amount active and reactive power generated by SMES. The proposed strategy is simulated in MATLAB/Simulink®. The proposed control strategy of SMES is robust, as it successfully controlled the PCC voltage, active and reactive powers during normal wind speeds and for different scenarios of wind gusts. The PCC voltage was regulated at 1.0 pu for the two studied scenarios of wind gusts. The fluctuation ranges of real power delivered to the grid were decreased by 53.1% for Scenario #1 and 56.53% for Scenario #2. The average reactive power supplied by the grid to the wind farm were decreased by 27.45% for Scenario #1 and 31.13% for Scenario #2.     

An integrated multi-energy flow calculation method for electricity-gas-thermal integrated energy systems

The modeling and multi-energy flow calculation of an integrated energy system (IES) are the bases of its operation and planning. This paper establishes the models of various energy sub-systems and the coupling equipment for an electricity-gas-thermal IES, and an integrated multi-energy flow calculation model of the IES is constructed. A simplified calculation method for the compressor model in a natural gas network, one which is not included in a loop and works in constant compression ratio mode, is also proposed based on the concept of model reduction. In addition, a numerical conversion method for dealing with the conflict between nominal value and per unit value in the multi-energy flow calculation of IES is described. A case study is given to verify the correctness and speed of the proposed method, and the electricity-gas-thermal coupling interaction characteristics among sub-systems are studied.     

基于惯量响应支撑功率的电力系统一次调频功率估算

随着新能源渗透率不断提高以及高压直流电量HVDC的大规模应用,电力系统惯量响应与一次调频响应的能力不断减弱,威胁电力系统的频率稳定.目前的研究工作主要针对于惯量响应的估算、新能源发电参与惯量响应和一次调频的控制策略设计,并未展开电力系统一次调频功率估算的研究.论文提出了基于惯量响应支撑功率的电力系统一次调频功率估算.阐...     

Assessing power system security. A framework and a multi model approach

This paper presents a methodological framework using a multi model approach to assess power system security. System security is viewed here as a multidimensional systemic property of the entire energy system. The paper shows that the different dimensions of a secure energy system are correlated, and hence their behaviour cannot be explained solely by an understanding of the individual dimensions or by system elements in isolation. The implication of this is that a proper assessment of the security of a power system requires a combination of different techno-economic models. The paper develops a comprehensive multi-model approach for investigating energy security issues within power systems, and applies it to a case study focussing on the Italian power sector. The core research activity involves using an energy systems model of Italy (MONET) to build a dedicated power systems model (PLEXOS_IT) and then undertaking a soft-linking exercise between the two models. The purpose is to use PLEXOS_IT to investigate the system adequacy of the power system results produced by MONET for future possible energy system scenarios.     

一种可改善失步振荡模式的风电虚拟惯性控制策略

高渗透率风电并网导致原有系统等值惯性下降,给电力系统失步振荡后的稳定控制过程带来新的挑战。但是目前尚未有文献将风电虚拟惯性控制应用于电力系统发生失步振荡后的稳定控制领域。提出一种可改善失步振荡模式的风电虚拟惯性控制策略,通过引入风机并网点频率偏差来修改风机有功输出,系统遭受大扰动后,风电机组可持续向系统提供大量功率支援。风电机组通过虚拟惯性控制向系统注入/吸收功率,能有效抑制系统群内功率振荡,使得群内同调,从而改善系统失步振荡模式。仿真结果验证了所提虚拟惯性控制策略的正确性和有效性。     

Forecasting electric power generation in a photovoltaic power system for an energy network

Recently, there has been an increase in concern about the global environment. Interest is growing in developing an energy network by which new energy systems such as photovoltaic and fuel cells generate power locally and electrical power and heat are controlled with a communication network. We developed the power generation forecast method for photovoltaic power systems in an energy network. The method makes use of weather information and regression analysis. We carried out forecasting power output of the photovoltaic power system installed in Expo 2005, Aichi Japan. As a result of comparing measurements with prediction values, the average prediction error per day was about 26% of the measured power. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(4): 16–23, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20755     

基于改进拉格朗日松弛算法的电力通信网络负载均衡优化策略研究

针对传统电力通信网络路由策略存在的负载分布不均和丢包率较高等问题,基于软件定义网络,提出了一种基于改进拉格朗日松弛算法的电力通信网络QoS路由策略。以链路时延、可用带宽和丢包率为约束建立路由模型,并采用改进的拉格朗日松弛算法进行路径选择。通过仿真与传统路由方法进行对比,验证了该方法的可行性。结果表明,与传统路由策略相比,该方法能够规划出符合QoS要求的路径,负载分布更加均衡,有效降低了业务丢包率,丢包率由45%降低到0.1%,具有一定的实用价值。