市场环境下基于Benders分解的输电网规划决策

市场条件下,由于不确定因素对市场经济运行的影响,输电网的扩展规划必须考虑发电公司和用户的需求,减缓输电系统阻塞,促进市场的公平竞争。首先以电力联营市场模式为研究背景,针对不确定因素作用下可能的未来场景,基于最优潮流的输电网边际定价模型,提出了以投资成本和运行成本为优化目标的输电网静态规划模型;然后基于奔德斯(B enders)分解算法先求解出各个典型场景下输电网规划优化方案,再根据决策理论中的最小最大悔则进行多场景规划决策;最后在IEEE-24节点系统上进行了仿真计算。与确定性输电网规划方法相比,该模型计及了电网规划与经济运行中不确定因素的影响,从而能更有效地指导市场环境下输电网规划综合决策,提高规划系统经济性能。     

Benders分解技术在输电网络规划中的应用

提出了一种基于Benders分解技术的非线性混合整数规划模型,并将其应用于输电网络扩展规划.输电网络扩展规划中的目标函数是使新线路投资和运行费用之和最小,用Benders分解技术求解,可把原始问题分解为投资决策主问题和运行模拟子问题,通过交替求解投资决策主模型和运行模拟子模型可以得到原规划问题最佳规划方案.并对6节点Garver系统进行了仿真计算,结果表明该方法是正确可行的.     

考虑风电极限场景的输电网鲁棒扩展规划

随着风电并网渗透率的快速增长,系统的随机性和波动性显著增强。针对大规模风电并网给输电网规划带来的影响,文中以线路投资成本与运行成本之和最小为优化目标,构建了考虑风电接入的输电网扩展规划模型,并引入辅助松弛变量将模型转化为线性混合整数规划问题。在此基础上,提出了风电极限场景的物理概念,并构建了基于风电极限场景的两阶段输电网鲁棒规划方法,第一阶段为在线路投资扩展约束下决策输电线路的投建状态,以保证第二阶段的运行调节变量可以适应风电的随机波动。针对鲁棒规划模型的特点,采用基于Benders分解的两阶段算法进行求解以获得最优鲁棒规划方案。最后,通过Garver 6系统与IEEE RTS 79系统进行算例分析,验证了所提模型的有效性与可行性。     

Value-based transmission planning and the effects of network models

A value-based automated transmission system planning model is presented in this paper and the impact of the various network representations on the results of the model is discussed. Value-based integrated resource planning provides a “societal cost” (utility operation and investment costs plus customer outage costs) minimizing composite generation-transmission system expansion plan. The model trades-off and compares the costs and benefits of alternative generation and transmission resources using a consistent economic and engineering criterion in order to determine an “optimal” resource expansion plan. The generalized Benders decomposition algorithm with “importance sampling” used to solve the problem enables the model to estimate certain average information about scenarios or contingencies by examining only a very small fraction of all the scenarios or contingencies. The impacts of system resources upon both real and reactive power can be analyzed when using the AC power flow equations. It is concluded that for transmission system planning where reactive power flows and voltage constraints are important, it is imperative that an AC power flow model be used. The combination of AC power flow and linearized power flow models, with linearization about the solution of the AC power flow model, was found to be a promising compromise between accuracy and computation time     

基于改进Benders分解的配电网扩展规划机会约束优化方法

为了解决已有配电系统规划中非线性潮流模型建模问题和不确定性优化效率问题,本文提出了基于双线性Benders分解的配电网扩展规划机会约束优化方法。首先通过在规划投资层面和运行优化层面进行分阶段,构建了两阶段随机混合整数二阶锥规划模型;然后为了避免极端场景下导致的高昂投资成本,进一步扩展了传统的Benders分解方法,设计了基于双线性Benders分解的机会约束优化方法。通过三个算例系统验证了本文所提出方法的卓越的优化性能。     

市场环境下计及阻塞集中度指标的输电网扩展规划

与传统的输电网规划相比,电力市场环境下的输电网扩展规划不仅要满足市场用户的需求,还对减缓输电系统阻塞、抑制市场力的滥用和提高社会效益起着重要作用。对于因网络充裕度不足造成的长期输电阻塞,首先参考市场集中度监管指标Lerner指数的定义,提出了新的阻塞集中度指标作为评估输电网络充裕度的指标;然后从市场运营的实际情况出发,以阻塞集中度指标作为约束条件来抑制网络的垂直市场力,构造了将阻塞收益用于回收投资成本的输电网扩展规划模型。IEEE-24节点算例系统分析表明该模型综合考虑了输电投资成本回收以及输电阻塞管理等实际问题,能有效减缓系统阻塞发生,降低投资风险,并为输电网监管提供可靠依据。     

A dynamic model for coordination of generation and transmission expansion planning in power systems

This paper presents a new dynamic approach on the expansion planning problem in power systems. First, the coordination between generation system expansion and transmission system expansion has been formulated as a mixed integer nonlinear programming (MINLP) problem. Then, it has been shown that this MINLP model cannot be efficiently solved by the traditional MINLP solvers. Since the nonlinear term comes from the multiplication of a binary variable by a continuous one, a Benders decomposition approach has been employed to convert the MINLP formulation into a mixed integer linear programming (MILP) master problem, and a linear programming (LP) sub-problem. Besides, different times of construction have been considered for different transmission and generation facilities. In addition, a clustering based algorithm has been proposed to evaluate the reliability of the system at hierarchical level II (HLII). Since this dynamic planning method is an upgraded version of a recent developed static model, the result from both methods have been also compared. A simple 6-bus test system and IEEE 30-bus system have been selected to confirm the effectiveness of the introduced method.     

Large scale transmission network planning using optimization andheuristic techniques

Pursuing optimal solutions for large scale transmission network planning problems is a formidable task due to their combinatorial nature and also due to the nonconvexities involved. Successful approaches using hierarchical Benders decomposition incur in a high computational cost mainly due to the need to solve a large integer program (the investment sub-problem) for every Benders iteration. In this work the authors propose to use heuristics within the decomposition framework, therefore avoiding to solve to optimality each integer sub-problem. The global computational effort is substantially reduced, and allows coping with large problems that would be intractable using classical combinatorial techniques. Case studies with the 6 bus Garver test system and a reduced Southeastern Brazilian power network are presented and discussed     

Particle Swarm Optimization and Its Application in Transmission Network Expansion Planning

The author introduced particle swarm optimization as a new method for power transmission network expansion planning. A new discrete method for particle swarm optimization was developed, which is suitable for power transmission network expansion planning, and requires less computer's memory. The optimization fitness function construction, parameter selection, convergence judgement, and their characters were analyzed. Numerical simulation demonstrated the effectiveness and correctness of the method. This paper provides an academic and practical basis of particle swarm optimization in application of transmission network expansion planning for further investigation.     

基于输电网扩展规划的OPA模型

针对已有利用直流潮流模拟连锁故障的OPA模型在慢动态过程中模拟线路升级方式的不足,提出一种基于输电网扩展规划的OPA停电模型。该模型不仅在模拟过程中考虑了通过增加传输容量升级线路,而且采用了输电网扩展规划方法新建线路实现电网升级,使慢动态模拟过程更加符合实际电力系统演化过程。用蒙特卡洛抽样方法获取快动态周期内每回线路的...     

考虑发电容量适应性的多目标输电网规划

电源和负荷增长的不确定性及发电出力变化将对电网规则方案的适应性和灵活性提出新的要求.文中引入发电容量适应性指标,衡量网络结构对发电出力容量变化的适应能力,建立考虑网络结构优化的多目标输电网规划模型,对多场景电网期望负载水平进行优化,改善电网运行环境和应对发电出力容量变化的能力,提高电网功率传输能力,减少各场景下的负荷损失.典型算例结果表明了文中模型和方法的有效性.     

A Decomposition Approach to Preventive Planning of Reactive Volt Ampere (VAR) Source Expansion

This paper presents a two-level approach for determining the minimum cost expansion pattern (location and size) of new reactive compensation sources that would ensure steady-state secure operation of large scale power systems not only under a given set of operating conditions for the intact system, but also under contingency conditions. This preventive planning problem is decomposed into a var dispatch (Level 1) problem and a var allocation (Level 2) problem which are related together using the generalized Benders decomposition. The methodology has been implemented in a prototype computer package which can handle power systems with up to 1500 buses. Results of testing the package with practical power systems of different sizes and characteristics are presented.     

基于交替方向乘子法的源网协同多适应规划

电源规划与电网规划紧密相关,有必要考虑其相互影响进行协同规划。该文兼顾分布式决策环境与多适应性条件,提出了一种电源与电网协同的多适应规划框架,利用交替方向乘子法(alternating direction method of multipliers,ADM M)分别构建了耦合共享变量的电源规划决策子问题与电网规划决策子问题,2个子问题相互通信、交替求解,实现了电源与网架协同的分布式自治规划。该框架和方法保留了决策主体信息的私密性,同时确保了电源规划方案和电网规划方案所构成的整体系统的经济性和适应性。在Garver-6系统上对该文方法的有效性进行了验证。     

Transmission Congestion and Competition on Power Generation Expansion

Generation expansion planning involves decisions on location and capacity of new generation, which may lead to adding or relieving congestion in transmission lines and to increasing or reducing competition in deregulated markets. Generation expansion may encounter congestion in the transmission network by constrained single-line flows as well as flowgate transfer capabilities. In this paper, a model to study the interaction between competition and transmission congestion on power generation expansion is proposed. The generation expansion problem is modeled as a Cournot competition game. Network transmission constraints are included in the optimal generation expansion problem to comply with power flow limits. Results from a five-bus power network and the IEEE 24-bus system are presented and discussed     

输电系统优化规划的研究

本文提出了一种新的输电系统扩建规划优化方法,首次把网络拓扑理论和电网规划的启发式方法相结合,采用直流潮流模型.应用最短片成树算法,Dijkstra最短路标号法、逐步扩展法和N-1检验进行多阶段求解决策,自动地生成所需规划输电系统扩建规划优化方案.避免了繁杂运算和维数过多的困难.具有简单快速、提供信息较全面、直观的优点.     

Security-constrained optimal generation scheduling for GENCOs

This paper presents an approach for maximizing a GENCO's profit in a constrained power market. The proposed approach considers the Interior Point Method (IPM) and Benders decomposition for solving the security-constrained optimal generation scheduling (SC-GS) problem. The master problem represents the economic dispatch problem for a GENCO which intends to optimize its profit. The formulation of the master problem does not bear any transmission network constraints. The subproblem will be used by the same GENCO to check the viability of its proposed bidding strategy in the presence of transmission network constraints. In this case if the subproblem does not yield a certain level of financial return for the GENCO or if the subproblem results in an infeasible solution of the GENCO's proposed bidding strategy, the GENCO will modify its proposed solution according to the Benders cuts that stem out of the subproblem. The study shows a more flexible scheduling paradigm for a GENCO in a competitive arena. The proposed approach proves practical for modeling the impact of transmission congestion on a GENCO's expected profit in a competitive environment.     

发电扩容与输电扩容的协调优化模型

以电厂和电网分离为主要特征的电力市场化改革给电力扩容规划带来了巨大的冲击。如何协调好发电与输电的扩容直接关系到电力系统的稳定运行和健康发展。通过分析市场化改革后电力扩容规划存在的主要问题,构筑了发电扩容与输电扩容的协调优化模型。该模型中提出了利用协调因子的思想来解决电力扩容的规划风险和保障竞争性电力市场的电价机制。协调因子计及了缺电成本和输电利用成本,这不仅能充分反映电力扩容的规划风险,而且能使双方共同承担其风险,从而促进两者扩容的协调。文章为厂网协调发展探索了新的途径。     

大规模风电集中接入的输电网扩展规划平台研发

为满足大规模风电集中接入对输电网扩展规划提出的安全性与经济性需求,提出了建设含大规模风电集中接入的输电网扩展规划平台的总体方案。应用综合考虑风险及经济性的输电网优化规划理论,开发了以风电场群功率波动分析、输电容量优化为核心,集运行中风电场出力的历史数据采集与管理、待建风电场信息处理以及最优规划方案综合评价一体化的信息管理和输电网扩展规划系统。构建了基于历史出力数据的风电场群出力汇聚演变模型、提出了利用在役风电场群历史出力规律性预测规划目标年风电场群出力的实用方法、建立了面对输电网的综合评价指标体系,为进行详尽的数据挖掘分析、高精度的出力预测、准确的方案评估和全局化的输电网扩展规划管理,提供了有力的技术支持。     

Pareto optimality-based multi-objective transmission planning considering transmission congestion

In the deregulated environment, transmission congestion is one major problem that needs to be handled in power system operation and network expansion planning. This paper aims to enhance the transmission system capability and have the congestion alleviated using the multi-objective transmission expansion planning (MOTEP) approach. A system congestion index called the congestion surplus is presented to measure the congestion degree of the transmission system. The proposed MOTEP approach optimizes three objectives simultaneously, namely the congestion surplus, investment cost and power outage cost. An improved strength Pareto evolutionary algorithm (SPEA) is adopted to solve the proposed model. A ranking method based on Euclidean distance is presented for decision-making in the Pareto-optimal set. The effectiveness of both the improved SPEA and the proposed multi-objective planning approach has been tested and proven on the 18-bus system and the 77-bus system, respectively.     

A simulated rebounding algorithm applied to the multi-stage security-constrained transmission expansion planning in power systems

This research discusses the multi-stage security-constrained transmission network expansion planning. In modern power systems, the problem is formulated as a large-scale, mixed-integer, non-linear programming problem, which for a real power systems is very difficult to solve. Although remarkable advances have been made in optimization techniques, finding an optimal solution to a problem of this nature can still be extremely challenging. In this paper, a new constructive heuristic approach, based on a local controlled random search (simulated rebounding algorithm) is proposed to choose the decision variables. The model can produce better solutions than other references techniques such as particle swarm optimization, evolutionary particle swarm optimization, genetic algorithms, and simulated annealing algorithm, among other evolutionary methods. The methodology is applied to assess the capabilities of the proposed approach in the Ecuadorian and Chilean Power Systems as an example of application. Simulation results show that the proposed approach is accurate and very efficient, and it has the potential to be applied to real power system planning problems. The algorithm has been presented and applied to the multi-stage security-constrained transmission expansion planning.