考虑多种主动管理策略的配电网扩展规划

提出了主动配电网扩展规划的混合整数二阶锥规划模型,该模型以总的投资与运行费用最小为目标函数。文中考虑了4种主动管理措施降低规划方案成本及未来的运行风险,包括有载调压变压器调节、切机、切负荷及无功补偿。规划措施包括主动管理、新建线路、新建变电站、扩建变电站、新建分布式电源。配电网规划是一个混合整数非线性规划问题,再加对各种主动管理措施及未来不确定性的考虑,配电网规划问题求解变得相当复杂。基于配电网潮流方程及约束松弛技术,建立了配电网规划的二阶锥规划模型,并利用改进的IEEE 33节点系统及Miranda 54节点系统进行了算例验证。     

Multistage and coordinated planning of the expansion of transmission systems

In this paper, an efficient genetic algorithm (GA) is presented to solve the problem of multistage and coordinated transmission expansion planning. This is a mixed integer nonlinear programming problem, difficult for systems of medium and large size and high complexity. The GA presented has a set of specialized genetic operators and an efficient form of generation of the initial population that finds high quality suboptimal topologies for large size and high complexity systems. In these systems, multistage and coordinated planning present a lower investment than static planning. Tests results are shown in one medium complexity system and one large size high complexity system.     

Generation expansion planning in electricity markets: A novel framework based on dynamic stochastic MPEC

This paper presents a novel framework for generation expansion planning (GEP) of restructured power systems under uncertainty in a multi-period horizon, which includes generation investment from a price maker perspective. The investment problem is modeled as a bi-level optimization problem. The first level problem includes decisions related to investment in order to maximize total profit in the planning horizon. The second level problem consists of maximizing social welfare where the power market is cleared. Rival uncertainties on offering and investment are modeled using sets of scenarios. The bi-level optimization problem is then converted to a dynamic stochastic MPEC and represented as a mixed integer linear program (MILP) after linearization. The proposed framework is examined on a typical six-bus power network, MAZANDARAN regional electric company (MREC) transmission network as an area of IRAN interconnected power system and IEEE RTS 24-bus network. Simulation results confirm that the proposed framework can be a useful tool for analyzing the behavior of investments in electricity markets.     

Congestion management solution under secure bilateral transactions in hybrid electricity market for hydro-thermal combination

The deregulation of power system has created an environment of competitiveness among different market players and the transmission lines are forced to operate near to their thermal or stability limits. It is a challenge with System Operators (SO) to ensure a secure and reliable transmission of power under these conditions. This paper proposes a rescheduling based congestion management strategy in hybrid (pool + bilateral) electricity market structure for a combination of hydro and thermal units. The proposed congestion management problem has been formulated as mixed integer nonlinear programming (MINLP) problem with an objective to minimize the congestion management cost by suitably rescheduling the hydro and thermal units based on their up and down generation cost bids. The hydro units having lowest operational cost and fast startup time have been used to alleviate the congestion by considering non-concave piecewise linear performance curves for them. The secure bilateral transactions have been ensured while rescheduling of the generators for alleviating the congestion. The performance of the proposed model has been demonstrated by solving the congestion management problem on modified IEEE-24 bus system.     

基于相关场景聚类的发输电联合扩展规划

电源规划和输电网规划是相互影响的,为应对电源和输电网联合规划,建立了多场景发输电联合扩展规划模型。该模型把支路分为已有支路和待选支路,并分别建立直流潮流方程以使得发输电联合扩展规划成为混合整数线性规划问题,其求解可使用成熟的混合整数线性规划软件。发输电联合扩展规划中负荷和风电的场景确定需要考虑相关性和空间分布特征,提出了保持相关性的负荷风电场景聚类方法。最后,通过在MATLAB平台上编写计算程序,使用标准Garver-6节点和IEEE RTS-24节点系统算例验证了所提方法的有效性,并通过对比说明了负荷空间分布对发输电联合扩展规划的影响。     

Robust dynamic network expansion planning considering load uncertainty

This paper presents a dynamic transmission expansion planning framework with considering load uncertainty based on Information-Gap Decision Theory. Dynamic transmission planning process is carried out to obtain the minimum total social cost over the planning horizon. Robustness of the decisions against under-estimated load predictions is modeled using a robustness function. Furthermore, an opportunistic model is proposed for risk-seeker decision making. The proposed IGDT-based dynamic network expansion planning is formulated as a stochastic mixed integer non-linear problem and is solved using an improved standard branch and bound technique. The performance of the proposed scheme is verified over two test cases including the 24-bus IEEE RTS system and Iran national 400-kV transmission network.     

计及激励型需求侧响应的发输电鲁棒规划策略

大规模风电等可再生能源广泛接入电网将成为新型电力系统发展的重要方向之一, 通过需求侧响应机制调整用户负荷需求, 可有效提高电力系统运行的灵活性并促进风电的消纳。在此背景下, 提出了一种计及激励型需求侧响应的发输电鲁棒规划策略。首先, 引入基于价格激励的需求侧响应机制, 构建基于分段激励价格的需求侧响应模型。其次, 为了有效应对风电的不确定性对规划方案的影响, 提出了基于信息间隙决策理论的计及激励型需求侧响应的发输电鲁棒规划模型, 并将所提出的模型构造为混合整数线性规划模型。最后, 以Garver 6节点系统和改进的IEEE 118系统为例证明所提方法的可行性与有效性。     

满足静态电压稳定增强要求的发电机最佳调整方法

为增强电力系统的静态电压稳定性,同时最大限度地减小运行人员的操作工作量,提出了一种综合经济性和静态电压稳定性的发电机最佳调整模型。该模型以发电机参与调整台数最少和发电成本最小为目标,约束条件包括系统负荷裕度满足设定提升要求和电力系统安全运行要求。该问题的数学本质是一个多目标非线性混合整数规划问题。为实现上述问题的求解,首先以线性灵敏度方法快速估算所需调整出力的发电机,求解控制数量最少的整数规划问题。然后以发电成本最小为目标,利用线性规划法求解各台发电机的调整出力值。最后在IEEE39节点算例和IEEE118节点算例进行仿真验证,结果表明所提模型与求解方法能很好地解决系统的静态电压稳定性增强控制问题。     

Robust voltage regulation in unbalanced radial distribution system under uncertainty of distributed generation and loads

This paper proposes a robust optimization technique to solve the voltage regulation problem in unbalanced radial distribution system in the presence of uncertainties in loads and distributed generation. The formulated problem is a mixed-integer nonlinear programming (MINLP) one and, to solve this MINLP problem efficiently, a two stage approach has been developed. To verify the robustness of the solution obtained by the proposed method, extensive Monte Carlo simulations studies have also been carried out. The efficacy of the proposed method has been tested in modified IEEE 123 bus unbalanced radial distribution system.     

Long-term expansion planning for hydrothermal electric power systems

This paper shows some aspects of the applicability of mixed integer programming (MIP) in expansion planning for regional electric utility systems, considering both power plants and the transmission network. The hydrothermal generation system may include significant run-of-river and reservoir power stations, and also pumped storage stations. Some essential elements of the model are explained to demonstrate the MIP modelling. The application of the model to the long-term expansion planning problem of a hydrothermal power system is also described.     

考虑风电消纳能力的电-气集成系统多目标运行优化

摘 要：以电力-天然气集成系统为代表的综合能源系统可以充分利用各类能源载体的运行特性,提升电力系统接纳间歇性可再生能源发电的能力。另一方面,电-气集成系统的整体运行费用、消纳间歇性可再生能源发电能力和网络损耗与风电等间歇性可再生能源发电的渗透水平率密切相关,因此有必要对考虑风电消纳能力的电-气集成系统多目标优化运行策略展开研究。首先,以最小化电-气集成系统运行费用、弃风成本和网络损耗为目标函数,建立考虑风电消纳能力的电-气集成系统运行优化的多目标混合整数非线性优化模型。接着,对优化模型中的非线性约束条件进行线性化处理,将原模型转化为混合整数线性规划问题。然后,利用基于增强ε约束的多目标优化方法求解所建立的优化模型,获得帕累托最优解集,并采用模糊综合评估方法寻找最优折中解。最后,利用修改的IEEE 39节点电力系统和比利时20节点天然气系统所构成的电-气集成系统对所提方法的可行性和有效性进行验证。     

Electric Power and Heat Generation Expansion Planning

Abstract

A short-term electric power and heat generation augmentation planning (EPHGAP) is portrayed and evaluated here. The objective of EPHGAP is to find out the most cost-effective and dependable expansion plan for meeting the forecasted electrical power demand and heat demand over a long-range horizon while fulfilling a large number of technical, cost-effective, reliability, and social constraints. The EPHGAP problem is a big-dimensional highly constrained mixed integer nonlinear programing (MINLP) problem. The general algebraic modeling system (GAMS) environment has been used to implement the proposed formulation, and the EPHGAP problem is solved by using Basic Open-source Nonlinear Mixed Integer (BONMIN) solver. An archetypal test system with existing thermal power plants, cascaded hydropower plants, cogeneration units, heat-only units and candidate cogeneration units, and cascaded hydro plants is considered to evaluate the proposed methodology. Simulation outcomes of the test system have been matched up to those acquired by differential evolution and particle swarm optimization. It has been observed from the comparison that the recommended BONMIN solver has the capability to bestow with superior quality solution.     

Nash equilibrium in strategic bidding: a binary expansion approach

This paper presents a mixed integer linear programming solution approach for the equilibrium problem with equilibrium constraints (EPEC) problem of finding the Nash equilibrium (NE) in strategic bidding in short-term electricity markets. A binary expansion (BE) scheme is used to transform the nonlinear, nonconvex, NE problem into a mixed integer linear problem (MILP), which can be solved by commercially available computational systems. The BE scheme can be applicable to Cournot, Bertrand, or joint price/quantity bidding models. The approach is illustrated in case studies with configurations derived from the 95-GW Brazilian system, including unit-commitment decisions to the price-maker agents.     

供热管网分布参数模型与电热耦合网络协同规划

随着多能源互联的逐步发展,电力系统(power system,PS)和供热管网(heating pipe network,HPN)系统的耦合程度不断加深,耦合形式也趋于多样化。需要适当考虑电力系统和供热管网系统在规划与运行方面的相互影响。在此背景下,对电力系统和供热管网系统的协同规划进行探讨。现有供热管网系统的数学模型和分析方法不够精细,无法满足协同规划的需要。为此,首先发展适用于电气分析的供热管网系统的分布参数模型,并对现有的温度场和压力场并行求解方法进行简化和统一。接着对所构造的分布参数模型进行线性化处理,并发展了基于管道和环境参数计算热能和压力损失的方法。之后构建了热网潮流方程,并与电力系统潮流方程统一求解。在此基础上,发展了电力系统和供热管网系统的协同规划模型,以发电成本与电力网损、热网损耗之和最小为优化目标,并考虑电力网络和供热网络的运行约束。该协同规划模型为0-1混合整数非线性规划问题,采用商业化的YALMIP工具箱求解。最后,以修改的IEEE 30节点电力系统和某实际供热管网系统为基础,构建了电力系统和供热管网系统耦合形成的集成系统,以说明所发展的供热管网电气化模型及协同规划方法的可行性和有效性。     

育种算法在输电网络优化规划中的应用

作为一个复杂的非线性的混合整数规划问题,目前电网优化规划使用较常见的是现代优化方法,其中又以遗传算法应用较多,但目前各种现代优化方法仍存在计算速度和收敛性的问题,介绍了一种从遗传算法改进而来的算法——育种算法,它将遗传算法中的选择、交叉、变异三个过程简化为一个过程,对18节点算例分析表明育种算法在电网规划应用中提高了计算速度和收敛度。     

计及风险约束的多阶段输电系统规划方法

多阶段输电系统规划问题是一个复杂的非线性组合优化问题。与传统的输电系统规划问题相比,电力市场环境下的输电系统规划更加复杂,需要处理的不确定性因素更多。在不确定性环境下所制定的输电系统规划决策不可避免地会带有一定的风险,包括安全风险与经济风险。因此,在制定输电系统规划方案时需要适当考虑风险的影响,亦即需要进行风险管理。在此背景下,文中利用机会约束规划可以显式描述风险的特点,构造了计及风险约束的多阶段输电系统规划的模型框架,并给出了相应的求解算法,为解决这一重要而困难的问题做了一些新的尝试。最后通过一个算例系统说明了所提出的方法的可行性。     

适应非光滑特性的交直流混合电力系统状态估计

交直流混合电力系统中的有载调压变压器(on-load-tap-changer, OLTC)和换流器模型存在大量限幅、死区等非光滑特性,如何处理换流器引入的分段函数约束是当前状态估计的研究难点。构建了OLTC的混合整数非线性(mixedintegernonlinearprogramming, MINLP)模型,通过控制二次侧电压水平得到OLTC挡位的估计值。针对换流器采用分段函数描述包含限幅、死区等下垂控制特性的问题,提出采用近似拟合函数将分段函数光滑化。与采用MINLP描述分段函数的方法相比,所提模型显著提高了计算效率。通过3节点和IEEE14节点交直流混合系统算例,验证了所提状态估计模型的正确性和实用性,同时分析了拟合系数对状态估计的影响。算例表明,所提模型增强了状态估计处理不良数据的能力,提高了对非光滑特性的适应能力,在保证计算精度的前提下能够提高状态估计的收敛性。     

配电网扩展规划方法研究

建立了以目标函数为配电网建设的投资费用、配电网网损费用和运行维护费用综合最优的混合非线性整数规划模型,以指导电力公司的电网建设规划方案,利用多个离散的二进制变量优化变电站、新建线路和变电站的扩建方案。考虑了分布式电源接入配电网,并以严格的数学模型保证配电网的辐射运行结构。提出用内点-分支定界法精确求解电力系统配电网扩展规划模型,结果表明该方法是一种可行的配电网扩展规划方法。     

Phase shifter placement in large-scale systems via mixed integer linear programming

This paper makes use of advances in mixed integer linear programming (MILP) to conduct a preliminary design study on the combinatorial optimal placement of thyristor controlled phase shifter transformers (TCPSTs) in large-scale power systems. The procedure finds the number, network location, and settings of phase shifters that maximize system loadability under the DC load flow model, subject to limits on the installation investment or total number of TCPSTs. It also accounts for active flow and generation limits, and phase shifter constraints. Simulation results are presented for the IEEE 24-, 118-, and 300-bus systems, as well as a 904-bus network. The principal characteristics of our approach are compared with those of other published flexible AC system transmission (FACTS) allocation methods.     

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.